Short answer: Cleaning validation for stamped parts should define what residue is unacceptable, how it is checked, and when the check happens. A wipe test can support visual cleanliness, oil control, solderability, adhesion, contact resistance, or cosmetic requirements, but the RFQ should state the surface, method, sample size, acceptance limit, drying rule, packaging state, and report format.
A drawing note that says clean is rarely enough. Stamping oil, polishing compound, plating residue, paper fiber, dust, fingerprints, or drying marks can affect soldering, coating adhesion, electrical contact, sealing, or customer appearance standards.
Use this page with the cleanliness contamination control guide, process sequence RFQ checklist, no-touch surface handling guide、および terminal solderability test guide.
Cleaning validation details to define
| Detail | Why it matters | RFQ evidence |
|---|---|---|
| Surface tested | Residue on a hidden face may matter less than a contact or weld face. | Marked surface, photo, zone map, or drawing note. |
| Method | A wipe test, visual check, particle test, and solderability test answer different questions. | Procedure, cloth type, solvent if used, area, pressure, and pass/fail rule. |
| Timing | Parts can be clean after washing and dirty after sorting or packing. | After stamping, after cleaning, after plating, after packing, or at receiving. |
| Packaging state | Clean parts can pick up fibers, moisture, or oil in the pack. | Bag, tray, separator, drying rule, and first-pack photos. |
Choose a test that matches the risk
A wipe test is a practical way to check visible residue, oil film, dust, or handling marks on a defined surface. It does not prove every cleanliness requirement. If particles, ionic residue, solderability, or contact resistance matter, the buyer may need a different test or an added functional check.
The RFQ should say whether the wipe is dry, solvent-based, visual-only, weighed, compared to a limit sample, or tied to a customer method. If the supplier guesses the method, both sides may pass different parts. For plated contacts, connect cleaning validation to the contact resistance guide and thermal aging guide when surface film can change performance over time.
Validate the final condition, not only the wash process
A part can pass after washing and fail after drying, sorting, counting, or packaging. Validation should define the final condition the buyer receives. If parts are cleaned before plating, the buyer may still need post-plating residue control. If parts are cleaned after stamping, packaging materials must not re-contaminate no-touch or solder surfaces.
Drying matters. Water spots, trapped moisture, oil bloom, or paper transfer can appear after sealed packaging. For corrosion-sensitive parts, link the cleaning rule to the pre-plated cut-edge corrosion guide and anti-tarnish packaging guide.
For repeat orders, keep one approved reference method instead of changing the wipe area or cloth by lot. A stable method makes trend issues easier to see, especially when a supplier changes oil, plating source, cleaning chemistry, drying time, or packaging material.
RFQ details to include
- Drawing, material, finish, cleaning-sensitive surfaces, contact zones, solder zones, weld zones, coating zones, and cosmetic zones.
- Residue risk: stamping oil, drawing compound, polishing media, plating residue, fibers, particles, fingerprints, water spots, or corrosion products.
- Test method: dry wipe, solvent wipe, visual comparison, particle count, residue weight, solderability, adhesion, or resistance check.
- Sample size, surface area, cloth or swab type, pressure or stroke count if specified, lighting, magnification, acceptance limit, and report format.
- Cleaning stage, drying rule, packaging state, no-touch handling, shelf-life expectation, and re-clean or hold rule if parts fail.
- Prototype quantity, pilot run, annual volume, shipment cadence, and whether buyer approval samples are needed.
How to compare supplier answers
A useful answer separates ordinary oil removal from validated cleanliness. It should explain the cleaning step, drying control, handling method, packaging, and the exact inspection evidence. A weak answer only says parts will be cleaned before shipment.
Ask for photos of the tested surface and the wipe result on first samples. If the buyer uses receiving inspection, the supplier and buyer should compare the same method before production release.
Send drawings, residue concerns, test method, surface zones, packaging needs, and current reject photos through the お問い合わせページ. Use the RFQ form to request cleaning validation when residue can affect assembly or appearance.
FAQ
What is a wipe test for stamped parts?
It is a practical cleanliness check where a defined surface is wiped with a specified cloth, swab, or solvent method to look for residue or contamination.
Does a wipe test prove a part is fully clean?
No. It supports a defined surface and residue risk. Particle, ionic, solderability, adhesion, or resistance requirements may need other tests.
When should cleaning be validated?
Validate after the final cleaning, drying, handling, and packaging condition that the buyer will actually receive.
What should buyers send for cleaning validation?
Send drawings, marked surfaces, residue concerns, test method, acceptance limit, sample size, packaging condition, and report needs.