关键词: 金锡合金, 密封, 界面金属化合物, 焊料

Abstract: AuSn20 solder ring is a commonly used sealing material in high-reliability sealing process. Using differential scanning calorimetry to detect the melting and solidification temperature of the imported AuSn20 solder ring, it is proved that the melting temperature is 280 ℃, the solidification temperature is 277 ℃, the purity is very high and almost no impurities. The surface state and morphology of the imported and domestic AuSn20 solder rings are compared. They are both the uniform distribution state of AuSn and Au₅Sn, and there is no obvious difference. The imported AuSn20 solder was used to seal the circuit, and after grinding and polishing, the section of the weld area was prepared, and the microscopic morphology of the section was observed. The element composition on the cross-section was detected by energy spectrum analysis, combined with the binary phase of gold and tin, it was determined that AuSn and Au₅Sn were the main compounds in the weld area after the eutectic reaction. At the same time, it was observed that the interface between the shell, cover and solder ring formed (Ni,Au)₃Sn₂. Furthermore, the AuSn20 solder sealing reaction is deduced.

Key words: gold-tinalloy, sealing, intermetalliccompounds, solder