Selection Guide

Thermal Interface Materials

Table of Contents

Introduction   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  2

Thermal Properties and Testing 

4

Interface Material Selection Guide 

5

GAP PAD Thermally Conductive Materials   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  6

GAP PAD Comparison Data 

7

Frequently Asked Questions 

8

GAP PAD VO 

9

GAP PAD VO Soft 

10

GAP PAD VO Ultra Soft 

11

GAP PAD HC 3.0 

12

GAP PAD 1000HD 

13

GAP PAD 1000SF 

14

GAP PAD HC1000 

15

GAP PAD 1450 

16

GAP PAD 1500 

17

GAP PAD 1500R 

18

GAP PAD 1500S30 

19

GAP PAD A2000 

20

GAP PAD 2000S40 

21

GAP PAD 2200SF 

22

GAP PAD A3000 

23

GAP PAD 3500ULM 

24

GAP PAD 5000S35 

25

Gap Filler Liquid Dispensed Materials and Comparison Data   .  .  .  .  .  26

Frequently Asked Questions 

27

Gap Filler 1000 (Two-Part) 

28

Gap Filler 1000SR (Two-Part) 

29

Gap Filler 1100SF (Two-Part) 

30

Gap Filler 1500 (Two-Part) 

31

Gap Filler 1500LV (Two-Part) 

32

Gap Filler 2000 (Two-Part) 

33

Gap Filler 3500S35 (Two-Part)  

34

Gap Filler 4000 (Two-Part) 

35

Thermal Interface Compounds Comparison and FAQs  .  .  .  .  .  .  .  .  .  .  .  36

TIC 1000A 

37

TIC 4000 

38

LIQUI-FORM 2000 

39

HI-FLOW Phase Change Interface Materials  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  40

HI-FLOW Comparison Data 

41

Frequently Asked Questions 

42

HI-FLOW 105 

43

HI-FLOW 225F-AC 

44

HI-FLOW 225UT 

45

HI-FLOW 300P 

46

HI-FLOW 565UT 

47

HI-FLOW 625 

48

HI-FLOW  650P 

49  

Thermal Interface Selection Guide 

 

 | 

1

 

Thermally Conductive Insulators 

50

Frequently Asked Questions 

51

Choosing SIL PAD Thermally Conductive Insulators 

52

SIL PAD Comparison Data 

53

Mechanical, Electrical and Thermal Properties 

54

SIL PAD Applications 

56

SIL PAD Selection Table 

56

SIL PAD 400 

58

SIL PAD 800 

59

SIL PAD 900S 

60

SIL PAD 980 

61

SIL PAD 1100ST 

62

SIL PAD 1200 

63

SIL PAD A1500 

64

SIL PAD 1500ST 

65

SIL PAD 2000 

66

SIL PAD A2000 

67

SIL PAD K-4 

68

SIL PAD K-6 

69

SIL PAD K-10 

70

Q-PAD II 

71

Q-PAD 3 

72

POLY-PAD 400 

73

POLY-PAD 1000 

74

POLY-PAD K-4 

75

POLY-PAD K-10 

76

SIL PAD Tubes 

77

BOND-PLY and LIQUI-BOND Adhesives   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  78

BOND-PLY and LIQUI-BOND Comparison Data and FAQs 

79

BOND-PLY 100 

80

BOND-PLY 400 

81

BOND-PLY 660P 

82

BOND-PLY 800 

83

BOND-PLY LMS 500P 

84

BOND-PLY LMS-HD 

85

LIQUI-BOND EA 1805 (Two-Part) 

86

LIQUI-BOND SA 1000 (One-Part) 

87

LIQUI-BOND SA 1800 (One-Part) 

88

LIQUI-BOND SA 2000 (One-Part) 

89

LIQUI-BOND SA 3505 (Two-Part) 

90

Ordering   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  91

SIL PAD Configurations 

91

HI-FLOW Configurations 

97

Solutions for Surface Mount Applications   .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  98
Ordering Information  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  100

2 

| Thermal Interface Selection Guide 

— INTRODUCTION

Henkel. Developing solutions 
for the electronics industry.

Proven thermal management solutions and 
problem-solving partnership . 

We make it our business to know your business. We understand your problems. We 
also know that there will always be a better way to help you reach your goals and 
objectives. To that end, our company continually invests considerable time and money 
into research and development.

Henkel is in the business of solving problems. 

With our history and experience in the 

electronics industry, our experts can help find ways to improve your process, control 
and manage heat, and back it all with exceptional service.

Let us show you the value Henkel offers.

Thermal Interface Selection Guide 

— INTRODUCTION

 | 

3

 

THERMAL 

MANAGEMENT LEADER

Our solutions to control and 

manage heat in electronic 

assemblies and printed circuit 

boards are used by many of the 

world’s largest OEMs in a wide 

range of industries

WHY Henkel?

Henkel, the leading solution provider 

for adhesives, sealants and functional 
coatings worldwide, uses high-quality 

BERGQUIST thermal management 

products—like BERGQUIST TCLAD, 

BERGQUIST SIL PAD and BERGQUIST 

LIQUI-BOND—to offer technological 

solutions for electronics. Beyond that, 

we work closely with our customers to 

understand your problems and deliver 

technologically advanced solutions  

backed by exceptional service.

GLOBAL SUPPLY CHAIN

to maintain a reliable supply of 

products to our customers 

BROAD PRODUCT 

PORTFOLIO 

that includes LOCTITE, 

TECHNOMELT and 

BERGQUIST products

R&D

Over 10 R&D Centers around the 

world staffed by 3,000 design and 

application professionals

GLOBAL SUPPORT 

with locations in North America, 

Asia and Europe, and sales staff in 

30 countries

INNOVATION

Henkel’s BERGQUIST thermal 

solutions were often developed for 

specific customer requests

4 

| Thermal Interface Selection Guide 

— INTRODUCTION

Thermal Properties and Testing

Thermal Conductivity

The time rate of heat flow through a unit area producing a unit 
temperature difference across a unit thickness.

Thermal conductivity is an inherent or absolute property of 
the material.

Thermal Impedance

A property of a particular assembly measured by the ratio of the 
temperature difference between two surfaces to the steady-state 
heat flow through them.

Factors affecting thermal impedance include:

Area:

  Increasing the area of thermal contact decreases 

thermal impedance.

Thickness:

  Increasing the insulator thickness increases 

thermal impedance.

Pressure:

  Increasing mounting pressure under ideal  

conditions decreases thermal impedance.

Time:

  Thermal impedance decreases over time.

Measurement:

  Thermal impedance is affected by the  

method of temperature measurement.

Thermal Impedance Per BERGQUIST TO-220 
Thermal Performance (25°C Cold Plate Testing)

Thermal Resistance

The opposition to the flow of heat through a unit area of material 
across an undefined thickness.

Thermal resistance varies with thickness.

Test Methods – ASTM D5470

2 in. diameter stack (ref. 3.14 in.

2

) – 10-500 psi, 1 hour per layer

i

Thermal Interface Selection Guide 

— INTRODUCTION

 | 

5

 

Interface Material Selection Guide

PRODUCT OVERVIEW

INTERFACE APPLICATIONS

MOUNTING METHODS

TYPICAL CONVERTED OPTIONS

MARKET APPLICATIONS

PRODUCTS

DISCRETE

 PO

WER

 DEVICES

 F

OR

 

PO

WER

 SUPPLIES

, C

O

MPUTERS

, 

TELEC

O

M

 (

THR

U

-HOLE

)

A

CTIVE

 PO

WER

 C

O

MPONENTS

: 

CAP

A

CIT

ORS

, INDUCT

ORS

, 

RESIST

ORS

ELECTR

ONIC

 M

ODULES

 F

OR

 

A

UT

O

M

O

TIVE

: M

O

TOR

 AND

 WIPER

 

CONTR

OLS

, ANTI

-L

OCK

, ET

C

.

ELECTR

ONIC

 M

ODULES

 F

OR

 

TELEC

O

M

 AND

 PO

WER

 SUPPLIES

CO

MPUTER

 APPLICA

TIONS

: CPU

, 

GPU

, ASICS

, HARD

 DRIVES

 (

I)

ELECTRICAL

 INSULA

TOR

CLIP

, L

O

W

 PRESSURE

SCREW

/RIVETS

, HIGH

 PRESSURE

NO

T APPLICABLE

SHEET

 ST

OCK

R

OLL

 F

ORM

, C

ONTINUOUS

ST

AND

ARD

 C

ONFIGURA

TIONS

CUST

O

M

 EXTERNAL

 SHAPES

CUST

O

M

 INTERNAL

 FEA

TURES

ST

AND

ARD

 PSA

 OFFERINGS

Grease Replacement Materials 

Q-PAD II

T

T

T

T

T

T

A

A

A

A

A

A

Q-PAD 3

T

T

T

T

T

T

A

A

A

A

A

A

HI-FLOW 105

T

AS

AS

T

A

A

A

A

A

A

HI-FLOW 300G

T

T

T

T

AS

A

A

A

A

A

A

HI-FLOW 225F-AC

T

T

T

A

A

A

AS

HI-FLOW 225UT

T

T

AS

A

A

AS

HI-FLOW 565UT

T

T

T

AS

A

A

AS

Grease Replacement 
Materials - Insulated

HI-FLOW 625

T

T

T

A

A

A

A

A

A

HI-FLOW 300P

T

T

T

A

A

A

A

A

A

HI-FLOW 650P

T

T

T

A

A

A

A

A

Bonding - Thin Film

BOND-PLY 660P

T

T

T

T

T

A

A

A

A

A

Bonding - Fiberglass

BOND-PLY 100

T

T

T

T

T

A

A

A

A

A

BOND-PLY 800

T

T

T

T

A

A

A

A

A

Bonding - Unreinforced

BOND-PLY 400

T

T

T

T

T

A

A

A

A

Bonding - Laminates

BOND-PLY LMS 500P

T

AS

T

A

A

A

A

A

BOND-PLY LMS-HD

T

AS

T

A

A

A

A

A

SIL PAD - Fiberglass

SIL PAD 400

T

T

T

T

T

T

A

A

A

A

A

A

SIL PAD 800

T

T

T

T

T

A

A

A

A

A

A

SIL PAD 900S

T

T

T

T

T

T

A

A

A

A

A

A

SIL PAD 980

T

T

T

T

T

A

A

A

A

A

A

SIL PAD 1100ST

T

T

T

T

T

T

A

A

A

A

A

SIL PAD 1200

T

T

T

T

T

T

A

A

A

A

A

A

SIL PAD A1500

T

T

T

T

T

T

A

A

A

A

A

A

SIL PAD I 500ST

T

T

T

T

T

T

A

A

A

A

A

SIL PAD 2000

T

T

T

T

AS

A

A

A

A

A

A

SIL PAD A2000

T

T

T

T

AS

T

A

A

A

A

A

A

SIL PAD - Thin Film Polyimide

SIL PAD K-4

T

T

T

T

T

T

A

A

A

A

A

A

SIL PAD K-6

T

T

T

T

T

T

A

A

A

A

A

A

SIL PAD K-10

T

T

T

T

T

T

A

A

A

A

A

A

GAP PAD

GAP PAD VO

T

T

T

T

T

T

T

A

A*

A

A

AS

A

GAP PAD VO Soft

T

T

T

T

T

T

T

A

A*

A

A

AS

A

GAP PAD VO Ultra Soft

T

T

T

T

T

T

T

A

A*

A

A

AS

A

GAP PAD HC 3.0

T

T

T

T

T

T

T

A

A*

A

A

AS

A

GAP PAD 1000HD

T

T

T

T

T

T

T

A

A*

A

A

AS

A

GAP PAD 1000SF

T

T

T

T

T

T

T

A

A

A

AS

GAP PAD HC 1000

T

T

T

T

T

A

A*

A

A

A

GAP PAD 1450

T

T

T

T

T

A

A*

A

A

A

GAP PAD 1500

T

T

T

T

T

A

A*

A

A

AS

GAP PAD 1500R

T

T

T

T

T

T

A

A*

A

A

A

GAP PAD 15000S30

T

T

T

T

AS

T

T

A

A

A

A

GAP PAD A2000

T

T

T

AS

T

T

A

A*

A

A

A

GAP PAD 2000S40

T

T

T

AS

T

T

A

A

A

A

GAP PAD 2200SF

T

T

T

T

T

T

T

A

A

A

AS

GAP PAD A3000

T

T

T

T

AS

T

T

A

A*

A

A

A

GAP PAD 3500ULM

T

T

T

T

AS

T

T

A

A*

A

A

A

GAP PAD 5000S35

T

T

T

T

AS

T

T

A

A

A

Gap Filler

Gap Filler 1000

T

T

T

AS

T

NA

Gap Filler 1000SR

T

T

T

AS

T

NA

Gap Filler 1100SF

T

T

T

T

AS

T

NA

Gap Filler 1500

T

T

T

AS

T

NA

Gap Filler 1500LV

T

T

T

AS

T

NA

Gap Filler 2000

T

T

T

AS

T

NA

Gap Filler 3500S35

T

T

T

AS

T

NA

Gap Filler 4000

T

T

T

AS

T

NA

Liquid Adhesive

LIQUI-BOND EA 1805

T

T

AS

T

NA

LIQUI-BOND SA 1000

T

T

AS

T

NA

LIQUI-BOND SA 1800

T

T

AS

T

NA

LIQUI-BOND SA 2000

T

T

AS

T

NA

LIQUI-BOND SA 3505

T

T

AS

T

NA

T = Typical; AS = Application-Specific (contact Henkel Sales); A = Available; * = Roll stock configurations are limited — contact your Henkel Sales Representative for more information. Note: For HI-FLOW 225UT, 225F-AC and HI-FLOW 565UT, the adhesive is not a 
pressure sensitive adhesive (PSA).

6 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD Thermally Conductive Materials

Solution-Driven Thermal Management Products for Electronic Devices

A Complete Range of Choices for Filling Air Gaps and Enhancing Thermal Conductivity

The BERGQUIST brand is a world leader in thermal interface 
materials. The GAP PAD family of products was developed 
to meet the electronic industry’s growing need for interface 
materials with greater conformability, higher thermal 
performance and easier application.

The extensive GAP PAD family provides an effective thermal 
interface between heat sinks and electronic devices where 
uneven surface topography, air gaps and rough surface textures 
are present. Henkel application specialists work closely with 
customers to specify the proper GAP PAD material for each 
unique thermal management requirement.

Features

Each of the many products 
within the GAP PAD family 
is unique in its construction, 
properties and performance. 
Following is an overview of the 
important features offered by 
the GAP PAD family.

• 

 Low-modulus 

polymer material

• 

 Available with fiberglass/ 

rubber carriers or in a non-

reinforced version 

• 

 Special fillers to achieve 

specific thermal 

and conformability 

characteristics

• 

 Highly conformable to 

uneven and rough surfaces

• 

Electrically isolating

• 

 Natural tack on one or both 

sides with protective liner

• 

 Variety of thicknesses  

and hardnesses

• 

 Range of thermal 

conductivities 

• 

 Available in sheets and 

die-cut parts

Benefits

GAP PAD thermal products 
are designed to improve 
an assembly’s thermal 
performance and reliability 
while saving time and money.

• 

 Eliminate air gaps to reduce 

thermal resistance

• 

 High conformability reduces 

interfacial resistance

• 

 Low-stress  vibration 

dampening

• 

Shock absorbing

• 

Easy material handling

• 

 Simplified  application

• 

 Puncture, shear and  

tear resistance

• 

 Improved performance for 

high-heat assemblies

• 

 Compatible with automated 

dispensing equipment

Options

Some GAP PAD products have 
special features for particular 
applications, including:

• 

 Available with or  

without adhesive

• 

 Rubber-coated  fiberglass 

reinforcement

• 

 Thicknesses from 0.010 in. 

to 0.250 in.

• 

 Available in custom die-

cut parts, sheets and rolls 

(converted or unconverted)

• 

 Custom thicknesses and 

constructions

• 

 Adhesive or natural inherent 

tack

• 

 Silicone-free  GAP PAD 

available in thicknesses of 

0.010 in. - 0.125 in.

We produce thousands of 
specials. Tooling charges vary 
depending on tolerance and 
complexity of the part.

Applications

GAP PAD products are well-
suited to a wide variety of 
electronics, automotive, 
medical, aerospace and 
military applications such as:

• 

 Between an IC and a heat 

sink or chassis. Typical 

packages include BGAs, QFP, 

SMT power components and 

magnetics

• 

 Between a semiconductor 

and heat sink

• 

CD-ROM/DVD cooling

• 

Heat pipe assemblies

• 

Memory modules

• 

DDR SDRAM

• 

Hard drive cooling

• 

Power supply

• 

IGBT modules

• 

Signal amplifiers

• 

 Between other heat-

generating devices  

and chassis

Thermal Interface Selection Guide 

— GAP PAD

 | 

7

 

GAP PAD Comparison Data

Conductivity, Hardness and General Overview

2.0

3.0

4.0

5.0

6.0

1.0

2.0

3.0

4.0

5.0

6.0

1.0

GAP PAD Thermal Interface Materials

Specialty GAP PAD Thermal Interface Materials

Ultra Low Modulus

(ULM)

High Performance

GAP PAD

3500ULM

VO Series

Extended Performance

GAP PAD

VO Ultra Soft

Value GAP PAD

Value Performance

GAP PAD

1450

Silicone-Free

GAP PAD

2202SF

GAP PAD

3004SF

GAP PAD

1000SF

GAP PAD

2200SF

GAP PAD

1500

GAP PAD

1500R

GAP PAD

VO Soft

GAP PAD

VO

High Compliance

(HC)

GAP PAD

HC 1000

High Durability

(HD)

GAP PAD

1000HD

Electromagnetic

(EMI)

GAP PAD

EMI 1.0

GAP PAD

HC 3.0

GAP PAD

HC 5.0

Soft Class

(S-Class)

GAP PAD

1500S30

GAP PAD

2000S40

GAP PAD

5000S35

Lo

w

est Modulus

Lo

w

est Modulus

Lo

w

est Modulus

8 

| Thermal Interface Selection Guide 

— GAP PAD

Frequently Asked Questions

Q:   What thermal conductivity test method was used to 

achieve the values given on the data sheets?

A: 

 A test fixture is utilized that meets the specifications outlined 
in ASTM D5470.

Q: Is GAP PAD offered with an adhesive?
A: 

 Currently,  GAP PAD VO, GAP PAD VO Soft, and GAP PAD VO 
Ultra Soft are offered with or without an adhesive on the  
SIL PAD 800/900 carrier-side of the material. The remaining 
surface has natural inherent tack. All other GAP PAD 
Materials have inherent tack.

Q:  Is the adhesive repositionable?
A: 

 Depending on the surface being applied to, if care is taken, 
the pad may be repositioned. Special care should be taken 
when removing the pad from aluminum or anodized surfaces 
to avoid tearing or delamination.

Q:  What is meant by “natural tack”?
A: 

 The characteristic of the rubber itself has a natural inherent 
tack, with the addition of an adhesive. As with adhesive-
backed products, the surfaces with natural tack may help in 
the assembly process to temporarily hold the pad in place 
while the application is being assembled. Unlike adhesive-
backed products, inherent tack does not have a thermal 
penalty since the rubber itself has the tack. Tack strength 
varies from one GAP PAD product to the next.

Q:   Can  GAP PAD with natural tack be repositioned?
A: 

 Depending on the material that the pad is applied to, in  
most cases they are repositionable. Care should be taken 
when removing the pad from aluminum or anodized  
surfaces to avoid tearing or delaminating the pad. The  
side with the natural tack is always easier to reposition  
than an adhesive side.

Q: Is GAP PAD reworkable?
A: 

 Depending on the application and the pad being used,  
GAP PAD has been reworked in the past. Some of our 
customers are currently using the same pad for reassembling 
their applications after burn-in processes and after fieldwork 
repairs. However, this is left up to the design engineer’s 
judgment as to whether or not the GAP PAD  
will withstand reuse.

Q:  Will heat make the material softer?
A: 

 From -60°C to 200°C, there is no significant variance in 
hardness for silicone GAP PAD Materials and Gap Fillers.

Q:  What is the shelf life of GAP PAD?
A: 

 Shelf life for most GAP PAD Materials is one (1) year after the 
date of manufacture. For GAP PAD with adhesive, the shelf 
life is six (6) months from the date of manufacture. After 
these dates, inherent tack and adhesive properties should be 
recharacterized. The GAP PAD material’s long-term stability is 
not the limiter on the shelf life; it is related to the adhesion or 
“age up” of the GAP PAD to the liner. Or in the case of a  
GAP PAD with adhesive, the shelf life is determined by how 
the adhesive ages up to the removable liner.

Q:  How is extraction testing performed?
A: 

 The test method used is the Soxhlet Extraction Method; 
please refer to GAP PAD S-Class White Paper.

Q:   What is the thickness tolerance of your pads?
A: 

 The thickness tolerance is ±10% on materials >10 mil and ±1 
mil on materials £10 mil.

Q:   What are the upper processing temperature limits for GAP 

PAD and for how long can GAP PAD be exposed to them?

A: 

 GAP PAD in general can be exposed to temporary processing 
temperatures of 250°C for five minutes and 300°C for 
one minute.

Q: Is GAP PAD electrically isolating?
A: 

 Yes,  all  GAP PAD materials are electrically isolating. However, 
keep in mind that GAP PAD is designed to fill  
gaps and it is not recommended for applications where  
high mounting pressure is exerted on the GAP PAD.

Q:  How much force will the pad place on my device?
A: 

 Refer to the Pressure vs. Deflection charts in BERGQUIST 
Application Note #116 at our website’s Technical Library. 
In addition, there are other helpful resources online at 
www.henkel-adhesives.com/thermal.

Q:   Why are “wet out,” “compliance” or “conformability” 

characteristics of GAP PAD important?

A: 

 The better a GAP PAD lays smooth “wets out” or conforms to 
a rough or stepped surface, giving less interfacial resistance 
caused by air voids and air gaps. GAP PAD Materials are 
conformable or compliant as they adhere very well to the 
surface. The GAP PAD Materials can act similarly to a “suction 
cup” on the surface. This leads to a lower overall thermal 
resistance of the pad between the two interfaces.

Q:   Is anything given off by the material (e.g., extractables, 

outgassing)?

A: 

1)   Silicone  GAP PAD and Gap Fillers, like all soft silicone 

materials, can extract low molecular weight silicone (refer 
to White Paper on GAP PAD S-Class). Also note that GAP 
PAD and Gap Filler have some of the lowest extraction 
values for silicone-based gap filling products on the 
market and if your application requires minimal silicone, 
see our line of silicone-free material. The White Paper on 
GAP PAD S-Class and information about our silicone-free 
materials are available on our website.

 

 2)   Primarily for aerospace applications, outgassing data is 

tested per ASTM E595.

Q:   Why does the Technical Data Sheet (on the website) 

describe the Shore hardness rating as a bulk rubber 
hardness?

A: 

 A reinforcement carrier is generally used in BERGQUIST 
GAP PAD Materials for ease of handling. When testing 
hardness, the reinforcement carrier can alter the test results 
and incorrectly depict thinner materials as being harder. To 
eliminate this error, a 250 mil rubber puck is molded with no 
reinforcement carrier. The puck is then tested for hardness. 
The Shore hardness is recorded after a 30-second delay.

Thermal Interface Selection Guide 

— GAP PAD

 | 

9

 

GAP PAD VO

Features and Benefits

• 

Thermal conductivity: 0.8 W/m-K

• 

 Enhanced puncture, shear and  

tear resistance

• 

Conformable gap filling material

• 

Electrically isolating

GAP PAD VO is a cost-effective, thermally 
conductive interface material. The 
material is a filled, thermally conductive 
polymer supplied on a rubber-coated 
fiberglass carrier allowing for easy 
material handling. The conformable 
nature of GAP PAD VO allows the pad to 
fill in air gaps between PC boards and 
heat sinks or a metal chassis.

Note: Resultant thickness is defined as the 

final gap thickness of the application.

1

3

5

7

9

11

13

250

200

150

100

50

0

Thickness vs. Thermal Resistance

GAP PAD VO

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Conformable, Thermally Conductive Material for Filling Air Gaps

Typical Applications Include:

• 

Telecommunications

• 

Computer and peripherals

• 

Power conversion

• 

Between heat-generating semiconductors and a heat sink

• 

 Area where heat needs to be transferred to a frame, chassis, or other type of 

heat spreader

• 

Between heat-generating magnetic components and a heat sink

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GPVO = GAP PAD VO Material

GPVO

0.040

AC

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.020", 0.040", 0.060",

0.080", 0.100", 0.125", 0.160", 0.200", 0.250"

AC = Adhesive on SIL PAD side, natural tack on one side

01 = No pressure sensitive adhesive, natural tack on one side

0816 = Standard sheet size 8" x 16" or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD VO

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Gold/Pink

Gold/Pink

Visual

Reinforcement Carrier

SIL PAD

SIL PAD

—

Thickness (in.) / (mm)

0.020 to 0.250

0.508 to 6.350

ASTM D374

Inherent Surface Tack (1-sided)

1

1

—

Density (Bulk Rubber) (g/cc)

1.6

1.6

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

40

40

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

100

689

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>6,000

>6,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.5

5.5

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

0.8

0.8

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

2.47

2.37

2.24

1)  Thirty-second delay value Shore 00 hardness scale.
2)  Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

. 

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

10 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD VO Soft

Highly Conformable, Thermally Conductive Material for Filling Air Gaps

Features and Benefits

• 

Thermal conductivity: 0.8 W/m-K

• 

Conformable, low hardness

• 

 Enhanced puncture, shear and  

tear resistance

• 

Electrically isolating

GAP PAD VO Soft is recommended for 
applications that require a minimum 
amount of pressure on components. 
GAP PAD VO Soft is a highly conformable, 
low-modulus, filled-silicone polymer on 
a rubber-coated fiberglass carrier. The 
material can be used as an interface 
where one side is in contact with a  
leaded device.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

1

2

3

4

8

7

6

5

9

10

200

180

160

140

120

100

80

60

40

20

Thickness vs. Thermal Resistance

GAP PAD VO Soft

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Telecommunications

• 

Computer and peripherals

• 

Power conversion

• 

Between heat-generating semiconductors or magnetic components and a heat sink

• 

Area where heat needs to be transferred to a frame, chassis, or other type of 

heat spreader

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GPVOS = GAP PAD VO Soft Material

GPVOS

0.060

AC

00

ACME10256 Rev. a

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.020", 0.040", 0.060",

0.080", 0.100", 0.125", 0.160", 0.200"

AC = Adhesive on SIL-PAD side, natural tack on one side

01 = No pressure sensitive adhesive, natural tack on one side

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD VO SOFT

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Mauve/Pink

Mauve/Pink

Visual

Reinforcement Carrier

SIL PAD

SIL PAD

—

Thickness (in.) / (mm)

0.020 to 0.200

0.508 to 5.080

ASTM D374

Inherent Surface Tack (1-sided)

1

1

—

Density (Bulk Rubber) (g/cc)

1.6

1.6

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

25

25

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

40

275

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>6,000

>6,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.5

5.5

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

0.8

0.8

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

2.48

2.29

2.11

1)   Thirty-second delay value Shore 00 hardness scale.
2)  Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

Thermal Interface Selection Guide 

— GAP PAD

 | 

11

 

GAP PAD VO Ultra Soft

Ultra Conformable, Thermally Conductive Material for Filling Air Gaps

Features and Benefits

• 

Thermal conductivity: 1.0 W/m-K

• 

Highly conformable, low hardness

• 

“Gel-like” modulus

• 

Decreased strain

• 

Puncture-, shear- and tear-resistant

• 

Electrically isolating

GAP PAD VO Ultra Soft is recommended 
for applications that require a minimum 
amount of pressure on components. 
The viscoelastic nature of the material 
also gives excellent low-stress vibration 
dampening and shock absorbing 
characteristics. GAP PAD VO Ultra Soft is 
an electrically isolating material, which 
allows its use in applications requiring 
isolation between heat sinks and high-
voltage, bare-leaded devices.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

1

2

3

5

8

4

6

9

7

10

250

200

150

100

50

0

Thickness vs. Thermal Resistance

GAP PAD VO Ultra Soft

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Telecommunications

• 

Computer and peripherals

• 

Power conversion

• 

Between heat-generating semiconductors or magnetic components and a heat sink

• 

Area where heat needs to be transferred to a frame, chassis, or other type of 

heat spreader

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GPVOUS = GAP PAD VO Ultra Soft Material

GPVOUS

0.100

AC

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.020", 0.040", 0.060",

0.080", 0.100", 0.125", 0.160", 0.200", 0.250"

AC = Adhesive on SIL-PAD side, natural tack on one side

01 = No pressure sensitive adhesive, natural tack on one side

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD VO ULTRA SOFT

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Mauve/Pink

Mauve/Pink

Visual

Reinforcement Carrier

SIL PAD

SIL PAD

—

Thickness (in.) / (mm)

0.020 to 0.250

0.508 to 6.350

ASTM D374

Inherent Surface Tack (1-sided)

1

1

—

Density (Bulk Rubber) (g/cc)

1.6

1.6

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

5

5

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

8

55

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

6,000

6,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.5

5.5

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-0

V-0

UL 94

THERMAL

Thermal Conductivity (W/m-K)

1.0

1.0

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

 

 

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

1.97

1.87

1.68

1)  Thirty-second delay value Shore 00 hardness scale.
2)  Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

12 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD HC 3.0

High-Compliance, Thermally Conductive, Low Modulus Material

Features and Benefits

• 

 Thermal conductivity: 3.0 W/m-K

• 

 High-compliance,  low   

compression stress

• 

 Fiberglass-reinforced for shear and tear 

resistance

GAP PAD HC 3.0 is a soft and compliant 
gap filling material with a thermal 
conductivity of 3.0 W/m-K. The material 
offers exceptional thermal performance at 
low pressures due to a unique 3.0 W/m-K 
filler package and low-modulus resin 
formulation. The enhanced material 
is ideal for applications requiring low 
stress on components and boards during 
assembly. GAP PAD HC 3.0 maintains 
a conformable nature that allows for 
quick recovery and excellent wet-out 
characteristics, even to surfaces with high 
roughness and/or topography.

GAP PAD HC 3.0 is offered with natural 
inherent tack on both sides of the 
material, eliminating the need for 
thermally impeding adhesive layers. The 
top side has minimal tack for ease of 
handling. GAP PAD HC 3.0 is supplied 
with protective liners on both sides. 

.25

.50

.75

1.00

1.25

1.50  1.75 2.00

140

120

100

80
60
40
20

0

Thickness vs. Thermal Resistance

GAP PAD HC 3.0

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Telecommunications

• 

ASICs and DSPs

• 

Consumer electronics

• 

Thermal modules to heat sinks

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GPHC3.0 = GAP PAD HC 3.0 Material with fiberglass

GPHC3.0

0.020

02

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.020", 0.040", 0.060", 

0.080", 0.100", 0.125"

02 = Natural tack, both sides (With fiberglass)

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD HC 3 .0

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Blue

Blue

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.020 to 0.125

0.508 to 3.175

ASTM D374

Inherent Surface Tack 

2

2

—

Density (Bulk Rubber) (g/cc)

3.1

3.1

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(4)

15

15

ASTM D2240 

Young’s Modulus (psi) / (kPa)

(1)

16

110

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

(3)

>5,000

>5,000

ASTM D149

Dielectric Constant (1,000 Hz) 

6.5

6.5

ASTM D150

Volume Resistivity (Ohmmeter)

10

10

10

10

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

(2)

3.0

3.0

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(2)

0.57

0.49

0.44

1)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

 after 5 minutes of compression at 10% strain on a 1 mm 

thickness material.

2)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied. 

3)  Minimum value at 20 mil. 
4)  Thirty-second delay value on Shore 00 hardness scale.

Thermal Interface Selection Guide 

— GAP PAD

 | 

13

 

GAP PAD 1000HD

Highly Durable, Conformable, Thermally Conductive, Gap Filling Material

Features and Benefits

• 

 Thermal conductivity: 1.0 W/m-K

• 

 Designed for high 

durability applications

• 

 Robust polyimide carrier provides 

excellent voltage breakdown, puncture 

and tear resistance

• 

Highly conformable

• 

 Ease of handling and rework 

in applications

GAP PAD 1000HD

GAP PAD 1000HD was designed to 
withstand applications requiring 
high durability. 

The coated polyimide carrier on one 
side of the material allows easy rework, 
excellent handling characteristics and 
puncture resistance. 

The conformable and elastic nature 
of GAP PAD 1000HD allows excellent 
interfacing and wet-out characteristics, 
even to surfaces with a high degree of 
roughness or uneven topography.

The asymmetric construction of  
GAP PAD 1000HD provides minimal  
tack on the polyimide side, with high 
inherent tack on the upcoated side.  
GAP PAD 1000HD can be assembled  
with manual or automated processes.

1.00

2.00

4.00

3.00

5.00

125

100

75

50

25

0

Thickness vs. Thermal Resistance

GAP PAD 1000HD

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

High durability applications

• 

Automotive energy storage: ultra capacitors, batteries, power transmissions, 

power inverters

• 

Industrial automotive applications such as trucks, buses and trains

• 

Computer and peripherals

• 

Telecommunications

• 

Between any heat-generating device and a heat sink

Configurations Available:

• 

Sheet form 

• 

Die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GP1000HD = GAP PAD 1000HD Material

GP1000HD

0.100

01

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.020", 0.040", 0.060",

0.080", 0.100", 0.125"

01 = Natural tack on one side

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD 1000HD

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Grey/Black

Grey/Black

Visual

Reinforcement Carrier

Polyimide

Polyimide

—

Thickness (in.) / (mm)

0.020 to 0.125

0.508 to 3.175

ASTM D374

Inherent Surface Tack (1- or 2-sided)

1

1

—

Density (g/cc)

2.1

2.1

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness, Bulk Rubber (Shore 00)

(1)

40

40

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

60

414

ASTM D575

Continuous Use Temp. (°C)

-76 to 358

-60 to 180

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>10,000

>10,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.5

5.5

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

1.0

1.0

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

 

 

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3) 

1.70

1.59

1.47

1)  Thirty-second delay value Shore 00 hardness scale.
2)  Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded values includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

14 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD 1000SF

Thermally Conductive, Silicone-Free Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 0.9 W/m-K

• 

No silicone outgassing

• 

No silicone extraction

• 

 Reduced tack on one side to aid in 

application assembly

• 

Electrically isolating

GAP PAD 1000SF is a thermally 
conductive, electrically insulating, 
silicone-free polymer specially designed 
for silicone-sensitive applications. The 
material is ideal for applications with high 
standoff and flatness tolerances.  
GAP PAD 1000SF is reinforced for easy 
material handling and added durability 
during assembly. The material is available 
with a protective liner on both sides of 
the material. The top side has reduced 
tack for ease of handling.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

0

1

2

4

3

5

125

100

75

50

25

0

Thickness vs. Thermal Resistance

GAP PAD 1000SF

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Digital disk drives / CD-ROM

• 

Automotive modules

• 

Fiber optics modules

Configurations Available:

• 

Sheet form

• 

Die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GP1000SF = GAP PAD 1000SF Material

GP1000SF

0.010

02

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available: 0.010", 0.015", 0.020",

0.040", 0.060", 0.080", 0.100", 0.125"

02 = Natural tack, both sides

0806: = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD 1000SF

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Green

Green

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.010 to 0.125

0.254 to 3.175

ASTM D374

Inherent Surface Tack (1- or 2-sided)

2

2

—

Density (g/cc)

2.0

2.0

ASTM D792

Heat Capacity ( J/g-K)

1.1

1.1

ASTM E1269

Hardness, Bulk Rubber (Shore 00)

(1)

40

40

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

34

234

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 257

-60 to 125

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>6,000

>6,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.0

5.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

10

10

10

ASTM D257

Flame Rating

V-1

V-1

UL 94

THERMAL

Thermal Conductivity (W/m-K)

0.9

0.9

ASTM D5470

1)  Thirty-second delay value Shore 00 hardness scale.
2)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

. For more information on GAP PAD modulus, refer to 

BERGQUIST Application Note #116 at our website’s Technical Library.

Thermal Interface Selection Guide 

— GAP PAD

 | 

15

 

GAP PAD HC1000

“Gel-Like” Modulus Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 1.0 W/m-K

• 

Highly conformable, low hardness

• 

“Gel-like” modulus

• 

 Fiberglass-reinforced for puncture, 

shear and tear resistance

GAP PAD HC1000 is an extremely 
conformable, low-modulus polymer that 
acts as a thermal interface and electrical 
insulator between electronic components 
and heat sinks. The “gel-like” modulus 
allows this material to fill air gaps to 
enhance the thermal performance of 
electronic systems. GAP PAD HC1000 is 
offered with removable protective liners 
on both sides of the material.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

0.25

0.30

0.40

0.35

0.50

0.45

0.55

20

18
16

14

12

10

Thickness vs. Thermal Resistance

GAP PAD HC1000

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Computer and peripherals

• 

Telecommunications

• 

Heat interfaces to frames, chassis, or other heat spreading devices

• 

Memory modules / chip scale packages

• 

CD-ROM / DVD cooling

• 

Areas where irregular surfaces need to make a thermal interface to a heat sink

• 

DDR SDRAM memory modules

• 

FB-DIMM modules

Configurations Available:

• 

Sheet form, die-cut parts, and roll form (converted or unconverted)

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

HC1000 = High Compliance 1000 Material

HC1000

0.015

02

0816

NA

Note:  To build a part number, visit our website at www.bergquistcompany.com.

Standard thicknesses available:  0.010", 0.015", 0.020"

02 = Natural tack, both sides

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

 

example

TYPICAL PROPERTIES OF GAP PAD HC1000

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Grey

Grey

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.010 to 0.020

0.254 to 0.508

ASTM D374

Inherent Surface Tack (1-sided)

2

2

—

Density (Bulk Rubber) (g/cc)

1.6

1.6

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

25

25

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

40

275

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>5,000

>5,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.5

5.5

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

1.0

1.0

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.020 in.

(3)

1.30

1.00

0.96

1)  Thirty-second delay value Shore 00 hardness scale.
2)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

16 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD 1450

Highly Conformable, Thermally Conductive, Reworkable Gap Filling Material

Features and Benefits

• 

 Thermal conductivity: 1.3 W/m-K 

(bulk rubber)

• 

 PEN film reinforcement allows easy 

rework and resistance to puncture and 

tear resistance

• 

 Highly conformable/low hardness

• 

 Low strain on fragile components

GAP PAD 1450 is a highly compliant  
GAP PAD material that is ideal for fragile 
component leads. The material includes 
a PEN film, which facilitates rework 
and improves puncture resistance and 
handling characteristics. The tacky side of 
GAP PAD 1450 maintains a conformable, 
yet elastic nature that provides excellent 
interfacing and wet-out characteristics, 
even to surfaces with high roughness or 
uneven topography.

GAP PAD 1450 has inherent tack on one 
side of the material, eliminating the need 
for thermally impeding adhesive layers.

It is highly recommended that the PEN 
film be left intact. However, film removal 
will not have a significant impact on 
thermal performance. 

Please contact your local Henkel Sales 
Representative for sample inquiries and 
additional product information.

Thermal Resistance (C-in.

2

/W)

Thickness vs. Thermal Resistance

GAP PAD 1450

Typical Applications:

• 

 Lighting and LED applications

• 

 Low strain is required for fragile component leads

• 

Computer and peripherals

• 

Telecommunications

• 

 Between any heat-generating semiconductor and a heat sink

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

GP1450

01

0816

0.020

||

 

example

Section A

Section B

Section C

Section D

Section E

NA

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

01 = Natural tack, one side

Standard thickness available:  0.020", 0.040", 0.060"

0.080", 0.100", 0.125"

GP1450 = GAP PAD 1450 Material

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

TYPICAL PROPERTIES OF GAP PAD 1450

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Light Pink

Light Pink

Visual

Reinforcement Carrier

PEN film

PEN film

—

Thickness (in.) / (mm)

0.020 to 0.125

0.508 to 3.175

ASTM D374

Inherent Surface Tack (1-sided)

1

1

—

Density (Bulk Rubber) (g/cc)

1.8

1.8

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

30

30

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

16

110

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 302

-60 to 150

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>6,000

>6,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.0

5.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

9

10

9

ASTM D257

Flame Rating

V-0

V-0

UL 94

THERMAL

Thermal Conductivity (W/m-K)

1.3

1.3

ASTM D5470

1)  Thirty-second delay value Shore 00 hardness scale.
2)  Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

. 

Thermal Interface Selection Guide 

— GAP PAD

 | 

17

 

GAP PAD 1500

Thermally Conductive, Unreinforced Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 1.5 W/m-K

• 

 Unreinforced construction for 

additional compliancy

• 

Conformable, low hardness

• 

Electrically isolating

GAP PAD 1500 has an ideal filler 
blend that gives it a low-modulus 
characteristic which maintains optimal 
thermal performance yet still allows 
for easy handling. The natural tack 
on both sides of the material allows 
for good compliance to adjacent 
surfaces of components, minimizing 
interfacial resistance. 

Note: Resultant thickness is defined as the final 

gap thickness of the application.

0

1

3

2

5

4

6

200

150

100

50

0

Thickness vs. Thermal Resistance

GAP PAD 1500

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Telecommunications

• 

Computer and peripherals

• 

Power conversion

• 

Memory modules / chip scale packages

• 

Areas where heat needs to be transferred to a frame chassis or other type  

of heat spreader

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GP1500 = GAP PAD 1500 Material

GP1500

0.100

02

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.020", 0.040", 0.060",

0.080", 0.100", 0.125", 0.160", 0.200"

02 = Natural tack, both sides

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD 1500

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Black

Black

Visual

Reinforcement Carrier

—

—

—

Thickness (in.) / (mm)

0.020 to 0.200

0.508 to 5.080

ASTM D374

Inherent Surface Tack (1-sided)

2

2

—

Density (Bulk Rubber) (g/cc)

2.1

2.1

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

40

40

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

45

310

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>6,000

>6,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.5

5.5

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

1.5

1.5

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

1.62

1.50

1.33

1)  Thirty-second delay value Shore 00 hardness scale.
2)  Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

18 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD 1500R

Features and Benefits

• 

Thermal conductivity: 1.5 W/m-K

• 

 Fiberglass-reinforced for puncture, 

shear and tear resistance

• 

Easy release construction

• 

Electrically isolating

GAP PAD 1500R has the same highly 
conformable, low-modulus polymer as  
the standard GAP PAD 1500. The 
fiberglass reinforcement allows for easy 
material handling and enhances puncture, 
shear and tear resistance. The natural  
tack on both sides of the material allows 
for good compliance to mating surfaces 
of components, further reducing  
thermal resistance.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

0.25

0.30

0.40

0.35

0.50

0.45

0.55

20

18
16

14

12

10

Thickness vs. Thermal Resistance

GAP PAD 1500R

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Thermally Conductive, Reinforced Gap Filling Material

Typical Applications Include:

• 

Telecommunications

• 

Computer and peripherals

• 

Power conversion

• 

Memory modules / chip scale packages

• 

Areas where heat needs to be transferred to a frame chassis or other type  

of heat spreader

Configurations Available:

• 

Sheet form, die-cut parts, and roll form (converted or unconverted)

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GP1500R = GAP PAD 1500R Material

GP1500R

0.020

02

00

ACME10256 Rev. A

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.010", 0.015", 0.020"

02 = Natural tack, both sides

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD 1500R

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Black

Black

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.010 to 0.020

0.254 to 0.508

ASTM D374

Inherent Surface Tack (1-sided)

2

2

—

Density (Bulk Rubber) (g/cc)

2.1

2.1

ASTM D792

Heat Capacity ( J/g-K)

1.3

1.3

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

40

40

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

45

310

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>6,000

>6,000

ASTM D149

Dielectric Constant (1,000 Hz)

6.0

6.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

1.5

1.5

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.020 in.

(3)

1.07

0.88

0.82

1)  Thirty-second delay value Shore 00 hardness scale.
2)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

Thermal Interface Selection Guide 

— GAP PAD

 | 

19

 

GAP PAD 1500S30

Highly Conformable, Thermally Conductive, Reinforced “S-Class” Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 1.3 W/m-K

• 

Highly conformable/low hardness

• 

Decreased strain on fragile components

• 

 Fiberglass-reinforced for puncture, 

shear and tear resistance

• 

Quick rebound to original shape

GAP PAD 1500S30 is a highly compliant 
GAP PAD material that is ideal for 
fragile component leads. The material 
is fiberglass-reinforced for improved 
puncture resistance and handling 
characteristics. GAP PAD 1500S30 
maintains a conformable, yet elastic 
nature that provides excellent  
interfacing and wet-out characteristics, 
even to surfaces with high roughness  
or uneven topography.

GAP PAD 1500S30 features an inherent 
tack on both sides of the material, 
eliminating the need for thermally 
impeding adhesive layers.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

 0.61

 1.21

 1.82

 2.42  3.03  3.79   4.85  6.06  7.57

250

200

160

125

100

80
60
40
20

0

Thickness vs. Thermal Resistance

GAP PAD 1500S30

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications:

• 

 Any heat-generating component and a heat sink

• 

Computers and peripherals

• 

Telecommunications

• 

Between any heat-generating semiconductor and a heat sink

• 

 Shielding  devices

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

GP1500S30

GP1500S30 = GAP PAD 1500S30 Material

02

0816

0.020

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

02 = Natural tack, both sides

Standard thicknesses available: 0.020", 0.040", 0.060"

0.080", 0.100", 0.125", 0.160", 0.200", 0.250"

Section A

Section B

Section C

Section D

Section E

|| 

example

TYPICAL PROPERTIES OF GAP PAD 1500S30

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Light Pink

Light Pink

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

ASTM D374

Thickness (in.) / (mm)

0.020 to 0.250

0.508 to 6.350

ASTM D374

Inherent Surface Tack (1-sided)

2

2

—

Density (Bulk Rubber) (g/cc)

1.8

1.8

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

30

30

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

16

110

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>6,000

>6,000

ASTM D149

Dielectric Constant (1,000 Hz)

5.0

5.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

1.3

1.3

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

1.69

1.41

1.26

1)  Thirty-second delay value Shore 00 hardness scale.
2)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

20 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD A2000

High Performance, Thermally Conductive Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 2.0 W/m-K

• 

 Fiberglass-reinforced for puncture, 

shear and tear resistance

• 

Electrically isolating

GAP PAD A2000 acts as a thermal 
interface and electrical insulator between 
electronic components and heat sinks. 
In the thickness range of 10 to 40 mil, 
GAP PAD A2000 is supplied with natural 
tack on both sides, allowing for excellent 
compliance to the adjacent surfaces 
of components. The 40 mil material 
thickness is supplied with lower tack on 
one side, allowing for burn-in processes 
and easy rework.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

0.20

0.30

0.50

0.40

0.70

0.60

0.80

40

35

30

25

20

15

10

0

Thickness vs. Thermal Resistance

GAP PAD A2000

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Computer and peripherals; between CPU and heat spreader

• 

Telecommunications

• 

Heat pipe assemblies

• 

Memory modules

• 

CDROM / DVD cooling

• 

Areas where heat needs to be transferred to a frame chassis or other type  

of heat spreader

• 

DDR SDRAM memory modules

Configurations Available:

• 

Sheet form, die-cut parts and roll form (converted or unconverted)

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GPA2000 = GAP PAD A2000 Material

GPA2000

0.010

02

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.010", 0.015", 0.020"

0.040"

02 = Natural tack, both sides

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD A2000

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Grey

Grey

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.010 to 0.040

0.254 to 1.016

ASTM D374

Inherent Surface Tack (1-sided)

2

2

—

Density (Bulk Rubber) (g/cc)

2.9

2.9

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

80

80

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

55

379

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

4,000

4,000

ASTM D149

Dielectric Constant (1,000 Hz)

6.0

6.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

2.0

2.0

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

1.04

1.00

0.95

1)   Thirty-second delay value Shore 00 hardness scale.
2)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

Thermal Interface Selection Guide 

— GAP PAD

 | 

21

 

GAP PAD 2000S40

Highly Conformable, Thermally Conductive, Reinforced “S-Class” Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 2.0 W/m-K

• 

 Low “S-Class” thermal resistance at 

very low pressures

• 

Highly conformable, low hardness

• 

Designed for low-stress applications

• 

 Fiberglass-reinforced for puncture, 

shear and tear resistance

GAP PAD 2000S40 is recommended for 
low-stress applications that require a mid- 
to high-thermally conductive interface 
material. The highly conformable nature 
of the material allows the pad to fill in air 
voids and air gaps between PC boards and 
heat sinks or metal chassis with stepped 
topography, rough surfaces and high 
stack-up tolerances.

GAP PAD 2000S40 is offered with 
inherent natural tack on both sides 
of the material allowing for stick-in-
place characteristics during application 
assembly. The material is supplied 
with protective liners on both sides. 
The top side has reduced tack for ease 
of handling.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

0.20

0.50

1.50

1.00

2.00

2.50

125

100

75

50

25

0

Thickness vs. Thermal Resistance

GAP PAD 2000S40

Thermal Resistance (

°

C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Power electronics DC/DC; 1/4, 1/2, full bricks, etc.

• 

Mass storage devices

• 

Graphics card/processor/ASIC

• 

Wireline/wireless communications hardware

• 

Automotive engine/transmission controls

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GP2000S40 = GAP PAD 2000S40 Material

GP2000S40

0.020

02

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.020", 0.040", 0.060",

0.080", 0.100", 0.125"

02 = Natural tack, both sides

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD 2000S40

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Grey

Grey

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.020 to 0.125

0.508 to 3.175

ASTM D374

Inherent Surface Tack (1-sided)

2

2

—

Density (Bulk Rubber) (g/cc)

2.9

2.9

ASTM D792

Heat Capacity ( J/g-K)

0.6

0.6

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

30

30

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

45

310

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>5,000

>5,000

ASTM D149

Dielectric Constant (1,000 Hz)

6.0

6.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

2.0

2.0

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

0.97

0.89

0.80

1)  Thirty-second delay value Shore 00 hardness scale.
2)  Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

22 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD 2200SF

Thermally Conductive, Silicone-Free Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 2.0 W/m-K

• 

 Silicone-free  formulation 

• 

Medium compliance with easy handling

• 

 Electrically  isolating

GAP PAD 2200SF is a thermally 
conductive, electrically isolating, 
silicone-free polymer specially designed 
for silicone-sensitive applications. 
The material is ideal for applications 
with uneven topologies and high 
stack-up tolerances. GAP PAD 2200SF is 
reinforced for easy material handling and 
added durability during assembly. The 
material is available with a protective 
liner on both sides. GAP PAD 2200SF is 
supplied with reduced tack on one side, 
allowing for burn-in processes  
and easy rework.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

GAP PAD 2200SF

140

0

0.5

1.0

1.5

2.0

2.5

0

Thermal Resistance (°C-in.

2

/W)

Typical Applications:

• 

Digital disk drives

• 

Proximity near electrical contacts (e.g., DC brush motors, connectors, relays)

• 

Fiber optics modules

Configurations Available:

• 

Sheet form

• 

Die-cut parts

• 

Standard sheet size is 8 in. x 16 in.

Building a Part Number 

Standard Options

GP2200SF = GAP PAD 2200SF Material

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Section B

Section D

Section E

Section A

Section C

GP2200SF

N

–

02

–

–

–

0.010

0816

NA = Selected standard option. If not selecting a standard
option, insert company name, drawing number, and
revision level.

0816 = Standard sheet size 8" x 16", or
00 = custom configuration

02 = Natural tack, both sides

Standard thicknesses available: 0.010", 0.015", 0.020",
0.040", 0.060", 0.080", 0.100", 0.125"

|| 

example

TYPICAL PROPERTIES OF GAP PAD 2200SF

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Green

Green

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.010 to 0.125

0.254 to 3.175

ASTM D374

Inherent Surface Tack (1- or 2-sided)

2

2

—

Density (g/cc)

2.8

2.8

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness, Bulk Rubber (Shore 00)

(1)

70

70

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

33

228

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 257

-60 to 125

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>5,000

>5,000

ASTM D149

Dielectric Constant (1,000 Hz)

6.0

6.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

8

10

8

ASTM D257

Flame Rating 

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

2.0

2.0

ASTM D5470

1)  Thirty-second delay value Shore 00 hardness scale.
2)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

. For more information on GAP PAD modulus, refer to 

BERGQUIST Application Note #116 at our website’s Technical Library.

Thermal Interface Selection Guide 

— GAP PAD

 | 

23

 

GAP PAD A3000

Thermally Conductive, Reinforced Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 2.6 W/m-K

• 

 Fiberglass-reinforced for puncture, 

shear and tear resistance

• 

 Reduced tack on one side to aid in 

application assembly

• 

Electrically isolating

GAP PAD A3000 is a thermally 
conductive, filled-polymer laminate, 
supplied on a reinforcing mesh for added 
electrical isolation, easy material handling 
and enhanced puncture, shear and 
tear resistance. GAP PAD A3000 has a 
reinforcement layer on the dark gold side 
of the material that assists in burn-in and 
rework processes while the light gold  
and soft side of the material allows for  
added compliance.

Note: Resultant thickness is defined as the final 

gap thickness of the application.

0.10 0.30 0.50 0.70

1.10

0.90

1.50

1.30

1.70

125

 

115

 

95

 

75

 

55

 

35

Thickness vs. Thermal Resistance

GAP PAD A3000

Thermal Resistance (C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Computer and peripherals

• 

Heat pipe assemblies

• 

CDROM / DVD cooling

• 

Area where heat needs to be transferred 

to a frame, chassis or other type of 

heat spreader

• 

Telecommunications

• 

Memory modules

• 

Between CPU and heat spreader

Configurations Available:

• 

Sheet form, die-cut parts and roll form (converted or unconverted)

Building a Part Number 

Standard Options 

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GPA3000 = GAP PAD A3000 Material

GPA3000

0.015

01

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.015", 0.020", 0.040",

0.060", 0.080", 0.100", 0.125"

01 = Natural tack, one side

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD A3000

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Gold

Gold

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.015 to 0.125

0.381 to 3.175

ASTM D374

Inherent Surface Tack (1-sided)

1

1

—

Density (Bulk Rubber) (g/cc)

3.2

3.2

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

80

80

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

50

344

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>5,000

>5,000

ASTM D149

Dielectric Constant (1,000 Hz)

7.0

7.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

10

10

10

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

2.6

2.6

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

0.78

0.73

0.68

1)  Thirty-second delay value Shore 00 hardness scale.
2)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

24 

| Thermal Interface Selection Guide 

— GAP PAD

GAP PAD 3500ULM

Highly Conformable, Thermally Conductive, Ultra-Low Modulus Material

Features and Benefits

• 

 Thermal conductivity: 3.5 W/m-K

• 

Fiberglass-reinforced for shear and tear 

resistance

• 

 Non-fiberglass option for applications 

that require an additional reduction 

in stress

GAP PAD 3500ULM (ultra-low modulus) 
is an extremely soft gap filling material 
with a thermal conductivity of 3.5 W/m-K. 
The material offers exceptional thermal 
performance at low pressures due to 
a unique 3.5 W/m-K filler package and 
ultra-low modulus resin formulation. 
The enhanced material is well-suited for 
high performance applications requiring 
extremely low assembly stress. GAP PAD 
3500ULM maintains a conformable nature 
that allows for excellent interfacing and 
wet-out characteristics, even to surfaces 
with high roughness and/or topography.

GAP PAD 3500ULM is offered with and 
without fiberglass and has higher natural 
inherent tack on one side of the material, 
eliminating the need for thermally 
impeding adhesive layers. The top side 
has minimal tack for ease of handling. 
GAP PAD 3500ULM is supplied with 
protective liners on both sides. 

.25

.50

.75

1.00

1.25

1.50  1.75 2.00

140

120

100

80
60
40
20

0

Thickness vs. Thermal Resistance

GAP PAD 3500ULM

Thermal Resistance (°C-in.

2

/W)

Resultant Thickness (

mils

)

Typical Applications Include:

• 

Consumer electronics

• 

Telecommunications

• 

ASICs and DSPs

• 

PC applications

Configurations Available:

• 

Sheet form and die-cut parts

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GP3500ULM = GAP PAD 3500ULM Material without fiberglass

GP3500ULM-G = GAP PAD 3500ULM Material with fiberglass

(GP3500ULM and GP3500ULM-G are also offered in a NT, 

non-tack, version)

GP3500ULM

0.020

02

0816

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Standard thicknesses available:  0.020"(fiberglass only), 0.040",  

0.060", 0.080", 0.100", 0.125"

02 = Natural tack, both sides (without fiberglass)

12 = Natural tack, both sides (with fiberglass)

05 = Non-tack, one side (without fiberglass), 7.87" x 15.75"

15 = Non-tack, one side (with fiberglass), 7.87" x 15.75"

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP PAD 3500ULM

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Grey

Grey

Visual

Reinforcement Carrier

Fiberglass or 
no fiberglass

Fiberglass or 
no fiberglass

—

Thickness (in.) / (mm)

0.020 to 0.125

0.508 to 3.175

ASTM D374

Inherent Surface Tack 

2

2

—

Density (Bulk Rubber) (g/cc)

3.1

3.1

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Young’s Modulus (psi) / (kPa)

(1)(2)

4

27.5

—

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>5,000

>5,000

ASTM D149

Dielectric Constant (1,000 Hz)

(3)

6.0

6.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

10

10

10

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

3.5

3.5

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(4)

0.50

0.44

0.39

1)   Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

 after 5 minutes of compression at 10% strain on a 1mm 

thickness material.

2)   Thirty-second delay value Shore 000 hardness scale is 70 for 125 mil.
3)   Minimum value at 20 mil.
4)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied. 

Thermal Interface Selection Guide 

— GAP PAD

 | 

25

 

GAP PAD 5000S35

High Thermal Conductivity Plus “S-Class” Softness and Conformability

Features and Benefits

• 

High thermal conductivity: 5.0 W/m-K

• 

 Highly conformable, “S-Class” softness

• 

Natural inherent tack reduces 

interfacial thermal resistance

• 

 Conforms to demanding contours and 

maintains structural integrity with 

little or no stress applied to fragile 

component leads

• 

 Fiberglass-reinforced for puncture, 

shear and tear resistance

• 

Excellent thermal performance at 

low pressures

GAP PAD 5000S35 is a fiberglass-
reinforced filler and polymer featuring a 
high thermal conductivity. The material 
yields extremely soft characteristics while 
maintaining elasticity and conformability. 
The fiberglass reinforcement provides 
easy handling and converting, added 
electrical isolation and tear resistance. 
The inherent natural tack on both 
sides assists in application and allows 
the product to effectively fill air 
gaps, enhancing the overall thermal 
performance. The top side has reduced 
tack for ease of handling. GAP PAD 
5000S35 is ideal for high-performance 
applications at low mounting pressures. 

Note: Resultant thickness is defined as the final 

gap thickness of the application.

Thermal Resistance (°C-in.

2

/W)

Thickness vs. Thermal Resistance

GAP PAD 5000S35

Typical Applications

• 

CDROM / DVD ROM

• 

Voltage Regulator Modules (VRMs) and POLs

• 

Thermally enhanced BGAs

• 

Memory packages / modules

• 

PC board to chassis

• 

ASICs and DSPs

Configurations Available:

• 

Die-cut parts are available in any shape or size, separated or in sheet form

Building a Part Number 

Standard Options

|| 

example

Section A

Section B

Section C

Section D

Section E

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

GP5000S35

0.020

02

0816

NA

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GPA5000S35 = GAP PAD 5000S35 Material

Standard thicknesses available:  0.020", 0.040", 0.060"

0.080", 0.100", 0.125"

02 = Natural tack, both sides

0816 = Standard sheet size 8" x 16", or

00 = custom configuration

TYPICAL PROPERTIES OF GAP PAD 5000S35

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Light Green

Light Green

Visual

Reinforcement Carrier

Fiberglass

Fiberglass

—

Thickness (in.) / (mm)

0.020 to 0.125

0.508 to 3.175

ASTM D374

Inherent Surface Tack (1-sided)

2

2

—

Density (Bulk Rubber) (g/cc)

3.6

3.6

ASTM D792

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Hardness (Bulk Rubber) (Shore 00)

(1)

35

35

ASTM D2240

Young’s Modulus (psi) / (kPa)

(2)

17.5

121

ASTM D575

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL

Dielectric Breakdown Voltage (Vac.)

>5,000

>5,000

ASTM D149

Dielectric Constant (1,000 Hz)

7.5

7.5

ASTM D150

Volume Resistivity (Ohmmeter)

10

9

10

9

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

5.0

5.0

ASTM D5470

THERMAL PERFORMANCE VS. STRAIN

Deflection (% strain)

10

20

30

Thermal Impedance (°C-in.

2

/W) 0.040 in.

(3)

0.41

0.34

0.30

1)  Thirty-second delay value Shore 00 hardness scale.
2)  Young’s Modulus, calculated using 0.01 in./min. step rate of strain with a sample size of 0.79 in.

2

.

3)   The ASTM D5470 test fixture was used. The recorded value includes interfacial thermal resistance. These values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

26 

| Thermal Interface Selection Guide 

— GAP FILLER

Gap Filler Liquid Dispensed Materials

Introduction

Effective thermal management is key to ensuring consistent 
performance and long-term reliability of many electronic 
devices. With the wide variety of applications requiring thermal 
management, the need for alternative thermal material solutions 
and innovative material placement methods continues to grow. 
Henkel’s family of dispensable liquid polymer materials with 
unique characteristics is especially designed for ultimate thermal 
management design and component assembly flexibility. 

Two-Part Gap Fillers

BERGQUIST two-part, cure-in-place materials are dispensed as a 
liquid onto the target surface. As the components are assembled, 
the material will wet-out to the adjacent surfaces, filling even the 
smallest gaps and air voids. Once cured, the material remains 
a flexible and soft elastomer, designed to assist in relieving 
coefficient of thermal expansion (CTE) mismatch stresses during 
thermal cycling. Gap Filler is ideally suited for applications where 
pads cannot perform adequately, can be used to replace grease 
or potting compounds, and is currently used in power supply, 
telecom, digital, and automotive applications. 

Liquid Gap Filler  
Key Performance Benefits

Ultra Low Modulus: Minimal Stress During Assembly

Because Gap Filler is dispensed and wet-out in its liquid state, 
the material will create virtually zero stress on components 
during the assembly process. Gap Filler can be used to interface 
even the most fragile and delicate devices.

Excellent Conformability to Intricate Geometries

Liquid Gap Filler materials are able to conform to intricate 
topographies, including multi-level surfaces. Due to its increased 
mobility prior to cure, Gap Filler can fill small air voids, crevices, 
and holes, reducing overall thermal resistance to the heat 
generating device.

GAP FILLER

1000

0

0.5

1.5

1.0

2.0

2.5

3.5

3.0

4.0

GAP FILLER

1000SR

Liquid Dispensable Gap Filler Thermal Conductivity

GAP FILLER

4000

GAP FILLER

3500S35

GAP FILLER

2000

GAP FILLER

1100SF

GAP FILLER

1500LV

GAP FILLER

1500

Gap Filler solutions provide easy 

dispensing and efficient heat transfer 

in electronic applications.

Single Solution for Multiple Applications

Unlike pre-cured gap filling materials, the liquid approach offers 
infinite thickness options and eliminates the need for specific 
pad thicknesses or die-cut shapes for individual applications.

Efficient Material Usage 

Manual or semiautomatic dispensing tools can be used to apply 
material directly to the target surface, resulting in effective use 
of material with minimal waste. Further maximization of material 
usage can be achieved with implementation of automated 
dispensing equipment, which allows for precise material 
placement and reduces the application time of the material.

Customizable Flow Characteristics

Although Gap Fillers are designed to flow easily under minimal 
pressure, they are thixotropic in nature which helps the material 
remain in place after dispensing and prior to cure. BERGQUIST 
Gap Filler offerings include a range of rheological characteristics 
and can be tailored to meet customer-specific flow requirements 
from self-leveling to highly thixotropic materials that maintain 
their form as dispensed.

Thermal Interface Selection Guide 

— GAP FILLER

 | 

27

 

Frequently Asked Questions

Q:   How is viscosity measured?
A: 

 Due to the thixotropic characteristics of most Gap Fillers, 
special consideration should be given to the test method(s) 
used to determine viscosity of these materials. Because 
the material viscosity is dependent on shear rate, different 
measurement equipment testing under varying shear rates 
will produce varied viscosity readings. When comparing 
apparent viscosities of multiple materials, it is important 
to ensure that the data was generated using the same test 
method and test conditions (therefore the same shear rate). 
Test methods and conditions for BERGQUIST products are 
noted in the individual Technical Data Sheets.

Q:  How are pot life and cure time defined? 
A: 

 Two-part Gap Filler systems begin curing once the two 
components are mixed together. Henkel defines the pot 
life (working life) of a two-part system as the time for the 
viscosity to double after parts A and B are mixed. Henkel 
defines the cure time of a two-part material as the time to 
reach 90 percent cure after mixing. Two-part Gap Fillers 
will cure at room temperature (25°C), or cure time can be 
accelerated with exposure to elevated temperatures. 

Q:  Can I use my Gap Filler after the shelf life has expired?
A: 

 Henkel does not advocate using Gap Filler beyond 
the recommended shelf life and is unable to recertify 
material that has expired. In order to ensure timely use 
of product, Henkel recommends a first-in-first-out (FIFO) 
inventory system.

Q:  How should I store my Gap Filler?
A: 

 Unless otherwise indicated on Technical Data Sheets, 
two-part Gap Fillers should be stored in the original 
sealed container in a climate-controlled environment 
at or below 25°C and 50% relative humidity. If stored at 
reduced temperatures, materials should be placed at room 
temperature and allowed to stabilize prior to use. Unless 
otherwise noted, all cartridges and tubes should be stored in 
Henkel-defined packaging with the nozzle end down.

Q:   Do temperature excursions above 25°C affect the 

shelf life?

A: 

 Short periods of time above the recommended storage 
temperature, such as during shipping, have not been shown 
to affect the material characteristics.

Q:  Does Gap Filler have adhesive characteristics?
A: 

 Although Gap Fillers are not designed as structural adhesives, 
when cured, they have a low level of natural tack, which will 
allow the material to adhere mildly to adjacent components. 
This aids in keeping the material in the interface throughout 
repeated temperature cycling and eliminates pump-out from 
the interface. 

Q:  Is Gap Filler reworkable?
A: 

 In many cases, Gap Filler can be reworked. The ease of 
rework is highly dependent on the topography of the 
application as well as the coverage area. 

Q:  What container sizes are available for Gap Fillers?
A: 

 Two-part materials are available in several standard dual 
cartridge sizes including 50 cc (25 cc each of parts A and 
B) and 400 cc (200 cc each of parts A and B). Gap Fillers 
are also available in kits of 1200 cc (two stand-alone 600 
cc containers, one of each part) and 10-gallon (two 5-gallon 
pails, one of each part) sizes for higher volume production. 
Other special and custom container sizes are available 
upon request. 

Q:  How do I mix the two-part Gap Fillers?
A: 

 Disposable plastic static mixing nozzles are used to mix parts 
A and B together at the desired ratio. Static mixers can be 
attached to the ends of cartridges or mounted on automated 
dispensing equipment. They are reliable, accurate and 
inexpensive to replace after extended down times. Unless 
otherwise indicated, mixing nozzles with a minimum of 21 
mixing elements are recommended to achieve proper mixing.

Q:   What is the tolerance on the mix ratio?
A: 

 Two-part materials should be mixed to the stated mix  
ratio by volume within a +/-5% tolerance to ensure  
proper material characteristics. If light-colored streaks 
or marbling are present in the material, there has been 
inadequate mixing. Henkel recommends purging newly 
tapped containers through the static mixer until a  
uniform color is achieved. In order to ensure consistent 
material characteristics and performance, BERGQUIST  
two-part systems are to be used with matching  
part A and B lot numbers.

Q:   What options are available for dispensing material  

onto my application?

A: 

 Henkel can provide manual or pneumatic applicator guns for 
product supplied in dual cartridge form. Gap Filler supplied in 
high volume container kits can be dispensed via automated 
dispensing equipment for high-speed in-line manufacturing. 
Henkel and our other experienced automated dispensing 
equipment partners can further assist our customers in 
creating an optimized dispensing process. For information 
regarding dispensing equipment, contact your local Henkel 
representative. For some materials, screen or stencil 
application may be an option and should be evaluated on a 
case by case basis.

Q:   Should I be concerned about Gap Filler compatibility  

with other materials in my application?

A: 

 Although not common, it is possible to encounter materials 
that can affect the cure of two-part Gap Fillers. A list of 
general categories of compounds that may inhibit the rate  
of cure or poison the curing catalyst in Gap Filler products  
is available to help assist with material compatibility  
evaluation. Please contact your local Henkel representative 
for more details.

28 

| Thermal Interface Selection Guide 

— GAP FILLER

Gap Filler 1000 (Two-Part)

Thermally Conductive, Liquid Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 1.0 W/m-K

• 

 Ultra-conforming, designed for fragile 

and low-stress applications 

• 

Ambient and accelerated 

cure schedules

• 

100% solids – no cure by-products

• 

 Excellent low and high temperature 

mechanical and chemical stability

Gap Filler 1000 is a thermally conductive, 
liquid gap filling material. It is supplied 
as a two-component, room or elevated 
temperature curing system. The material 
is formulated to provide a balance of 
cured material properties highlighted by 
a low modulus and good compression set 
(memory). The result is a soft, thermally 
conductive, form-in-place elastomer ideal 
for coupling “hot” electronic components 
mounted on PC boards with an adjacent 
metal case or heat sink. Before cure, 
Gap Filler 1000 flows under pressure like 
a grease. After cure, it does not pump 
from the interface as a result of thermal 
cycling. Unlike thermal grease, the cured 
product is dry to the touch. Unlike cured 
gap filling materials, the liquid approach 
offers infinite thickness with little or no 
stress during displacement and eliminates 
the need for specific pad thickness and 
die-cut shapes for individual applications. 
Gap Filler 1000 is intended for use in 
thermal interface applications when a 
strong structural bond is not required. 

Typical Applications Include:

• 

Automotive electronics

• 

Computer and peripherals

• 

Between any heat-generating semiconductor and a heat sink

• 

Telecommunications

• 

Thermally conductive vibration dampening

Configurations Available:

• 

Supplied in cartridge and kit form

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GF1000 = GAP FILLER 1000 Material

GF1000

00

15

50cc

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

00 = No spacer beads

07 = 0.007" spacer beads

Pot Life:  15 = 15 minutes

Cartridges:  50cc = 50.0cc, 400cc = 400.0cc

Kits:  1200cc = 1200.0cc, or 10G = 10 gallon

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP FILLER 1000

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color / Part A

Grey

Grey

Visual

Color / Part B

White

White

Visual

Viscosity as Mixed (cPs)

(1)

100,000

100,000

ASTM D2196

Density (g/cc)

1.6

1.6

ASTM D792

Mix Ratio

1:1

1:1

—

Shelf Life @ 25°C (months)

6

6

—

PROPERTY AS CURED

Color

Grey

Grey

Visual

Hardness (Shore 00)

(2)

30

30

ASTM D2240

Heat Capacity ( J/g-K)

1.0

1.0

ASTM E1269

Continuous Use Temp. (°F) / (°C)

-76 to 347

-60 to 175

—

ELECTRICAL AS CURED

Dielectric Strength (V/mil)

500

500

ASTM D149

Dielectric Constant (1,000 Hz)

5.0

5.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL AS CURED

Thermal Conductivity (W/m-K)

1.0

1.0

ASTM D5470

CURE SCHEDULE

Pot Life @ 25°C (mins.)

(3)

15

15

—

Cure @ 25°C (mins.)

(4)

60 - 120

60 - 120

—

Cure @ 100°C (mins.)

(4)

5

5

—

1)  Brookfield RV, Heli-Path, Spindle TF @ 20 rpm, 25°C.
2)  Thirty-second delay value Shore 00 hardness scale.
3)   Time for viscosity to double.
4)  Cure schedule (rheometer - time to read 90% cure)

Thermal Interface Selection Guide 

— GAP FILLER

 | 

29

 

Gap Filler 1000SR (Two-Part)

Thermally Conductive, Liquid Gap Filler Material

Features and Benefits

• 

 Thermal conductivity: 1.0 W/m-K 

• 

 Excellent slump resistance (stays  

in place)

• 

 Ultra-conforming, with excellent wet-

out for low stress interface applications

• 

 100% solids – no cure by-products

• 

 Excellent low and high temperature 

mechanical and chemical stability

Gap Filler 1000SR is a two-part, thermally 
conductive, liquid gap filling material that 
features exceptional slump resistance. 
The mixed system will cure at room 
temperature and can be accelerated with 
the addition of heat. 

Unlike cured thermal pad materials, a 
liquid approach offers infinite thickness 
variations with little or no stress to 
sensitive components during assembly. 
As cured, Gap Filler 1000SR provides 
a soft, thermally conductive, form-in-
place elastomer that is ideal for fragile 
assemblies or for filling unique and 
intricate air voids and gaps.  

Gap Filler 1000SR exhibits low level 
natural tack characteristics and is 
intended for use in applications where a 
strong structural bond is not required.

Typical Applications:

• 

Automotive electronics

• 

Computer and peripherals

• 

 Between any heat-generating semiconductor and a heat sink

• 

Telecommunications

Configurations Available:

• 

Supplied in cartridge or kit form

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GF1000SR = GAP FILLER 1000SR Material

GF1000SR

00

60

50cc

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

00 = No spacer beads

07 = 0.007" spacer beads

Pot Life:  60 = 60 minutes

Cartridges:  50cc = 50.0cc, 400cc = 400.0cc

Kits:  1200cc = 1200.0cc, or 10G = 10 gallon

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP FILLER 1000SR

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color / Part A

Violet

Violet

Visual

Color / Part B

White

White

Visual

Viscosity, High Shear (Pa·s)

(1)

20

20

ASTM D5099

Density (g/cc)

2.0

2.0

ASTM D792

Mix Ratio

1:1

1:1

—

Shelf Life @ 25°C (months)

6

6

—

PROPERTY AS CURED

Color

Violet

Violet

Visual

Hardness (Shore 00)

(2)

75

75

ASTM D2240

Heat Capacity ( J/g-K)

1.0

1.0

ASTM D1269

Continuous Use Temp. (°F) / (°C)

-76 to 347

-60 to 175

—

ELECTRICAL AS CURED

Dielectric Strength (V/mil)

500

500

ASTM D149

Dielectric Constant (1,000 Hz)

5.1

5.1

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL AS CURED

Thermal Conductivity (W/m-K)

1.0

1.0

ASTM D5470

CURE SCHEDULE

Pot Life @ 25°C (mins.)

(3)

60

60

—

Cure @ 25°C (hrs.)

(4)

20

20

—

Cure @ 100°C (mins.)

(4)

10

10

—

  1)  Capillary Viscosity, Initial, 4,500 sec-1. Part A and B measured separately.
2)  Thirty-second delay value Shore 00 hardness scale.
3)   ARES Parallel Plate Rheometer - Working life as liquid, time for modulus to double.
4)  ARES Parallel Plate Rheometer - Estimated time to read 90% cure.

30 

| Thermal Interface Selection Guide 

— GAP FILLER

Gap Filler 1100SF (Two-Part)

Thermally Conductive, Silicone-Free, Liquid Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 1.1 W/m-K

• 

No silicone outgassing or extraction 

• 

 Ultra-conforming, designed for fragile 

and low-stress applications

• 

Ambient and accelerated 

cure schedules

• 

100% solids – no cure by-products

Gap Filler 1100SF is the thermal solution for 
silicone-sensitive applications. The material is 
supplied as a two-part component, curing at 
room or elevated temperatures. The material 
exhibits low modulus properties, then cures 
to a soft, flexible elastomer, helping reduce 
thermal cycling stresses during operation and 
virtually eliminating stress during assembly of 
low-stress applications.

The two components are colored to assist as a 
mix indicator (1:1 by volume). The mixed system 
will cure at ambient temperature. Unlike cured 
thermal pad materials, the liquid approach 
offers infinite thickness variations with little or 
no stress during assembly displacement. Gap 
Filler 1100SF, although exhibiting some natural 
tack characteristics, is not intended for use 
in thermal interface applications requiring a 
mechanical structural bond.

Application

Gap Filler 1100SF can be mixed and dispensed 
using dual-tube cartridge packs with static mixers 
and manual or pneumatic gun or high volume 
mixing and dispensing equipment (application of 
heat may be used to reduce viscosity).

TEMPERATURE DEPENDENCE OF VISCOSITY

The viscosity of the Gap Filler 1100SF material is 
temperature dependent. The table below provides 
the multiplication factor to obtain viscosity at various 
temperatures. To obtain the viscosity at a given 
temperature, look up the multiplication factor at that 
temperature and multiply the corresponding viscosity 
at 25°C.

Temperature

Multiplication Factor

°C

Part A

Part B

20

1.43

1.57

25

1.00

1.00

35

0.58

0.50

45

0.39

0.30

50

0.32

0.24

Example - Viscosity of Part A @ 45°:

Viscosity of Part A @ 25°C is 450,000 cPs. 

The multiplication factor for Part A @ 45°C is 0.39. 

Therefore: (450,000) x (0.39) = 175,500 cPs.

Typical Applications Include:

• 

Silicone-sensitive optic components

• 

Silicone-sensitive electronics

• 

 Filling various gaps between heat-generating devices to heat sinks and housings

• 

Mechanical switching relay

• 

Hard disk assemblies

• 

Dielectric for bare-leaded devices

Configurations Available:

• 

Supplied in cartridge or kit form

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GF1100SF = GAP FILLER 1100SF Material

GF1100SF

00

240

400cc

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

00 = No spacer beads

07 = 0.007" spacer beads

Pot Life:  240 = 240 minutes

Cartridges:  400cc = 400.0cc

Kits:  1200cc = 1200.0cc, or 10G = 10 gallon

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP FILLER 1100SF

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color / Part A

Yellow

Yellow

Visual

Color / Part B

Red

Red

Visual

Viscosity as Mixed (cPs)

(1)

450,000

450,000

ASTM D2196

Density (g/cc)

2.0

2.0

ASTM D792

Mix Ratio

1:1

1:1

—

Shelf Life @ 25°C (months)

6

6

—

PROPERTY AS CURED

Color

Orange

Orange

Visual

Hardness (Shore 00)

(2)

60

60

ASTM D2240

Heat Capacity ( J/g-K)

0.9

0.9

ASTM E1269

Continuous Use Temp. (°F) / (°C)

-76 to 257

-60 to 125

—

ELECTRICAL AS CURED

Dielectric Strength (V/mil)

400

400

ASTM D149

Dielectric Constant (1,000 Hz)

5.0

5.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

10

10

10

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL AS CURED

Thermal Conductivity (W/m-K)

1.1

1.1

ASTM D5470

CURE SCHEDULE

Pot Life @ 25°C

(3)

240 mins. (4 hrs.)

240 mins. (4 hrs.)

—

Cure @ 25°C (hrs.)

(4)

24

24

—

Cure @ 100°C (mins.)

(4)

10

10

—

1)  Brookfield RV, Heli-Path, Spindle TF @ 2 rpm, 25°C.
2)  Thirty-second delay value Shore 00 hardness scale.
3)  Time for viscosity to double.
4)  Cure schedule (rheometer - time to read 90% cure).

Thermal Interface Selection Guide 

— GAP FILLER

 | 

31

 

Gap Filler 1500 (Two-Part)

Thermally Conductive Liquid Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 1.8 W/mK

• 

 Optimized shear thinning 

characteristics for ease of dispensing

• 

Excellent slump resistance 

(stays in place)

• 

 Ultra-conforming with excellent wet-

out for low stress interface applications

• 

100% solids – no cure by-products

• 

 Excellent low and high temperature 

mechanical and chemical stability

Gap Filler 1500 is a two-part, high 
performance, thermally conductive, 
liquid gap filling material, which 
features exceptional slump resistance 
and high shear thinning characteristics 
for optimized consistency and control 
during dispensing. The mixed system 
will cure at room temperature and can 
be accelerated with the addition of heat. 
Unlike cured thermal pad materials, a 
liquid approach offers infinite thickness 
variations with little or no stress to the 
sensitive components during assembly. 
Gap Filler 1500 exhibits low level natural 
tack characteristics and is intended 
for use in applications where a strong 
structural bond is not required. As cured, 
Gap Filler 1500 provides a soft, thermally 
conductive, form-in-place elastomer that 
is ideal for fragile assemblies and filling 
unique and intricate air voids and gaps. 

Typical Applications Include:

• 

Automotive electronics

• 

Computer and peripherals

• 

Between any heat generating semiconductor and a heat sink

• 

Telecommunications

Configurations Available: 

• 

Supplied in cartridge or kit form

• 

With or without glass beads

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GF1500 = GAP FILLER 1500 (Two-Part) Material

GF1500

00

60

10G

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

00 = No spacer beads, 07 = 0.007" spacer beads,

10 = 0.010" spacer beads 

Pot Life:  60 = 60 min, 480 = 480 min

Cartridges:  50cc = 50.0cc, 400cc = 400.0cc

Kits:  1200cc = 1200.00cc, 10G = 10 gallon

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP FILLER 1500

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color / Part A

Yellow

Yellow

Visual

Color / Part B

White

White

Visual

Viscosity, High Shear (Pa·s)

(1)

25

25

ASTM D5099

Density (g/cc)

2.7

2.7

ASTM D792

Mix Ratio

1:1

1:1

—

Shelf Life @ 25°C (months)

6

6

—

PROPERTY AS CURED

Color

Yellow

Yellow

Visual

Hardness (Shore 00)

(2)

50

50

ASTM D2240

Heat Capacity ( J/g-K)

1.0

1.0

ASTM D1269

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL AS CURED

Dielectric Strength (V/mil)

400

400

ASTM D149

Dielectric Constant (1,000 Hz)

6.4

6.4

ASTM D150

Volume Resistivity (Ohmmeter)

10

10

10

10

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL AS CURED

Thermal Conductivity (W/m-K)

1.8

1.8

ASTM D5470

CURE SCHEDULE

SCHEDULE 1

SCHEDULE 2

Pot Life @ 25°C

(3)

60 mins.

480 mins. (8 hrs.)

—

Cure @ 25°C

(4)

5 hrs.

3 days

—

Cure @ 100°C

(4)

10 mins.

30 mins.

—

1)  Capillary viscosity, initial, 3000 sec-1. Part A and B measured separately.
2)  Thirty-second delay value Shore 00 hardness scale.
3)  Parallel Plate Rheometer - Working life as liquid.
4)  Parallel Plate Rheometer - Estimated time to read 90% cure.

32 

| Thermal Interface Selection Guide 

— GAP FILLER

Gap Filler 1500LV (Two-Part)

Thermally Conductive, Liquid Gap Filler Material

Features and Benefits

• 

 Thermal conductivity: 1.8 W/m-K

• 

 Low volatility for silicone-sensitive 

applications

• 

 Ultra-conforming, with excellent 

wet-out

• 

 100% solids — no cure by-products

• 

 Excellent low and high temperature 

chemical and mechanical stability 

Gap Filler 1500LV is a two-part,  
high performance, thermally conductive, 
liquid gap filling material. This material 
offers the high temperature resistance 
and low modulus of a silicone material 
with significantly lower levels of silicone 
outgassing for use in silicone-sensitive 
applications. 

The mixed material will cure at room 
temperature and can be accelerated  
with the addition of heat. As cured,  
Gap Filler 1500LV provides a soft, 
thermally conductive, form-in-place 
elastomer that is ideal for fragile 
assemblies or for filling unique and 
intricate air voids and gaps.

Liquid dispensed thermal materials 
offer infinite thickness variations and 
impart little to no stress on sensitive 
components during assembly. Gap Filler 
1500LV exhibits low level natural tack 
characteristics and is intended for use 
in applications where a strong structural 
bond is not required.

Typical Applications:

• 

Lighting

• 

Automotive electronics

• 

Silicone sensitive applications

Configurations Available:

• 

Supplied in cartridge or kit form

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GF1500LV = GAP FILLER 1500LV Material

GF1500LV

00

120

50cc

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

00 = No spacer beads

07 = 0.007" spacer beads

10 = 0.010" spacer beads

Pot Life:  120 = 120 minutes

Cartridges:  50cc = 50.0cc, 400cc = 400.0cc

Kits:  1200cc = 1200.0cc, or 10G = 10 gallon

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP FILLER 1500LV

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color / Part A

Yellow

Yellow

Visual

Color / Part B

White

White

Visual

Viscosity, High Shear (Pa·s)

(1)

20

20

ASTM D5099

Density (g/cc)

2.7

2.7

ASTM D792

Mix Ratio

1:1

1:1

—

Shelf Life @ 25°C (months)

6

6

—

PROPERTY AS CURED

Color

Yellow

Yellow

Visual

Hardness (Shore 00)

(2)

80

80

ASTM D2240

Heat Capacity ( J/g-K)

1.0

1.0

ASTM D1269

Siloxane Content, SD4-D10 (ppm)

<100

<100

—

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL AS CURED

Dielectric Strength (V/mil)

400

400

ASTM D149

Dielectric Constant (1,000 Hz)

6.2

6.2

ASTM D150

Volume Resistivity (Ohmmeter)

10

10

10

10

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL AS CURED

Thermal Conductivity (W/m-K)

1.8

1.8

ASTM D5470

CURE SCHEDULE

Working Time @ 25°C

(3)

120 mins. (2 hrs.)

120 mins. (2 hrs.)

—

Cure @ 25°C (hrs.)

(3)

8

8

—

Cure @ 100°C (mins.)

(3)

10

10

—

1)  Capillary Viscosity, 3000/sec, Part A and B measured separately.
2)  Thirty-second delay value Shore 00 hardness scale.
3)  Parallel plate rheometer, see reactivity application note.

Thermal Interface Selection Guide 

— GAP FILLER

 | 

33

 

Gap Filler 2000 (Two-Part)

Thermally Conductive, Liquid Gap Filling Material

Features and Benefits

• 

Thermal conductivity: 2.0 W/m-K

• 

 Ultra-conforming, designed for fragile 

and low-stress applications

• 

Ambient and accelerated 

cure schedules

• 

100% solids – no cure by-products

• 

 Excellent low and high temperature 

mechanical and chemical stability

Gap Filler 2000 is a high performance, 
thermally conductive, liquid gap-filling 
material supplied as a two-component, 
room or elevated temperature curing 
system. The material provides a balance 
of cured material properties and good 
compression set (memory). The result is 
a soft, form-in-place elastomer ideal for 
coupling “hot” electronic components 
mounted on PC boards with an adjacent 
metal case or heat sink. Before cure, it 
flows under pressure like grease. After 
cure, it won’t pump from the interface  
as a result of thermal cycling and is dry to 
the touch. 

Unlike cured gap filling materials, 
the liquid approach offers infinite 
thickness with little or no stress 
during displacement and assembly. It 
also eliminates the need for specific 
pad thickness and die-cut shapes for 
individual applications.

Gap Filler 2000 is intended for use in 
thermal interface applications when a 
strong structural bond is not required. 

Typical Applications Include:

• 

Automotive electronics

• 

Computer and peripherals

• 

Between any heat-generating semiconductor and a heat sink

• 

Telecommunications

• 

Thermally conductive vibration dampening

Configurations Available:

• 

Supplied in cartridge or kit form

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GF2000 = GAP FILLER 2000 Material

GF2000

00

60

10G

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

00 = No spacer beads

07 = 0.007" spacer beads

Pot Life:  15 = 15 minutes, 60 = 60 minutes

600 = 600 minutes

Cartridges:  50cc = 50.0cc, 400cc = 400.0cc

Kits:  1200cc = 1200.0cc, or 10G = 10 gallon

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP FILLER 2000

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color / Part A

Pink

Pink

Visual

Color / Part B

White

White

—

Viscosity as Mixed (cPs)

(1)

300,000

300,000

ASTM D2196

Density (g/cc)

2.9

2.9

ASTM D792

Mix Ratio

1:1

1:1

—

Shelf Life @ 25°C (months)

6

6

—

PROPERTY AS CURED

Color

Pink

Pink

Visual

Hardness (Shore 00)

(2)

70

70

ASTM D2240

Heat Capacity ( J/g-K)

1.0

1.0

ASTM D1269

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL AS CURED

Dielectric Strength (V/mil)

500

500

ASTM D149

Dielectric Constant (1,000 Hz)

7

7

ASTM D150

Volume Resistivity (Ohmmeter)

10

11

10

11

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL AS CURED

Thermal Conductivity (W/m-K)

2.0

2.0

ASTM D5470

CURE SCHEDULE

SCHEDULE 1

SCHEDULE 2

SCHEDULE 3

Pot Life @ 25°C

(3)

15 mins.

60 mins.

600 mins. (10 hr)

Cure @ 25°C

(4)

1-2 hrs.

3-4 hrs.

3 days

Cure @ 100°C

(4)

5 mins.

15 mins.

1 hr

  1)  Brookfield RV, Heli-Path, Spindle TF @ 20 rpm, 25°C.
2)  Thirty-second delay value Shore 00 hardness scale.
3)  Time for viscosity to double.
4)  Cure schedule (rheometer - time to read 90% cure).

34 

| Thermal Interface Selection Guide 

— GAP FILLER

Gap Filler 3500S35 (Two-Part)

Thermally Conductive Liquid Gap Filling Material

Features and Benefits

• 

 Thermal conductivity: 3.6 W/m-K

• 

 Thixotropic nature makes it easy 

to dispense

• 

 Two-part formulation for easy storage

• 

 Ultra-conforming – designed for fragile 

and low stress applications

• 

Ambient or accelerated cure schedules

Gap Filler 3500S35 is a two-component, 
liquid gap-filling material, cured at either 
room or elevated temperature, featuring 
ultra-high thermal performance and 
outstanding softness. Prior to curing, 
the material maintains good thixotropic 
characteristics as well as low viscosity. 
The result is a gel-like liquid material 
designed to fill air gaps and voids yet flow 
when acted upon by an external force 
(e.g., dispensing or assembly process). 
The material is an excellent solution for 
interfacing fragile components with high 
topography and/or stack-up tolerances 
to a universal heat sink or housing. 
Once cured, it remains a low modulus 
elastomer designed to assist in relieving 
CTE stresses during thermal cycling yet 
maintain enough modulus to prevent 
pump-out from the interface.  
Gap Filler 3500S35 will lightly adhere 
to surfaces, thus improving surface 
area contact. Gap Filler 3500S35 is not 
designed to be a structural adhesive.

Typical Applications Include:

• 

Automotive electronics

• 

Discrete components to housing

• 

PCBA to housing

• 

Fiber optic telecommunications equipment

Configurations Available:

• 

Supplied in cartridge or kit form

Building a Part Number 

Standard Options

|| 

example

Section A

Section B

Section C

Section D

Section E

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

GF3500S35

00

60

400cc

NA

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GP3500S35 = GAP PAD 3500S35 Material

00 = No spacer beads

07 = 0.007" spacer beads

Pot Life: 60 = 60 minutes

Cartridges: 50cc = 50.0cc, 400cc = 400.0cc

Kits: 1200cc = 1200.0cc, or 6G = 6 gallon

TYPICAL PROPERTIES OF GAP FILLER 3500S35

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color / Part A

White

White

Visual

Color / Part B

Blue

Blue

Visual

Viscosity as Mixed (cPs)

(1)

150,000

150,000

ASTM D2196

Density (g/cc)

3.0

3.0

ASTM D792

Mix Ratio

1:1

1:1

—

Shelf Life @ 25°C (months)

5

5

—

PROPERTY AS CURED

Color

Blue

Blue

Visual

Hardness (Shore 00)

(2)

35

35

ASTM D2240

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL AS CURED

Dielectric Strength (V/mil)

275

275

ASTM D149

Dielectric Constant (1,000 Hz)

8.0

8.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

9

10

9

 

ASTM D257

Flame Rating

V-O

   V-O

UL 94

THERMAL AS CURED

Thermal Conductivity (W/m-K)

3.6

3.6

ASTM D5470

CURE SCHEDULE

Pot Life @ 25°C (mins.)

(3)

60

60

—

Cure @ 25°C (hrs.)

(4)

15

15

—

Cure @ 100°C (mins.)

(4)

30

30

—

1)   Brookfield RV, Heli-Path, Spindle TF @ 20 rpm, 25°C.
2)  Thirty-second delay value Shore 00 hardness scale.
3)  Time for viscosity to double.
4)  Cure schedule (rheometer - time to read 90% cure).

Thermal Interface Selection Guide 

— GAP FILLER

 | 

35

 

Gap Filler 4000 (Two-Part)

Thermally Conductive, Liquid Gap Filler Material

Features and Benefits

• 

 Thermal conductivity: 4.0 W/m-K

• 

 Extended working time for 

manufacturing flexibility

• 

 Ultra-conforming with excellent 

wet-out

• 

100% solids – no cure by-products

• 

 Excellent low and high temperature 

chemical and mechanical stability 

Gap Filler 4000 is a two-part, high 
performance, thermally conductive, liquid 
gap-filling material. The mixed material 
will cure at room temperature and can be 
accelerated with the addition of heat.  
Gap Filler 4000 offers an extended 
working time to allow greater flexibility  
in the customer’s assembly process.

Liquid dispensed thermal materials offer 
infinite thickness variations and impart 
little to no stress on sensitive components 
during assembly. Gap Filler 4000 exhibits 
low level natural tack characteristics and 
is intended for use in applications where  
a strong structural bond is not required. 

As cured, Gap Filler 4000 provides a 
soft, thermally conductive, form-in-
place elastomer that is ideal for fragile 
assemblies or for filling unique and 
intricate air voids and gaps.

Typical Applications:

• 

Automotive electronics

• 

Computer and peripherals

• 

 Between any heat-generating semiconductor and a heat sink

• 

Telecommunications

Configurations Available:

• 

Supplied in cartridge or kit form

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

GF4000 = GAP FILLER 4000 Material

GF4000

00

240

50cc

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

00 = No spacer beads

07 = 0.007" spacer beads

10 = 0.010" spacer beads

Pot Life:  240 = 240 minutes

Cartridges:  50cc = 50.0cc, 400cc = 400.0cc

Kits:  1200cc = 1200.0cc, or 6G = 6 gallon

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF GAP FILLER 4000

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color / Part A

Blue

Blue

Visual

Color / Part B

White

White

Visual

Viscosity, High Shear (Pa·s)

(1)

50

50

ASTM D5099

Density (g/cc)

3.1

3.1

ASTM D792

Mix Ratio

1:1

1:1

—

Shelf Life @ 25°C (months)

5

5

—

PROPERTY AS CURED

Color

Blue

Blue

Visual

Hardness (Shore 00)

(2)

75

75

ASTM D2240

Heat Capacity ( J/g-K)

0.8

0.8

ASTM D1269

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

ELECTRICAL AS CURED

Dielectric Strength (V/mil)

450

450

ASTM D149

Dielectric Constant (1,000 Hz)

7.9

7.9

ASTM D150

Volume Resistivity (Ohmmeter)

10

10

10

10

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL AS CURED

Thermal Conductivity (W/m-K)

4.0

4.0

ASTM D5470

CURE SCHEDULE

Working Time @ 25°C

(3)

240 mins. (4 hrs.)

240 mins. (4 hrs.)

—

Cure @ 25°C (hrs.)

(3)

24

24

—

Cure @ 100°C (mins.)

(3)

30

30

—

1)  Capillary Viscosity, 1,500/sec., Part A and B measured separately.
2)  Thirty-second delay value Shore 00 hardness scale.
3)  Parallel plate rheometer, see reactivity application note.

36 

| Thermal Interface Selection Guide 

— 

TIC

Thermal Interface Compounds (One-Part)

Thermally Conductive Grease Compounds

The BERGQUIST line of thermally conductive thermal interface 
compounds (TIC) will flow under assembly pressure to wet-out 
the thermal interface surfaces and produce very low thermal 

impedance. TIC products are designed for use between a  
high-end computer processor and a heat sink or other high 
watt density applications. 

Features

The TIC portfolio has  
diverse thermal and  
electrical characteristics.  
Key criteria when selecting 
TIC products include:

•

 Viscosity

•

Volume resistivity

•

Thermal conductivity

•

Thermal performance

•

Filler size

Benefits

TIC products are ideal for high 
watt density applications. 
Primary benefits include:

•

 Low interfacial resistance

•

Low thermal impedance

•

Resist dripping

•

 Ideally suited to screen

printing applications

•

 No post “cure”

conditioning required

Options

TIC products can be obtained 
with application-specific 
options such as:

•

Containers

Applications

TICs have a variety of 
applications such as:

•

 CPU

•

GPU

•

IGBT

•

High power density

applications

Comparison Data and FAQs

Q:  What is the best fastening method for a TIC interface?
A: 

 A constant-pressure fastener is preferred when using TIC for 
high performance applications. The constant pressure from a 
clip or spring washer will ensure adequate pressure is being 
applied with varying bond line thickness.

Q:  How should the TIC be applied?
A: 

 Screenprinting the TIC is a fast, low-cost method that 
delivers a consistent and accurate amount of material on 
each application. Alternate methods include stenciling, pin 
transfer and needle dispensing.

Q:  Will the grease stay in the interface?
A: 

 All the TIC materials were specifically designed to resist 
pump-out of the interface, even after many hours of thermal 
and power cycling. 

Thermal Interface Selection Guide 

— 

TIC

 | 

37

 

TIC 1000A

High Performance, Value Compound for High-End Computer Processors

Features and Benefits

•

 High thermal performance:

0.32°C/W (@ 50 psi)

•

Good screenability

•

Room temperature storage

•

No post “cure” required

•

Exceptional value

TIC 1000A is a high performance, 
thermally conductive compound  
intended for use as a thermal interface 
material between a high-end computer 
processor and a heat sink. Other high 
watt density applications will also 
benefit from the extremely low thermal 
impedance of TIC 1000A.

TIC 1000A compound wets-out the 
thermal interface surfaces and flows to 
produce the lowest thermal impedance. 
The compound requires pressure of the 
assembly to cause flow. The TIC 1000A 
compound will resist dripping.

For microprocessor applications, 
traditional screw fastening or spring 
clamping methods will provide 
adequate force to optimize the thermal 
performance of TIC 1000A.

An optimized application would utilize 
the minimum volume of TIC 1000A 
material necessary to ensure complete 
wet-out of both mechanical interfaces.

Assembly – No Post-Screen Cure

TIC 1000A has good screenability. No solvent is used to reduce the viscosity, 
so no post “cure” conditioning is required.

Application Cleanliness

1.  Pre-clean heat sink and component interface with isopropyl alcohol prior

to assembly or repair. Ensure heat sink is dry before applying TIC 1000A.

Application Methods

1.  Dispense and/or screenprint TIC 1000A compound onto the processor or heat sink

surface like thermal grease (see a Henkel Representative for application information).

2.  Assemble the processor and heat sink with spring clips or

constant-pressure fasteners.

Typical Applications Include:

•

High performance CPUs

•

High performance GPUs

Building a Part Number 

Standard Options

 

example

Note:  To build a part number, visit our website at www.bergquistcompany.com.

Section A

Section B

Section C

Section D

Section E

TIC1000A

00

00

25cc

NA

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

TIC1000A = Thermal Interface Compound 1000A

00 = No options

00 = No options

Containers: 5cc = 5.0cc, 25cc = 25.0cc, 200cc = 200.0cc

Cartridge: 600cc = 600.0cc

TYPICAL PROPERTIES OF TIC 1000A

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Grey

Grey

Visual

Density (g/cc)

2.1

2.1

ASTM D792

Continuous Use Temp. (°F) / (°C)

302

150

—

ELECTRICAL

Electrical Resistivity (Ohmmeter)

(1)

N/A

N/A

ASTM D257

THERMAL

Thermal Conductivity (W/m-K)

1.5

1.5

ASTM D5470

THERMAL PERFORMANCE VS. PRESSURE

Pressure (psi)

10

25

50

100

200

TO-220 Thermal Performance (°C/W)

(2)

0.32

0.32

0.32

0.31

0.28

1) The compound contains an electrically conductive filler surrounded by electrically nonconductive resin.
2) TO-220 performance data is provided as a reference to compare material thermal performance.

38 

| Thermal Interface Selection Guide 

— TIC

TIC 4000

High Performance Thermal Interface Compound for Copper-Based Heat Sinks

Features and Benefits

•

Thermal conductivity: 4.0 W/m-K

•

 Exceptional thermal performance:

0.19°C/W (@ 50 psi)

TIC 4000 is a thermally conductive grease 
compound designed for use as a thermal 
interface material between a computer 
processor and a copper-based heat sink. 
Other high watt density applications will 
benefit from the extremely low thermal 
impedance of TIC 4000.

TIC 4000 compound wets-out the thermal 
interface surfaces and flows to produce 
low thermal impedance. The compound 
requires pressure of the assembly to cause 
flow. TIC 4000 compound will not drip.

For a typical 0.5 in. x 0.5 in. application 
at 0.005 in. thick, Henkel estimates 
approximately 0.02 ml (cc) of TIC 4000.

Although Henkel estimates a 0.02 
ml (cc) volumetric requirement for a 
0.5 in. x 0.5 in. component interface, 
dispensed at a thickness of 0.005 in., 
Henkel also recognizes that an optimized 
application would use the minimum 
volume of TIC 4000 material necessary 
to ensure complete wet-out of both 
mechanical interfaces.

Application Methods

1.  Pre-clean heat sink and component interface with isopropyl alcohol prior to

assembly or repair. Ensure heat sink is dry before applying TIC 4000.

2.  Dispense TIC 4000 compound onto the processor or heat sink surface like

thermal grease.

3. Assemble the processor and heat sink with clip or constant-pressure fasteners.

Typical Applications Include:

•

 High performance computer processors (traditional screw fastening or clamping

methods will provide adequate force to optimize the thermal performance of

TIC 4000)

•

High watt density applications where the lowest thermal resistance interface

is required

Building a Part Number 

Standard Options

|| 

example

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

Section A

Section B

Section C

Section D

Section E

TIC4000

00

00

200cc

NA

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

TIC4000 = Thermal Interface Compound 4000

00 = No options

00 = No options

Containers: 5cc = 5.0cc, 25cc = 25.0cc, 200cc = 200.0cc

TYPICAL PROPERTIES OF TIC 4000

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Grey

Grey

Visual

Density (g/cc)

4.0

4.0

ASTM D792

Continuous Use Temp. (°F) / (°C)

302

150

—

ELECTRICAL

Electrical Resistivity (Ohmmeter)

(1)

N/A

N/A

ASTM D257

THERMAL

Thermal Conductivity (W/m-K)

4.0

4.0

ASTM D5470

THERMAL PERFORMANCE VS. PRESSURE

Pressure (psi)

10

25

50

100

200

TO-220 Thermal Performance (°C/W)

(2)

0.21

0.20

0.19

0.19

0.18

1) The compound contains an electrically conductive filler surrounded by electrically nonconductive resin.
2) TO-220 performance data is provided as a reference to compare material thermal performance.

Thermal Interface Selection Guide 

— TIC

 | 

39

 

LIQUI-FORM 2000

Thermally Conductive, One-Part, Liquid Formable Material

Features and Benefits

•

 Thermal conductivity: 2.0 W/m-K

•

 Applies very low force on

components during assembly

•

Low volumetric expansion

•

 Excellent chemical and mechanical

stability even at higher temperatures

•

 No curing required

•

 Stable viscosity in storage and in

the application

LIQUI-FORM 2000 is a high thermal 
conductivit y liquid formable material 
designed for demanding applications 
requiring a balance between 
dispensability, low component stresses 
during assembly and ease of rework. 

LIQUI-FORM 2000 is a highly 
conformable, shear-thinning material 
which requires no curing, mixing or 
refrigeration. Its unique formulation 
assures excellent thermal performance, 
low applied stress and reliable long-term 
performance. LIQUI-FORM 2000 is 
thixotropic and has a natural tack, 
ensuring it forms around the component 
and stays in place in the application.

Typical Applications Include:

•

Bare die to heat spreader lid

•

Filling various gaps between heat-generating devices to heat sinks and housings

•

Devices requiring low assembly pressure

•

BGA, PGA, PPGA

Configurations Available:

•

Supplied in 30 cc or 600 cc cartridges or 5 gallon pails

Building a Part Number 

Standard Options

Section A

Section B

Section C

Section D

Section E

NA = Selected standard option. If not selecting a standard

option, insert company name, drawing number, and

revision level.

LF2000 = LIQUI-FORM 2000 Material

LF2000

00

00

5G

NA

Note:  To build a part number, go to www.bergquistcompany.com/Part_Number_Builder.php.

00 = No spacer beads

07 = 0.007" spacer beads

00: No options

Cartridges:  30cc = 30.0cc, 600cc = 600.0cc

Pails:  5G = 5 gallon

–

–

–

–

|| 

example

TYPICAL PROPERTIES OF LIQUI-FORM 2000

PROPERTY

IMPERIAL VALUE

METRIC VALUE

TEST METHOD

Color

Grey

Grey

Visual

Low Shear Viscosity (Pa·s) @ 0.01 sec-1

(1)

20,000

20,000

ASTM D4473

High Shear Viscosity (Pa·s) @ 300 sec-1

(2)

110

110

ASTM D2196

Volumetric Expansion 
(25 to 275°C), ppm/K

600

600

ASTM E228 modified

Outgassing, % Total Mass Loss

0.53

0.53

ASTM E595

Density (g/cc)

2.8

2.8

ASTM D792

Continuous Use Temp. (°F) / (°C)

-76 to 392

-60 to 200

—

Shelf Life at 25°C (Months)

6

6

—

ELECTRICAL

Dielectric Strength (V/mil)/(V/mm)

250

10,000

ASTM D149

Dielectric Constant (1,000 Hz)

8.0

8.0

ASTM D150

Volume Resistivity (Ohmmeter)

10

9

10

9

ASTM D257

Flame Rating

V-O

V-O

UL 94

THERMAL

Thermal Conductivity (W/m-K)

2.0

2.0

ASTM D5470

THERMAL PERFORMANCE VS. PRESSURE

Pressure (PSI)

10

25

50

Thermal Impedance (°C-in.

2

/W)

(3)

 

0.13

0.12

0.12

1) Parallel Plate Rheometer, See Product Management Liqui-Form Application Note on our website under Liquid Thermal Interface Materials.
2) Capillary Rheometer, See Product Management for Viscosity and Dispensing Application Note.
3)  The ASTM D5470 test fixture was used. The recorded values include the interfacial thermal resistance. The values are provided for reference only. Actual 

application performance is directly related to the surface roughness, flatness and pressure applied.

40 

| Thermal Interface Selection Guide 

— HI-FLOW

HI-FLOW Phase Change Interface Materials

Solutions-Driven Thermal Management Products for Electronic Devices

Use phase change materials for excellent thermal performance without the mess of grease.

HI-FLOW phase change materials are an excellent replacement 
for grease as a thermal interface between a CPU or power device 
and a heat sink. The materials change from a solid at specific 
phase change temperatures and flow to assure a total wet-out of 
the interface without overflow. The result is a thermal interface 
comparable to grease, without the mess, contamination  
and hassle.

The HI-FLOW family of phase change thermal interface materials 
covers a wide range of applications. Henkel’s BERGQUIST brand 
offers leading thermal management solutions and we work 
closely with customers to ensure that the proper HI-FLOW 
material is specified.

Features

HI-FLOW handles like 
BERGQUIST SIL PAD materials 
at room temperature, but flows 
like grease at its designed 
phase change temperature. 
The following is an overview of 
the important features shared 
by the HI-FLOW family:

• 

 Comparable  thermal 

performance to grease in 

most applications

• 

 Thermally conductive phase 

change compound

• 

 Aluminum, film or fiberglass 

carriers and non-reinforced 

versions

• 

Low volatility

• 

 Easy to handle and apply 

in the manufacturing 

environment

• 

 Tackified or tack-free at 

room temperature

Benefits

Using HI-FLOW materials 
instead of grease can 
save time and money 
without sacrificing thermal 
performance. Here are some 
other benefits:

• 

 No mess – thixotropic 

characteristics of the 

materials keep it from 

flowing out of the interface

• 

 Easier handling –  

tackified or tack-free at 

room temperature

• 

 No protective liner required

• 

 High thermal performance 

helps ensure CPU reliability

• 

Do not attract contaminants

• 

 Easier material handling and 

shipping

• 

 Simplified  application 

process

Options

The broad HI-FLOW family 
offers a variety of choices 
to meet the customer’s 
performance, handling and 
process needs. Some of the 
choices include:

• 

 Some HI-FLOW materials are 

available with or  

without adhesive

• 

 Aluminum carrier for 

applications not requiring 

electrical isolation

• 

 Film or fiberglass carrier for 

electrical isolation

• 

Dry, non-reinforced material

• 

 Tackified or tack-free at 

room temperature

• 

 Tabbed parts, die-cut parts, 

sheets or bulk rolls

• 

 Adhesive specifically for 

cold application without 

preheating heat sink

We produce thousands of 
specials. Tooling charges vary 
depending on the complexity 
of the part.

Applications

HI-FLOW materials are suited 
for consumer and industrial 
electronics, automotive, 
medical, aerospace and 
telecommunications 
applications such as:

• 

 UPS and SMPS AC/DC, DC/

DC or linear power supplies

• 

Between a CPU and 

heat sink

• 

Power conversion devices

• 

 Fractional and integral 

motor control

• 

 Leaded, surface mount and 

power module assemblies

Thermal Interface Selection Guide 

— HI-FLOW

 | 

41

 

HI-FLOW Comparison Data

TO-220 Thermal Performance

0

50

100

150

200

0.50

0.70

0.90

1.10

1.30

1.50

HI-FLOW 105

Non-Isolating HI-FLOW Series 105 Grease Replacement Materials

Interface Pressure (psi)

Thermal P

erformance (°C/

W)

Isolating HI-FLOW Series 300p to 650P Grease Replacement Materials

HI-FLOW 625

HI-FLOW 300P2.0

HI-FLOW 300P1.5

HI-FLOW 300P1.0

HI-FLOW 650P2.0

HI-FLOW 650P1.5

HI-FLOW 650P1.0

Interface Pressure (psi)

Thermal P

erformance (°C/

W)

0

50

100

150

200

0.50

0.70

0.90

1.10

1.30

1.50

1.70

1.90

2.10

2.30

2.50

HI-FLOW 225FT
HI-FLOW 225F-AC
HI-FLOW 225UT
HI-FLOW 565UT

0

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

Non-Isolating HI-FLOW 225 to 565 Grease Replacement Materials

Thermal P

erformance (°C/

W)

Interface Pressure (psi)

0

50

100

150

200

42 

| Thermal Interface Selection Guide 

— HI-FLOW

Frequently Asked Questions

Q:   How is the ASTM D5470 test modified to characterize 

phase change thermal performance? 

A: 

 ASTM classifies a phase change as a Type 1, viscous liquid 
that exhibits unlimited deformation when a stress is applied. 
Henkel uses test equipment that is designed to meet ASTM 
D5470 specifications for Type 1, which requires a shim or 
mechanical stop to precisely control the thickness. The 
phase change material is conditioned at 5°C over the stated 
phase change temperature. Understanding that time is 
also a key variable for material flow, the over-temperature 
condition is limited to 10 minutes and then allowed to cool, 
prior to initiating the actual test at the given pressure. The 
10-minute time has been demonstrated to be an acceptable 
time period for the thermal mass inherent in the test setup. 
Note: Actual application testing may require more or less 
time to condition, depending upon the heat transfer and 
associated thermal mass. The performance values are 
recorded and published at 10, 25, 50, 100 and 200 psi to 
give the designer a broad-based understanding of HI-FLOW 
material’s performance.

Q:   What is the minimum pressure required to optimize the 

thermal performance of the HI-FLOW material?

A: 

 Upon achieving phase change temperature (e.g., pre-
conditioning), Henkel has demonstrated that 10 psi 
provides adequate pressure to achieve exceptional thermal 
performance. Henkel continues to research lower pressure 
wet-out characteristics in an effort to minimize interfacial 
losses associated with ultra-thin material interfaces.

Q:   Will  the  HI-FLOW replace a mechanical fastener?
A: 

 Mechanical fasteners are required. Henkel recommends the 
use of spring clips to maintain consistent pressure over time.

Q:   Can I use screw-mount devices with HI-FLOW material?
A: 

 HI-FLOW works best with a clip or spring washer-mounted 
assembly. The continuous force applied by these devices 
allows the HI-FLOW material to flow and reduce the cross 
sectional gap. Henkel suggests that design engineers evaluate 
whether a screw-mount assembly will have acceptable 
performance. See TO-220 Technical Note.

Q:   Is the adhesive in HI-FLOW 225F-AC repositionable?
A: 

 The adhesive in the current construction does adhere more 
to the heat sink aluminum than to the HI-FLOW material. 
There is the potential that the adhesive will be removed by 
the heat sink surface when it is removed to reposition on 
the heat sink. Time and/or pressure will increase the bond to 
the aluminum, increasing the potential for the adhesive to 
adhere to the heat sink. 

Q:    Is there any surface preparation required before applying 

the adhesive-backed HI-FLOW to the heat sink? 

A: 

 Standard electronics industry cleaning procedures apply. 
Remove dirt or other debris. Best results are attained when the 
HI-FLOW material is applied to a heat sink at a temperature 
of 25° +/- 10°C. If the heat sink has been surface treated (e.g., 
anodized or chromated), it is typically ready for assembly. For 

bare aluminum, mild soap and water wash cleaning processes 
are typically used to eliminate machine oils and debris. 

Q:   Is  HI-FLOW material reworkable?
A: 

 If the material has not gone through phase change, the 
material will readily release from the device surface. For  
this situation, the HI-FLOW material will not likely have  
to be replaced. 

 

 If the material has gone through the phase change, it will 
adhere very well to both surfaces. In this case, Henkel 
suggests warming the heat sink to soften the HI-FLOW 
compound for easier removal from the processor. Replace 
with a new piece of HI-FLOW material.

Q:   What is meant by “easy to handle” in manufacturing?
A: 

 Insulated  HI-FLOW products are manufactured with inner 
film support. This film stiffens the material, allowing parts to 
be more readily die-cut as well as making the material easier 
to handle in manual or automated assembly.

Q:   What is meant by “tack-free” and why is this important?
A: 

 Many  HI-FLOW materials have no surface tack at room 
temperature. The softer materials will pick up dirt more 
readily. Softer resins are more difficult to clean if any dirt 
is on the surface. If you try to rub the dirt away, the dirt is 
easily pushed into the soft phase change materials. HI-FLOW 
coatings are typically hard at room temperature rendering 
them easier to clean off without embedding dirt.

Q:   What does “more scratch resistance” mean on 

HI-FLOW 625?

A: 

 HI-FLOW 625 does not require a protective film during 
shipment. HI-FLOW has a higher phase change temperature 
and remains hard to a higher temperature. The HI-FLOW 
material is harder and is not as easy to scratch or dent in 
shipping and handling.

Q:  Why is HI-FLOW phase change temperature 65°C?
A: 

 The 65°C phase change temperature was selected for two 
reasons. First, it was a low enough temperature for the phase 
change to occur in applications. Second, it would not phase 
change in transport. Studies show that shipping containers 
can reach 60°C in domestic and international shipments. The 
higher phase change temperature eliminates the possibility 
of a product being ruined in shipment. We offer a standard 
line of HI-FLOW 225 and 300 series products with 55°C phase 
change for those customers wanting the lower phase change 
temperature.

Q:  In which applications should I avoid using HI-FLOW?
A: 

 Avoid  using  HI-FLOW in applications in which the device will 
not reach operation at or above phase change temperature. 
Also avoid applications in which the operating temperature 
exceeds the maximum recommended operating temperature 
of the compound.