Abstract
Advanced electronic device packaging has several kinds of joint structures of metal, ceramic and polymer. It is well known that the stress singularity occurs at the cross point and line of free surface and interface. Then, a crack initiates from the vertex and joints fail. Hence, a lot of studies on the joints have been carried out theoretically and experimentally. In the previous study, two-dimensional joints are extensively investigated, however, few studies on three-dimensional joint structures have been carried out until now. For instance, CSP has a three-dimensional bonded structure of IC chip and polymers, and delamination occurs frequently at an interface between IC and a resin. Therefore, a method for estimating the strength of interface at the vertex based on the three dimensional intensity of singularity is needed. In the present paper, energy release rate at an initial step of crack growth for four kinds of crack area in a three-dimensional joint is calculated and discussed..
