Film Capacitors Overview

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

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

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

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.

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

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

General Purpose DC Film Competitors

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

Custom Taser Orange Drop Capacitors Segmented Metallized Film

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)

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

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

Custom Film Competitors

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

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

IGBT Snubber Competitors 17

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

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

DC Link Competitors 20

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