The arc-shaped failure morphology of bridge rectifier chips used in LED power supplies exhibits a certain typicality,which suggests a specific failure mechanism. Starting from the interconnection method of the rectifier bridge,the analysis shows that this interconnection inevitably creates a radial current. The distribution of this current is non-uniform at the outer edge of the welding zone,resulting in uneven temperature rise at the PN junctions due to the power dissipation in that region. This temperature rise leads to the formation of several peak temperature points,one of which becomes the initiation point for the chip failure during reverse operation. Additionally,the arc high-temperature regions between the junction temperature peaks will evolve into the arc failure area.
关键词
LED电源/整流桥/正向偏置/反向偏置
Key words
LED switching power supply/bridge rectifier/forward bias/reverse bias
维普
万方数据