CSP assembly reliability and effects of underfill and double-sidedpopulation

摘要

The JPL-led MicrotypeBGA Consortium of enterprises representinggovernment agencies and private companies have jointed together to poolin-kind resources for developing the quality and reliability of chipscale packages (CSPs) for a variety of projects. In the process ofbuilding the Consortium CSP many challenges were identified regardingaspects of technology implementation. Last year, ball shear test resultsbefore and after isothermal aging were presented and compared to ballgrid array packages. These package were assembled on single- and doublesided printed circuit board (PWB) without and with underfill. These testvehicles are subjected to various environmental tests including fourthermal cycling conditions. These cycles represent the extreme harshaccelerated testing in the range of -55 to 125° C to a commercialrequirement in the range of 0 to 100° C. This paper presents thethermal cycling test results to 2,000 cycles performed under differentenvironmental conditions for single- and double-sided assemblies withand without underfill