Thermal Materials Technical Tips

Thermally conductive materials are an effective way to resolve a variety of design and processing challenges. They fall into the categories of adhesives, coatings, films, encapsulants, and greases. The products are differentiated by the degree of thermal conductivity that measures the ability / efficiency by which a material transfers heat energy through its volume at a given temperature.

The following thermal material technical tips are provided with links to the SinoGuide Blog where these tips were originally posted.


Soft gap filler pads – gap filler are usually measured on the Shore00 scale since they are very soft, they are easily squeezed by finger.

Permanent deformation – thermal gap filler pads have a dough or gum like composition, they generally do not rebound fully after being compressed.

Toughness – since gap filler are heavy loaded with conductive particles they can tear easily if handled roughly. This is not typically an issue due to how these material are used.

Thermal pad was cut to size – parts can be cut into basic or complex geometries.

Release liners – gap filler pads are supplied with lines since they are tacky.

Fast install and no greasy mess – pre-cut, tacky gap fillers, install quickly without messy grease or paste.

Tacky gap filler – generally there is no adhesive applied to gap filler but they are tacky enough to stick in place.

High temperature – thermal gap filler pads have a typical operating temperature of 200°C (392°F).

Why thermal gap filler from SinoGuide – Less air entrapment, more surface contact, better heat transfer.


The Fillers

Very few fillers significantally aid thermal conductivity. Tabular alumina (aluminum oxide), zinc oxide, silica (quartz, sand), aluminum, iron oxide, mica, wollastonite, and calcium sulfate (anhydrous) are the most common fillers used for thermally conductive and electrically insulating systems. Aluminum is not used in high dielectric applications due to its electrical properties. Silver and nickel are used when an application requires both thermal and electrical conductivity.

Other high thermally conductive materials are available but are rarely used due to toxicity (beryllium), high cost (boron nitride or aluminum nitride), or processing / handling considerations (diamond dust and polyaramide fibers). Dust and fibers require so much loading to get superior conductivity that the material often becomes too stiff and unworkable.

Contact SinoGuide today for your complete application solutions.

For help selecting a Gap Pad, thermal gap filler, or thermal interface material (TIM), please contact SinoGuide at +86-755-89375091 or email