Nano-themit bonding for electronics packaging of power semiconductor

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560883
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Material processing/treatments
• Research Institution: Osaka University
• Principal Investigator: FUKUMOTO SHINJI 大阪大学, 工学(系)研究科(研究院), 准教授 (60275310)
• Co-Investigator(Kenkyū-buntansha): FUJIMOTO Kozo 大阪大学, 大学院工学研究科, 教授 (70135664) ; MATSUSHIMA Michiya 大阪大学, 大学院工学研究科, 助教 (90403154)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: パワーデバイス / 固相液相反応 / 金属間化合物 / カーケンダルボイド / 拡散 / 熱応力 / マイクロ接合

Outline of Final Research Achievements

A novel mounting technology for next generation semiconductors such as SiC and GaN on the power devices are expected to save energy efficiently. In the case of the next generation power device, conventional soldering technology is not available. In the present study, solid-liquid reaction bonding process using Sn thin film has been developed to apply it to bonding of semiconductor chip to Cu substrate. The formation of intermetallic compounds at the bond interface was investigated by detailed metallurgical examination. Firstly, Cu6Sn5 was formed by solid-liquid reaction, that is the reaction between solid copper and liquid tin, and it transformed to Cu3Sn during the bonding process. The addition of Zn to Sn film was effective to suppress formation of voids. The addition of Ag to Sn thin film formed Ag4Sn layer instead of Cu-Sn intermetallic compounds, which could reduce thermal stress on a Si chip because of its lower elastic modulus than Cu3Sn.

Free Research Field

接合工学