Failure Analysis Methods in Electronics Assembly Technology

Abstract

The aim of this paper is to describe a failure analysis methodology applicable to reveal the root causes of electronic assembly failures. The most relevant properties of the applied techniques, i.e. optical microscopy, X-ray microstructure analysis, SEM (scanning electron microscopy) combined with EDX (energy dispersive X-ray spectroscopy) analysis, are given. Three recent failure analysis case studies are also presented. In case of a burnt component the microwire and the leadframe formed AlCu intermetallic compound in the length of several millimeters. The low joint strength of gullwing leads were deduced back to paste printing and wetting problems. The fracture surface morphology of a joint broken on the field showed different structure from the ones broken at room temperature. It was revealed that SnPb solder fracture surface is different at room temperature and above 100°C.