Research Progress on Preparation of Ceramic-Based Copper Cladding Laminates by Brazing with AgCuTi Alloy Filler

Active metal brazing of copper cladding is achieved by forming a sandwich structure with a copper plate, active metal filler and ceramic substrate, and then applying high temperature processing to realize the connection between copper and ceramics. AgCuTi alloy filler is the mainstream brazing metal used in preparation of copper cladding laminates by active metal filler brazing, and the ceramic-based copper cladding laminates prepared have good thermal conductivity and relatively high bonding strength. The wetting ability of AgCuTi alloy filler on ceramic substrate and copper plate and the interfacial reactions during brazing are reviewed. The application forms, advantages and disadvantages of AgCuTi alloy filler in preparation of ceramic-based copper cladding laminate, as well as influencing factors on the void rate of welding layer and thermal cycling reliability of ceramic-based copper cladding laminate are summarized. It is pointed out that the future development should be focused on developing low-silver and silver-free solders, and adjusting process parameters to reduce voids of of welding layer.