Finite Element Analysis of Flip Chip Ball Grid Array Packages for BGA LifePrediction: 2D, 3D or Axisymmetric?

摘要

A variety of mechanical and thermal stress related problems related to Flip Chip Ball Grid Array Packages (FCBGAs) arernoften solved by the Finite Element Method. Often, the question for the stress analyst is how to simplify the problem at handrnand come up with a sufficiently accurate model in a reasonable amount of time. The aim of this paper is to examine severalrndifferent modeling strategies and compare the performance of various models so as to provide a guideline for selection of arnmodeling strategy. For the comparison of various models, the problem of thermal cycling is addressed here. The comparisonrnof various models is based on strains in the critical solder ball. A common geometric layout is assumed. Properties of thernlaminate are varied so as to cover the range of properties of various laminates available. Pros and cons of variousrnmethodologies are pointed out and are expected to provide useful guidelines for the stress analysts in the electronic packagingrnarea. The paper shows that making meaningful comparisons and predictions using modeling requires in-depth knowledgernexperience in the field of modeling as well as the physical phenomena being modeled.