Ag-based Thermal Interface Materials for GaN-on-Si Assembly Chips in Power Applications

The paper aims to develop an assembly technique for the connection of bare Si or TiAu metallized Si chips to NiAu plated Cu surface. The thermal interface material (TIM) based on Ag paste was used for this purpose. It was found that Ag-based TIM allows creating sound joints between NiAu plated Cu and both types of Si chips. The analysis of the joints showed that the adhesion is in the range of 10 MPa and thermal resistance is less than 0.3 K/W. Therefore, the fabricated joints fulfil the mechanical and thermal requirements for this type of assemblies.