Glob-top reliability characterization: evaluation and analysis methods

Glob-top encapsulation has found widespread acceptance in electronics assembly for low-end, consumer products. To extend the use of this encapsulation method to high reliability and harsh environment conditions, a rigorous evaluation of the available materials is needed. Evaluations based on variables such as encapsulant type, chip size, substrate material and stress test were performed to compare a number of glob-top materials. Analysis techniques to determine failure modes and mechanisms are also necessary to fully understand and improve glob-top performance. This paper outlines the results of glob-top reliability trials and also includes findings on both destructive and nondestructive analysis techniques.