1. Film Capacitors Overview

2. Film Capacitors
A film capacitor is made by winding or “stacking” plastic film between two electrodes.
Polypropylene and Polyester are the two most widely used film dielectric materials.
Each end is sprayed with a metal coating “endspray” to lower the resistance and acts as a base to solder or weld wire leads to.
The winding or stack, a.k.a “sections” may be placed in a can or box or tape wrapped and end filled with epoxy.
Wound Construction
Stacked Construction

3. Dielectrics, Polyester
Higher loss than polypropylene: best suited for DC applications.
Lower Cost per CV rating
Higher temperature up to 105°C without derating.
Blocking circuits
By-passing
Coupling/Decoupling
Filtering
Timing
Across the line X2

4. Dielectrics, Polypropylene
Lower loss than polyester. Lower ESR
Used in high frequency, snubber and pulse applications.
Cost more per CV rating than polyester.
Rated to 85°C without derating.
High frequency coupling / decoupling
High pulse operation
Snubber
High voltage circuits
Input / output filtering
Across the line X2

5. Electrode Types Metallized Electrodes
Metal deposited electrodes (metallized capacitors) are used for volumetric efficiency and for self healing. Typically, aluminum is used for DC, Zinc for AC.
Metallized Self Healing
When a short occurs in the dielectric, the metallization evaporates in the fault area, creating a “clearing” that allows the capacitor to continue to operate with minimal capacitance loss.
Aluminum Foil Electrodes
Foil electrodes are used in DC applications for high pulse current or high ripple current.

6. Package Styles General Purpose and Commodity Custom Packaging
Wrap & Fill
SMT
General Purpose and Commodity
Dipped Radial
Large Wrap and fill with screw Terminals
Custom Packaging
Molded or Custom Box
Custom Plastic or Metal Case
DC Link, Plastic cylindrical Case, Hockey Puck
IGBT Snubber, Plastic Case
DC Link, Plastic cylindrical Case
IGBT Snubber and DC Link
DC Link, Cylindrical Aluminum Case, Plastic Header
DC Link, Plastic Case

7. General Purpose DC Film Applications
Primarily used for DC Filtering/Smoothing
Electronic Controls
Power Supplies
Motor Controls
Communications
Audio

8. General Purpose DC Film Competitors

9. Custom Film Capacitors
Variations of existing part numbers
Terminal modifications / crimps
Size constraint modification
Custom metallization for optimal performance in specific applications:
Highly Customized Design
Customer specific requirements
Tooled boxes or custom terminations

10. Custom Taser Orange Drop Capacitors
Segmented Metallized Film

11. Custom Film Applications
Specialty Strobe (Pulse)
Tasers
Airport Runway Lighting
Aircraft Lighting
Flashing Beacons
Motion Control (Bus Filter and Snubbers)
Motor Drives
Elevators
Aircraft actuators to control flap movement
Computer Numerical Control Equipment
HVAC (Filters and Snubbers)
Electric Vehicles (Filters and Snubbers)
Electric Trains
Electric Cars & Trucks
Welding and Induction Heating (Filters and Snubbers)

12. Custom Film Applications
Battery Chargers (Filters and Snubbers)
Electric vehicles
Power Supplies (Filters and Snubbers)
UPS
Cable Backup
Linear Power Supplies SMPS
Alternative backup (Filters and Snubbers)
Flywheel Energy Storage
Medical (Filters, Snubbers and Energy Discharge)
X-Ray and MRI imaging
Defibrillation, Energy Discharge
Emergency Vehicle Strobe Lighting (Pulse)
Ambulance, Police, Fire, Strobe Lighting

13. Custom Film Applications
Generators (Filters and Snubbers)
Gasoline or Diesel to Electric
Commercial / Residential Power Backup (Filters and Snubbers)
Fuel Cell Technology
Military
Electric Vehicles
Aircraft
Power Supplies
Motion Control

14. Custom Film Competitors

15. Power Film Capacitors IGBT Snubber Axial Leaded – 940, 941, 942, 943
Direct Mount – SCD, SCC, SCM
Medium Power DC Link
Radial – UNL, BLC
High Power DC Link
Bus Mount – 944, 947C, 947D

16. Power Film IGBT Snubber
IGBT snubbers are designed to protect IGBTs in large inverters
The snubber capacitor reduces the voltage spike across the IGBT during switching 16

17. IGBT Snubber Competitors17

18. Power Film Medium / High Power DC Link
Smooth the rectified DC
High Capacitance
Filter switching frequency currents
Low ESR

19. DC Link Applications Inverter Unit Renewable Energy Power Supply
Solar Inverter
Wind Inverter
Fuel Cell Inverter
Power Supply
UPS (Uninterruptible Power Supply) Induction Heater
SMPS (Switch Mode Power Supply)
Welder, Cutter
Medical Equipment (X-Ray, CT Scan)
Motor Drive
VVVF (Variable Voltage Variable Frequency) Inverter
AC Servo / Spindle / Robot
HVAC (Heating, Ventilation, and Air Conditioning)
Elevators
Traction
HEV/EV

20. DC Link Competitors 20

21. Film Capacitor Selling Tips
Identify most important characteristic:
Capacitance
Voltage
AC or DC?
Peak current or ripple current
Ambient temperature
Size, packaging
Obtain Competitive PN and/or part specification.
Highly customized parts benefit from direct engineering communication 21