OS0730 絶縁モールド用エポキシ樹脂の熱疲労き裂進展特性評価法(構造用材料の疲労挙動と寿命評価,オーガナイズドセッション)

抄録

In resin-metal composite structures such as electronic products with epoxy resin molding insulator, thermal stress is induced to epoxy resin during thermal cycle due to the mismatch of thermal expansion, and often the case it is a thermal fatigue problem of epoxy resin under out-of-phase loading. In this paper, the technique of predicting thermal fatigue crack growth rate in epoxy resin is studied. We proposed the evaluation temperature of crack growth characteristics where strain intensity factor K/E takes maximum value, based on K/E - da/dN relationship. In order to evalute thermal fatigue crack growth rate under out-of-phase loading, both crack propagation test by thermal cycle test and thermal stress evaluation by viscoelastic FEM analysis were carried out. As a result, it was fouond that crack growth rate under out-of-phase thermal fatigue test was nearly in accordance with that of iso-thermal fatigue test under the evaluation temperature.