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 quality of products. Much effort has been invested by the electronics industry to evaluate and optimize the most popcorn free conditions during the process of packaging and assembly. 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 card, graphic card and motherboard for desktop computer is conducted and presented in this paper. C-mode Scanning Acoustic Microscope (C-SAM) and X-ray Microscope is used to investigate delamination and possibly other 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), Pall 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) as well as Flip Chip. Some packages were found to have delamination. The most common type of delamination seem to be on the die paddle, both front and backside. One chip showed a topside delamination of about 35% together with 26% on backside of package. However, it is still considered acceptable according to JEDEC criteria. X-ray survey for other defects such as wiresweep was not found.