Separate the circuit from its ingredients
FPC commonly refers to a flexible printed circuit. Polyimide names a material family, while a finished circuit also includes conductors, insulation, and other specified constituents. Use the material guides to identify the complete system. A film brand or color does not establish a laminate grade, copper construction, or manufacturing process.
Terms used in this library
| Term | Working meaning | Clarify in your project |
|---|---|---|
| Coverlay | An insulating covering construction used over flex conductors | Film, adhesive, openings and side |
| Bondply | A specified bonding layer in a laminated construction | Material, thickness and bonded regions |
| Stiffener | Local mechanical reinforcement | Material, side, attachment and boundary |
| Rigid-flex | A circuit construction with rigid and flexible regions | Electrical layers and transitions |
| Finished thickness | Thickness of the completed local construction | Region, contributions and tolerance |
| Bend radius | A dimension describing a curved region | Reference surface and motion state |
| Netlist | A representation of intended electrical connectivity | Source revision and test relationship |
Use mechanical terms with a region
Stiffener describes local reinforcement; rigid-flex describes a construction incorporating rigid and flexible circuit regions. Static and dynamic describe aspects of use, not simply thickness or softness. The duty guide explains why assembly and service events belong in that description. Name the affected region whenever a term could be interpreted across the whole board.
Define ambiguous words in the release package
Terms such as thickness, bend radius, ground, and test need an object and a method. State local finished thickness, inside or centerline radius, the intended reference or return function, and the actual test coverage. Add a short terminology note to the drawing if teams use different conventions. Resolving language early can prevent an apparently complete quote from describing a different construction.
Before you release the design
- Use exact material and connector part identities where available.
- Name the region whenever thickness or reinforcement is specified.
- Expand uncommon abbreviations in the drawing notes.
- Define test coverage instead of relying on tested as a description.
Watch points
- A shared abbreviation does not guarantee that two suppliers mean the same construction.
Practical questions
Are flex PCB and FPC interchangeable terms?
They are often used for the same general type of circuit. For purchasing, the layer construction, terminals, materials, and duty provide the useful definition.
Does adhesiveless mean the finished circuit contains no adhesive?
No. It can describe the copper-clad laminate structure while coverlay, bonding, or reinforcement elsewhere still uses adhesive. Read the complete regional stackup.
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.