Fabrication of AlN/Cu composite structure via laser metallization assisted direct bonding technology

Abstract In this work, an innovative and cost-effect method was proposed to fabricate AlN/Cu composite structure. The AlN ceramic was metallized by nanosecond laser irradiation without consuming extra materials. The metallurgical combination between AlN ceramic and Cu was successfully achieved based on the Al-Cu eutectic reaction at a relatively low temperature of 620 ℃. Under the laser irradiation, the AlN ceramic was thermal decomposed to form Al laeyer and microgroove. As the laser power increased, more Al was produced on the the ceramic surface and the micgroove became deeper. The microstructure, mechanical and heat transfer properties of the AlN/Cu joints were investigated. The maximum shear strength of the joint was 11.25MPa when the laser power was 56 W, and the maximum thermal conductivity was 162 W/(m·K) when the laser power was 42 W. The approach of laser-induced direct metallization of ceramics in this work provides a novel strategy for the integration of ceramics/metals composite structures.