Quality & acceptance
PCBA Traceability: Serial Numbers, Lots & Test Records
PCBA traceability connects an assembly to its build configuration, relevant material lots and manufacturing/test history. A barcode is only an identifier. It becomes useful when the linked records can answer which units are affected by a defect or a change.
The practical decision
Agree the depth of traceability before ordering: lot-level, unit-level and component genealogy are different requirements. Define what will be captured, how it is linked, how long it is retained and how an authorized request retrieves it.
- IdentifyOrder + lot + unit
- LinkMaterials + build revision
- RecordTests + rework + release
- RetrieveAffected population + evidence
Choose the traceability depth your product needs
Avoid requesting “full traceability” without defining the records. A practical specification starts from a containment question: if a particular component lot or process issue is identified, how precisely must affected assemblies be located? More detailed genealogy requires capture at the right point in production, not reconstruction from a shipping list later.
| Scope | What it can answer | What to agree |
|---|---|---|
| Order / build lot | Which assemblies were built under one order and revision? | Lot split/merge rules and shipment linkage |
| Unit serial number | What happened to this specific assembly? | Marking location, uniqueness, readability and record key |
| Material genealogy | Which material/component lots could be in each unit or lot? | Coverage, capture method and reel/splice handling |
| Process history | Which controlled operations affected the build? | Required process identifiers and exception recording |
| Test history | What was measured, with which program and limits? | Raw/pass-fail data, program revision and retests |
| Service / rework | Has the configuration changed after first completion? | Rework event linkage and final configuration |
A usable record relationship
Illustrative identifiers: assembly SN-DEMO-001 links to build lot BUILD-DEMO-A, BOM revision C and firmware revision 1.2. The build lot links to the bare-board lot and the component lots covered by the agreement. Test event TEST-DEMO-07 links to the serial number, test-program revision, timestamp and results. These are template identifiers, not actual customer or 吃瓜tv production records.
| Record | Key | Relationship |
|---|---|---|
| Assembly | Unique serial or agreed lot ID | References the released configuration |
| Material issue | Component/bare-board lot and quantity | References the build or unit population |
| Test event | Unique event ID | References unit, procedure and result |
| Rework event | Authorized action ID | Retains before/after configuration and retest |
| Shipment | Packing/shipment reference | Lists the released units or lot quantities |
Plan for split lots, rework and unreadable labels
Define how to handle a reel change, mixed material lots, panel separation, replacement labels and a board that returns for repair. Preserve the original identity and event sequence. Where records cannot identify a narrower affected set, containment may need to include a broader lot. Do not imply precise unit-level genealogy when only batch-level data was collected.
Use the engineering change workflow when a repair or revision changes the final configuration.
Make retrieval and retention part of the order
Agree the record retention period, allowed recipients, export format, response process and treatment of sensitive design or personal data. Request an example of the proposed report with confidential details removed. Test a sample retrieval before relying on the system for a critical production order. IPC-1782 provides a risk-based traceability framework; specify the applicable requirements and agreed edition rather than assuming every order uses the same depth.
Include the selected records in the order acceptance checklist before production starts.
Working document
Prepare your handoff checklist
Open the editable text worksheet, save a copy and record the requirement, owner and evidence for each item. Keep unanswered points visible when requesting review.
- Containment question and required traceability depth
- Serial/lot format and marking location
- Material genealogy coverage and split-lot rules
- Controlled hardware/BOM/firmware revisions
- Test data, limits and program revisions
- Rework and replacement-label handling
- Retention, authorized access and export format
- Example retrieval demonstration and agreed exceptions
The Contact page is a separate enquiry step. Attach your completed worksheet and relevant files there using its available submission options; this page does not automatically transfer your answers.
Questions before you release the files
Is a date code the same as a unique lot number?
Not necessarily. Manufacturers use different coding schemes. Record the actual identifiers and their meaning rather than assuming every date code identifies one unique manufacturing lot.
Does serializing every board guarantee component genealogy?
No. Unit identification and material-to-unit linkage are separate. The required relationships must be captured during the relevant material and production operations.
Should all customers request identical retention periods?
No. Agree a period that matches the product, contract and applicable requirements. This page does not prescribe a universal period or claim a current 吃瓜tv retention policy.
Continue with the next engineering task
Technical references
Public contents identify risk assessment, user agreement and traceability levels. Consult the applicable licensed standard for full requirements.
