So the BGA reballing kit (stencil + holder type) I ordered arrived today and I start trying it using one of the cheapest BGA chips that I need to reball. Well that is where the hope ends as no matter how I try there is always a few balls that refuse to stick to the chip. The solder balls are supposed to mely at 217 degrees Celsius (lead-free balls) but even with my hot air turned to 285 degrees it won't stick.
I am on the verge of returning the kit (except the 0.6mm balls which I have used some - I am an honest customer and would not return my used consumables) and throwing away the chips (that includes some SoC I was planning to experiment with, but without reballing it is going nowhere.) Do you have any suggestion, both on the technical side (as how to reball using stencil and balls - my previous post on this fell on silent ears, and the online material almost always called for preform which I cannot find) and on the anger management side.