a. Firstly, the production department, engineering department, and quality department need to confirm the accuracy of the information. Ensure that the information is accurate and there are correct samples available for reference, preferably provided by the customer as physical samples. For example, product drawings, process documents, Bill of Materials (BOM), PCBA related documents, technical documents for special process requirements, etc. If any differences are found, they should be promptly reported and confirmed with the customer< br/>
2. The key node of the first inspection of PCBA processing
a. The first piece in the order refers to the initial board and panel, which typically includes two panels: one for SMT modeling and one for functional and full-function testing.
b. At the start of a shift or when production resumes, the first panel produced should be inspected to assess the shift’s quality and prevent errors from continuing unnoticed.
c. For ECN changes, such as replacing over 15 pieces, a new glue board must be attached for quality measurement. The first piece test can be performed concurrently with production to maintain efficiency.
d. For process changes like program re-optimization, station modifications, or replacing over five feeders, re-pasting of the cardboard is necessary for quality measurement. The first piece test can be conducted simultaneously with production without affecting efficiency.
3. Matters needing attention in the first inspection of PCBA processing
a. Implement protective measures such as electrostatic protection, and ensure all information is accurate.
b. Verify that the position, polarity, angle, etc., of mounted components meet the technical document requirements.
c. Confirm that incoming components are of qualified quality, including aspects like color, size, and polarity.
d. Check that the soldering quality of components meets customer or related technical document standards.
e. The inspector should mark the passed first piece as per regulations and retain it until the batch is complete.
f. The first article inspection must be timely to avoid reducing production efficiency.
g. If the first piece fails inspection, no further processing or operation should proceed.
4. The first inspection mechanism of PCBA processing is interlocking
a. Self-inspection: Engineers perform a self-inspection on the first product they produce, focusing on component orientation and placement effects.
b. Mutual inspection: After the engineer’s inspection, the operator performs a mutual inspection, focusing on BOM and drawings to check for material shortages, and promptly notifies the production engineer of any issues.
c. Full inspection: After passing initial checks, the product undergoes a full inspection by quality inspectors using multimeters or ECR bridges. For large-scale factories, bridges are preferred. This includes component measurement, orientation checks, and X-ray inspection for BGA devices to verify soldering quality. The product is evaluated against the customer’s BOM and requirements to ensure it meets production standards. The PCBA samples passing these inspections are retained until the end of batch production.
d. The basis of the three-inspection system is the first piece, compared against the sample and guidance documents agreed upon by the factory and customer. Document accuracy and sample correctness are prioritized, with documents taking precedence if available. This principle ensures quality and reduces the risk of errors impacting both the foundry and the customer.
Summary:
The long-term practical experience in PCBA processing shows that the first inspection system is crucial for early problem detection and prevention of batch scrap. It helps identify systemic issues such as fixture wear, installation errors, instrument accuracy, and misreading of drawings, allowing for corrective measures. The ultimate goal is to discover factors affecting product quality early and prevent the production of unqualified products or scrapped batches.
1. Data requirements for first article inspection of PCBA processing