Chip Scale Package Integrity Assessment by Isothermal Aging

Many aspects of chip scale package (CSP) technology, with focus on assembly reliability characteristics, are being investigated by the JPL-led consortia. Three types of test vehicles were considered for evaluation and currently two configurations have been built to optimize attachment processes. These test vehicles use numerous package types. To understand potential failure mechanisms of the packages, particularly solder ball attachment, the grid CSPs were subjected to environmental exposure. Package I/Os ranged from 40 to nearly 300. This paper presents both as assembled, up to 1, 000 hours of isothermal aging shear test results and photo micrographs, and tensile test results before and after 1,500 cycles in the range of -30/100 C for CSPs. Results will be compared to BGAs with the same the same isothermal aging environmental exposures.