What are the categories of polymer capacitors?

Polymer capacitors are a type of capacitor that uses conductive polymers as electrodes or electrolytes, with advantages such as low equivalent series resistance (ESR), high ripple current carrying capacity, and long lifespan. They are widely used in consumer electronics, automotive electronics, industrial control, and other fields. The following are the main categories, characteristics, applications, and selection points of polymer capacitors:
1、 Classified by medium material
Conductive Polymer Tantalum Capacitors
Medium: Tantalum oxide (Ta ₂ O ₅) as the dielectric layer, conductive polymers (such as PEDOT, PPy) as the cathode.
characteristic:
Ultra low ESR: ESR values can be as low as 5m Ω or below, with excellent high-frequency performance.
Long lifespan: Conductive polymers have high stability and a lifespan of over 100000 hours.
High reliability: Strong surge resistance, suitable for high stress environments.
Applications: high-end computing devices (such as servers, GPUs), automotive electronics, aerospace.
Common models: TPS, TPM series.
Conductive Polymer Aluminum Capacitors
Medium: Aluminum oxide (Al ₂ O3) as the dielectric layer, conductive polymer as the cathode.
characteristic:
Low ESR: ESR values are usually less than 20m Ω, suitable for high-frequency applications.
High capacity density: With the same volume, the capacity is greater than that of traditional aluminum electrolytic capacitors.
Long lifespan: The lifespan can reach thousands to tens of thousands of hours.
Applications: LED drivers, power adapters, laptops.
Common models: PAN, PAS series.
Conductive Polymer Hybrid Capacitors
Medium: Combining conductive polymers with traditional electrolytes to form a mixed electrolyte.
characteristic:
Balanced performance: combines low ESR and high capacity density.
Cost optimization: Compared to all polymer capacitors, the cost is lower.
Applications: General power filtering, consumer electronics.
Common models: PHC, PHM series.
2、 Classified by structural form
Coiled polymer capacitor
Structure: The electrode is made of conductive polymer and the dielectric material is wound.
characteristic:
Large capacity: suitable for high current applications.
Large volume: not suitable for high-density circuit boards.
Applications: Power electronics, industrial control, audio equipment.
Common models: TPS winding series.
Stacked polymer capacitors (MLPC)
Structure: Composed of multiple layers of conductive polymers and media alternately stacked.
characteristic:
Compact size: suitable for high-density circuit boards.
Excellent high-frequency characteristics: low equivalent series inductance (ESL) and high self resonant frequency.
Capacity stability: low temperature coefficient.
Applications: 5G base stations, medical equipment, aerospace.
Common models: MLPC-X2, MLPC-Y2.
3、 Classified by application scenario
High frequency polymer capacitor
Features: Ultra low ESR, high self resonant frequency, suitable for high-frequency circuits.
Applications: RF circuits, communication equipment, high-frequency switching power supplies.
Selection: Conductive polymer tantalum capacitor or stacked polymer capacitor.
Large capacity polymer capacitor
Features: High capacity density, low ESR, suitable for energy storage and filtering.
Applications: electric vehicle charging stations, high-voltage direct current transmission (HVDC), industrial power sources.
Selection: Conductive polymer aluminum capacitor or coiled polymer capacitor.
High temperature polymer capacitor
Features: High temperature resistance, high stability, suitable for harsh environments.
Applications: automotive electronics, aerospace, industrial control.
Selection: Specially designed polymer capacitors, such as PPS or PEN dielectric capacitors.
4、 Classified by security level
Safety compliant polymer capacitor
Definition: Polymer capacitors that have undergone safety certification (such as UL, ENEC, CQC) and are specifically designed to prevent electric shock and electromagnetic interference.
characteristic:
X capacitor (X1/X2/X3): Connected across power lines to suppress differential mode interference.
Y capacitor (Y1/Y2/Y3/Y4): Connected across the power line and ground to suppress common mode interference.
Applications: Home appliances, industrial equipment, power adapters.
Selection: Prioritize X2/Y2 capacitors, balancing safety and cost.
5、 Key parameters for selection
Rated voltage: It needs to be 1.25 times higher than the actual working voltage (such as selecting a 315VAC capacitor for a 250VAC circuit).
Capacity: Choose based on filtering or energy storage requirements, excessive capacity may increase costs.
ESR: High frequency circuits should choose models with ESR<10m Ω.
Temperature range: For extreme environments, products should be selected between -55 ℃ and+150 ℃.
Package size: In space limited scenarios, surface mount or miniaturized packaging is preferred.
Safety certification: Must comply with safety standards such as UL, ENEC, CQC, etc. (for safety capacitors).
6、 Typical application scenarios
Consumer electronics: Smartphones use stacked polymer capacitors to ensure high-frequency performance.
Automotive electronics: Electric vehicle charging stations use high-capacity polymer capacitors to ensure high current filtering stability.
Communication equipment: 5G base stations use high-frequency polymer capacitors to resist high-frequency signal loss.
Aerospace: The satellite power system uses high-temperature polymer capacitors to resist radiation and vibration.
By reasonable classification and selection, polymer capacitors can fully leverage their advantages of low ESR, high frequency, and high stability to meet diverse circuit needs.