Novel Methods for Manufacturing of W85-Cu Heat Sinks for Electronic Packaging Applications

Abstract

High-velocity compaction (HVC) is a production technique that uses a high-speed punch motion on powder materials to achieve superior mechanical properties. However, as the particle size of the powder metals decreases, achieving higher-density numbers becomes increasingly challenging. For this reason, the HVC technique cannot be adopted for manufacturing W85-Cu heat sinks as the particle size of the tungsten powder is very fine (FSSS 3 μm or finer). In this study, the HVC process at elevated temperatures is studied for W85-Cu heat sinks (HTHVC). Tungsten skeletons prepared by conventional uniaxial methods are compacted by the HTHVC method at various elevated temperatures. The compacted tungsten skeletal blanks are infiltrated with copper at an elevated temperature of 1,350 °C for 2h. The mechanical properties including density, thermal conductivity, hermeticity, and coefficient of thermal expansion, have been found to be in line with the requirements for W85-Cu heat sinks.