Manufacturing, DFM & DFT — question 2 of 10
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You've just gotten reflow-soldered prototype boards back from assembly, and you notice a handful of 0402 resistors are standing up on one end with the other pad unsoldered -- a defect called tombstoning -- instead of lying flat and soldered on both pads. Walk me through why this happens during reflow and what you'd change in the footprint or process to prevent it on the next spin.