
电容器(英文:capacitor,又稱為condenser)是將儲存在中的。电容器的儲能特性可以用表示。在中鄰近的之間即存在電容,而電容器是為了增加電路中的而加入的電子元件。 電容器的外型以及其構造依其種類而不同,目前常使用的電容器也有許多不同種類(英语:)。大部份的電容至少會有二個金屬板或是金屬. . are manufactured in many styles, forms, dimensions, and from a large variety of materials. They all contain at least two , called plates, separated by an layer (). Capacitors are widely used as parts of in many common electrical devices. Capacitors, together with and , belong to the group of [pdf]
Capacitors are very important elements of electrical and electronic circuits. Sometimes a capacitance of a proper value may not be available. In such situations, grouping of capacitors helps to obtain desired (smaller or larger) value of capacitance with available capacitors.
They all contain at least two electrical conductors, called plates, separated by an insulating layer (dielectric). Capacitors are widely used as parts of electrical circuits in many common electrical devices. Capacitors, together with resistors and inductors, belong to the group of passive components in electronic equipment.
In electrical engineering, a capacitor is a device that stores electrical energy by accumulating electric charges on two closely spaced surfaces that are insulated from each other. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the condenser microphone.
The formula for the total capacity of a group of series capacitors is equal to the sum of the capacitor’s individual resistances: C total = 1/ (1/C1 + 1/C2 + 1/C3 + 1/Cn) where C total is the total capacity and C is the parallel capacitors capacity. Let’s take for instance the case of a circuit with 3 capacitors in series.
• A capacitor is a device that stores electric charge and potential energy. The capacitance C of a capacitor is the ratio of the charge stored on the capacitor plates to the the potential difference between them: (parallel) This is equal to the amount of energy stored in the capacitor. The E surface. 0 is the electric field without dielectric.
Capacitors have many important applications in electronics. Some examples include storing electric potential energy, delaying voltage changes when coupled with resistors, filtering out unwanted frequency signals, forming resonant circuits and making frequency-dependent and independent voltage dividers when combined with resistors.

The classic capacitor failure mechanism is dielectric breakdown. The dielectric in the capacitor is subjected to the full potential to which the device is charged and, due to small capacitor physical sizes, high electrical stresses are common. Dielectric breakdowns may develop after many hours of satisfactory operation.. . Open capacitors usually occur as a result of overstress in an application. For instance, operation of DC rated capacitors at high AC current levels. . The following list is a summary of the most common environmentally "critical factors" with respect to capacitors. The design engineer must take into. [pdf]
No, capacitors do not have resistance in the same way that resistors do. However, real-world capacitors have an inherent resistance known as Equivalent Series Resistance (ESR). This resistance arises from the materials used in the capacitor’s construction, such as the dielectric and the conductive plates.
In addition to these failures, capacitors may fail due to capacitance drift, instability with temperature, high dissipation factor or low insulation resistance. Failures can be the result of electrical, mechanical, or environmental overstress, "wear-out" due to dielectric degradation during operation, or manufacturing defects.
The primary failure mechanism of electrolytic capacitors is due to the thermal stress . In the literature, equivalent series resis-tance (ESR), capacitance C, ripple voltage, volume, and temperature are the proposed lifetime indicators for capacitor monitoring.
Capacitor failure is a significant concern in electronics, as these components play a critical role in the functionality and longevity of electronic circuits. Understanding the nuances of capacitor failure is essential for diagnosing issues in electronic devices and implementing effective solutions.
Real-World Considerations: Parasitic Resistance: Even in the most ideal circuit, there will always be some resistance, whether it’s from the wires, the internal resistance of the voltage source, or the ESR (Equivalent Series Resistance) of the capacitor itself.
The failure rate of capacitors can be divided into three regions by time and is represented by a bathtub curve as shown in Figure 37. (1) Early failures *31 exhibits a shape where the failure rate decreases over time. The vast majority of capacitor's initial defects belong to those built into capacitors during processing.

Electrolytic capacitors use a chemical feature of some special metals, earlier called "valve metals". Applying a positive voltage to the anode material in an electrolytic bath forms an insulating oxide layer with a thickness corresponding to the applied voltage. This oxide layer acts as the dielectric in an electrolytic capacitor. The properties of this aluminum oxide layer compared with tantalum pentoxide dielectric layer are given in the following table: [pdf]
A second aluminum foil, the so-called cathode foil, serves as a large-surfaced contact area for passing current to the oper-ating electrolyte. The anode of an aluminum electrolytic capacitor is an aluminum foil of extreme purity.
The cathode foil has a capacitance (Cc) that uses the oxide layer, which formed by the forming voltage or formed naturally during storage (generally 1V or less), as a dielectric. According to the construction of aluminum electrolytic capacitors, Ca and Cc are connected in a series.
In contrast to other capacitors, the counter electrode (the cathode) of alumi-num electrolytic capacitors is a conductive liquid, the operating electrolyte. A second aluminum foil, the so-called cathode foil, serves as a large-surfaced contact area for passing current to the oper-ating electrolyte.
A 0.05~0.11 mm thick anode foil and a 0.02~0.05 mm thick cathode foil are continuously etched electrochemically in a chloride solution with an AC or DC current. This enlarges the effective surface area of the aluminum foils to attain smaller capacitor sizes. The process develops aluminum oxide (Al203) to form a capacitor dielectric.
1. General Description of Aluminum Electrolytic Capacitors An aluminum electrolytic capacitor consists of cathode aluminum foil, capacitor paper (electrolytic paper), electrolyte, and an aluminum oxide film, which acts as the dielectric, formed on the anode foil surface.
The anode of an aluminum electrolytic capacitor is an aluminum foil of extreme purity. The effec-tive surface area of this foil is greatly enlarged (by a factor of up to 200) by electrochemical etch-ing in order to achieve the maximum possible capacitance values.
We are deeply committed to excellence in all our endeavors.
Since we maintain control over our products, our customers can be assured of nothing but the best quality at all times.