Warpage Prediction of Ball Grid Array Package with the Homogenization Method

Abstract

We developed a simple method for accurately predicting the warpage of the ball grid array (BGA) interposer in consideration of the wiring layers. In recent years, this interposer has become thinner, so the influence of the wiring layers has become larger. Consequently, modeling the wiring layers is important for predicting the warpage of the BGA package. However, detailed modeling of the wiring layers causes an increase of the analysis scale. For this reason, we calculated the anisotropic material properties of the wiring layers using the homogenization method. From this, we reveal that it is possible to achieve the same precision as that of a real wiring shape model while decreasing the analysis scale by using this method. We also reveal that this method is effective for high temperatures.

Warpage modeling technique of organic interposer considering deformation by insulator material shrinkage

“…Since the detail modeling the circuitry pattern leads to an increase in mesh size, we divided the laminate into sections having similar circuitry patterns. We obtain equivalent properties of each divided area by homogenization method [7]. The values of equivalent properties are used as the material properties in the analyses of the laminate.…”