flexpcb.orgFLEXPCB.ORG / informational
Flex PCB Design Rules: A Release Checklist
Get a Flex PCB Quote ↗Use a controlled rule set
A design-rule table is useful only when it matches the supplier, material system and construction. Request approved limits for trace and space, drill and pad geometry, copper-to-outline clearance, coverlay openings and registration. Record the revision and any project-specific exceptions. A competitor's capability table is not evidence that your selected process supports the same geometry.
Separate the mechanical regions before routing
Mark moving bends, installation bends, connector contacts, supported component areas and rigid-flex transitions. Place pads, vias and components outside moving bend regions where possible, and review unavoidable features explicitly. Define the installed geometry as well as the flat outline. Check whether the enclosure imposes twisting or vibration at a support edge even when the circuit is described as static.
Make layer purpose unambiguous
Use consistent filenames and identify the copper, drill, coverlay, stiffener and outline data in a fabrication drawing. State whether dimensions are millimetres or inches and give datums for critical features. Include the approved stackup, material grades, copper system and surface finish. If an illustration is not to scale, label it; if a dimension is only a reference, distinguish it from an acceptance requirement.
Review electrical and assembly requirements together
Document controlled impedance, current-related constraints, shielding and the intended test method. For assembly, include a controlled BOM, placement data, polarity information and component-side references. Agree support fixtures and handling requirements before fixing the panel or outline. Specify substitutions that require approval. A mechanically convenient change should be reviewed for its electrical and assembly effects before release.
Release a versioned package and acceptance plan
Bundle the fabrication data, drill files, outline, stackup, mechanical notes and inspection requirements under one revision. Check that exported data matches the drawing and that no obsolete layer files remain in the archive. State the applicable standard revision and class where required by the procurement agreement. IPC-2223 concerns design; IPC-6013 concerns qualification and performance. A reference to either standard does not replace an agreed inspection plan or establish supplier certification.
Close the review loop
Keep a record of engineering questions, agreed changes and the released files. Ask the supplier to identify unresolved assumptions before manufacturing starts. Review first-article results against the controlled package, then feed confirmed changes back into the source design. When the material, stackup or installed support changes, assess which previous checks and test results need repeating.
Make the requirements reviewable.
| Define | Include in the review | Why it matters |
|---|---|---|
| Mechanical duty | Installed shape, bend location, motion and cycle target | Distinguishes installation bending from service fatigue |
| Construction | Layer order, copper, film, adhesive and coverlay | Establishes finished thickness and material compatibility |
| Interfaces | Connector thickness, pad finish and local reinforcement | Controls fit, assembly support and contact reliability |
| Acceptance | Dimensions, electrical test and applicable standard revision | Creates an agreed basis for inspection and quotation |
CONTINUE THE DESIGN REVIEW
Connect the decisions.
YOUR NEXT STEP
Bring the requirements.
Start the conversation.
Tell us what the circuit needs to do, how it will bend and when you need it. A complete build brief makes a quote easier to evaluate.
Preparing files?
Include Gerber and drill data, a fabrication drawing and stackup notes. Put related files in one ZIP. Add a BOM and placement file when assembly is required.