Die Attach Delamination Analysis and Modeling Between Temperature Cycling and Thermal Shock for Exposed Pad Lead Frame Devices

Continued standards in reliability and shorter time to market have resulted in an increased focus on reliability modeling and correlation to shorten robust device development. One of the most time consuming and mechanically stressful reliability tests to qualify a product is Temperature Cycling (TC). In plastic packages with exposed pads to be connected to a printed circuit board, a common failure mode in TC test is die pad delamination due to coefficient of thermal expansion mismatches within the package. Thermal Shock (TS) reliability test is similar to TC with the advantage of being much faster to execute. In this study, die pad delamination is correlated for TS and TC using three test vehicles. A scanning acoustic microscopy based delamination extraction approach is described, and a Finite Element Analysis is used to develop a predictive TC thermo-mechanical model.