| Film Thickness | 1–12 μm | Polypropylene and polyester dielectric films are selected according to voltage, capacitance density, pulse stress, and mechanical requirements. | Thinner films support higher volumetric capacitance; thicker films generally provide greater voltage and mechanical margin. | DC-link, snubber, EMI suppression, energy storage |
| Primary Dielectric Materials | Polypropylene (PP); polyester (PET) | PP offers low dielectric loss and strong electrical performance, while PET provides higher dielectric constant and compact construction. | Material selection balances loss, size, temperature capability, and cost. | Power electronics, motor drives, industrial controls |
| Metallization Material | Aluminum or zinc-aluminum alloy, typically vacuum deposited | A very thin metal layer is deposited on the polymer film to form the electrodes while keeping the component lightweight and compact. | Compared with foil electrodes, metallization reduces mass and enables self-healing behavior. | General-purpose and power-film capacitors |
| Self-Healing Function | Localized dielectric fault clearing | When a localized breakdown occurs, the fault current vaporizes the nearby metallization, electrically isolating the damaged spot without destroying the entire winding. | Improves operational reliability and allows continued service after minor localized defects. | DC-link, AC filtering, lighting, industrial equipment |
| Capacitance Tolerance | Commonly ±5% or ±10% | Actual tolerance depends on the capacitor series, dielectric system, rated voltage, and customer specification. | Supports circuit tuning, filtering accuracy, and replacement compatibility. | Power conversion, control circuits, EMI filters |
| Rated Voltage Classes | Approximately 63 VDC to 2,000 VDC; higher ratings available in specialized designs | Rated voltage is determined by dielectric thickness, metallization pattern, winding design, insulation system, and safety margin. | Provides design options from low-voltage electronics to high-voltage DC-link systems. | Inverters, photovoltaic systems, EV powertrains, industrial drives |
| AC Rated Voltage | Typically from 100 VAC to 1,000 VAC depending on construction | AC-rated capacitors must account for RMS current, peak voltage, frequency, temperature rise, and repetitive pulse stress. | Suitable for AC filtering, power-factor correction, and suppression networks. | Motor drives, UPS systems, grid-connected converters |
| Operating Temperature | Common ranges: −40°C to +85°C; −40°C to +105°C; selected designs up to +125°C | Temperature capability depends on film type, winding structure, encapsulation, internal hot-spot temperature, and lifetime requirements. | Enables use in equipment exposed to ambient temperature variation and thermal cycling. | Automotive electronics, renewable energy, factory automation |
| Dissipation Factor | Typically below 0.1% for polypropylene designs at reference conditions | Dissipation factor varies with frequency, temperature, dielectric material, and manufacturing structure; PET designs generally have higher loss than PP. | Lower loss reduces heat generation and improves high-frequency efficiency. | High-frequency converters, resonant circuits, pulse applications |
| Insulation Resistance | Commonly specified in the GΩ range or by RC product requirements | Insulation resistance is evaluated after charging under defined conditions and is influenced by film quality, moisture, temperature, and construction. | Reduces leakage current and supports stable long-term electrical performance. | DC-link storage, precision filtering, instrumentation |
| High-Frequency Current Capability | Application-specific; determined by RMS current, frequency, ESR, and thermal design | Current capability is not defined by capacitance alone. Internal losses, terminal design, winding dimensions, cooling, and ambient conditions must be considered. | Supports reliable operation under switching ripple and repetitive current pulses. | IGBT and SiC inverters, welding equipment, induction heating |
| Construction Formats | Radial leaded, axial leaded, box-type, cylindrical, flat-wound, and busbar-mounted | Form factor and terminal layout are customized for PCB mounting, chassis mounting, low-inductance connections, or high-current busbars. | Improves installation flexibility and helps reduce parasitic inductance. | PCB assemblies, converter cabinets, traction systems |
| Safety and Flame Protection | Design-dependent; may include flame-retardant encapsulation and pressure-interrupt devices | Safety-related construction is selected according to application risk, operating voltage, fault behavior, and the relevant capacitor standard. | Improves fault containment and application safety when correctly specified. | AC mains suppression, lighting, appliances, industrial equipment |
| Reference Standards | IEC 60384-1; IEC 61071; IEC 60384-14; UL and national requirements where applicable | The applicable standard depends on whether the component is used for electronic equipment, power electronics, or across-the-line and line-to-ground suppression. | Provides a framework for electrical, mechanical, environmental, and endurance testing. | Global procurement, qualification, and compliance programs |
| Typical Quality Tests | Capacitance, dissipation factor, insulation resistance, voltage proof, self-healing behavior, temperature cycling, endurance | Production and qualification tests are selected according to the product specification and applicable standard. | Helps verify consistency, electrical safety, durability, and suitability for the intended duty cycle. | Incoming inspection, production control, reliability validation |