Strength evaluation of an interfacial corner of jointed dissimilar materials considering the multi-scale effect

2016 Fiscal Year Final Research Report

• Project/Area Number: 26420022
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Kagoshima University
• Principal Investigator: Ikeda Toru 鹿児島大学, 理工学域工学系, 教授 (40243894)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 界面 / 破壊 / 接合 / 応力拡大係数 / パワーモジュール / 信頼性 / ナノ薄膜 / ミスフィット転位

Outline of Final Research Achievements

We developed numerical methods to analyze the scalar parameters of asymptotic solutions for three-dimensional corners along the bonded interface between dissimilar anisotropic materials under mechanical and thermal loads.
We measured the delamination toughness of an interface crack between metal and molding resin in a power module, and analyzed stress intensity factors of a critical crack in a power module under thermal stress. We can expect the delamination in a power module under thermal cycle test, which needs very long testing time.
We calculated the stress-strain fields around misfit dislocations between Si and Ge using the molecular statics and the dislocation elastic theory, and found out that those stress-strain fields obtained by two methods correspond each other. We need to take account of the difference of crystal lattice constants of bonded materials in the nano-scale.

Free Research Field

破壊力学、計算固体力学、電子実装工学