www.bergquistcompany.com
All statements, technical information and recommendations herein are based on tests we believe to be reliable, and
THE FOLLOWING IS MADE IN LIEU OF ALL WARRANTIES, EXPRESSED OR IMPLIED,INCLUDING THE IMPLIED
WARRANTIES OF MARKETABILITY AND FITNESS FOR PURPOSE.Sellers’ and manufacturer s’ only obligation shall be to
replace such quantity of the product proved to be defective. Before using, user shall determine the suitability of the product
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MANUFACTURER SHALL BE LIABLE EITHER IN TORT OR IN CONTRACT FOR ANY LOSS OR DAMAGE,DIRECT,
INCIDENTAL, OR CONSEQUENTIAL,INCLUDING LOSS OF PROFITS OR REVENUE ARISING OUT OF THE USE OR
THE INABILITY TO USE A PRODUCT. No statement, purchase order or recommendations by seller or purchaser not
contained herein shall have any force or effect unless in an agreement signed by the officers of the seller and manufacturer.
PDS_GF_3500S35_12.08
The Bergquist Company -
North American Headquarters
18930 West 78th Street
Chanhassen, MN 55317
Phone: 800-347-4572
Fax: 952-835-0430
The Bergquist Company -
European Headquarters
Bramenber g 9a, 3755 BT Eemnes
Netherlands
Phone: 31-35-5380684
Fax: 31-35-5380295
The Bergquist Company - Asia
Room 15,8/F W ah Wai Industrial Centre
No.38-40,Au Pui Wan Street
Fotan, Shatin, N.T. Hong Kong
Ph: 852.2690.9296
Fax: 852.2690.2344
Gap Filler 3500S35 (Two-Part)
Ther mally Conductive Liquid Gap Filling Material
Gap Pad ®: U.S.Patent 5,679,457 and others
Features and Benefits
• Thermal Conductivity: 3.6 W/m-K
• Thixotropic nature makes it easy to
dispense
• Two-part for mulation for easy storage
• Ultra-confor ming - designed for fr agile and
low stress applications
• Ambient or acceler ated cure schedules
Gap Filler 3500S35 is the technology leader
in ther mally conductive, liquid gap filling mate-
rials, featuring ultra-high ther mal perfor mance
and super ior softness.The mater ial is two-
component, cured either at room or elevated
temper ature . Pr ior to cur ing, the mater ial
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
exter nal force (e .g. dispensing or assembly
process).The mater ial is an excellent solution
for interfacing fragile components with high
topogr aphy and/or stack-up tolerances to a
univer sal heat sink or housing. Once cured,it
remains a low modulus elastomer designed
to assist in relieving CTE stresses during ther-
mal 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
str uctural adhesive.
Typical Applications Include:
• Automotive electronics • PCBA to housing
• Discrete components to housing • Fiber optic telecommunications equipment
Configurations Available:
• Supplied in cartr idge or kit for m
Building a Part Number Standard Options
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 —
PR OPER TY 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 (1000 Hz) 8.0 8.0 ASTM D150
Volume Resistivity (Ohm-meter) 109109ASTM D257
Flame Rating V-O V-O U.L. 94
THERMAL AS CURED
Thermal Conductivity (W/m-K) 3.6 3.6 ASTM D5470
CURE SCHEDULE
Pot Life @ 25°C (min) (3) 60 60 —
Cure @ 25°C (hr s) (4) 15 15 —
Cure @ 100°C (min) (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)
0.25
0.20
0.15
0.10
0.05
0.00
0.0 0.5 1.0 1.5 2.0 2.5 3.0
Thermal Resistance (C-in2/W)
Thickness vs.Thermal Resistance
Gap Filler 3500S35
Thickness (inch)
