Research on SnSbNi solder joints between light emitting diode chip and heat sink

The SnSbNi solder pastes were reflowed at 270°C and 280°C between the MvpLED chip and the AlN ceramic substrate, and then the SnSbNi solder joints were aged respectively at 200°C for 1h and at 250°C for 3h. The interfacial microstructure and constituents were investigated by SEM and EDS. After the reflow reactions, a thin layer of IMCs was formed at the chip/solder and solder/substrate interfaces, and a few of voids were formed inside the solder joint. Even if the solder joint was aged at 200°C for 1h, the solder-bonded interface almost had no change. However, the solder joint was seriously damaged after aged at 250°C for 3h.