Today in China, Azitech produces a 24 layer board with a solder mask dam of 80 µm and we can support even smaller solder mask dams. In general you always need to ensure the best soldering yield on your BGAs. For µBGA’s where the pitches equal to or is smaller than 0.5 mm, you need to pay extra attention to your PCB factory selection. Normally, on such circuits you must demask the solder mask in the whole BGA area, as 98% of the PCB factories in China have a minimum solder mask dam of 0.125 mm. This is however too large a solder mask dam for such a circuit, which is why they are often removed, with the result of facing yield issues. Through our production network we can supply PCBs with special technologies from our niche factories and therefore the solution was that we produced with 80 µm solder string, which prevents the solder of the BGA’s legs from floating together.