The components arrived on time. The price was competitive. Three months later, during process qualification, the MTR heat numbers don't match the physical material markings, the leak test report has identical values across all 40 fittings, and the cleaning certificate is a one-page template with no batch reference. The qualification fails.
Why Documentation Is Not a Formality
In semiconductor fab procurement, supplier documentation serves two distinct functions. The first is compliance — confirming components meet specified requirements. The second is traceability — creating a verifiable record connecting the physical component to every step of its production and qualification history.
A document that satisfies compliance but fails traceability is not a qualified document. It is a statement. Statements can be fabricated. Traceable records have verification paths.
The Six Documents That Matter
Material Test Report (MTR)
The MTR connects the component to a specific melt of raw material. It must contain actual chemical composition values — C%, Cr%, Ni%, Mo% — not compliance statements. For 316L, C% must read ≤ 0.030%. The heat number on the MTR must correspond to a real melt at a real mill, and must match the heat marking on the physical material.
Certificate of Conformance (COC)
The COC is a supplier declaration that components meet the purchase order specification. It is the easiest document to produce and the least meaningful in isolation. A COC is only meaningful when cross-referenced to supporting documents — MTR, leak test report, cleaning certificate — that independently verify its claims.
Helium Leak Test Report
For UHP fittings, valves, and assemblies, the leak test report must show individual test results for each fitting or weld. The report must include instrument calibration data, test method, test pressure, and background helium level at test start.
Identical values across multiple fittings to several significant figures may indicate copied or non-representative data. Real test data has natural variation from fitting geometry, spray gun distance, and background fluctuation.
Cleaning Certificate
Confirms the component has been cleaned to a specified standard — passivated and cleaned for UHP service, bagged under cleanroom conditions, end-capped. The certificate must reference the specific batch or lot and the cleaning procedure used. A generic cleaning certificate with no batch reference cannot be matched to the specific components in a shipment.
Dimension Report
Confirms critical dimensions — face-seal geometry, tube OD, fitting thread dimensions — are within specification.
Surface Finish Report
For EP-treated components, confirms Ra values with measurement locations identified. Without location data, the Ra figure cannot be verified.
Which Documents Are Most Commonly Falsified
COC requires nothing to produce. The falsification is usually not the COC itself — it is the absence of supporting documents that would allow its claims to be verified.
Cleaning Certificate is frequently a template with no batch number, no lot reference, and no connection to the specific components in the shipment.
Helium Leak Test Report — identical values across multiple fittings indicate copied data. This is the most directly detectable form: the statistical signature is visible in the data itself.
MTR is the hardest to falsify convincingly because a legitimate MTR has a verification path — the heat number can be checked with the originating mill. The common fraud pattern is relabeling a genuine MTR for a different material grade, or reusing one MTR across multiple shipments.
The Minimum Acceptable Package
For UHP component qualification, require:
- MTR with actual composition values and verifiable heat number
- COC cross-referenced to MTR heat number and leak test report
- Helium leak test report with individual fitting data showing natural variation
- Cleaning certificate with batch reference matching the shipment
- Surface finish report with measurement location map for EP components
A supplier who cannot provide this package is not qualified for UHP semiconductor component supply, regardless of price or lead time.
KTIC supplies UHP components with complete documentation packages — MTR, COC, helium leak reports, and cleaning certificates. Contact us to request a sample documentation package.
Related: MTR Traceability — What to Verify When Qualifying UHP Component Suppliers Related: Helium Leak Testing — Standards, Methods, and Acceptance Criteria for UHP Systems