1. Polyimide, a heating sheet for power batteries, is one of the organic polymer materials with better overall performance. Its high temperature resistance is above 400℃, the long-term use temperature range is -200～300℃, some have no obvious melting point, high insulation performance, the dielectric constant is 4.0 at 103 Hz, and the dielectric loss is only 0.004～0.007, belonging to F to H. According to the chemical structure of the repeating unit, the pi heating film can be divided into three types: aliphatic, semi-aromatic and aromatic polyimides. According to the interaction force between chains, it can be divided into cross-linked type and non-cross-linked type. The flexible electric heating film has excellent insulation strength; excellent electrical strength; excellent heat conduction efficiency; excellent resistance stability. Transparent polyimide heating film
Traditional PI films, such as the company’s Kapton H series or Zhongyuan Chemical's Apical series, are homopolyphenylene polyimide heating films with low visible light transmittance and 100% absorption near 400nm wavelength. The heating film is brown-yellow. At present, with the rapid development of the optoelectronic communication field, the optoelectronic packaging materials, photovoltaic materials, optical waveguide materials and orientation film materials in the liquid crystal display field urgently need to be heated, with good optical properties, low dielectric constant, and good thermal stability. And excellent mechanical properties. Film materials, more and more people are paying attention to the development of transparent polyimide heating film.
2. Corona resistant polyimide heating film
With the miniaturization of electrical appliances and the popularization and application of variable frequency speed regulation technology, higher requirements are put forward for insulating thermal film materials. For example, in the high-frequency pulse wave and its transmission process, it is easy to produce high-frequency overvoltage. Once the air gap in the motor insulation is corona discharged under high voltage, the service life of the insulation structure will be greatly shortened. This polyimide thermal film with corona resistance can meet market demand.
The company's Kapton cr series heating film is a corona-resistant polycarbodiimide heating film product that has been put on the market in batches, and a method for preparing a corona-resistant heating film is disclosed. The corona-resistant polycarbodiimide heating film It is obtained by high-temperature imidization. The heating film has excellent anti-corona performance, and its anti-corona performance is more than 10 times that of conventional materials.
3. Black polyimide heating film
The black polyimide heating film has good shading, thermal conductivity, electrical conductivity, antistatic properties, etc., and is widely used in the fields of optics, electronic materials, aerospace, etc. Its preparation method is to coat the polyimide heating film Various shade materials, such as carbon black, graphite, metal oxides, inorganic or organic dyes, or these shade materials are added to polyimide resin, and then cast and imidized to form a film.
4. Conductive polycarbodiimide heating film
At present, common conductive heating films on the market include ink printing heating films and polytetrafluoroethylene heating films. These thermal films have shortcomings such as narrow thermal resistance, large temperature fluctuations, and poor mechanical properties, and have not been widely used. With the development of aerospace and transportation technology, higher requirements are placed on conductive films. For example, car seat cushions need conductive films with good mechanical properties to be heated in cold climates, which presents a new topic for researchers.
5. High thermal conductivity polyimide heating film
Miniaturization has become one of the main directions for the development of printed circuit boards and electronic packaging materials. Polymer-based electronic packaging materials have broad application prospects in electronic device packaging. In order to meet the increasing thermal conductivity (heat dissipation) requirements of circuit boards and devices, it is necessary to consider making the dielectric material have a larger thermal conductivity, and filling the PI with aluminum nitride (A1N) or silicon carbide (SiC) to Improving the thermal conductivity of materials has gradually become a research hotspot.
Flexible PI heating film
Flexible heaters are single-layer flexible circuits that use resistance alloys (such as nickel-chromium alloys and copper-nickel alloys) instead of copper to form conductive paths. When current is driven through a higher resistance conductor, heat is generated. The width and thickness of the conductor are selected according to the power supply voltage to provide the required resistance value
Advantages of PI heating elements:
The flexible heater provides good heat transfer to the radiator in a very small form factor and low-quality packaging. Because they are flexible, they can also be applied to and heat irregular surfaces that other types of heaters cannot reach. The TCR (Temperature Coefficient of Resistance) of the custom heater alloy provides the smallest resistance change when the temperature changes.
Application areas:
Medical diagnostic equipment
Disk drive heater
Electronic equipment
Automobile industry
Production capacity:
A variety of resistance band alloys are available to provide a wide range of customized resistance values.
The custom heater element layout service can provide heater resistance, which will provide the required power output based on the voltage input.
Assembly function can add thermistor, connector, lead, potting, etc.
A variety of pressure-sensitive adhesive backings are available
Custom install the heater to the radiator
Manufacturing of radiator specified by the customer
material selection:
Heating element-Inconel, cupronickel, constantan, copper
Insulation-polyimide film/epoxy resin glue, polyimide PI film/acrylic glue PET, PVC
Heat dissipation material-aluminum, copper
Pressure sensitive adhesive-3M 467, 3M 468, 3M 6035, 3M 9077, 3M 9460, 3M 9469, TESA 8853, TESA 8854
031474 Shaped heater area can provide uneven heating when needed
The final layer of aluminum or copper heat sink helps transfer heat to the heat sink.
The thermistor, wire and connector assembly.
Epoxy resin potting or assembly of components and wires.