Solution for the Board Level Drop Test in Vertical Direction of BGA Package under Ultrahigh Acceleration

With the population of portable device growing, mechanical drop reliability of BGA soldering becomes more and more important. Drop test for the BGA-PCB assemblies can be performed in both horizontal and vertical directions. Unfortunately, soldering in vertical drop test will generally fail only under such an ultrahigh acceleration that is too high to be achieved by the conventional drop tester. So a thick copper block working as an additional load is mounted onto the package to simulate the conditions in ultrahigh acceleration drop test. Then ANSYS LS-DYNA is employed to analyze the soldering and establish the corresponding relationship between the acceleration of package without copper block and that of package with copper block. The combination of drop test and simulation reveal that it´s a feasible solution for the study of soldering failure in the vertical drop test