Moisture-Induced Delamination in Plastic Encapsulated Microelectronic Devices: A Physics of Failure Approach

By identifying the moisture concentration at the weakest material interface as the critical parameter for the defect onset, the quantitative prediction of moisture-induced delamination between the molding compound and die surface in plastic packages was realized using a simple 1-D diffusion model. As a result, the delamination onset during multiple soak and reflow procedure, as prescribed by customers´ specifications, was predicted from the IPC/JEDEC J-STD-020C moisture sensitivity level. For the case studied here, the soldering peak temperature had the most significant influence on the moisture sensitivity of the package. The remaining part of the soldering temperature profile (ramp up and down) was found to have a rather small influence.