Title: Microstructure and drop/shock reliability of Sn-Ag-Cu-In solder joints

Authors: A-Mi Yu; Jae-Won Jang; Jong-Hyun Lee; Jun-Ki Kim; Mok-Soon Kim

Addresses: Division of Materials Science and Engineering, Inha University, 253, Yonghyun-Dong, Nam-Gu, Incheon 402-751, South Korea ' Division of Materials Science and Engineering, Inha University, 253, Yonghyun-Dong, Nam-Gu, Incheon 402-751, South Korea ' Department of Materials Science and Engineering, Seoul National University of Science and Technology, 232, Gongneung-ro, Nowon-gu, Seoul 139-743, South Korea ' Advanced Welding and Joining R&D Department/Microjoining Center, Korea Institute of Industrial Technology, 7-47, Songdo-Dong, Yeonsu-Gu, Incheon 406-840, South Korea ' Division of Materials Science and Engineering, Inha University, 253, Yonghyun-Dong, Nam-Gu, Incheon 402-751, South Korea

Abstract: The drop/shock reliability of new quaternary Sn-Ag-Cu-In Pb-free solder alloy with increasing amounts of copper was investigated on the basis of their mechanical properties and microstructures in comparison with ternary Sn-1.2Ag-0.5Cu Pb-free solder alloy and quaternary Sn-1.2Ag-0.5Cu-0.4In Pb-free solder alloy as suggested in a previous work. The results showed that Sn-1.2Ag-0.7Cu-0.4In solder alloy has excellent drop/shock reliability compared to Sn-1.2Ag-0.5Cu and Sn-1.2Ag-0.5Cu-0.4In solder alloys owing to the thin IMC thickness and the increased mechanical strength. It was considered that indium addition restrained the IMC growth and increasing the amount of copper promoted the formation of Cu₆Sn₅ and Ag3Sn phase, which resulted in an increase in the alloy strength.

Keywords: drop/shock reliability; Sn-Ag-Cu-In alloys; lead-free soldering; microstructure; solder joints; indium; tin; silver; copper; alloy strength.

DOI: 10.1504/IJMSI.2014.064772

International Journal of Materials and Structural Integrity, 2014 Vol.8 No.1/2/3, pp.42 - 52

Published online: 21 Oct 2014 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article