Brazing Sapphire/Sapphire and Sapphire/Copper Sandwich Joints Using Sn-Ag-Ti Active Solder Alloy

摘要

In this paper, a preliminary study in the wetting behavior and interface reaction between active Sn-Ag-4Ti solder alloy and C-plane sapphire was given. An in-situ observation of Sn-Ag-4Ti alloy on C-plane sapphire revealed a decrease in contact angles at temperature close to 550°C. Moreover, sapphire/sapphire and sapphire/copper sandwich joints were brazed using Sn-3.5Ag-4Ti alloy at 500°C, 550°C and 600°C to investigate the microstructure evolution and interface reaction. Microstructure characterization and element analysis indicated that the temperature affected the diffusion of active Ti element by modifying the formation of Sn-Ti intermetallics compounds in Sn-Ag-Ti solder alloy. The absorption of Ti together with the release of Al from sapphire suggested the interface reaction between Sn-Ag-Ti alloy and sapphire was triggered at 550°C.