Need help reflowing XHP70.2 on sink pad

BoxCarWillie · 2018-07-17T20:23:06.000Z

I’m trying to reflow an XHP70.2 on a large sinkpad for a 12V configuration. This will be used in the GT flashlight. I’ve already reflowed one, but only 2 of the dyes work on one side, the other 2 are dead. So I have 2 more 70.2’s to make work correctly.

I have attached a photo of the LED and sinkpad that only 2 dyes on the right side work. I have the circle on the top right that indicates the positive? Perhaps some solder may have grounded between the 4 solder lines on the sinkpad?

Any advice or suggestions would be appreciated!

BoxCarWillie · 2018-07-17T20:25:19.000Z

Lexel · 2018-07-17T21:47:59.000Z

usually thermal shock during too quick reflow or reflow too hot
easily kills flip chip LEDs