An analytical model for thermal stress analysis of multi-layered microelectronic packaging

Compared to numerical methods, analytical solutions can offer a faster and more accurate procedure for obtaining the interfacial stresses in laminated structures. An analytical model for thermal stress analysis of multi-layered thin stacks on a thick substrate under isothermal loading is proposed in this paper. This analytical approach considers each layer as a beam-type plate with orthotropic material properties. Highly sensitive Moiré interferometry is used to validate the model. The strain field in the bi-material interfaces is obtained experimentally. The test data is in good agreement with the proposed analytical solution. Finite element analysis results are also compared with the analytical solution and the test data.