Two suppliers can quote the same printed circuit board assembly and plan different inspections. One may use automated optical inspection for visible components. The other may also include X-ray inspection of selected hidden joints and a functional test against your specification. If the quote says only “built to IPC,” those differences can stay hidden until the first delivery.
Before you issue a PCBA RFQ, specify the applicable standards, revisions, and product class. Then agree on inspection and test coverage, the records you will receive, and who can authorize release or approve a deviation.
At XWONDER, we recommend reviewing those items against the actual assembly drawing, bill of materials, and test specification. The same requirements can then guide quotation, first-article review, and batch acceptance. For the broader manufacturing process, see our PCB and PCBA manufacturing guide.
Which PCBA Quality Standards Apply to Your Assembly?
Assembly acceptance, soldering, and bare-board requirements
Start by identifying what each document governs. The bare PCB, the soldered assembly, and the finished board’s electrical behavior have separate requirements. Each needs a clear source in the build package.
| Reference | What it covers | What the buyer should specify |
|---|---|---|
| IPC-A-610 | Acceptability criteria for completed electronic assemblies. | The agreed revision, class, and applicable addendum or supplemental criteria. |
| IPC J-STD-001 | Requirements for producing soldered electrical and electronic assemblies, including materials, methods, and applicable acceptance requirements. | The agreed revision, class, applicable addendum, and any project-specific process requirements. |
| IPC-A-600 and applicable IPC-601x specification | Bare printed board acceptability and performance requirements. IPC-6012 applies to rigid printed boards. | The applicable bare-board documents and evidence expected from fabrication. |
| OEM drawing and test specification | Project-specific features, test limits, and acceptance requirements. | Controlled revisions, required records, and how conflicting requirements will be resolved. |
Quality system certificates describe a site and scope. Check the certificate against the manufacturing location and work being quoted. For the assembly itself, review the agreed workmanship criteria and the inspection and test records. Consult the official IPC standards revision table to confirm document titles and published revisions.
How Should OEMs Specify the IPC Class and Revision?
Product risk and controlled documents
IPC uses three product classes. Class 1 covers general electronic products. Class 2 covers dedicated service products where continued performance and extended life are expected. Class 3 covers high-performance or harsh-environment products where performance on demand is critical or downtime cannot be tolerated. Ask the design authority to confirm the class against intended use, failure consequences, and customer requirements. Avoid assigning a class from an industry label alone.
Record the agreed revision and any applicable addendum in the RFQ and purchase documentation. Identify the drawing, BOM, and test specification by revision. If the drawing calls for one condition and the referenced IPC document appears to call for another, check the contract’s document precedence and request written clarification before work proceeds.
If a supplier proposes a change, record the affected requirement and scope. A one-time concession for a defined lot and a permanent drawing revision call for different approvals.
What Can AOI, X-Ray, ICT, and Functional Testing Verify?
Inspection coverage and test limits
Ask what each method checks on your board, which units it covers, and what record it produces. For example, a temperature controller may need inspection of a hidden solder joint and a functional check of its response to a simulated sensor input. Specify each check separately in the test plan.
| Method | Typical coverage | Evidence to request when specified |
|---|---|---|
| Automated optical inspection (AOI) | Visible placement, polarity, and selected visible solder features within the programmed coverage. | Inspection summary, board or lot identifier, and disposition of flagged defects. |
| X-ray inspection | Selected concealed solder features under packages such as BGAs or QFNs, subject to image quality and the agreed method. | Target locations, sample or unit IDs, applicable criteria, and review results. |
| In-circuit testing (ICT) | Specified circuit checks, such as shorts, opens, or selected component values, where the fixture and test access permit. | Coverage statement, program revision, and results linked to the tested units or lot. |
| Functional circuit testing (FCT) | Specified input and output behavior under defined conditions with the agreed firmware and setup. | Test specification and firmware revisions, measured results or pass/fail data as agreed, and unit or lot IDs. |
Agree on inspection and test coverage before pricing the build. Document whether a check is first-article only, sampled by lot, or performed on every unit. Record how failed units are identified, segregated, and retested after authorized rework. See our comparison of PCBA inspection and test methods for more on coverage.
What Should Buyers Put in a PCBA Quality RFQ?
Acceptance matrix and supplier exceptions
Send a controlled build package with the RFQ. Include the assembly drawing, BOM, placement data, and test specification as applicable. If the supplier also provides the bare board, include the fabrication package. Ask the supplier to confirm the versions reviewed and return any exceptions in writing.
Use one row per requirement. This example uses a hypothetical industrial temperature controller. Replace each example entry with your project’s approved documents, criteria, and inspection scope.
| Requirement and source | Criterion and verification | Scope and delivery record | Responsible reviewer |
|---|---|---|---|
| Visible assembly features Assembly drawing and referenced IPC documents | Apply the criteria in the agreed revisions and class. Inspect designated features with AOI or another approved method. | Record the inspection scope and provide the agreed inspection summary and defect disposition. | Supplier quality records results. OEM quality reviews exceptions under the quality agreement. |
| Selected hidden solder joints Assembly drawing and inspection plan | Apply the drawing’s acceptance criterion at the listed locations using the agreed X-ray method. | Record whether coverage is first-article, sampled, or per unit. Link reviewed images or results to sample IDs and lot. | Supplier inspection reviews the images. The designated approver dispositions any deviation. |
| Sensor input and controller output Functional test specification and firmware release | Apply the specified simulated input. Compare the output response with the approved limits. | Record the agreed test frequency, program and firmware revisions, result, and lot or serial identifier. | Supplier test team runs the test. OEM engineering confirms changes to test limits. |
Ask bidders to identify excluded tests, fixture or programming charges, records available at shipment, and open decisions. Use the same matrix for each bidder so differences in quality scope are visible in the comparison. See our guide to comparing PCB assembly suppliers.
Preparing a PCBA RFQ? Share your drawing revision, applicable standards, and expected test coverage so we can review the requirements with you.
Discuss Your PCBA Quality Requirements
What Evidence Should OEMs Review Before Releasing a Batch?
First-article records, lot traceability, and deviation approval
When a first-article review is part of the agreement, use it to confirm how the supplier applied the approved build package and recorded the results. For shipment release, review the records required for the actual lot. Where sampling applies, verify that the identified samples belong to that lot and match the agreed plan.
- Confirm the build identity. Match the assembly part number, drawing revision, and lot or serial identifiers to the shipment and purchase documentation.
- Check inspection and test evidence. Match the report references, coverage, and results to the acceptance matrix. Check firmware or test program revision where it affects the result.
- Resolve open exceptions. Review the affected units, rework or retest evidence, and any approved concession. Confirm that the authorized person approved the disposition before release.
Example. The X-ray report for the controller batch cites the previous assembly drawing revision. Hold the release decision while the supplier verifies which revision governed the build and inspection. If the report contains a reference error, request a controlled correction supported by the inspection records. If the work used the previous requirement, determine whether reinspection or formal deviation approval is needed.
Agree up front on whether the supplier must link each result to a lot, a sample, or a specific serial number. See our guide to PCBA traceability from component batch to finished assembly for ways to maintain that link.
Which XWONDER PCBA Examples Can You Explore?
These assemblies illustrate different applications. Define workmanship, test coverage, and release evidence for your own board and its operating requirements.
Automotive OBD-II 4G GPS Telematics Control PCBA 
MTK Android 4G Smartwatch Mainboard 
ODM Temperature Control PCBA 
Industrial Control PC Main Board PCBA What Else Should OEM Buyers Clarify Before Ordering?
What is the difference between IPC-A-610 and J-STD-001?
IPC-A-610 gives acceptance criteria for completed electronic assemblies. J-STD-001 specifies requirements for producing soldered electrical and electronic assemblies. State the applicable scope, revision, and class for each document referenced by your project.
Should my PCBA be built to IPC Class 2 or Class 3?
Have the design authority review the operating environment, required performance, failure consequences, and customer terms. Document the agreed class before comparing quotes.
Which IPC revision should I put on a purchase order?
Use the revision and applicable addendum agreed for the build. When a new revision is published, review its impact and update the controlled purchase documents through the agreed change process.
Does passing AOI mean the PCBA passed functional testing?
AOI checks programmed visible assembly features. A functional test checks specified board behavior under defined conditions. Request the functional test result if the project requires one.
What quality records should I request with each PCBA shipment?
Start with the shipment identifier, assembly revision, and the inspection or test records named in the quality agreement. Add serial-level data, sample-level records, or approved deviation documents where your project requires them.
What if the assembly drawing conflicts with an IPC requirement?
Review the contract’s order of precedence, identify the affected feature and documents, and obtain a written decision from the authorized parties before accepting the affected work.
