What are the characteristics of metallized film capacitors?

Introduction

Film capacitors are a high-performance capacitor due to their many excellent properties. Its main characteristics are as follows: non-polarity, high insulation impedance, excellent frequency characteristics (wide frequency response), and very small media loss. Based on the above advantages, film capacitors are heavily used on analog circuits. Especially in the part of the signal cross-linking, it is necessary to use capacitors with good frequency characteristics and very low media loss to ensure that the signal is transmitted without too much distortion. Of all the film capacitors, polypropylene (PP) capacitors and polystyrene (PS) capacitors are the most significant, and of course the prices of these two capacitors are high. However, in recent years, audio equipment in order to improve the quality of sound, the use of parts materials has become more and more advanced, price is not the most important consideration, so in recent years PP capacitors and PS capacitors are used in audio equipment frequency and quantity is also increasing.

2. Category

The usual film capacitors method is to make foils such as aluminum as electrodes and plastic films that overlap and wrap them together. But another method of manufacturing, called metalized film, is to vacuum-coat a thin layer of metal on a plastic film as an electrode. This can save the thickness of electrode foil, reduce the volume of capacitor unit capacity, so thin film capacitors are easier to make small, large capacity capacitors. A common MKP capacitor, for example, is the name of Metailized Polypropylene Film Capacitor, while MKT is the name of Metailized Polyester Capacitor. 

3. Features

Good heat resistance, rated operating temperature of 70 degrees C, the maximum operating temperature of up to 155 degrees C. (2) The voltage stability is good and the temperature coefficient is small.

Very widely used for AC, DC and pulse circuits. 

4. Features

Metallized film capacitors are non-inductive, using polyester film as a medium and aluminum foil for electrode winding, tinned copper-coated steel wire, with epoxy envelope; 4, ESR low. Technical requirements: rated temperature: -40 degrees C to 85 degrees C; Rated voltage: 100V, 250V, 400V, 630V; power capacity range: 0.001UF to 0.47UF; Power capacity deviation: ±5%(J), ±10 (K), ±20% (M), loss positive cut angle: 1.0% (max) at 1KHz, voltage resistance: Teminal to (at20±5 degrees C). This product is ideal for commercial and industrial equipment that require noise-reducing small signal circuits. 

5. Features

High impedance, with good weldability and self-responsion properties, micro-saving size space. Specifications: 1, operating temperature: -40 degrees C to 85 degrees C; 3, capacitor tolerances: ±5% (J), ±10 (K), ±20% (M); 1.0%(max) at 1KHz; voltage resistance: Teminal to (at20±5 degrees C). This product is suitable for coupling, filtering, rectation and timing circuits and is widely used in remote communication, data processing, industrial instrumentation and automatic control system equipment.