J. C. P. Salimbangon, R. G. Mendaros, Analog Devices Inc, Brgy. Javalera, Gen. Trias, Cavite, Philippines

Summary: Access to critical die and package structures for failure analysis purposes is complicated in stacked die devices in small packages such as thin 3 x 5 x 1.45mm, 14 lead, plastic LFCSP. The essential concern is exposing the bottom die and wire bonding profiles while maintaining electrical functionality in preparation for extensive visual examination and fault isolation. This technical paper discusses the failure analysis solutions developed to effectively access the areas of interest. Figure 1 and 2 shows the die stack construction and a packaged part respectively.