TECHNICAL GUIDES
BGA Soldering & X-Ray Verification Guide
BGA Soldering & X-Ray Verification Guide
From 0.3mm Pitch Placement to Void-Controlled Joints
BGA joints are hidden under the package — you cannot see them, solder them by eye, or inspect them visually. That is why a BGA build lives or dies by process discipline: a controlled stencil, a profiled reflow, and an X-Ray verdict on every board.
Stencil Design
The stencil decides how much solder paste reaches each ball site — too little means dry joints, too much means bridging. For 0.3mm pitch, aperture ratio and thickness are the two levers that matter.
Placement Accuracy
At 0.3mm pitch, ball centers are only 300µm apart — the pick-and-place machine must land each ball well inside its pad zone. Misalignment under 50% of the pad pitch is the practical ceiling before self-centering during reflow can no longer rescue the joint.
Reflow Profiling
The profile must fully melt the paste, let volatiles escape before peak, and stay above liquidus long enough for self-centering — without cooking the package. A typical lead-free SAC305 window: soak 150–200°C, peak 240–250°C, above 217°C for roughly 40–70 seconds.
X-Ray Inspection
X-Ray is the only way to see hidden BGA joints: it reveals voids, bridges, and ball collapse without touching the board. Voids are graded by area ratio to the ball — and the widely used benchmark comes from IPC-7095 guidance.
Acceptance Criteria
Every BGA lot is signed off against the same checklist — ball diameter consistency, void percentage, no bridges, and full wetting confirmed on both rows and the package corners.
We run 0.3mm pitch BGA with 0.08–0.1mm laser-cut stencils, zone-profiled nitrogen reflow, and 100% X-Ray on BGA/QFN against IPC-7095 void limits — with the full image log archived per board. Send us your package data and a free DFM review will confirm your stencil and profile before the first board.
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