Abstract:In recent years, diamond/Al composites as a new generation of thermal conductive metal matrix composites
have gradually entered the field of vision, with the increasing demand for heat dissipation of electronic
equipment. Thermal expansion performance is an important index to measure the matching between electronic
packaging materials and semiconductor materials. High pressure infiltration method was used to investigate the influence
of bimodal particles diamond on thermal expansion properties of diamond/Al composites by adding fine
particles into 120 mesh’coarse particle diamond to improve the volume ratio of diamond. The results show that the
bimodal particles diamond/Al composite has a higher diamond volume ratio, and the smaller the added fine particles
are, the lower the thermal expansion coefficient is, as low as 6.885×10-6 K-1, which is closer to the thermal expansion
coefficient of semiconductor materials. The addition of fine particles diamond not only improves the volume
ratio of diamond, but also increases the number of interfaces of composite materials and the interfacial thermal
resistance, which will affect the heat conduction between Al matrix and diamond.