A PARAMETRIC APPROACH TO OPTIMIZING BGA DESIGN FOR REFLOW RELIABILITY

摘要

Thermal warpage is a keen reliability concern for BGA (Ball Grid Array) and surface mounted PCBA (Printed Circuit Board Assembly). The authors previously proposed a hybrid method that correlates analytically modeled and directly measured warpage for a real package. While iteratively reaching the high correlation, the accuracy of the input material properties is simultaneously improved. An application of the model to a specific package is basically a model refining and verification process which ensures a high confidence level of the final modeling output such as the stresses/strains along the adhesive interfaces and the package warpage. Given that the output parameters are expressed as functions of temperature, geometric dimension and materials' properties, the approach enables a quick, quantitative and full scale evaluation of the package's performance. This paper presents an application example to illustrate how the method is executed in a package performance evaluation and prediction and how the evaluation facilitates the package design and manufacturing for reliability.