Birk Products

Kapton® Heaters

Birk Manufacturing can provide Kapton® heaters with lengths to 65″ long (1,651 mm), temperature capability to 500°F (260°C), cutouts, shaded watt density-flex circuits, sensors, temperature accumulators, multi-voltage circuits, and intricate shapes. Kapton® is a polyimide film used in conjunction with etched foil circuits to produce very thin flexible heaters. Kapton® has excellent dielectric qualities to provide 5000 volts dielectric per .001 inch (.025mm) thickness. Birk uses many types of Kapton® with two bonding systems. An FEP Teflon® which is a thermo flow polymer and a thermo flow acrylic. The FEP bonded Kapton® has a continuous temperature capability of 500°F (260°C), the acrylic bonded Kapton® has a continuous temperature capability of 250°F (120°C). Birk can manufacture Kapton® heaters up to 6 inches (300mm) wide by 65 inches (1651mm) long, the largest in the industry, and thickness from .003 inches (.07mm) to .010 inches (.254mm). Using a proprietary process, Birk bonds foil to Kapton® prior to etching, and after etching then bonds a top insulation ply to the assembly. Birk can also bond these heaters to metal surfaces with a bond line as thin as .0005 inch (.0127mm) providing excellent bond strength and heat transfer. Etched foil circuits can be very accurately produced on Kapton® with line widths down to .010 inches (.254 mm) thick. Various patterns can be etched into circuits such as holes, cut-outs and flex circuits. Birk builds Kapton® heaters into assemblies which include sensors, heat sinks, fuses, probes and electronics. Many of these products are completely assembled and tested at Birk and shipped directly to our customer inventory. Termination of Kapton® heaters can be in many forms including leads, connectors, solder terminal pads or card-edge-ready.

Silicone Rubber Heaters

Birk Manufacturing started in business in 1989 making silicone rubber heaters. Silicone rubber flexible heaters are still a very important part of our product line. Birk offers a wide variety of silicone heaters along with many components which we add to the heaters to provide our customers with complete assemblies. Birk offers silicone rubber heaters 35 inches wide and unlimited in length, voltages up to 750 volts, and watt densities to 30 watts per square inch. Silicone heaters can be made as thin as .020 inches (.5mm) and any thickness a customer requires. Both resistance wire and etched foil circuits are used in silicone heaters. We can vulcanize silicone heaters to metal surfaces with a proprietary process that ensures an excellent bond and efficient heat transfer. Birk has millions of silicone heaters in service bonded to metal surfaces with very few failures. Silicone heaters can be combined with many components such as thermostats, fuses, thermocouples, RTDs, thermistors, connectors, heat sinks, wiring harnesses, motors or any other hardware our customer desires. Birk can build, test and package assemblies to be shipped directly to our customer’s warehouse. All products are inspected 100% prior to shipment to meet our customer and agency specifications. Birk stands behind its products and is always available in the unlikely event a field problem should arise.

Wire Harness

Birk Manufacturing’s thermal systems design capability is one of the best in the industry. When customers first come to Birk they are generally looking for only a flexible heater. When they find out about our capability in designing complete thermal systems, they are pleasantly surprised. Birk performs many of its assembly work using microscopes because the assemblies are so small. We have even made heater and sensor assemblies with a total diameter of 0.028 inches! Norman Birk and his engineering team are responsible for many innovations in the heater industry. Birk makes quite a few assemblies which have no heaters at all, including wiring harnesses, temperature sensor assemblies, heat sinks and control assemblies. Quite a few of these products require micro welding and assembly under microscopes. Birk’s micro welding capability eliminates many soldering problems in order to comply with RoHS requirements.

Battery Heaters

Birk Manufacturing has designed and manufactured battery heaters for many years. Etched foil and wire wound heaters can be insulated with Kapton®, silicone rubber or butyl rubber. These heaters can be made in many shapes and sizes using various materials to suit the specific application. Heaters can be designed to be impervious to battery electrolytes and waterproof for outdoor applications. Battery heaters can have thermostats or sensors built in to regulate temperature. These heaters can be custom designed in odd shapes and conform to the specific battery surface. They can be held in place with various fasteners such as Velcro®, snaps, eyelets and boot hooks.

Butyl Heaters

Butyl Heaters can be made up to 35″ (889mm) x 120″ (4248mm) and as thin as 0.080″ (2mm). Features:

  • Heaters made from Butyl rubber can have thermostats molded in place to offer a waterproof self controlled heater assembly.
  • Butyl Heaters can be bonded to metal surfaces.
  • Butyl heaters offer long service and shelf life


Circuit Design

Birk Manufacturing designs thousands of wire and etched foil circuits each year to meet the specific needs of our customers. Birk can offer our customers many features highlighted below.

Accommodate Holes and Cutouts:

Many times heaters need to fit around holes and cutouts. This can be designed in either etched foil or wire circuits to provide heating of the entire surface area.

Multi-layer Circuits:

Many times we need to maximize surface area to spread the watt density. Multi-layer circuits can be used to fit a high resistance in a small area by putting two circuits in series. The multi-layer circuit also allows us to put a sensor flex circuit on top of the heater circuit to maximize the heated area.

Sensors and Fuses within a circuit:

To control heat and temperature limits properly, thermostats, RTDs, thermocouples, thermistors, solid state sensors and fuses are strategically placed within a circuit to achieve the best operating thermal system.

Various Terminations:

Birk can offer many different terminations such as: leads from 36 gauge to 10 gauge, soldered terminals, connectors, pins and zero insertion force connections.

Shaded Watt Density:

Different heat intensities in the same circuit can provide an even heat across an entire heated area, and can compensate for cool heat sink edges.

Dual Voltage Circuits:

A single heater can be designed to operate on more than one voltage by including dual circuits with three leads.

Resistance Taps:

Since the heater circuit is a resistor, taps can be taken anywhere along that circuit to provide a given voltage to an LED or other component that requires other than line voltage.

Flex Circuits for Sensors:

Sensors are generally located within a heated area. Non-heated flex circuits can be built into the circuit design to carry the signal to the instruments.