Flexible heaters place a patterned circuit close to the heated surface. Their low mass supports fast response, but performance depends on contact, circuit layout, attachment and feedback.
Use this guide to prepare a design review or RFQ. Final ratings depend on the complete product, installation, controls and operating environment.
Selection inputs that change the design
| Decision | Information to provide | Why it matters |
|---|---|---|
| Substrate | Silicone rubber or polyimide | Balances durability, profile and environment. |
| Attachment | PSA, bonded, clamped or captured | Must suit temperature, surface and serviceability. |
| Circuit | Heated zones, cutouts and edge clearance | Keeps traces away from fasteners and folds. |
| Feedback | Integrated or separate sensor | Controls the temperature that matters. |
Define the heated area
Provide a dimensioned outline with cutouts, holes, no-heat zones and lead exit. The circuit must stay clear of fasteners, folds and trimmed edges.
Show non-uniform heat zones and expected losses. A custom trace can compensate for edges, clamps or heat sinks.
Select attachment and power together
Adhesive is convenient but has temperature and surface limits. Clamping improves serviceability but requires even pressure.
Review power density against the substrate, contact, insulation and maximum local temperature. Air gaps produce hot spots.
Place feedback at the controlled surface
The sensor should represent the component or medium. A sensor on the heater may under-represent a distant process mass.
Route sensor and heater leads with strain relief and coordinate fault protection with the system.
Common specification mistakes
- One watt-density rule for every substrate
- Adhesive on a dirty surface
- Air pockets under the circuit
- Sensor reading only the heater
RFQ checklist
- Outline, holes and no-heat zones
- Substrate and finish
- Voltage, power and temperatures
- Attachment, insulation and leads
- Sensor and controller
Review the matching Flexible Heaters product range, then send this checklist with your drawing for an engineer-reviewed quotation.
Engineering review and validation
Before approving Flexible Heater Design Guide for Silicone Rubber and Polyimide, document the measured installation dimensions, normal and peak operating temperatures, available electrical supply, controller input, surrounding atmosphere and expected duty cycle. Compare these values with the supplier drawing rather than relying only on a catalog family name. During commissioning, record resistance, current, warm-up time, sensor response and temperature distribution. Retain this baseline with the machine records so maintenance teams can distinguish normal aging from poor contact, contamination, wiring damage or a control-system fault.
Frequently asked questions
Which is thinner?
Polyimide is generally chosen for a thin, low-mass profile; silicone rubber offers robust conformability.
Can it be folded?
Do not sharply fold the active circuit. Confirm bend radius and flex requirements.
Does adhesive replace control?
No. The system still needs suitable control and protection.