If you are talking about Nvidia's flip chip problems. Those were actually caused by the glue holding the chip onto the substrate, not the solder. The glue expan

If you are talking about Nvidia's flip chip problems. Those were actually caused by the glue holding the chip onto the substrate, not the solder. The glue expanded at a different rate from the solder balls and caused them to crack. This was especially the case on consoles. People kept reballing and doing other useless repairs that solved the problem by accident by melting the solder balls between the substrate and the silicon chip. Some even managed to remelt the solder balls simply by replacing capacitors, which then made everyone think the capacitors were the problem and everyone swallowed it because replacement capacitors were cheap.