Design the installation sequence first
Sketch the order of battery placement, display connection, flex forming and case closure. Record where an assembler can grip the circuit and actuate each connector. The installation guide helps distinguish the free shape from the final route and identify folds made only during assembly.
Smartwatch review points
| Constraint | Specify | Verify |
|---|---|---|
| Case closure | Installed flex envelope | No trapped branch or tail |
| Compact connectors | Drawing and local thickness | Accessible, correct mating |
| Service access | Opening and replacement sequence | Controlled handling after assembly |
Control height at local interfaces
A thin interconnect can still exceed the available envelope at a stiffened tail or mounted connector. Use reinforced thickness planning at each interface, including adhesive and finish where relevant. Check the circuit against neighboring components in the installed model rather than the empty case.
Separate the display or sensor interface from battery and charging routes in the requirements brief. Specify reference needs, current conditions and contact orientation. An electrical reference or additional copper should be assessed within the actual local stack, because it may change the formed geometry.
Verify closure and foreseeable servicing
Build a trial using representative enclosure parts and assembly tools. Inspect the route after closure for pinching, edge contact and displaced reinforcement. If the product can be serviced, define how many openings or connector operations the procedure involves and what parts are replaced. Environmental protection belongs to the complete enclosure and interface design, not to the polyimide label alone.
Before you release the design
- Provide an exploded assembly and connection order.
- Mark folds made during installation and movement in use.
- Check reinforced regions against the closed-case envelope.
- Define protection and servicing assumptions.
Watch points
- A circuit that fits an open enclosure can be pinched when the display and seal are installed.
Practical questions
Does a watch require dynamically rated flex?
Only the actual motion determines the requirement. A fixed internal route and a moving strap connection need different duty definitions and tests.
Can the same tail fit any connector with matching pitch?
No. Verify contact face, dimensions, thickness, stiffener and retention features against the exact connector drawing.
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.