Hello, I tryed to solder 3 qfn chips recently, and same problem : I press it hard and the chip stay in the air, there is a quarter of millimeter between board and chip, I don't see the sides pads of chip soldered to board and I guess the chip is not properly soldered (not tested).
I tryed with qfn 20 and 28, the same.
I start to solder with board pads tinned (lead solder wire), I place the chip without flux under but I put a little bit of flux at two sides of the chip to hold it in place.
After solder, I reflow (400 degree) while pressing chip, two times at two places of the chip.
What I'm doing wrong please ?
I tryed with qfn 20 and 28, the same.
I start to solder with board pads tinned (lead solder wire), I place the chip without flux under but I put a little bit of flux at two sides of the chip to hold it in place.
After solder, I reflow (400 degree) while pressing chip, two times at two places of the chip.
What I'm doing wrong please ?
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