Fabrication and infiltration kinetics analysis of Ti-coated diamond/copper composites with near-net-shape by pressureless infiltration

Abstract

Abstract The Ti-coated diamond/copper composites with near-net-shape are manufactured by pressurelessly infiltrating liquid copper into porous Ti-coated diamond preforms. The contact angle between diamond and copper, relative density, thermal conductivity (TC), coefficient of thermal expansion (CTE), leak rate and microstructure are evaluated and characterized. In addition, the numerical analysis of the pressureless infiltration kinetics is also discussed. The results indicate that the relative density, TC and CTE of composites are 99.3%, 385 Wm−1 k−1 and 3–8 × 10−6 K−1, respectively. It can meet heat-sink package requirement of high-power electronic devices as LED, insulated gate bipolar transistor (IGBT), etc. The liquid copper exhibits a turbulent flow with the Reynolds number in the range of 27.83–49.7. The porosity ϕ and the pressure drop Δp are the main influence factors controlling the velocity of liquid copper. Moreover, under vacuum condition of 8.7 × 10−3 Pa, the maximum theoretical infiltration length Lmax of Ti-coated diamond/copper composites is found to be 552 mm.