Closed-Form Solution for Thermo-Elastoplastic Strains in Semiconductor Chip Bonding Structures

Abstract

A closed-form solution is presented for calculating the strains produced by temperature changes in semiconductor chip bonding structures ; it is based on beam theory and elasto-perfect plastic bonding layer assumptions. This solution agrees well with three-dimensional FEM and experimental results. The parameters that govern the strains produced in bonding structures are derived from this solution. These parameters are charted in order to obtain the maximum shearing strains of bonding layers and the maximum normal stresses of chips.