The main raw materials of snubber film capacitors are base film, metal foil, wire and outer packaging resin, etc., of which the base film is the core raw material of film capacitors, occupying 60%-70% of the material cost. Base film is mainly generated by the resin through the stretching process, the film stretching process is more difficult, requiring equipment operators to control the production process of temperature, speed, humidity, tension, pressure and several other parameters, the production process is higher. Therefore, how to reduce the cost of raw materials through vertical integration and other ways is the key to achieve competitive advantage of industry companies. Depending on the base film material, snubber film capacitors can be categorized into polyethylene terephthalate, polypropylene, polyphenylene sulfide and polyethylene naphthalate. Generally speaking, small size, low price PET material film capacitors are mainly used in home appliances, lighting and other general areas, with the continuous penetration of new energy vehicles and wind energy storage, is expected to be in the future in the high-frequency, high-voltage, high-current performance of PP film capacitors will continue to increase the share of better.
Snubber Film Capacitors Overview: Classification, Advantages, Applications
- Capacitor classification
Capacitor is a kind of component made of two pieces of conductors close to and insulated from each other for storing electric charge, which is mainly used in circuits such as tuning, filtering, coupling, bypassing and energy conversion. According to the dielectric material used in capacitors, they are mainly divided into ceramic capacitors, aluminum electrolytic capacitors, film capacitors and tantalum electrolytic capacitors. According to the China Electronic Components Association cited by Wisdom Research Consulting, the market size of ceramic capacitors, aluminum electrolytic capacitors, film capacitors, and tantalum electrolytic capacitors accounted for 49%, 29%, 8%, and 7% of the market size of capacitors, respectively, in 2019.
- Classification of snubber film capacitors: Winding + metallized film type is commonly used
Sub-dielectric materials: PP, PET, PEN, PPS. film capacitors mostly use PP (polypropylene) and PET (polyester film), of which PET (polyester film) film capacitors are mostly used in low voltage, miniaturized electronic instruments and household appliances with lower heat resistance requirements, while PP (polypropylene) film capacitors have good self-healing and high reliability, and are widely used in automotive and industrial fields. The
- Advantages of snubber film capacitors: Long service life and outstanding reliability
Film capacitors are characterized by nonpolarity, high insulation resistance, excellent frequency characteristics, low dielectric loss, long service life, and self-healing properties, which make them a good substitute for traditional capacitors in some fields that require high voltage and harsh working environments.
- Snubber film capacitors applications: DC support, buffering, filtering in energy conversion circuits
Energy conversion circuit: energy input – intermediate DC link (AC/DC or DC/DC) – energy output (DC/DC or DC/AC). Capacitor 1 – Buffer Capacitor: Trans-switching devices are used to suppress the inherent voltage transient noise and current pulses generated by the switching of semiconductor devices. Capacitor 2 – AC Filter Capacitor: Used for input and output AC voltage filtering. Capacitor 3 – DC-Link Capacitors: Capacitors in DC circuits used for DC voltage filtering, providing transient current to downstream circuits, and storing energy for fail-safe power-down operations.
New energy takes over home appliance lighting, the industry opens a new round of growth
- Snubber film capacitors in China market size is the largest, the growth rate is higher than the global market
To the Chinese market, for example, due to the home appliance market since 2018 by the domestic real estate market growth is weak, corresponding to the home appliance market film capacitor demand decline, and the lighting market fluorescent lamps replaced by LEDs also bring supporting snubber film capacitors dosage reduction, and the new energy field (new energy vehicles, photovoltaic, wind power) has gradually become a new engine of film capacitance industry growth. Farad Electronics, for example, in 2014 the company’s household appliances lighting revenue accounted for 45%, 2020H1 household appliances lighting revenue accounted for only 18%, new energy business revenue accounted for 54%.
- New Energy Vehicles: New Energy Vehicle Penetration Rate Continues to Increase
Under the general trend of electrification and intelligentization, the sales and penetration rate of new energy vehicles continue to increase. According to the IEA, China Automotive News public number cited China Electric Vehicle Association research forecast, optimistically expected in 2025 global new energy vehicles, China’s new energy vehicle sales will reach 19.69 million, 9 million, penetration rate corresponding to 18%, 30%.
The voltage and output power of the new energy vehicle system have been greatly increased, and the requirements for electronic components to withstand pressure and impact have been improved. Aluminum electrolytic capacitors are more suitable for medium and low voltage circuits, and snubber film capacitors have outstanding performance advantages in high frequency performance, high withstand current capability, long life, reliability and safety, and are more suitable for high voltage circuits, gradually replacing traditional capacitors, and are widely used in new energy vehicle power and motor control system modules, including inverters, on-board chargers, and motor control system modules, which are widely applied to new energy vehicle power and motor control system. They are widely used in new energy vehicle power supply and motor control system modules, including inverters, on-board charger OBCs, DC-DCs, and so on.
- Photovoltaic: Declining power generation costs coupled with policy support as a long-term driver of snubber film capacitors’ installed capacity
The rapid development of distributed PV in China: according to the National Energy Administration, Solar Power Europe, in 21 years, China’s new PV installed capacity reached 54.88GW, accounting for 33% of the global new PV installed capacity, distributed PV accounted for the first time more than the centralized power plant. We expect that falling power generation costs and policy support will be the long-term driving force behind the increase in PV installations. According to Solar Power Europe, under the neutral situation, it is expected that the global and domestic PV installed capacity will reach 314GW and 100GW respectively in 25 years.
According to the national energy bureau, polaris wind power network, GWEC, China’s 21 years of wind power installed 47.57GW, accounting for 51% of the global market, of which the new offshore wind power installed in 21 years to benefit from subsidies before the withdrawal of the rush to install the peak, amounted to 16.90GW, accounted for more than the global offshore wind power installed 80% of the amount of new, for the previous cumulative total size of the built 1.8 times. We believe that the domestic market with 21, 22 years of sea and land wind subsidies end one after another, the arrival of the parity era is expected to stimulate the wind power industry demand, and promote the industry to reduce costs and increase efficiency.
Base film supply is tight in the short term and is expected to improve in FY23, easing cost pressures
- Snubber film capacitors materials account for a high proportion of the cost, vapor deposition and slitting as the core process
Base film and non-ferrous metals are the main raw materials: the main raw materials of buffer film capacitors are non-ferrous metals and various polymer film materials (base film, including polypropylene film, polyester film, etc.), while other raw materials include resin materials, lead wires and lead sheets, and case materials. Metallized film materials account for a high proportion of the cost. Metallized film is a composite material required for manufacturing film capacitors, which is obtained by heating and vaporizing high-purity metal in vacuum, evaporating it and depositing it on dielectric film, and then slitting, inspecting and packaging it. The key processes are evaporation and slitting. Metallized film accounts for a relatively high proportion of the material cost of film capacitors, which is estimated to be 50%-60%.
- Domestic snubber film capacitors manufacturers still have bottlenecks in raw materials, equipment and processes
International enterprises, such as Germany’s Trespa Group and Japan’s Toray Co., Ltd. started early, with strong R&D and production capacity, among which Toray Co., Ltd. dominates the field of automotive capacitor film. Domestic capacitive film manufacturers include Tongfeng Electronics, Nanyang Technology, Jadeli, Dongmai Technology, etc. Domestic capacitive film manufacturers are still in the process of developing snubber film capacitors in terms of raw materials and equipment. Domestic capacitor film manufacturers still rely on imported raw materials and equipments, and there are difficulties in the film drawing process: 1) Polypropylene, the raw material for polypropylene capacitor film, is mainly imported from Europe and Korea, such as Scandinavian Chemical Industry and Korea Oil & Chemical Industry; 2) Most of the production lines and equipments are imported from Bruckner (Germany), DMT (France), and Dornier (Germany), and so on; 3) The film drawing process has an effect on the thickness deviation, roughness, and film-forming property of polypropylene film. The level of film drawing process of some enterprises cannot support stable mass production.
- Structural shortage of base film, supply gap may ease in 23 years
Tight supply of snubber film capacitors under the rapid development of new energy industry. With the second half of 2020, China increased investment in new energy, new energy industry with polypropylene film volume climbed. Due to the new energy industry, photovoltaic, wind energy, new energy vehicles with polypropylene film is mainly concentrated in 2-4 microns, while the ordinary film is 6-8 microns, resulting in structural tension in the supply problem. It is expected that the gap between supply and demand of base film still exists in the short term, and may be alleviated in 2023. Global new energy with ultra-thin film manufacturers equipment supply shortage, in which the domestic manufacturers are mainly from Germany Bruckner equipment procurement, equipment delivery in 2-3 years, resulting in new production lines put into operation longer cycle. We believe that with the expansion of capacitive film manufacturers, the supply and demand gap may be alleviated in 2023.
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