Interfacial shear stress, peeling stress, and die cracking stress in trilayer electronic assemblies

Interfacial shear stress, peeling stress, and die cracking stress due to th ermal and elastic mismatch in layered electronic assemblies are one of the major causes of the mechanical failure of electronic packages. A simple but rather accurate method is developed to estimate these thermal stresses for packages with different layer lengths. For layered electronics with thin a dhesives, analytical expressions are obtained for interfacial shear stress and peeling stress, and they agree well with the finite element analysis, e specially when the moduli of adhesive layers are significantly lower than t he moduli of the other layers. An analytic expression of die cracking stres s is also obtained for multilayer electronic assemblies.