Thermal Insulating Pads

Henkel Gap Pad


Parker Chomerics' Thermal Insulating Pads

Cho-Therm 1671 

Cho-Therm 1678 

Cho-Therm T500

Cho-Therm T609

Cho-Therm T441 

Cho-Therm 1674 

Cho-Therm T444 

Cho-Therm: thermally conductive electrical insulator pads are designed for use where the highest possible thermal, dielectric, and mechanical properties are required. These products are designed for use as alternatives to greased mica insulators between discrete power devices and heat sinks, offered as dry pads or with an optional acrylic adhesive (PSA) layer for attachment.

Key Attributes

  • Excellent mechanical strength and puncture resistance

  • Available with & without acrylic PSA

  • UL recognized V-0 flammability rating

Commercial grade:

  • Good thermal properties

  • Good to excellent dielectric strength

  • Available on continuous rolls for easy peel and stick application

High power demand requirements:

  • Excellent thermal properties

  • High dielectric strength

  • 100% inspected for dielectric properties on every sheet

  • Extremely low NASA outgassing

  • Proven through decades of use in demanding military and aerospace applications


  • Power conversion equipment

  • Power supplies & UPS

  • Power semiconductors

  • Automotive electronics

  • Motor and engine controllers

  • Televisions and consumer electronics

A user-friendly insulator between discrete power devices and heat sinks; conducting very large heat loads and maintaining electrical insulation between heat sinks and components.

Parker Chomerics


Bergquist Sil Pad Range

Bergquist Sil Pads TSP 1500

Bergquist Sil Pads TSP 1800ST

Bergquist Sil Pads TSP 1800

Bergquist Sil Pads TSP PP900

Bergquist Sil Pads TSP 1100ST

Bergquist Sil Pads TSP A2000

Bergquist Sil Pads TSP PPK1300

Bergquist Sil Pads TSP PP1200

Bergquist Sil Pads TSP A3000

Bergquist Sil Pads TSP Q2000*

Bergquist Sil Pads TSP 900

Bergquist Sil Pads TSP K900

Bergquist Sil Pads TSP PPK900

Bergquist Sil Pads TSP 3500

Bergquist Sil Pads TSP 1416

Bergquist Sil Pads TSP 1600S

Bergquist Sil Pads TSP Q2500*

Bergquist Sil Pads TSP K1100

Bergquist Sil Pads TSP K1300

Bergquist Sil Pads TSP 1600

*Aluminium foil coated on both sides.

Frequently Asked Questions

What test method does Parker Chomerics use to characterise thermal interface material (TIM) performance?

Their standard test method is ASTM D5470.

What is the output of ASTM D5470 thermal conductivity test?

ASTM D5470 measures thermal impedance (resistance) of a flat disk-shaped specimen or controlled volume of a liquid TIM between two flat polished calorimeter surfaces under controlled load.

What is apparent thermal conductivity?

Apparent thermal conductivity is a calculated value that uses the thermal impedance (resistance) measured from ASTM D5470 and the sample thickness to calculate a thermal conductivity value. This value is influenced by how effectively the sample contacts (or 'wets out' if a dispensable) the calorimeter surfaces. The thermal resistance at the interface between the sample and the probes is called contact resistance. Contact resistance adds to the overall thermal impedance and may produce a lower measurement than bulk thermal conductivity.

Is there a recommended surface roughness?

As a general rule, increased surface roughness will create a larger surface area available for wetting. For vertical applications, increased surface roughness will provide an greater resistance to slide. Generally, increasing the shot size, contact area and surface roughness will aid in slide resistance of the material. Surface roughness of N8 or rougher is recommended.

What materials do you recommend where applications require thin bondline thickness from a thermally conductive material?

This type of application would require a smooth/flat surface roughness. For this we recommend Ablefilm, ​Thermattach tapes, Cho-Therm, thermal greases or pastes/gels.

Why is apparent thermal conductivity useful?

A material can have a very high intrinsic bulk thermal conductivity but be outperformed by a material of lower bulk conductivity that is softer and conformable. Measuring apparent thermal conductivity can help better identify real world performance of a thermal interface materials in many cases.

What should be considered when comparing reported thermal conductivity values for materials from varying sources on supplier datasheets?

It is always difficult to compare values since it is unlikely that reported values from varying sources were generated using the same test method and parameters. There are many test instruments and methods used in the marketplace.

What thermal data do Parker Chomerics report and what is the frequency that these measurements are made for their products?

Parker Chomerics report bulk thermal conductivity for most TIM products on technical datasheets. Thin bond line product (such as phase change materials and thermal greases) datasheets will show thermal impedance at fixed pressure instead of bulk thermal conductivity as this is more practical and useful to the designer. For lot-to-lot conformance testing, Parker Chomerics measures and retains apparent thermal conductivity and thermal impedance for every manufacturing lot of product.