Film & Mica Capacitors

This natural mineral insulator has outstanding dielectric properties that are ideal for long-life high-stability capacitors with low loss at all frequencies, and high dielectric strength. This type of capacitor is used particularly for high frequency and delay line applications, oscillating circuits, emission devices and calibrators.

Mica dielectric capacitor technology allows for several custom design applications including: 

• High voltage capacitors (up to 50 kV)
• High temperature capacitors (up to 250°C)
• Precision capacitors (up to ± 0.1%)
• High stability capacitors (– 20 + 30 ppm/°C)
• High frequency capacitors ( up to several GHz). 

The majority of these capacitors are manufactured to comply to specifications NF-C-83120;MIL-C-5 and MIL-PRF-39001 standards.

Mica capacitors are noted for the following characteristics:

• Temperature performance
• Low loss at all frequencies
• High dielectric strength
• Stability over time

MIL-qualified capacitors meet stringent military specifications (e.g., MIL-PRF and MIL-STD standards) ensuring high reliability, durability, and performance in critical applications like aerospace, defense, and industrial electronics.

Silver mica capacitors provide superior stability and low loss when used in RF power circuits that require low pico farad (pF) and nano farad (nF) ranges. Older silver mica capacitors were manufactured in layers of mica and silver, but the layering allowed room for air gaps that reduced the stability and could also create stress fractures in the assembly.

Modern manufacturing uses silver plated to mica layers, eliminating the gaps. When the desired number of layers is obtained, the assembly is coated in an epoxy or ceramic resin. The coating reduces fracturing of the layers and seals the assembly from moisture and particles that could interfere with the capacitance value.

Mica capacitors are useful in circuits for ripple filtering and are often found in time constant, coupling or resonance circuits. In addition to radio circuits, they are used in TV transmitters and Cable TV amplification circuits. Mica is also a superior choice in high-voltage inversion and power conversion for energy absorbing snubber applications with capacitances of up to 10 nF.

Exxelia manufactures its MIL-qualified capacitors in accordance with all relevant military specifications. Capacitors are tested, marked, and validated to meet operational parameters outlined in MIL standards such as MIL-PRF-39006 and MIL-PRF-55514.

Standard silver mica capacitors are normally designed to handle voltages from 100 to 1000 volts. High-voltage RF transmitter applications can call for higher tolerances. Mica capacitors are available for voltages up to 20kV.

Our expert engineering team can create the mica capacitor with the characteristics you require. Send us your drawing or file and we will work with you to manufacture the correct size, lead style and capacitance you desire.

Exxelia offers capacitors with established reliability, achieving failure rates as low as 0.001% per 1,000 hours (S level) at a 90% confidence level. Other available levels include M (1%), P (0.1%), and R (0.01%).

Plastics come in such a wide range that they can cater to most of our technical needs. They can be used in high-temperature applications (Teflon), power (polypropylene), energy conversion (polyester), and for functions requiring high stability (polycarbonate). 

The product range extends from capacitor outputs for implementation on printed circuits, to metal housings with terminal output for power capacitors in wired circuits. Surface mounted devices (SMD) and film capacitors withstanding high temperatures are also manufactured.

Exxelia's MIL-qualified capacitors comply with key specifications such as:

• MIL-PRF-39006: Wet tantalum capacitors for high-reliability applications.
• MIL-PRF-55514: Film capacitors for DC and AC circuits.
• MIL-PRF-83421: Metallized plastic film capacitors.

Yes, Exxelia offers custom configurations and extended/intermediate values upon request. This flexibility allows for tailored solutions to meet specific application requirements and could help your design with easiest integration, cost saving, thermal management optimization, sensors or filter integrations etc...

MIL-qualified capacitors guarantee:

• Resistance to extreme conditions (temperature, vibration, humidity).
• Long operational life and low failure rates.
• Strict quality assurance processes validated by military standards.

General Electrical Specifications:

• Capacitance Range: From 1µF to 2 000µF depending on the series.
• Voltage Range: From 50V to 2000V DC.
• Operating Temperature: From -55°C to +140°C, with some derating above 125°C.
• Dissipation Factor (Tg d): Typically 60 . 10^-4
• Insulation Resistance: Minimum of 10,000 MΩ-µF at rat ed voltage and 25°C.
• Current: few Amps to hundreds of Amps (according to  the capacitor construction)

MIL specifications are publicly accessible via government websites like www.dla.mil/Land-and-Maritime 

Exxelia also provides guidance to help you select the right components for your projects.

MML capacitors are tested to meet various environmental and durability standards:

• Humidity (Steady-State): MIL-STD-202 Method 103.
• Barometric Pressure (Reduced): MIL-STD-202 Method 105.
• Thermal Shock: MIL-STD-202 Method 107.
• Life Test (Elevated Ambient Temperature): MIL-STD-202 Method 108.

These capacitors are ideal for industries requiring high reliability, such as:

• Aerospace and aviation
• Defense and military equipment
• High-performance industrial electronics