Evaluation of Estimation Method for Thermal Fatigue Crack Growth Rate in Epoxy Resin Composites

Abstract

In resin-metal composite structures, such as electronic products with an epoxy resin molding insulator, the thermal fatigue of the epoxy resin during thermal cycling is a critical issue. Because the thermal stress in the epoxy resin and its strength simultaneously change during the thermal cycling, an estimation method for the thermal fatigue reliability in consideration of the temperature dependence of the fatigue strength is required. In this study, the technique of predicting the thermal fatigue crack growth rate in epoxy resin is studied and we proposed an estimation method using the strain intensity factor range ΔK/E as an evaluation parameter. In order to evaluate the proposed method, both the crack growth test by thermal cycling and the thermal stress evaluation by the visco-elastic FEM analysis were carried out. As a result, it was found that the proposed method estimated the crack growth rate under thermal fatigue test less than that of the iso-thermal fatigue test.

Evaluation of thermal fatigue crack propagation in underfill resin materials for electronic packages

“…However, the studies on thermal fatigue that have focused on fatigue crack propagation in underfill resins are very limited. [10][11][12] Furthermore, in thermal cycle tests on IC packages, it is difficult to determine where and when the crack initiated and how it propagated in underfill resins because the disconnection of solder joints was usually measured electrically. 13,14 Therefore, it is important to clarify the thermal fatigue crack growth characteristics of underfill resins to understand the failure mechanism and design reliable IC packages.…”

“…The works described above demonstrate that research on mechanical fatigue and thermal cycle evaluations of IC packages with underfill resins have been performed. However, the studies on thermal fatigue that have focused on fatigue crack propagation in underfill resins are very limited 10–12 . Furthermore, in thermal cycle tests on IC packages, it is difficult to determine where and when the crack initiated and how it propagated in underfill resins because the disconnection of solder joints was usually measured electrically 13,14 .…”

Fatigue Crack Growth Characteristics of Epoxy Resin Reinforced by Silica Particles at Elevated Temperature

“…al. (8) also investigated the crack growth behavior of an epoxy resin at high temperature by using the parameter ∆K /E for taking account of temperature dependency of mechanical property into the fracture mechanics parameter.…”