1. Overview

Film capacitors are a type of electronic component using plastic films (e.g., polypropylene, polyester) as dielectric materials. They are non-polarized capacitors with high insulation resistance, low loss, and excellent long-term stability. These capacitors play critical roles in power electronics, automotive systems, renewable energy, and consumer devices due to their reliability and high voltage-handling capabilities.

2. Main Types and Functional Classification

3. Structure and Composition

Film capacitors typically consist of metalized plastic films wound or stacked into a cylindrical/rectangular core. The dielectric thickness ranges from 1-10 m, with electrode materials like zinc or aluminum. The assembly is encapsulated in epoxy resin or plastic housings. Key structural elements include:

• Dielectric layer (plastic film)
• Metallized electrode patterns
• Termination electrodes (sprayed metal contacts)
• Protective outer coating

4. Key Technical Parameters

5. Application Fields

Main industries and equipment:

• Power electronics: AC/DC converters, frequency inverters
• Automotive: Electric vehicle (EV) on-board chargers, battery management systems
• Consumer electronics: LED lighting, plasma TVs
• Industrial: Uninterruptible power supplies (UPS), welding machines
• Renewable energy: Solar inverters, wind turbine converters

6. Leading Manufacturers and Products

7. Selection Guidelines

Key considerations:

1. Determine required capacitance and voltage ratings with safety margins
2. Assess environmental conditions (temperature, humidity, vibration)
3. Evaluate dielectric absorption and frequency response requirements
4. Consider packaging constraints (through-hole vs. surface-mount)
5. Analyze cost-performance trade-offs for mass production

8. Industry Trends

Emerging trends include: development of high-power-density capacitors for EVs, adoption of nanodielectric materials for improved thermal stability, growth of biodegradable film technologies, and integration of smart monitoring features in industrial capacitors. The market is projected to grow at 7.2% CAGR (2023-2030), driven by renewable energy and 5G infrastructure demands.