Analysis of Influence of Process Parameters on Microstructure of Welds in AuSn Seals

AuSn solder ring seals are a typical high-reliability hermetic package. The preparation process of the AuSn solder ring is strictly controlled, in which the mass fraction of gold and tin is generally 80:20, in order to expect a stable eutectic reaction to form a uniform and good sealing structure. However, in practical applications, due to the segregation of the coating composition of the shell and the cover plate, and the influence of important process parameters such as temperature and pressure in the sealing process, the reaction tends to deviate from the eutectic point and obtain different welding states. By scanning the cross section of the welded sample, observing the state and distribution of the interface compound, studying the influence of the process parameters on the microstructure of the sealing zone during the sealing process, the main influencing factors were obtained, and an effective control method was proposed, which provides a theoretical basis for obtaining an excellent welding interface and further improving the sealing reliability.