Thermal Interface Materials

Finding the right thermal interface materials is crucial to maintaining an adequate energy flow through the heatsink. While a heatsink is a component designed to draw heat out of high energy electronics devices, the thermal interface is the point at which the heatsink connects to the actual source of heat. This heat source can either be the semiconductor package, the computer CPU or any other component that requires the removal of thermal energy. In order to make sure that there are no flaws in this connection area that would inhibit the flow of energy, heatsink designers have experimented with many different materials and joining techniques to optimize thermal conductivity.

In order to promote heat flow at the thermal interface, materials must be used which reduce thermal resistance. That's because thermal resistance - which is a blocker to the flow of heat energy, and should be avoided - is caused by microscopic pockets of air that naturally occur between two surfaces, however flat they may seem to the naked eye. Although it is important to make sure that the conjoining surfaces are cut perfectly level, and done so from metals with high thermal conductivity, the use of thermal interface materials is crucial to stopping thermal resistance.

One of the easiest materials that can be used is thermal grease. This can be made out of silicone or other materials and serves the purpose of eliminating air pockets and providing a certain level of conductivity. To be used with - not instead of - clips or screw-based mounting systems, thermal grease works about as well as an adhesive tape solution. A better alternative to these bonding methods is a thermal compound that flows when wet but dries up solid to create a strong bond on the thermal interface. Even better, however, are the silicone-based elastomer pads which respond extremely well to pressure mounting, filling in all the air spaces and delivering a dependable thermal interface solution.