PCBA Engineering Change Notice (ECN) Template
Every change to a PCB assembly, from a swapped passive to a new stackup, needs a record that shows what changed, why, who approved it and what happens to stock. This ECN template covers the fields that cause problems when they are skipped.
Fill in
PCBA Engineering Change Notice Template
Engineering Change Notice ECN-2026-0142
Company: Lakeshore Electronics Assembly Date raised: 2026-10-20 Assembly: PCBA-20418 Revision: C to D Change type: Obsolescence replacement Priority: Urgent
Reason for change
Manufacturer issued end of life notice for the 0.5 A buck regulator at U7. Last time buy window closes 2026-12-31.
Description of change
Replace U7 with the pin compatible alternate from the AVL. No change to footprint. Output inductor L3 value unchanged. Update BOM, pick and place data and assembly drawing note 5.
Impact assessment
Fit and function unchanged per datasheet comparison. Reflow profile unaffected (same MSL 3 rating). Requires a first article inspection and in-circuit test program regression. Customer notification required.
Documents affected
| Document | Affected | Revision | Owner |
|---|---|---|---|
| Bill of materials | |||
| Gerber / fabrication data | |||
| Assembly drawing | |||
| Pick and place / centroid file | |||
| Stencil design | |||
| Test program / fixtures | |||
| Work instructions | |||
| Approved vendor list |
Inventory and effectivity
Inventory disposition: Use up existing stock Effectivity: Work orders released after 2026-11-02, or serial number 40500 and above
Approvals
This template is a general starting point. Match it to your configuration management procedure and any customer change control clauses, which may require advance notice or approval for form, fit or function changes. Not legal advice.
Connect ECNs to your ERP BOM
Optional: discuss pulling BOM and revision data into change documents.
Optional. The tool and every export work without this. No spam.
How to fill it in
Start with the assembly number and the revision change, then pick the change type and priority. State the reason in plain terms, such as obsolescence, a yield issue or a customer request. Describe exactly which reference designators and files change. The impact section is where you decide whether a first article, new test program or customer notice is required. Finish with the inventory disposition and effectivity, because that is where manufacturing most often gets surprised.
- List reference designators, old part number and new part number.
- State whether the change affects form, fit or function.
- Define effectivity by date, work order or serial number.
- Decide what happens to WIP and stock before approval.
Why the documents table matters
A PCB assembly is defined by more than the BOM. The pick and place file, stencil, test program, work instruction and approved vendor list all need to move together. If one is missed, the line builds boards that match the old drawing or fail a test that has not been updated. The affected documents table forces the originator to check each one and name an owner, which is the cheapest control against partial implementation.
Worked example
A buck regulator goes end of life. The originator raises ECN-2026-0142 as an obsolescence replacement, selects an alternate from the AVL and notes that the package and reflow rating are unchanged. Process engineering confirms a first article is required, test engineering confirms a regression run on the in-circuit program, and purchasing sets the last time buy quantity. Existing stock is used up first, with the new revision effective on work orders released after the stated date.
Common mistakes
A frequent error is writing a vague description such as update BOM, which leaves production guessing. Another is missing customer approval clauses: many contracts require notice before changing a part on a controlled design, even for like for like alternates. Also avoid mixing multiple unrelated changes in one ECN; a single change per notice keeps approvals and rollback clean.
Frequently Asked Questions
What is the difference between ECN and ECO?
Practice varies by company. Many treat the engineering change order (ECO) as the request and approval record and the engineering change notice (ECN) as the notification that the change is released. Some use the terms interchangeably. Follow your own procedure and be consistent.
Do I need a new revision for a part alternate?
If the alternate is already approved on the AVL and the BOM allows it, many companies do not change the assembly revision. If the change affects form, fit or function, or the customer controls the BOM, a new revision and notice is normal.
Who should approve a PCBA ECN?
At least design, process and quality engineering, with purchasing for cost and supply impact. Add the customer when contract terms require it. Approval authority should be defined in your configuration management procedure.
How should existing inventory be handled?
Decide before release: use up, scrap, rework or return. For safety or reliability changes, stock usually must be quarantined. For cost or supply changes, using existing stock until it runs out is common and is controlled by effectivity.
If your BOMs and revisions live in an ERP or PLM, we can help generate and route change documents from the system of record instead of retyping them.
Related Tools
PCBA First Article Inspection Report Template
A fill-in first article report for a new PCB assembly job: setup verification, BOM and placement checks, solder inspection and sign-off.
Quality & InspectionPCBA RMA Failure Analysis Report Template
A structured report for returned boards: incoming condition, test results, root cause, containment and corrective action.
Quality & InspectionPCBA AOI Defect Log and DPMO Worksheet
An editable defect log that computes defects per million opportunities (DPMO) and defect rate for each lot or shift.
MES & Shop FloorSMT Line Changeover and Feeder Setup Worksheet
Plan the daily SMT schedule with changeover, feeder setup and run time per job so you can see true line utilization.
More Engineering & PLM tools
See all- Last Time Buy Quantity Calculator
- PCB Trace Width Calculator (IPC-2221)
- Electronics BOM Scrub Checklist
- Resistor Power Derating Calculator
- SAP Super BOM Design Worksheet
- SAP Engineering Change Number Checklist
- SAP Document Info Record Template
- SAP Change Master and Revision Level Log
- SAP Engineering Change Request (ECR) Template