The MicroDAC Method: A Powerful Means for Microdeformation Analysis in Electronic Packaging

Abstract

Besides different accelerated testing methods finite element analysis (FEA) of stressed components together with appropriate failure hypothesizes allow to estimate life time characteristics. However, most of structures of interest are rather complex and often all necessary material laws or parameters are not available. For simplified simulations the problem arises, whether the results describe adequately the real component under stress. MicroDAC — an established versatile approach to measurement of displacement and strain fields on thermally or mechanically stressed specimens can help to overcome the problem. The underlying measurement principle is a correlation based computer algorithm. It allows to track a set of local object pattern on optical or scanning electron micrographs for different load conditions. The resultant displacement and strain fields are being compared with finite element analysis (FEA) findings or used as an independent source of data. The measurement method has been applied mainly to solder interconnects at flip chip assemblies and chip scale packages.