Survey on delamination of IC packages in electronic products

The electronics industry is concerned about the delamination of plastic-encapsulated IC packages to assure high product quality. Much effort has been invested by the electronics industry to evaluate and optimize the most popcorn-free conditions during the packaging and assembly processes. However, it may be interesting to know the degree of delamination of IC packages that are already mounted on boards. A delamination survey of various IC packages from several used electronic products including cellular phones, VCR, Discman, display cards, graphics cards and motherboards for desktop computers is conducted and presented in this paper. C-mode scanning acoustic microscopy (C-SAM) and X-ray microscopy are used to investigate delamination and other possible defects like wire-sweep or cracking. IC packages under survey included thin small outline package (TSOP), small outline integrated circuit (SOIC), small outline J-lead package (SOJ), ball grid array (BGA), quad flat package (QFP), plastic leaded chip carrier (PLCC), chip-on-flex (COF), dual-in-line package (DIP), single-in-line package (SIP), and flip chip. Some packages were found to have delamination. The most common type of delamination seemed to be on the die paddle, both front and backside. One chip showed a topside delamination of about 35% together with 26% on the package backside. However, it is still considered acceptable according to JEDEC criteria. X-ray surveys for other defects such as wiresweep found nothing.