Home reflow soldering of BGAs

[jgalak]

I recently tried reflow soldering for the first time.  I'd done hand soldering of SMD parts before, down to QFP-type pacakges, but this time was confronted with a QFN-20 that I didn't see any way to hand solder (especially the center ground pad), so I gave reflow soldering a try. 

Got a stainless stencil from OSHStencils and some paste, and made up two versions of a small board - one with a hot air station, the other with an unmodified toaster oven (just my Fluke DMM temp probe stuck through the door and a piece of thin aluminum placed under the board on top of the rack).  The hot air station did ok, the toaster did great.

So now I'm wondering - does this sort of home technique work on BGA chips?  Or are those too finicky for this to work?

[SlowBro]

I’m a beginner but I did read an article on Hackaday.com showing how to do it. Just google home reflow bga and there are many hits.

[agehall]

Showing how to do it isn't the problem - that part is simple, just apply heat (i.e. hot air) and it will reflow.

The tricky parts is understanding how much heat you need to put into the board and how to distribute it evenly across the device so that all of it solders properly. In a home-gamer situation, one may not have the specific nozzles for the device in question which means a lot more reliance on experience to apply the heat.

I can't say that I'm experienced with BGA chips (yet!) but I've played quite a bit with my hot air station by now and I'm starting to get a feel for how to apply the heat to ICs to get things to happen.

My $0.02 would be to practise. A lot. The general idea of how to do a reflow is simple but the actual motions you need to go thru requires more than meets the eye.

[jgalak]

I was thinking more toaster oven than hot air station.  I got better results on the QFN with it (perfect connections, whereas the hot air station generated one solder bridge), and it was easier.  I think the heat would be more even, too.

[agehall]

Whatever you have access to and works for you. I don't have a reflow oven (yet) but I'd assume it would, as you say, distribute heat more evenly. The main concern is that it is a bit harder to see what is happening but with some trial and error I'm sure you'll get the hang of it in no-time.