Map the duty before drawing copper
For each span, specify whether it is positioned once, handled during maintenance, or moved in use. Include the actual path and supported endpoints; the phrase flexible PCB leaves all of these open. Start with duty classification and bend geometry planning. Record open questions so an early enclosure assumption does not become an accidental production requirement.
Design reviews in dependency order
| Review | Resolve first | Release evidence |
|---|---|---|
| Mechanical duty | Motion envelope, support and installation sequence | Flat and installed views with regional callouts |
| Interfaces | Mating parts, contact side and local thickness | Connector drawing references and dimensional checks |
| Electrical layout | Reference paths, loads and critical nets | Stackup, routing constraints and test requirements |
| Fabrication handoff | Layer meaning, openings and tolerances | Consistent archive and approved drawing |
Resolve interfaces and local construction
Choose mating connector parts, terminal contact side, reinforced areas, and the assembly support strategy together. A connector footprint establishes only part of the interface. Its tail geometry or support drawing can control local thickness and outline details. Review ZIF terminals and component areas against the regional stackup, including adhesives and finishes.
Electrical priorities belong in this stage too. Decide which nets need controlled reference geometry, what loads share a return, and where current enters or leaves the circuit. Avoid treating a plane, shield, or thicker copper layer as a free addition: each changes the construction that the mechanical team is packaging.
Release a coherent manufacturing description
Build the drawing alongside the CAD layout. Identify every coverlay opening, reinforcement boundary, controlled dimension, and acceptance requirement. Check exported files independently rather than assuming a clean design-rule check proves the output package. Use the DFM checklist for the design discussion, then the fabrication drawing checklist for release.
Choose verification around the feature at risk. Terminal fit, finished thickness, netlist coverage, and movement endurance need different evidence. A prototype plan should state which design question each measurement closes and who approves a deviation. Keep the reviewed file set and drawing revision linked so later production builds inherit the same intent.
Before you release the design
- Give each distinct construction region a stable name.
- Review critical terminals with both electrical and mechanical owners.
- Separate proposed dimensions from agreed manufacturing limits.
- Reopen relevant reviews after a material, support, or motion change.
Watch points
- A passed CAD rule check verifies only the rules configured in that project.
- A visually plausible folded model does not establish fatigue life.
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Practical questions
Which design decisions should be frozen earliest?
Freeze the interfaces that constrain other work: mating parts, mounting references, motion envelope, and critical electrical requirements. Keep material alternatives explicit until their construction and process implications are reviewed.
Can fabrication start while the enclosure is still changing?
A prototype may be useful, but identify the unfrozen geometry and its purpose. Do not treat a fit experiment as a qualified production design without reviewing the final enclosure and motion.
Technical references
References support the material or design context. Check the exact grade, part number, document revision and project conditions before release.Updated 27 September 2026 · Technical content policy · Engineering guidance supports project review; the agreed drawing defines the build.