How to Manage Manufacturing Deviations.

Identify • Contain • Assess • Authorise • Verify

Control the change before the change controls the product.

1. Baseline (Released) — Released PCB Baseline — Approved design, BOM, process requirements and drawings.
2. No Silent Changes — Proposed / Actual Departure — Change to design, process, material or specification.
3. Manufacturing Deviation — A controlled departure from a product, process or procurement requirement for a defined scope.

Why Formal Control Matters

#	Heading	Caption
1	Protects configuration baseline	Maintains a trusted reference for what was approved.
2	Prevents unapproved CAM, material or process changes	Ensures changes follow the right path and approvals.
3	Assesses risk before shipment	Quality, reliability, schedule and cost impacts understood before decisions.
4	Preserves what was actually built	Accurate records enable traceability and learning.
5	Prevents temporary exceptions becoming permanent	Time-box, review and re-validate or revert to baseline.
6	Supports audits, investigations and corrective action	Evidence-based decisions that drive improvement.

Terminology at a Glance

Term	Definition
Deviation	Authorised departure from a requirement for a defined scope.
NCR	Requirement not fulfilled.
Concession	Authorised use of nonconforming product.
Rework	Returns product to full conformity to all original requirements.
Repair	Makes product usable but may not restore original conformity.
Use-AS-is	Accepts known condition with defined impact and controls.
Scrap	Prevents unintended use of nonconforming product.
Engineering change	Formally revises the baseline (released data, documents).

Three Situations

#	Situation	Statement	Bullets	Rule
1	Normal process adjustment	Small, routine adjustments within approved limits.	Within process window; No impact on fit, form, function; Managed by standard work/instructions	Document and monitor.
2	Supplier-proposed DFM change	Change to released data or process to improve manufacturability.	Must be proposed and documented; Requires formal evaluation; Approval before implementation	Do not implement without approval.
3	Actual nonconformance	Product already fails a requirement.	Stop, contain and evaluate; Record facts and impact; Disposition with authorisation	Control and close the loop.

No deviation is implemented merely because the supplier believes it is harmless.

Contain, Define and Assess.

Stop Work • Identify Scope • Collect Evidence • Review Risk

1. Identify — deviation/ proposed change
2. Stop — affected work
3. Contain — boards, panels, lots
4. Cite — exact requirement
5. Quantify — actual condition
6. Collect — objective evidence
7. Assess — technical and quality risk
8. Identify — approval authority
9. Select — disposition
10. Obtain — written approval
11. Implement — exactly
12. Inspect / Test
13. Update — CoC / NCR / traveler
14. Close — corrective action and trend

• Stop shipment. Do not release or ship any affected product.
• Segregate physical product. Clearly label and segregate all affected boards, panels, and lots.
• Identify work orders / lots. Record WO, lot number, quantity, location, process step, and operator.
• Assess earlier shipments. Identify customer shipments and quantities already delivered.
• Freeze processing. Hold at current step; do not continue processing or rework.
• Preserve coupons / data. Retain panels, coupons, photos, and process data for analysis.
• Notify engineering / quality. Escalate immediately per procedure.
• Block ERP / MES release. Place holds to prevent movement or further processing.
• Record time / person. Document when, by whom, and what was contained.

• Drawing & revision. Refer to the latest released drawing and revision.
• Fabrication note. Applicable fabrication note and revision.
• Manufacturing dataset revision. CAM, drill, etch, route files and revision level.
• Stack-up. Layer build-up, material and thickness requirements.
• PO clause. Purchase order clause or special requirements.
• IPC standard / revision / class / paragraph. Exact IPC requirement and section.
• Customer quality specification. Customer specification and revision.
• Approved DFM & supplier qualification condition. DFM guidelines and supplier qualification status at time of order.

• Specified vs measured value. Exact requirement compared to actual measurement.
• Affected quantity. How many boards/panels/lots are affected.
• Lot / work order / date code. Traceability identifiers.
• Layer / feature / location. Where on the board and in which layer/feature.
• Photos / micrographs. High-resolution, scaled, and documented.
• Microsection. Cross-section with measurements and callouts.
• Et / impedance / material / process records. Test data and process parameters.
• Isolated or systemic. Single event or recurring pattern.

Risk Assessment (Consider All Impacts

Segment	Caption
Electrical	Function, impedance, isolation, crosstalk
Thermal	Heat dissipation, Tg, CTE mismatch
Material	Laminate, copper, resin, finish
Compliance	Regulatory, safety, environmental
Mechanical	Strength, stress, vibration, handling
Reliability	Life, failure modes, field performance
Manufacturing margin	Process capability, variation sensitivity
Configuration	Design intent, fit, form, function
Traceability	Data integrity, end-to-end trace
Programme / qualification	Customer programme, qualification status

“The board still works” is not a high-reliability risk assessment.

Contain first, debate second. Facts before opinions. Document before decisions.

Choose the Correct Disposition.

Rework • Repair • Use-AS-Is • Scrap • Remake

1. Can Full Conformity Be Restored? — Yes → controlled rework / no → next question
2. Controlled Rework — Return to original requirement.
3. Can Known Condition Be Justified by Authorised Design/quality? — Yes → repair or use-AS-is / no → scrap / remake
4. Repair or Use-AS-Is — Under approval.
5. Scrap / Remake — Product cannot be justified or corrected.

Disposition	Definition	Conditions
Rework	Returns to original requirement.	Approved instruction or process.; Extra exposure or intervention assessed for side effects.; Reinspect/retest 100% as required by plan.; Traceability and acceptance recorded.
Repair	Makes product usable but not necessarily fully conforming.	Approved repair method.; Evaluated for reliability impact.; Customer or design authority where required.; Post-repair evidence and disclosure.
Use-AS-is / concession	Requirement remains unmet.	Exact condition and rationale documented.; Limited to specific lot/quantity.; Usage restrictions and limitations defined.; Authorised approval obtained.; Referenced in shipment records.; Does not change future drawing automatically.
Scrap / remake	When risk cannot be justified or conformity restored.	Physically control scrap to prevent unintended use.; Preserve analysis samples as required.; Correct process before remake.

Approval Authority Matrix – Who Can Authorise?

Situation	Examples	Typical Authority
Process setting within approved window	Laminate cycle time, drill speed, plating current within limits	Supplier manufacturing / quality
Noncritical DFM feature	Nonfunctional copper balancing, fiducial count, tooling marks	PCB / design engineering
Impedance / geometry feature	Trace width/spacing within impedance tolerance, length match	PCB + si / design authority
Material substitution	Laminate, prepreg, copper foil substitution	Materials / PCB engineering + customer quality (AS required)
IPC acceptance departure, repair or use-AS-is	IPC-6012 / 6013 acceptance, use-as-is concession	Authorised mrb / design / customer authority
Site / source change	New supplier, alternate site, new equipment line	Supply chain + quality + engineering / requalification

Disposition = what happens to this product. ≠ corrective action = why it happened and how recurrence is prevented.

Schedule pressure never justifies an unsafe disposition.

Assess PCB-Specific Deviations.

Stack-up • Material • Impedance • Vias • Finish

Every deviation must be reviewed, measured, and approved.

#	Card	Checklist items	Diagram labels
1	Stack-up change	Core / prepreg thickness; Board thickness (finished); Glass style / material family; Dk / Df at frequency; Impedance recalculation; Resin fill content; Aspect ratio (lamination); Dielectric spacing; Sequential lamination impact; Approved revision level	Top, L1, pp, L2, core, L3, pp, L4, bottom; Core thickness; Pp thickness; Board thickness
2	Material substitution	Exact manufacturer / grade; Tg (dsc) / Td; Z-axis CTE; Dk / Df at frequency; Moisture absorption; CAF resistance; UL recognition; Reflow compatibility; Matching prepregs / cores; Prior qualification data; Impact on signal loss
3	Controlled impedance	Required value / tolerance; Original geometry (W/H); Proposed geometry (W/H); Actual dielectric (Er); Model used & assumptions; Coupon correlation data; Production measurement; SI / crosstalk review; Design approval before copper change	W; H; Er
4	Hole / via	Finished hole vs production drill; Aspect ratio (depth / dia.); Plating allowance; Annular ring (min / target); Press-fit / interference; Backdrill (depth / method); Current / thermal rating; Microsection verification; Assembly fit (connectors, pins); Impact to IPC Class 3 product	Ø finished hole; Drill diameter
5	Annular ring / registration	Layer / feature location; Remaining land / breakout; Acceptance criteria (min / target); Drill-to-copper and layer trend; Isolated vs systemic issue; Plating connection integrity; Process capability / margin	Annular ring; Registration offset
6	Copper thickness / plating	Base copper (weight / thickness); Finished copper PTH (min / target); Finished copper surface (min / target); Local vs average thickness; HAR distribution & uniformity; Current capacity & reliability impact; Representative microsection; Plating bath control records	Base copper (foil); Finished copper (after plating)
7	Microvias	Diameter / depth (target / capture); Stacked vs staggered; Target / capture geometry; Via fill (filled / capped / tented); Interface plating integrity; Lamination cycle compatibility; Microsection verification; Thermal / reliability evidence; Qualified HDI process scope	Stacked; Staggered
8	Surface finish / mask / dimensions / backdrill	Finish type / thickness and functional interface; Mask registration / web / creepage; Board thickness / profile / slots / bow; Target layer for backdrill; Residual stub (min / target); Backdrill depth tolerance; Registration checks; SI verification after backdrill	Finish; Mask; Dimensions; Backdrill

1. Marked Drawing
2. Measurements
3. Microsection
4. Et / Impedance
5. Material Data — Dk / Df; Tg / Td
6. Process Capability — Cp; Cpk
7. Reliability Results
8. Risk Assessment

“Equivalent” material or “standard factory change” is not technical approval.

Control the Record and Prevent Recurrence.

Approval • Configuration • COC • Corrective Action • Trending

Explicit Approval Record

Item	Detail
Deviation ID	Unique identifier for traceability.
Part / revision	Exact part number and revision.
PO / lot / quantity	Purchase order, lot number and quantity impacted.
Exact requirement	Cited drawing, specification or standard.
Actual condition	Observed condition and measured results.
Supporting evidence	Photos, reports, measurements, test data.
Disposition	Use as-is, rework, sort, scrap or other.
Limitations / conditions	How and where the product may be used.
One-time or permanent	Indicate one-time concession or permanent change.
Required inspection / test	Additional inspection, testing or 100% screen as required.
Approver name / function / date	Qualified approver with role and date.
Document changes	All document or record updates required.

Temporary Deviation vs Permanent Engineering Change

Temporary Deviation	Permanent Engineering Change
Defined lot, quantity and time scope.	Changes the product definition.
Requirement remains unchanged.	New revision baseline established.
Future lots must revert to requirement.	Future lots follow ECN / ECO.
Exception record with explicit approval.	Controlled design update.

VS

Configuration Control Flow

1. Released Baseline — (Requirement)
2. Approved Lot-Specific Departure — (Concession)
3. AS-Built Record / CoC — (Disposition, Evidence, Limits, Tests)
4. One Time Only — Future lots revert to baseline requirement.

1. Released Baseline — (Requirement)
2. ECN / ECO — (Change Control Process)
3. New Released Baseline — (New Revision)
4. Permanent Change — Future lots follow new revision.

• State exact part number, revision and lot.
• Include concession ID where required.
• Include statement consistent with disposition.
• Reference all applicable NCRs (retrievable).
• Confirm no carryover to future lots.
• Disclose repair or rework where required.

1. Contain
2. Define
3. Occurrence Root Cause
4. Escape Root Cause
5. Systemic Contributors
6. Action
7. Verify Effectiveness
8. Review Similar Products

Weak vs Strong Response

Response	Detail
Weak (symptom only)	Operator error / retrained. No objective evidence of effectiveness.
Strong (system solution)	System change prevents recurrence. Objective effectiveness evidence provided (data, metrics, audit).

Deviation Log Fields

Field	Description
Supplier	Supplier name and location.
Category	Plating, drilling, lamination, finish, etc.
Repeated part family	Part family / platform identified.
Unauthorised vs approved-before-build	Unauthorised deviation or approved concession before build.
Material substitutions	Material changes, supplier, grade.
Impedance / plating / registration	Technical performance categories.
Customer escapes	Escaped to customer (Yes/No, details).
Approval turnaround	Time from submission to approval.
Recurrence indicator	Repeat deviation (Yes/No, count).

Trend Dashboard (What to Watch

Metric	Unit	Direction arrow
Total deviations	(# per period)	down (green)
Repeat deviations	(% of total)	up (red)
Customer escapes	(# per period)	up (red)
Material substitutions	(% of total)	flat (amber)
Approval turnaround	(Avg days)	flat (amber)
Recurrence rate	(% within 90 days)	up (red)

Supplier-Status Impact Ladder

#	Status	Meaning
1	Monitor	Meets expectations. Continue standard oversight.
2	Capability-margin review	Minor issues or tight margins. Review capability and plans.
3	Corrective action / increased inspection	Issues identified. CAPA required. Increase oversight and inspection.
4	Restrict	Performance not acceptable. Restrict new business / volume.
5	Suspend / requalify	Severe or repeated issues. Suspend until requalified.

A one-lot concession must never become the supplier’s new standard process.

Control Every Departure Before Release.

Managed Workflow • Review Checklist • Red Flags • Final Control

1. Manufacturer — raises DFM/ deviation before implementation.
2. Novatronic — checks completeness and evidence.
3. Classify — process-only / DFM change / nonconformance / supplier change.
4. PCB Manufacturing Risk Review — assess impact to function, yield, reliability, cost and schedule.
5. Customer / Design Authority — receives focused decision package with facts and recommendation.
6. Approve / Reject — decision and conditions are documented.
7. Manufacturer — implements exact disposition as authorised.
8. Evidence Verified — before shipment or release.
9. Link to CoC and Lot — deviation linked to Certificate of Conformance and lot record.
10. Supplier History — add event to supplier history. Recurring events trigger CAR or qualification review.

• Deviation ID / Reference
• Supplier / Site
• Part Number / Revision Level
• Purchase Order / Lot / Quantity
• Exact Requirement (spec, drawing, IPC, contract)
• Actual Condition (quantified)
• Evidence Attached (photos, reports, data)
• Scope Contained (lot, panels, areas)
• Previous Shipments Assessed (same condition? impact?)
• Impact Assessment Completed
• Electrical
• Mechanical
• Reliability
• Material
• Compliance
• Configuration
• Qualification
• Proposed Disposition (rework, use-as-is, concession, scrap)
• Decision Authority (name / role / company)
• Customer / Design Authority Approval
• Controlled Rework / Repair Instructions (if any)
• Verification / Test Plan and Results
• Certificate of Conformance Updated
• Corrective Action Required (CAR / Preventive Action)
• Deviation Logged (system / log) and AVL / Scorecard Updated
• Retention Period Confirmed

No deviation is complete without documented approval, verification, linkage to the lot and retention.

• Already changed because “it is our factory standard.”
• “Equivalent” material used — no approval needed.
• Automatic impedance / trace adjustment without notification.
• Electrical test used to dismiss a plating / finish issue.
• “We will update the drawing after shipment.”
• Cosmetic claim without evidence or quantified impact.
• “Class 3 allows it” — requirement not verified.
• No lot / quantity identified or scope not defined.
• Blanket permanent approval after only one production run.
• Repeated concessions on the same requirement.
• NCR issued without root cause or corrective action.
• Certificate of Conformance that hides a known exception.

• Lot and quantity match the approved deviation.
• Required rework / test complete and recorded.
• Board markings / date code verified.
• CoC reference and deviation ID present.

• Affected characteristic inspected or tested per approval.
• No additional, unapproved departures.
• Deviation record archived with receiving record.

1. Identify Exactly — Define the exact requirement and the actual condition. No assumptions.
2. Contain Completely — Limit scope to what is affected. Stop spread. Protect the customer and the process.
3. Assess Objectively — Evaluate risk to function, yield, reliability, cost and delivery.
4. Authorise Correctly — Obtain the right authority. Document the decision and any conditions clearly.
5. Verify and Retain — Verify results. Link to CoC and lot. Retain records for the required period.

No silent changes — Every controlled departure is traceable to authority, lot and evidence.