Capacitor films refer to capacitors made by stacking metal foils as electrodes on electronic film of electrical grade plastic as dielectric material and winding them into shape.

Categories of capacitor films

Capacitor films can be divided into two types: direct current capacitor films and alternating current capacitor films, according to the type of current. The characteristics of direct current capacitor films are large capacitance, low withstand voltage, polarity, self-healing properties, high reliability, good temperature stability and long service life. Typical applications include drivers, UPS, solar inverters, electronic ballasts, small motors for automobiles, household appliances, various types of power supplies, etc.

Alternating current capacitor films have the characteristics of small capacitance and high withstand voltage, and are indispensable components in conventional industrial alternating current power supply applications and asynchronous motor starting and operation. AC capacitor is widely used in AC output filters, especially output filters for uninterruptible power supplies (UPS) and photo-voltaic inverters.

The role of capacitor film in photovoltaic inverters is mainly to absorb high pulse currents, stabilize and control the voltage fluctuations at the inverter end, and play an important role in the stability and performance of photovoltaic equipment.

Industrial chain of capacitor films

The upstream of the industrial chain of capacitor films mainly includes base films and metal foils, of which the base film is the core raw material, and different materials of base film correspond to capacitors with different performances.

The downstream application scenarios are relatively scattered. capacitor films can be used in DC, AC, power electronics and other equipment occasions, mainly including household appliances, photovoltaics, wind power, new energy vehicles, etc.

The upstream of the capacitor film industrial chain mainly includes base films, metal foils, wires, and outer packaging resins and other materials. Among them, the base film, as electronic film of electrical grade, is the most important upstream raw material for capacitor films, which determines the performance of capacitor films and accounts for 60%-70% of the material cost.

Capacitor films have different performances according to different dielectric materials

Among them, the base film includes metallised polypropylene film, polystyrene film, polyester film, and polycarbonate film. From the perspective of the global base film market pattern, currently, Japanese manufacturers have a clear leading advantage in high-end capacitor films, and the global capacitor film market competition pattern is diversified, with a relatively diverse industry structure.

High-voltage and high-capacity capacitor films are high-end products mainly used in new energy and industrial control fields, with high technical barriers, high added value, and core technologies controlled by international leading enterprises. The market in this field is dominated by Japanese and European and American manufacturers.

Low and medium voltage capacitor films are mainly used in electronic devices, household appliances and other fields, with a relatively mature development level, high popularity in manufacturing technology, and intense market competition. Chinese enterprises have cost advantages in this field, and the competition pattern is dominated by Chinese and Japanese enterprises.