Improvement in Mechanical and Thermal Properties of Graphite Flake/Cu Composites by Introducing TiC Coating on Graphite Flake Surface

In this work, TiC coating was successfully deposited on a graphite flake surface via molten salt technique, for the purpose of promoting the interfacial connection between Cu and graphite flake. Vacuum hot pressing was then employed to prepare TiC-coated graphite flake/Cu composite. The results indicate that introducing TiC coating on graphite flake surface can evidently reduce the pores and gaps at the interface, resulting in a significant improvement on the bending strength. When the TiC-coated graphite flake content is 60 vol%, the bending strength is increased by 58% compared with the uncoated one. The coefficient of thermal expansion dropped from 6.0 ppm·K−1 to 4.4 ppm·K−1, with the corresponding thermal conductivity as high as 571 W·m−1·K−1. The outstanding thermal conductivity, apposite coefficient of thermal expansion, as well as superior processability, make TiC-coated graphite flake/Cu composite a satisfactory electronic packaging material with vast prospect utilized in microelectronic industry.

Research Progress of Diamond/Al Composites

Due to the good physical properties of diamond, diamond/Al composites as a new generation electronic packaging material receive more and more attention. It is one of the greatest potential for the development of packaging materials. The paper on the diamond/Al composite materials research at home and abroad was summarized in detail.

Thermal properties of nanocrystalline Al composites reinforced by AlN nanoparticles

To explore potential applications of nanocomposites for microelectronic packaging, the thermal properties were investigated on newly developed nanocrystalline Al composites reinforced by AlN nanoparticles. It was found that the thermal conductivity (TC) is reduced with increasing AlN volume fraction (Vp), since connectivity of Al matrix is decreased by introduction of the nanoparticles. Although AlN nanoparticles introduce thermal resistance, they still have significant contribution to the TC of the composite as high-TC inclusion. Particularly, a percolation behavior of AlN nanoparticles is thought to occur with the threshold at 23–30%. Measurements at elevated temperatures (∼500 °C) show almost no distinct degradation of TC relative to room temperature. Moreover, the coefficient of thermal expansion (CTE) is remarkably lowered as Vp increases, e.g., from 26 × 10−6 to 13.9 × 10−6 K−1, by raising Vp to 39%. Therefore, the nanocomposites may be applicable as electronic packaging material, due to the combination of acceptable TC and low CTE.