Combining Diffusion Bonding With Rolling to Manufacture CPC Composites With High Bond Strength for Electronic Packaging Applications

A new technology, which combines diffusion bonding with rolling, was used to manufacture Cu/Mo70-Cu/Cu (CPC) composites for electronic packaging applications. Three samples with different thickness ratios were manufactured. CPC composites with low coefficient of thermal expansion (8.5×10^-6 K^-1), high thermal conductivity (278 W/(m·K)), low density (9.2 g/cm³), and particularly high bond strength (265 MPa) were manufactured. The bond mechanism of CPC composites is a combination of the metallic bond, direct Cu-Cu bonding and surface rupture mechanism. Compared with the traditional processes, CPC composites manufactured by this method have such advantages as high bond strength, controllable thickness ratio, and miniaturization.