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Film Capacitors

Semec Film capacitors are available with Polyester, Metallized Polyester, Metallized Polypropylene and High voltage Polypropylene type.

For Value and voltage, we have offer from 100PF to 10UF and from 63V to 2000V, among this you can find 250VAC type MKT, 275VAC X2 Capacitor and 1000V~ 2000V Polypropylene film cap etc.

For size, we have Box type MKT, Box X2, Mini size MKT and common type MPP and MKT.

Semec Film capacitors are used in bypassing and coupling applications, stable oscillators, sample-and-hold circuits, pulse-handle circuits, timers and filters etc.

Film Capacitors List

Feature AC Voltage MKT Box type MKT Mini size MKT Commom MKT
Capacitance range 0.01uF to 1uF 0.001uF to 2.2uF 0.001uF to 3.3uF 0.01uF to 10uF
Rated Voltage 250VAC DC 63V, 100V, 250V, 400V, 630V DC 50/63V, 100V DC 100V, 250V, 400V, 630V
Common Tolerance ±10% ±10% ±10% ±10%
Operating Temperature -40℃ ~ + 85℃ -40℃ ~ + 85℃ -40℃ ~ + 85℃ -40℃ ~ + 85℃
Photo SCA AC Metallized Polyester Film capacitor SCB Box Metallized Polyester Film capacitor SCC Mini size Metallized Polyester Film capacitor SCD Metallized Polyester Film capacitor
Feature Mylar Film capacitor Common MPP Film capacitor High Voltage MPP Film capacitor X2 Film capacitor
Capacitance range 1000pF to 0.47μF 0.01uF to 10uF 0.001uF to 0.15uF 0.0022uF to 4.7uF
Rated Voltage DC 100V, 250V, 400V, 630V, 1000V, 1200V DC 100V, 250V, 400V, 630V DC 1000V, 1250V, 1500V, 1600V, 2000V 250VAC, 275VAC
Common Tolerance ±10% ±10% ±10% ±10%
Operating Temperature -40℃ ~ + 85℃ -40℃ ~ + 85℃ -40℃ ~ + 85℃ -40℃ ~ + 100℃
Photo SCE Polyester Film capacitor SCF Metallized Polypropylene Film capacitor SCG High Voltage Polypropylene Film capacitor SCX X2 Metallized Polypropylene Film capacitor

About Film Capacitors

Film capacitors are insulated with polyester, polycarbonate, polypropylene, polystyrene, or other dielectric materials. Polyester film capacitors offer a high dielectric constant and high dielectric strength with volumetric. Metallized polyester film provides excellent self-healing properties, allowing capacitors to withstand high-pulsed voltages without breaking the dielectric. Polycarbonate film capacitors offer very low temperature dependency, wide operating temperature range, good long-term stability and low losses. Polypropylene film capacitors provide very low losses, low dielectric absorption, and high dielectric strength. They also offer very high insulation resistance and negative temperature coefficient. Polystyrene film capacitors provide extremely low losses, low dielectric absorption, good long-term stability, very high insulation resistance and a small negative temperature coefficient.

Selecting film capacitors requires an analysis of general specifications such as form factor and capacitance type, and a full complement of performance specifications. There are two basic form factors or configurations for film capacitors: leaded and surface mount. Leaded film capacitors have leads for connections to circuits. Surface mount film capacitors or chip film capacitors do not. There are two choices for capacitance type: fixed and variable. Fixed capacitors have a nonadjustable capacitance value. With variable film capacitors, specific capacitance values can be set via an adjustment mechanism, typically a potentiometer. Performance specifications for film capacitors include capacitance range, capacitance tolerance, equivalent series resistance (ESR), DC rated voltage range, AC rated voltage range, rated current, leakage current, pulse rise time, dissipation factor, insulation resistance, and operating temperature.

Film capacitors differ in terms of product features, approvals and applications. Polarized capacitors may be operated safely with only one DC polarity. By contrast, nonpolar capacitors can be operated without regard to polarity. Film capacitors that are destined for sale in European Union (EU) countries must with Restriction of Hazardous Substances (RoHS). In the United States, film capacitors that are designed for military applications must meet military specifications (MIL-SPEC). Polyester capacitors are used in bypassing and coupling applications. Uses for polycarbonate capacitors include timers and filters, as well as high ambient temperature applications. Polypropylene capacitors are used in stable oscillators, sample-and-hold circuits, and pulse-handle circuits. Like other types of film capacitors, polystyrene capacitors can be used in timers and filters.

Semec X2 EMI Suppression Film Capacitor

Semec SCX series X2 Suppression Film Capacitor features value from 0.0022uF to 4.7uF and with pitch from 10mm to 27.5mm. It is ideal for Ideal for filters, power supplies, and mains applications.

SCX series X2 Suppression film capacitor offer tolerance ±10%. For some different values, different case sizes are available for choice which is more suitable for different PCB design. The rated voltage is 250VAC or 275VAC.

This SCX X2 film Capacitor is usually supplied with standard long leads, or also can be cut to shorter leads. Standard offer is bulk pack.

Film Capacitors Comparisons

Capacitor type Dielectric used Features/applications Disadvantages
PET film Capacitor Polyester film Smaller in size when compared to paper or polypropylene capacitors of comparable specifications. May use plates of foil, metalized film, or a combination. PET film capacitors have almost completely replaced paper capacitors for most DC electronic applications. Operating voltages up to 60,000VDC and operating temperatures up to 125°C. Low moisture absorption. Temperature stability is poorer than paper capacitors. Usable at low (AC power) frequencies, but inappropriate for RF applications due to excessive dielectric heating.
Kapton Capacitor Kapton polyimide film Similar to PET film, but significantly higher operating temperature (up to 250°C). Higher cost than PET. Temperature stability is poorer than paper capacitors. Usable at low (AC power) frequencies, but inappropriate for RF applications due to excessive dielectric heating.
Polystyrene Capacitor Polystyrene Excellent general purpose plastic film capacitor. Excellent stability, low moisture pick-up and a slightly negative temperature coefficient that can be used to match the positive temperature co-efficient of other components. Ideal for low power RF and precision analog applications Maximum operating temperature is limited to about +85°C. Comparatively bigger in size.
Polycarbonate Plastic Film Capacitor Polycarbonate Superior insulation resistance, dissipation factor, and dielectric absorption versus polystyrene capacitors. Moisture pick-up is less, with about +/- 80 ppm temperature co-efficient. Can use full operating voltage across entire temperature range (-55°C to 125°C) Maximum operating temperature limited to about 125°C.
Polypropylene Plastic Film Capacitors Polypropylene Has become the most popular capacitor dielectric[citation needed]. Extremely low dissipation factor, higher dielectric strength than polycarbonate and polyester films, low moisture absorption, and high insulation resistance. May use plates of foil, metalized film, or a combination. Film is compatible with self-healing technology to improve reliability. Usable in high frequency applications due to very low dielectric losses. Larger value and higher voltage types from 1 to 100μF at up to 440V AC are used as run capacitors in some types of single phase electric motors. More susceptible to damage from transient over-voltages or voltage reversals than oil-impregnated Kraft paper for pulsed power energy discharge applications.
Polysulphone Plastic Film Capacitors Polysulfone Similar to polycarbonate. Can withstand full voltage at comparatively higher temperatures. Moisture pick-up is typically 0.2%, limiting its stability. Very limited availability and higher cost
PTFE Fluorocarbon (TEFLON) Film Capacitors Polytetra- fluoroethylene Lowest loss solid dielectric. Operating temperatures up to 250°C, extremely high insulation resistance, and good stability. Used in stringent, mission-critical applications Large size (due to low dielectric constant), and higher cost than other film capacitors.
Polyamide Plastic Film Capacitors Polyamide Operating temperatures of up to 200°C. High insulation resistance, good stability and low dissipation factor. Large size and high cost.
Metalized Plastic Film Capacitors Polyester or Polycarbonate Reliable and significantly smaller in size. Thin metalization can be used to advantage by making capacitors "self healing". Thin plates limit maximum current carrying capability.

Thin film capacitors

Electronic circuits are becoming increasingly smaller with the development of integrated circuit techniques. Accordingly, compact electronic circuit units have been developed which have thin-film circuit elements, such as resistors, capacitors, and inductors, on an insulative substrate. Film capacitors exist for a wide capacitance range. In general, the dielectric in such film capacitors comprises a plastic film. The electrodes comprise conductive metal areas. These metal areas are either thin conductor films or conductor layers vapor-deposited onto the plastic film. Thin film capacitor devices generally have a substrate and a lower electrode, a dielectric layer, and an upper layer which are deposited on the substrate in that order. The thin-film capacitors also have a semiconductor substrate functioning as a lower electrode and have a dielectric layer and an upper layer which are deposited on the semiconductor substrate in that order in some cases. The operational characteristics of thin film capacitors become increasingly important as the operation frequency of the various circuits in which these capacitors are included increases. Examples of such circuits include dynamic random access memories, filters and multi-chip modules, in which the thin-film capacitor is employed as a decoupling capacitor. A dielectric thin film capacitor used in a semiconductor device such as DRAM or a noise filter has a structure in which a substrate, a lower electrode, a dielectric thin film, and an upper electrode are stacked in order. The dielectric thin film can be deposited by a sputtering process, a CVD process (chemical vapor deposition), a MBE process (molecular beam epitaxy), a sol-gel process, or a MOD process (metalorganic decomposition).