BGA solder depletion looks like a paste problem until you profile the board and see the cold spots. This post breaks down reflow shadowing, what it does to BGAs, and the fixes that actually hold up on the line.
Most “insufficient solder joints” aren’t a reflow mystery. They’re a paste-volume problem plus a placement-contact problem, and you can prove it fast with SPI data and a few targeted checks.
Tombstoning looks like a placement problem, but it usually isn’t. This post breaks down the real failure physics, the telltale data signals, and the fixes that hold up on production lines.
Fix solder beading and balling fast: control paste volume, placement force, stencil apertures, reflow ramp/soak, moisture handling, and IPC acceptance checks.