Engineered chemistry of Cu–W composites sintered by field-assisted sintering technology for heat sink applications

High performance microelectronics require superior thermal management systems. Heat sink plates that dissipate the heat generated by the microelectronic components are of critical importance for this purpose. The two primary concerns with heat sink materials are the coefficient of thermal expansion (CTE), which should be low to match that of silicon (4 × 10⁻⁶/°C), and the thermal conductivity, which should be as high as possible to move the heat efficiently. This study created copper–tungsten composite materials using the field assisted sintering technology (FAST) process. The amount of tungsten used in the composites was varied from 0 to 70 wt% to study the effects of tungsten as well as to show the ability of the composite’s properties to be tailored based on the percentage of tungsten in the composite. It is shown that increasing pressure has a positive effect on final density while heating rate has no effect. High densities of >97.5% were achieved in all of the composites. As predicted, the CTE decreases as the percentage of tungsten increases. Thermal conductivities are also reported for each sample.