PROJECT TITLE :

Fabrication of Electronic Packaging Grade Cu–W Materials by High-Temperature and High-Velocity Compaction

ABSTRACT:

High-velocity compaction (HVC) may be a production technique that uses a high-speed punching motion on powder materials to achieve superior mechanical properties. However, because the particle size of the metal powder decreases, achieving higher density becomes increasingly challenging. For this reason, the HVC technique cannot be adopted for producing W85-Cu (85 wt% W and fifteen wt% Cu) heat sinks if the particle size of the tungsten powder is very little [Fisher sub sieve sizer (FSSS) 3 $murm m$ or finer]. In this paper, the HVC method at elevated temperature [or high-temperature high-velocity compaction (HTHVC)] was studied for W85-Cu heat sinks. Tungsten skeletons prepared by the traditional uniaxial technique were further compacted by HTHVC at various elevated temperatures. The compacted tungsten skeletal blanks were then infiltrated with copper at 1350$^circrm C$ for 2 h. It is concluded that the HTHVC method significantly increases the density of the tungsten skeleton. The distribution of copper within the tungsten skeleton is uniform and no vital clustering is observed within the scanning electron microscopy pictures, and therefore the resultant W85-Cu material possesses a relative density of 99.5%, hermeticicty of $1times 10^-10~rm Pa~rm m^3/rm s$, and thermal conductivity of 185 W/(mK). Thus the following conclusions are drawn: 1) overall, the material meets the necessity for heat sinks for electronic packaging applications; and a pair of) the HTHVC technique is terribly useful for processing W85-Cu composites for obtaining high-density composites with uniform material distribution and fascinating mechanical properties.