Generally, semiconductor components dissipate heat generated into the air or through the substrate. However, when decreasing package size the surface area of the back of the electrode and mold also becomes smaller, resulting in lower heat dissipation.
The PMDE package, to solve this problem, increases the back electrode area to facilitate the heat dissipation path from the lead frame to the substrate. The result is significantly improved heat dissipation performance, achieving the same electrical characteristics as the standard SOD-123FL package (3.5mm × 1.6mm) with in a smaller 2.5mm × 1.3mm size. This translates to a 42% smaller mounting area, making it ideal for automotive applications where higher component density is needed.

The PMDE package achieves a mounting strength of 34.8N, approximately 1.4 times higher than that of the SOD-123FL package, by increasing the area of the metal portion that ensures a larger backside electrode area. This reduces the risk of solder cracking when stress is applied to the board, contributing to greater reliability. High surge current withstand capability (I_FSM) is also achieved by adopting a wire-free structure whereby the chip is directly sandwiched between frames. The resulting high surge current withstand capability (I_FSM) provides superior resistance to destruction caused by high instantaneous currents, such as during vehicle start or abnormal device operation.