Authors: Robert Darveaux and Bhuvaneshwaran Vijayakumar Company: Skyworks Solutions, Inc. Date Published: 2/6/2017
Pan Pacific Symposium
Abstract: The board level reliability of BGA multichip modules was characterized under thermal shock and drop test conditions. The variables studied were BGA pattern, substrate surface finish, solder joint size, and module size. Thermal cycle reliability was quite robust for all test vehicles since the body sizes were less than 7mm on a side. Drop test reliability improved with smaller body size, larger solder mask opening on the package, and ENEPIG surface finish. Measured test results were compared to finite element analysis predictions. Accumulated strain energy density over 30ms of board vibration correlated better to drop test reliability than peak stress level. Recommendations are made for optimizing design and material set relative to board level reliability performance.