Polyimide Flexible Heater Design Tips


Question: Why should you put an aluminum backing on a polyimide heater?

There are two main reasons:
1. To improve the life and reliability of the heater.
2. To help retain shape when applied to curved surfaces.
(This Tech Note will review the improvement to life. Look for a future article regarding improvement to curved surfaces.)

All Flex typically adds a .003”/0.076mm thick aluminum layer between the heater surface and any mounting Pressure Sensitive Adhesive (PSA). The resulting benefit is better temperature uniformity resulting in a “cooler” running heater which will improve long term reliability.

While most applications for polyimide flexible heaters are mounted to an aluminum heatsink, the thin layer of .003”/0.076mm thick aluminum foil helps reduce the temperature that the PSA will see prior to the heat being transferred to the heatsink and also reduce the temperature the internal adhesive will see, resulting in a more reliable heater construction.

All Flex makes heaters capable of withstanding normal operating temperatures to 1112F/600C and 110 watts per square inch/ 17 watts per square centimeter. Consult All Flex for your particular heater application.

NOTE: Aluminum backing does not replace the need for heater profiling in medical applications. Contact All Flex for help with special requirements where uniformity down to ±0.5C is required.


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