I'm new to SMD soldering, and tried to assemble a couple of boards, using a reflow oven.
I 'm using a stencil (Kapton – mylar) and so far it worked fine except for the LQFP48 devices (pitch 0.5mm). In this case, the pins are bridged (too much paste creating short circuits between the pins). I guess the problem is too much paste in the pads, but I'm using just one pass over the stencil.
Is there any way to do this and avoid this problem? Should I reduce the IC pads area in the solder paste layer?
Best Answer
I have been building boards for a long time and can tell you that the best approach here is usually to use solder wick and a soldering iron to suck up the excess solder. Then if needed, retouch the component by heating it up with a soldering iron and gently move it. It will self align and will look great.
Also, just taking the soldering iron and moving it against the solder towards you does it as well.
I have also found that using a hot air gun, heat up the place where there's excess solder paste and using tweezers just move them between the pins. Because solder paste has metallic balls, it tends to ball up and you can pick it up.