Consolidation of Nano-Composites for Thermal Management

Abstract

Abstract This paper describes the consolidation of ultra fine (“nano”) grained W-Cu and Mo-Cu composite materials used as thermal management substrates in microelectronics applications. Both W/Cu and Mo/Cu composites having W and Mo dispersed phases in the size range of 300-700 nm and excellent microstructural homogeneity were synthesized by chemical precursor techniques. Consolidation to high densities (96 - 99% of theoretical) was accomplished by the standard commercial practice of cold pressing followed by pressureless sintering and also by rapid consolidation at high pressures. The high pressure short duration consolidation techniques allowed the benefits of nano-powders to be preserved by minimizing grain growth during consolidation. The use of these methods provides alternatives to the costly and tedious techniques of infiltration of a refractory metal skeleton or powder mixing. Both of the latter approaches are subject to local inhomogeneities and variations in thermal properties. Thermal conductiv...