Analysis of multi-layered microelectronic packaging under uniformly distributed loading

An accurate estimate of interfacial stresses in multi-layered microelectronic packaging is very important for design and prediction of delamination-related failures. An analytical model for stress analysis of multi-layered stacks, which is based on an extension of Valisetty's model (Bending of Beams, Plates and Laminates: Refined Theories and Comparative Studies, Ph.D. thesis, Georgia Institute of Technology, Atlanta, March 1983), is proposed in this paper. This analytical approach considers each layer as a beam-type plate with orthotropic material properties. A new miniature material testing unit is developed. High sensitive Moiré interferometry was used to measure the strain field in the bi-material interfaces. The test data is in good agreement with the proposed analytical solution. The problem is also analyzed by a finite element analysis. Comparison of all three results indicates that the analytical procedure is far superior to finite element analysis for this problem.