Die Attach Failure Modes Analysis and Thermal Warpage Simulation of MicroSD Card COB Packaging

Influenced by the trend of terminal electronic products being thinner and shorter, the packaging of MicroSD cards also tends to be thinner. The packaging yield of such products has always been a challenge faced by packaging companies. The COB type Micro SD produced by Guangxi Kelin Semiconductor Company is taken as the target research object. We first investigate the main failure modes in the die attach process and conducts a preliminary analysis of the failure causes. And we conduct an experimental design to find the best parameters. Then, a thermal warpage simulation is performed in ANSYS to simulate the warpage of the package under heating conditions. It is found that the warpage was significantly reduced at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$130^{\circ} \mathrm{C} \sim 140^{\circ} \mathrm{C}$</tex>. It also indirectly proves that the parameter obtained from the experimental design is effective. Therefore, our research has important reference implications for the process optimization before mass production of Micro SD cards.