The problem we have with unplug via is when we clean the BGA pad, the solder resist cover the trace between pads and vias will be removed. During the solder removal process certain amount of solder will also get into the unplug vias as well. During BGA replacement process, two thing will happen. First, due to vias plug with solder, explosion might happen and cause solder short or open. Second, due to the solder resist has been removed, the solder from BGA ball will flow into the vias and cause insufficient or unsolder BGA balls.
Looking at purchasing an inexpensive BGA rework machine. Saw Weller's BGA system (model 3000) a few months ago . . . seemed to work Ok. Now that I am ready to buy, read on one of their resellers website that this model is being discontinued. I am apprehensive about contacting Weller directly as I doubt that they will give me a straight answer. Problem: even if some are available, don't want to be stuck with a discontinued machine (service and spares will like be problematic). Does anyone know if they are coming out with a new model or are they removing this product line altogether?
I would like to hear any one have any process that could take care of such problem.