Board level reliability testing of μBGA(R) packaging with lead-free solder attachment

To maximize the benefit of chip-scale packaging for portable and handheld electronics, the user must consider efficient and cost effective assembly processing. Factors that an engineer should review before developing the product using CSP may include physical features and construction of the device, environmental limitations, suitable substrate materials and a general understanding of the attachment methodology. Many of the electronic products being developed using miniature chip-scale packages are moving toward lead-free, environmentally safe assembly processes. This paper reviews chip-size flash and RAMBUS memory test device applications utilizing μBGA^(R) package technology, explore alternative solder alloy compositions, furnish recommendations for solder process temperature profiles and present the results from extensive thermal cycle testing, comparing eutectic solder to lead-free solder ball contacts and attachment materials