Combination of solid-liquid interdiffusion and sintering bonding for GaN devices

In this paper the combination of solid-state interdiffusion with silver sintering is presented as a supplementary technique for assembly of high temperature devices. The design of the experiments technique is used to study the influence of process temperature, time and thickness of used Sn layers on the assembly process. Identical pressure for assembly and flux application was used in every experiment. In the study GaN chips (Ammono) with Au bottom metallization and DBC (alumina ceramic, double sided covered Cu) were used as test materials. Shear test was performed to test adhesion of the chip to the substrate. Results of statistical analysis of adhesion are presented and the best process parameters for GaN assembly to DBC substrate are identified.