Before shipment, automotive FPCs require verification beyond appearance and electrical performance — including version and batch identity, critical dimensions, connector ends, stiffeners, test reports, and packaging labels. This article outlines the OQC release logic.
After production completion, an automotive FPC that appears normal and passes continuity testing does not automatically qualify for shipment. The OQC outgoing inspection task is to confirm that product identity, critical quality results, test reports, packaging, and traceability information all align with the customer’s purchase order and approved status.
If an automotive flexible circuit board manufacturer only performs final visual sampling, it cannot compensate for errors in drawing revision, material batch, or incorrect application of inspection procedures. Effective outgoing release relies on complete records from incoming materials, in-process controls, and finished goods.
I. First, verify product, order, and revision
OQC must confirm customer name, part number, drawing revision, engineering change notice (ECN), order quantity, production batch number, and label information. If multiple revisions or material solutions exist for the same part number, they must be clearly distinguished by batch number and packaging.
Products with unclear revision status must not be released solely because dimensions and continuity meet specifications. Outgoing inspection must first prove: 'This is the customer-approved revision.'
II. Visual inspection must align with usage risk
Common visual items include scratches, creases, contamination, oxidation, coverlay lifting, stiffener misalignment, pad condition, burrs, and packaging-induced damage. Dynamic bending zones, connector ends, and soldering areas require focused attention.
Visual acceptance must reference approved standards and limit samples — subjective judgment by inspectors alone is insufficient. Lighting conditions, magnification level, and sampling methodology must also be standardized.
III. Electrical testing cannot substitute for other inspections
Final electrical testing detects opens, shorts, and insulation failures but cannot verify end thickness, stiffener placement, outline tolerances, flex-life performance, or assembly fit.
Automotive projects typically require full electrical testing combined with critical dimensional checks, visual inspection, assembly verification, and targeted reliability sampling. Each inspection type addresses distinct risks; '100% electrical testing' does not represent comprehensive quality assurance.
IV. Critical dimensions must be measured relative to assembly datums
Beyond overall length, width, and hole locations, inspection should include connector-end thickness, contact point position, coverlay window, stiffener edge, mounting holes, and key outline features. Measurement methods and datums must match those specified in the drawing.
Flexible products easily deform in free state; arbitrary stretching or flattening prior to measurement is unacceptable. Where necessary, validated gauges must be used to replicate actual assembly datums.
V. Batch-level reports must match physical units and orders
Customer-required reports — including dimensional data, electrical records, material certifications, reliability test results, and outgoing inspection reports — must specify part number, revision, batch number, quantity, and date. Samples cited in reports must originate from the current release batch or a customer-approved representative batch.
Generic certificates or historical reports cannot substitute for current-batch inspection records. When sampling is applied, the sampling standard, sample size, and acceptance criteria must be explicitly documented.
VI. Packaging and labeling are integral to quality
FPCs are vulnerable during transit to bending, compression, ESD, moisture, and contamination. Packaging must provide structural support and isolation based on product geometry, stiffener configuration, and connector presence — preventing stacking-induced creasing.
Labels must include customer-specified part number, revision, quantity, batch number, date, and required traceability fields. Packing lists, labels, reports, and physical quantities must be fully consistent.
VII. Abnormalities must not be cleared via sorting alone
When abnormalities are found during outgoing inspection, the affected batch must be isolated and impact assessed. Sorting, rework, or concession release require controlled procedures, re-inspection results, and formal approval documentation.
If the abnormality relates to materials, process, or revision, traceability must extend to other batches and in-process inventory — not limited to the sampled units.
Automotive FPC Outgoing Inspection Checklist
Customer, part number, revision, purchase order, and engineering change notice;
Visual condition, pads, coverlay, stiffeners, and edge integrity;
Full electrical test results and critical dimensional inspection data;
Connector end, mounting holes, and assembly datums;
Material certifications, dimensional reports, reliability results, and outgoing inspection report;
Labels, packaging, quantity, and batch traceability information.
For incoming material control guidance, refer toIncoming Inspection for Automotive Flexible Circuit Boards; for production batch management, seeBatch Consistency Control for Automotive FPCs.
Hongyi Precision implements process management per IATF 16949, ISO 9001, and ISO 14001, supporting automotive electronics programs with FPC and FPCA engineering review, prototype validation, and volume production. Specific OQC items, sampling plans, and release criteria follow customer specifications and mutually agreed quality agreements.
Summary:OQC is not merely a final glance at the product — it is formal confirmation that the current batch conforms to approved status across identity, physical attributes, data integrity, and packaging, and that any issue can be traced and isolated.