Interfacial Reactions of Pure Sn, Sn-3.0Ag-0.5Cu and Sn-9.0Zn Lead-free Solders with the Fe-42Ni Substrate

摘要

The study investigated the interfacial reactions between Sn, Sn-3.0Ag-0.5Cu (SAC) and Sn-9.0Zn (SZ) solders with the Fe-42Ni (Alloy42) substrate at 240, 255 and 270°C. The experimental results indicated that two intermetallic compounds (IMCs) with different surface morphologies were observed in the Sn/Alloy42 couple. However, both they were the FeSn_2 phases. In the SAC/Alloy42 couples, Only the (Fe, Ni)Sn_2 phase was formed in the interface. Three layers structure of IMCs were observed in SZ/Alloy42 couples and they were the (Ni, Fe)_5Zn_(21) phase. Two stages of IMC thickness change were found in three couples. The IMC thickness in these couples increased as increasing reaction times and temperatures, and it was proportional to the square root of reaction time. As the results, the interfacial reaction mechanism of them was diffusion controlled.