A fast passive-heating setup to investigate die-attach delamination in packaged devices

Packaged devices reliability is a topic of primary importance in product development and, in particular, die-attach reliability investigations must be integrated into the development cycle. In order to assess die-attach robustness, temperature cycle tests are performed to evaluate its thermal fatigue. The most common way for thermal cycling is the use of climatic chambers as specified in the JEDEC standard Temperature Cycling (JESD22-A104). Temperature cycling to pass qualification typically lasts between one and three months. In this work, we demonstrate and validate an alternative passive cycling concept which is roughly 10 times faster. The Devices Under Tests (DUTs) are periodically analyzed via Scanning Acoustic Microscopy (SAM) in order to determine the amount of delamination induced by the thermal cycling. A model based on Finite Elements (FE) has been developed to understand the crack propagation in the die-attach, based on a linear-elastic fracture mechanics (LEFM) approach.