Disadvantages of metal film commonly used in microelectronic integrated circuits

Metal film commonly used in microelectronic integrated circuits disadvantages: the role of different metal film capacitors

1: CBB91 type metalized polypropylene capacitors

Characteristics and uses: insulating tape wrapped around the outside, epoxy resin potting, axial lead; Features: with high insulation, low loss, good frequency characteristics, low equivalent series resistance and so on; Role: for audio The function: suitable for audio crossover, power amplifier, and post-compensation circuits, also suitable for electronic equipment in the DC AC and pulse circuits.

2: CL20/CBB20 axial metallized film capacitors

Non-inductive structure; Features: excellent electrical performance, good reliability, high temperature resistance, small size, large capacity, high frequency loss is small, strong overcurrent ability; Role: for high current, high insulation resistance, good self-healing, long life, stable temperature characteristics, widely used in instruments, meters and Widely used in instruments, meters and household appliances AC and DC circuits, frequency conversion, crossover and other AC, large pulse circuits, especially high-fidelity requirements of the audio crossover circuit.

3: Metallized polypropylene film capacitors

Use: Used for power meter voltage reduction, carrier signal transmission.

Features: (1) low loss, high impedance, high withstand voltage; (2) excellent moisture resistance; (3) excellent flame retardant properties; (4) special process to prevent the generation of destructive corona; (5) excellent capacitance stability under long-term load.

4,: Metallized polyester film capacitors

Use: Bypass, isolation, coupling, decoupling, pulse, logic, timing, circuit oscillator.

Features: (1) excellent pulse resistance; (2) excellent moisture resistance; (3) excellent flame retardant properties; (4) high capacity stability.

5: Metallized polypropylene film capacitors

Use: Specially designed for capacitive step-down circuits with power supplies connected in series

Characteristics: (1) Low loss, high impedance, high withstand voltage; (2) Excellent moisture resistance; (3) Excellent flame retardant properties; (4) High capacity stability, using a special process, to prevent destructive corona generation. (5) Powder encapsulation, smaller capacitor size

6: Metallized polypropylene film capacitors

Use: Used for meter voltage reduction power supply, carrier signal transmission.

Features: (1) low loss, high impedance, high withstand voltage;: (2) excellent moisture resistance; (3) excellent flame retardant properties; (4) using a special process to prevent the generation of destructive corona; (5) excellent capacitance stability under long-term load.

Film capacitor advantages

1, good heat resistance.

Rated operating temperature of 70 ℃, the maximum operating temperature of up to 155 ℃; good voltage stability, temperature coefficient is small.

2, very wide range of applications, suitable for AC, DC and pulse circuits.

3, no polarity, high insulation impedance, excellent frequency characteristics (wide frequency response), and dielectric loss is very small. Based on the above advantages, film capacitors are used in a large number of analog circuits. Especially in the signal interconnection part, must use the good frequency characteristics, dielectric loss is very low capacitance, to ensure that the signal in the transmission, not too much distortion occurs.

Metal Film Capacitor Advantages

1) The main circuit inside the movement adopts the process structure of copper strip bridge, the thickness of the copper strip is guaranteed, the main circuit has strong overcurrent capability, and the temperature rise of the copper strip is low. Installation and operation is simple, convenient, fast, efficient, greatly reducing the chance of error.

2) The main circuit of metallized film capacitor only needs two copper strips, instead of the previous large piece of PCB, in the product material cost

3) The main circuit is separated from the drive control part, so as to achieve the separation of strong/weak power. Reduce the interference of the main resonance circuit to the chip drive part. After-sales maintenance of the product to bring convenience, components can be reused, reducing maintenance costs.

4) As the capacitors are packaged in the form of modules, the aluminum shell can be used to dissipate heat, and the movement can be completely sealed. Solve the problem of grease, smoke, water, cockroach, metal dust, etc. into the movement of the internal problems, improve the reliability and service life of the product.

5) metallized film capacitors from a number of discrete parallel to a single module form, to solve the problem of discrete capacitors overcurrent uniform, uneven voltage and other issues, shorten the line distance of the main circuit, reduce the distribution of the line inductance on the impact of power components.

6) The biggest feature of this capacitor is that it is self-healing. If the voltage is too high, so that the capacitor internal media at a certain point is broken, then the short-circuit current will make the media damage at the metal film evaporates, so as to avoid a short circuit between the two poles, so that the capacitor continues to work. Of course, the range of breakdown should not be too large, or affect the capacitance of the capacitor. Metal film paper j capacitors are usually encapsulated with epoxy resin, so the moisture-proof performance is very good.

Metallized film capacitors disadvantages

Principle_of_analysis, metallized film capacitors should not have a short-circuit failure mode, while metal foil capacitors will be a lot of short-circuit failure now. Metallized film capacitors have the above great advantages, but compared with metal foil capacitors, there are two disadvantages:

One is the stability of the capacity is not as good as the foil capacitors, this is due to the metallized capacitors in the long term operating conditions prone to loss of capacity, as well as self-healing can lead to a reduction in the capacity, therefore, such as in the capacity of stability of the requirements of the oscillator circuit is very high use, should be better to use a metal foil capacitor.

Another major drawback is the ability to withstand large currents is poor, this is due to the metallized film layer is much thinner than the metal foil, the ability to carry large currents. In order to improve this disadvantage of metallized film capacitors, the current manufacturing process has been improved in the high-current metallized film capacitors