Clarification of Damage Mechanism of Micro-sized Next-generation Low-temperature Solder under High Current Density and its Applications

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K17931
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Materials/Mechanics of materials
• Research Institution: Akita University
• Principal Investigator: Xu ZHAO 秋田大学, 理工学研究科, 助教 (20650790)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 低温はんだ / エレクトロマイグレーション / バックフロー / Sn58Bi

Outline of Final Research Achievements

Electromigration (EM) damage mechanism of Sn58Bi (wt%) solder, which is so called next-generation low-temperature solder, was clarified.　In addition, in terms of EM reliability issues in solder joint, several countermeasures for enhancing EM resistance of Sn58Bi solder were proposed, as well as the proposition of applying EM mechanism to new metal recycle technology.
On the basis of a developed test structure, in which different micro-sized solder strips were jointed and the minimum solder length was 50μm, the critical condition for initiation of EM damage was investigated with a high degree of accuracy. The variations in growth of intermetallic compound layer and local electrical resistance and temperature with the decreasing solder size, were investigated. Moreover, coating of artificial passivation layer and addition of microelements for enhancing EM resistance were proposed, and their effects were verified.

Free Research Field

機械材料・材料力学