Hi,

I am trying to solder a memory chip like this -

on to a PCB like this -

But any which way we try, half of them hardly work. Have used low temp solder paste with heat gun ( don't have access to a reflow oven) but 60% work the first time and have to be removed and resoldered several time to work. Is there a better way to do this?

Thanks!

 

I personally prefer lead / tin / silver solder paste, as it flows and wets more easily. If you cant use this, then add a bit more flux when you do the soldering. Also try heating from the underside, or use a hot plate. When the solder melts, you should be able to slightly jiggle the chip from side to side, and the surface tension of the molten solder should pull it back into alignment - then you know its in position.

If your still struggling, you could actually "tin" the board and the chip with a soldering iron first, just to make sure all contacts are wettable. Then add a bit of flux and heat the 2 up together in position.