Design of Hybrid Composites for Thermal Interface Materials

摘要

We have been designing thermal interface materials(TIMs) for use in between chips andheat spreaders or heat sinks. TIM is composed of conductive fillers (such as carbon fiber) and phasechangeable polymer matrix. The matrix consists of two different materials, one of which is Trilene that isliquid state at room temperature, and the other is Astorwax whose melting point is around 54°C. Due tothe low melting point of the matrix, the thickness of the TIMs is reduced under certain pressure if TIM isheated up over 50°C. So, the thermal conductivity of TIM is significantly reduced when it is heated over50°C for the first time. Likewise, the thermal resistance of the TIMs is also decreased. Thermalresistance is usually stable after the first heat up, reaching to the constant value, as the thickness of theTIM remains constant. The measured thermal resistance of several different types of TIM turns out to bean almost linear function of specimen thickness.