Impact pin-pull test and simulation on the micro-pads of package substrates

Pad Peeling and Pad Cratering have become the primary failure modes in board-level test of electronic devices, attracting significant attention from the industry. However, due to the size and precision constraints of micro-solder pads, as well as the complexity and diversity in their practical applications, research and testing on the performance of micro-solder pads under impact have become increasingly challenging. This study is based on the current trend toward miniaturization and integration in electronic packaging devices, and explores changes in the strength of micro-fine pads when subjected to impact. The effects of parameters such as pull - off acceleration, pull - off speed, pad diameter, and pad type on pad strength are analyzed by the study, and the differences in strength changes between pads subjected to impact forces and gentle forces are compared. The results show that at acceleration of 5–100 mm/s², the maximum pull-off force increases with increasing acceleration; at speeds of 5–10 mm/s, the maximum pull-off force increases with increasing speed; when subjected to impact forces, larger pad diameters result in greater strength; pads with leads exhibit the highest strength, while pads with through-holes beneath them exhibit the lowest strength. The proposed pull-out test method provides a viable approach for quality inspection and testing of electronic packaging substrates.