Modal analysis for BGA shock test board and fixture design

This work serves to evaluate solder joint shock reliability for Intel's desktop motherboard and OEM desktop systems. A component level dynamic test system was developed to represent motherboard system behavior and modal analysis was introduced to evaluate and calibrate the test board fundamental frequency. By mounting a mass to the test board, the test system was adjusted to simulate the BGA solder joint dynamic behavior at the motherboard and desktop system level. Modal testing was performed with various mounting masses on the test board, which represents designed heatsink masses on the motherboard. The resonance frequencies and the corresponding mode shapes of the test boards were measured. Finite element modal analysis was performed for the test board/fixture. Numerical results showed excellent agreement with the modal testing data. The testing/modeling data provides the ground work for the component level shock test and the solder joint dynamic failure strength evaluation.