MML : Capacitors + Bus Bar

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

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.

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.

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...

The MML capacitors feature:

• Non-Inductive Stacked Metallized Polymer Film: Ensures high performance and reliability.
• Encapsulation: Encapsulated in a flame-retardant high-temperature epoxy resin or molded diallyl phthalate (DAP) housing for mechanical and environmental protection.

The MML Series includes several types:

• D Series (bus bars integrated for power electronic conversion or filtering)
• M Series (Small package with radial, DIL or SMD connections)
• C Series (Flat package with DIL connections)
• Custom solution with specific casing and connections to optimize the integration, the heat management and some electrical characteristics.

Each type offers various configurations to suit different applications.

Exxelia's MML Series capacitors boast several key features:

• High Energy Density and High Temperature Capability: Operates effectively up to 140°C.
• Size and Weight Reduction: Up to 50% reduction compared to traditional film technologies and up to 10 times lighers comparing to the ceramic capacitors.
• Stable Performance: Maintains consistent performance across a wide temperature and voltage range.
• Open circuit defect mode with self healing advantage
• Rugged and Lightweight Construction: Ideal for demanding applications.
• Self-Healing Properties: Ensures long-term reliability and safety.

MML Series capacitors are suitable for aerospace & defense: withstand harsh environments and high reliability requirements.

• Inverter
• DC-Link
• Rectifier
• Energy storage

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)

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.