パワーモジュールにおけるアルミワイヤ接合部の熱疲労に対する材料非線形の効果

抄録

Reliability issue on bonding structures of power modules becomes more important due to new products which consist of compound semiconductors and can operate under higher temperature condition than conventional products. Higher temperature condition leads to severer non-linear deformation of component materials. In particular, both plastic and creep deformation that are dominant factors of fatigue, drastically appear in bonding materials under the temperature close to a half of melting point. In this paper, thermal fatigue of wire bonding structure was investigated with non-linear finite element analysis considering plastic and creep deformation. Results of the analysis suggest that inelastic strain energy density can describe thermal fatigue behavior, especially the saturation of fatigue lifetime over 200℃, rather than the range of inelastic strain.