Material Review Board (Mrb)
Material Review Board (MRB) is a cross-functional team that evaluates and decides the disposition of nonconforming materials, components, or products — determining whether to use-as-is, rework, return to supplier, or scrap items that don't meet specifications, preventing both wasteful scrapping of usable material and risky acceptance of truly defective items.
What Is an MRB?
- Definition: A formally constituted committee (typically quality, engineering, manufacturing, and procurement representatives) authorized to make disposition decisions on nonconforming material.
- Authority: MRB decisions are binding — only the MRB can approve the use of out-of-specification material in production.
- Standard: Required by ISO 9001, IATF 16949, AS9100, and most customer quality agreements for semiconductor manufacturing.
Why MRB Matters
- Cost Recovery: Automatically scrapping all nonconforming material is wasteful — the MRB evaluates whether minor deviations actually affect product functionality.
- Risk Management: Conversely, using out-of-spec material without formal evaluation can cause field failures, customer complaints, and safety issues.
- Documentation: MRB decisions create a formal quality record that satisfies auditors, customers, and regulatory bodies.
- Continuous Improvement: MRB data (frequency, root causes, disposition patterns) drives supplier improvement and process optimization.
MRB Process
- Step 1 — Nonconformance Report (NCR): Document the deviation — what failed, how it was discovered, and potential impact.
- Step 2 — Containment: Quarantine affected material and identify any product already processed with the nonconforming material.
- Step 3 — Impact Analysis: Engineering evaluates whether the deviation affects product performance, reliability, or safety.
- Step 4 — Disposition Decision: MRB decides: use-as-is, rework to specification, return to supplier, or scrap.
- Step 5 — Customer Notification: If deviation affects shipped product, notify affected customers per contractual requirements.
- Step 6 — Root Cause and CAPA: Initiate corrective and preventive action to eliminate the root cause of the nonconformance.
Disposition Options
| Disposition | When Used | Risk Level |
|---|---|---|
| Use-As-Is | Deviation doesn't affect function or reliability | Low (engineering analysis confirms) |
| Rework | Can be brought to spec with additional processing | Medium (verify after rework) |
| Return to Vendor | Supplier-caused, can be replaced | Low (replace with good material) |
| Scrap | Cannot be used safely or reworked economically | None (material destroyed) |
Material Review Board is the essential governance mechanism for nonconforming material in semiconductor manufacturing — balancing waste reduction against quality risk through disciplined, cross-functional decision-making documented for the lifetime of the product.