How to get new chips to stick to the right pads

Nintendo Questions Nintendo Switch
1

So I’ve been messing with my broken board and trying to remove and readd chips. Mt92 was first. I used 450 air and no tape which was dumb so capacitors went flying.

I’m trying to put it back but I can’t seem to get it to line up. I cleaned the pads, tinned them. Added flux. Put the chip on top and heated. The surface tension never came. Do I need to tin both the pads and the chip? I also hadn’t preheated. From my understanding that makes a huge difference for both removal and readding. Opinions?

Thanks for all the help. This site is as close as I have to a mentor.

2

Without preheating your chips won’t come off because that big pad under the qfn chips goes directly to the big ground plane of the pcb and basically keep the solder “cold”

I tin the pads on the board (i also remove the solder on the center pad because it is always too much), so that i don’t risk breaking the chip

Take some time to bring the board up to temperature, apply flux, place chip where you want it to be and heat it up until it “sinks in”

On mid-low airflow components should also stay in place so you don’t neet capton tape