What Is a PI Heater? Working Principle, Benefits and Applications

PI Heater, also known as a polyimide or Kapton flexible heater, is an ultra-thin heating element designed for fast, uniform heating on flat or curved surfaces. It uses an etched Ni-Cr foil circuit sealed between two layers of polyimide film, providing a lightweight and flexible alternative to conventional heating elements.

Standard models are available with PSA pressure-sensitive adhesive backing for easy installation, while no-adhesive versions can be supplied for special applications. Custom sizes, shapes, wattage, voltage and temperature-sensing options are also available for OEM projects.

How Does a PI Heater Work?

The heater uses the principle of electrical resistance heating. When electrical current passes through the etched nickel-chromium foil, electrical energy is converted into heat across the designed heating area.

The thin polyimide insulation layer protects the heating circuit while allowing heat to transfer quickly to the target surface. K-type or J-type thermocouples can also be integrated when temperature feedback is required.

Why Choose a Polyimide Flexible Heater?

• Ultra-thin construction: Only 0.15 mm without adhesive or approximately 0.25 mm with PSA backing.
• Flexible installation: Minimum bending radius can be as small as 0.8 mm for suitable configurations.
• Fast thermal response: Low thermal mass allows rapid heat transfer and temperature response.
• Uniform heating: Etched-foil technology distributes heat across the designed heating area.
• Easy installation: Standard PSA backing allows the heater to be attached directly to compatible surfaces.
• Custom design: Shapes, dimensions, cut-outs, mounting holes, voltage and wattage can be customized.
• Temperature sensing: K-type and J-type thermocouples are available for custom configurations.

Typical Applications

Because of its thin profile and flexibility, this type of flexible heater is suitable for applications where conventional heaters are too bulky or difficult to install.

• 3D-printer hot-bed plate heating
• Lithium-ion battery pack pre-heating
• PCB and LCD module temperature maintenance
• Optical lens and optical component heating
• Sensor anti-condensation heating
• Medical analyzer and reagent cell heating
• Instrument and cabinet internal component heating
• Small laboratory test plate heating
• Camera module low-temperature pre-heating

Standard and Custom Options

Standard rectangular, square and round heaters are available in 12V and 24V DC configurations. Stock sizes range from compact 25 × 50 mm heaters to larger 200 × 200 mm models.

For OEM applications, we can manufacture custom shapes including rings, long strips and irregular geometries. Inner holes, cut-outs, mounting holes, special lead positions and custom connectors can also be incorporated into the design.

Custom projects can also include different voltage and wattage requirements, PSA or no-adhesive construction, and integrated K-type or J-type thermocouples.

Standard PI Heater Specifications

Item	Specification
Heating Element	Etched Ni-Cr foil
Film Material	Polyimide film
Thickness	0.15 mm without adhesive / 0.25 mm with PSA
Stock Voltage	12V DC / 24V DC
Stock Wattage	15-200W
Recommended Watt Density	0.1-0.6 W/cm²
Maximum Watt Density	Up to 0.8 W/cm² with suitable heat dissipation
Working Temperature	-60°C to 180°C with PSA / short-term up to 200°C without adhesive
Minimum Bending Radius	0.8 mm
Standard Lead Length	300 mm

PI Heater vs Other Flexible Heating Solutions

A polyimide heater is particularly suitable when the installation requires an extremely thin, lightweight and flexible heating element. For applications requiring thicker and more mechanically robust flexible heating, a Silicone Rubber Heater may be a better option.

For cylindrical insertion heating rather than surface heating, a Standard Cartridge Heater may be more appropriate.

Need a Custom PI Heater?

We manufacture standard and custom flexible heating elements according to your required size, voltage, wattage, heating area and installation method.

For a quotation, please provide:

• Heater dimensions or diameter
• Working voltage
• Required wattage
• Target working temperature
• Actual heating-area size
• Required lead-wire length
• Sensor requirement: K-type / J-type / none
• PSA adhesive or no-adhesive version
• Required quantity
• Drawing for irregular shapes or cut-outs

Send us your heater dimensions, voltage and wattage requirements for a fast quotation.

Standard sizes available. Custom polyimide flexible heaters supported for OEM applications.