Technical resource

DFM checklist before a PCB assembly RFQ

Give engineering enough information to find assembly risks before price and schedule are fixed. Focus on issues that change the process, fixture or inspection plan.

Practical checklist

Agree the inputs, responsibilities and acceptance

TopicPrepare or defineCheck before release
Revision controlGerber/ODB++, BOM, placement data and drawingsConsistent revision and component references
Panel and handlingPanel drawing, fiducials, tooling and board supportEdges and support permit printing, placement and depaneling
ComponentsPackage drawings, polarity and height restrictionsFootprints and assembly access fit the parts
Thermal processSensitive parts, large copper areas and mixed thermal massSolder process can be profiled for the actual board
Hidden jointsBGA/QFN details and inspection requirementsX-ray and test coverage are agreed where needed
Through-hole and coatingConnector drawings, masking and coating materialProcess sequence and protected areas are defined

Worked example

Turn the checklist into an engineering decision

Example: a connector that prevents fixture contact may require a test-point change before tooling is ordered. Record the issue, proposed action, owner and approved revision.

Action log

Close the gaps before production

  • List the missing file or unresolved decision
  • Assign a customer or supplier owner
  • Record the proposed action and approval needed
  • Identify the affected revision and target build
  • Carry open items into the pilot release decision

Sources and use

A practical guide for project preparation

Editorial guidance from Keep Best EMS, organized around the manufacturing and engineering workflow described in the company profile. The worked example is illustrative, not a customer performance claim. Updated 28 September 2026.

Use this checklist with your product drawings, component data and agreed acceptance requirements. The final manufacturing and test plan is specific to the released product.

Engineering requirements

Include the bare-board manufacturing definition

Where bare-PCB procurement is included, provide the controlled fabrication drawing and stack-up with laminate requirements, layer structure, copper requirements, finished thickness and tolerances, surface finish and hole details. Include controlled-impedance requirements and their verification method where applicable. These requirements may be supplied in referenced drawings rather than duplicated in the enquiry.

Keep fabrication data, BOM, placement data and assembly drawings at the same approved revision. Identify applicable workmanship and acceptance requirements, including the standard revision and class where specified; mark unresolved requirements for review before the build is released.

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