1. Field of the Invention
The present invention relates to a method of analyzing thermal stress, a method of analyzing a resin flow and an analysis processing apparatus of an electronic part including a package using resin material.
2. Description of Related Art
An example of techniques of evaluating an amount of warpage deformation of an electronic part integrally molded with thermosetting resin such as a semiconductor package is disclosed in Japanese Patent Laid-Open No. 2006-205740. This document describes a method for calculating an amount of warpage deformation using results such as a modulus of elasticity and resin temperature variation calculated by flow analysis using thermosetting resin as input values of a structural analysis.
In order to meet demands for a reduction in thickness or size of electronic apparatuses such as mobile phones in recent years, a so-called “PonP (Package on Package) structure” and a stack structure in which chips are stacked in the thickness direction are used for semiconductor packages. Therefore, in manufacturing semiconductor packages, gaps through which resin flows are becoming smaller. Resin materials are generally filled with inorganic filler such as talc or silica. As gaps through which resin flows become smaller, there occurs a problem in which a filling factor of the filler varies depending on places in the package.
Furthermore, when the filling factor of the filler varies, its coefficient of linear expansion also varies. In correspondence with the coefficient of linear expansion, the amount of warpage deformation of a thin package caused by a temperature variation also varies. In order to accurately evaluate the amount of warpage deformation of the thin package caused by a temperature variation, it is necessary to calculate a filler filling factor using flow analysis of resin in different places of the package and to predict the amount of warpage deformation through a structural analysis using a coefficient of linear expansion corresponding to the filler filling factor.
However, no prediction technique for the amount of warpage deformation by a structural analysis using a coefficient of linear expansion corresponding to a filler filling factor is so far known. Therefore, prototype molding needs to be repeated to select resin material including a structure and a filler filling factor that allow the amount of warpage deformation of a semiconductor package to be suppressed.