PCB Incoming Inspection: Check the Right Evidence

Incoming inspection should establish whether the delivery matches the agreed order and preserve useful evidence when something appears wrong. Begin with identification and the approved requirements. A visual impression alone cannot prove that every electrical or internal construction requirement has been met.

Confirm what arrived

Record the order reference, package labels, quantities and board or assembly identifiers. Compare the visible revision with the approved release. For multiple variants, keep them separate and use distinguishing component or label features from the variant matrix. Photograph damaged packaging before discarding it.

Decide the inspection scope from your quality plan and the product's needs. This article does not prescribe a universal sample size or acceptance standard. If the order specifies a particular inspection method or report, use that requirement rather than inventing a replacement after delivery.

Check critical physical interfaces

Measure the dimensions that affect fit using suitable equipment and the measurement method agreed in the drawing. Include critical holes, board thickness, connector position or cutout geometry as appropriate. Record measured values, units, locations and instrument details when they matter to the conclusion.

For example, if a board does not fit its enclosure, compare the board and enclosure measurements with their respective drawings. “Does not fit” identifies a symptom; the measurements help determine which interface is responsible. Avoid modifying the sample before the original condition is documented.

Keep visual and functional checks distinct

Inspect visible features such as missing components, obvious damage, polarity marks and labeling against the approved assembly view. Perform functional checks only using the authorized procedure and setup. A successful power-on does not demonstrate every manufacturing requirement, and a bare-board electrical test does not replace a product functional test.

• Save an overview photo and a close-up with the affected location marked.
• Identify the board, reference designator or feature in question.
• Record how many units were checked and how many showed the symptom.
• State the expected result and its drawing or procedure reference.
• Preserve the original files, labels and test records.

Send a focused quality report

Provide the order number, revision, evidence and a concise description of the issue through DIYIPCB support. Explain whether production use has been paused and whether the issue affects all inspected units or a subset. Ask for review before carrying out destructive analysis or unapproved repairs that could remove the evidence needed to resolve the problem.