Metallized Film Capacitors: MKP, Polyester & PPS
Metallized film capacitors across dielectric and mounting formats
A metallized film capacitor uses a thin metal electrode deposited on a plastic-film dielectric. “Metallized” describes its electrode construction, not a single dielectric, capacitance range or safety rating. This collection contains predominantly metallized polypropylene (MKP) radial and axial audio/circuit parts, plus metallized polyester through-hole choices, small PPS and other SMD film listings, selected X2-labeled suppression products and CBB60/CBB61 AC motor capacitors. Identify the exact selected product before assuming any of these are interchangeable.
Compare the actual component families
- MKP / metallized polypropylene: CBB21 and CBB81 fixed-value listings, radial audio-coupling and axial crossover parts have differing capacitance, voltage and lead geometry. Selected CBB81 listings advertise 2000 V DC, while some audio variants advertise 100, 250, 400 or 630 V; these ratings are not shared across products.
- Metallized polyester: selected 33 nF through-hole MMXV and other polyester listings have their own dielectric, 400 V listing and lead pitch. Polyester and polypropylene differ in application-dependent losses and pulse behavior and must not be swapped just because both are metallized film.
- SMD film: an ECHU-labeled 1206/3216 listing describes 22 nF, 16 V and PPS, while an ECPU-labeled 0805/2012 listing describes 100 nF, 16 V and 20% tolerance. Verify the original manufacturer's part number, dielectric, solder footprint and termination before use; SMD dimensions alone are insufficient.
- Axial audio and crossover: the Bevenbi MKPA-E listing has many independent capacitance and 100/250/400 V combinations, including additional options after the first 100. Confirm the selected pair, size and crossover schematic; subjective “HiFi” or brand references do not prove electrical performance or genuine origin.
- AC applications: X2-labeled MKP 275 VAC options and CBB60/CBB61 motor parts require different application-specific verification. Check the actual safety marking and approvals for across-line suppression; motor duty, terminals and AC voltage for a run capacitor.
Selection workflow
- Define circuit position: signal coupling, loudspeaker crossover, filter, pulse circuit, AC line suppression or motor running.
- Match capacitance and tolerance on the actual variant, converting pF, nF and µF carefully. Capacitance alone never establishes a replacement.
- Confirm the dielectric and construction, then compare DC and AC ratings without equating them. High DC voltage is not an X2 safety approval.
- Measure mounting style, radial pitch or axial lead span, case dimensions and, for SMD parts, both land pattern and soldering requirements.
- Check temperature and relevant dissipation, ripple-current, pulse and dv/dt data in the exact part's documentation before high-stress use.
- For mains or motors, verify the required X-class approvals or motor-run duty and equipment specification; do not rely on a marketplace title or generic wiring advice.
Procurement checklist
- Full part number, exact variant and dielectric
- Capacitance, tolerance and appropriate DC/AC rating
- Pulse, ripple, dissipation and temperature limits where required
- X2 classification and verified approvals for across-line use
- Motor duty and terminal arrangement for CBB60/CBB61
- Radial/axial/SMD geometry, lead pitch and order quantity
Frequently asked questions
Does metallized film mean polypropylene?
No. Metallized electrodes are also used with polyester and other film dielectrics. Read the exact product's dielectric.
Can a 2000 V CBB81 replace a 275 VAC X2 part?
No. DC voltage does not establish an approved across-the-line safety classification.
Are axial crossover capacitors interchangeable with radial MKP parts?
Not by capacitance alone. Check tolerance, voltage, losses, mounting dimensions and circuit design.
Can a 16 V SMD film capacitor replace a 16 V ceramic capacitor?
Not automatically. Compare effective capacitance, dielectric behavior, temperature, losses and PCB footprint for the specific parts.
