Why Do Electrolytic Capacitors Explode?

If you want to know why the electrolytic capacitor explodes, first you have to know what the electrolytic capacitor is. An electrolytic capacitor is a kind of capacitance. The metal foil is the positive electrode (aluminum foil or tantalum foil), and the oxide film (aluminum oxide or tantalum oxide), which is closely attached to the metal, is the dielectric. The cathode consists of conductive material, electrolyte (which can be liquid or solid) and other materials. Because the electrolyte is the main part of the cathode, the electrolytic capacitor is hence named. At the same time, the capacitance of the electrolytic capacitor cannot be connected wrongly.


Tantalum electrolytic capacitor mainly consists of sintering solid, foil winding solid, sintering liquid, and so on. The sintered solids account for more than 95% of the current production and are mainly composed of non-metallic sealed resin.

The aluminum electrolytic capacitor can be divided into four types: the lead type aluminum electrolytic capacitor; Horn type aluminum electrolytic capacitor; Bolted aluminum electrolytic capacitor; Solid aluminum electrolytic capacitor.

The possible reasons for the capacitor explosion are as follows:

  1. The breakdown of the internal components of the capacitor is mainly due to the poor manufacturing process.
  2. The capacitor is damaged by insulation to the shell. The high voltage side of the capacitor is made of a thin steel sheet. If the manufacturing process is poor, the edge is uneven with burr or serious bend. The tip is prone to corona, and the corona causes the breakdown of oil, the expansion of the case and the drop of oil. In addition, when the cover is closed, if the welding time is too long, the internal insulation burns and produces oil and gas, causing the voltage to drop greatly and damage.
  3. Poor sealing and oil leakage. The insulation resistance is reduced due to the poor sealing of the assembly casing. Or the oil spill caused the oil surface to drop, resulting in the extreme shell direction discharge or component breakdown.
  4. The belly and the inside dissociate. Due to the internal corona, breakdown discharge, and serious dissociation, under the action of overvoltage, the starting free voltage of the element is reduced to the working electric field intensity. This causes the physical, chemical and electrical effects to accelerate the aging and decomposition of the insulation, producing gas and forming a vicious circle, the pressure of the case is increased, causing the drum to explode
  5. A capacitor explodes with an electric charge. All capacitors with rated voltages are forbidden to be charged. Each time the capacitor bank recloses, the capacitor must be discharged for 3min after the switch is disconnected. Otherwise, the voltage polarity of the closing moment may be caused by the opposite polarity of the residual charge on the capacitor. For this purpose, a capacitor bank with a capacity of more than 160kvar is generally required, and automatic tripping device should be installed when there is no pressure. And the capacitor bank switches are not allowed to install automatic reclosing.

In addition, it may be caused by high temperature, poor ventilation, high operating voltage, excessive voltage harmonic component or operating overvoltage, etc.

Stanford Advanced Materials (SAM) is a leading supplier and manufacturer of high-quality capacitor grade tantalum powder and tantalum wire with competitive price and great delivery time. Please visit http://www.samaterials.com for more information.

What Are the Advantages of Tantalum Electrolytic Capacitors

Tantalum electrolytic capacitors are widely used in communications, computers, aerospace, and military, as well as advanced electronic systems, portable digital products, and other fields.

Tantalum electrolytic capacitor is made of tantalum (Ta) metal as anode material, which can be divided into foil type and tantalum powder sintered type according to different anode structures. Among tantalum powder sintered tantalum capacitors, there are tantalum capacitors with solid electrolyte and tantalum capacitors with non-solid electrolyte due to different electrolytes. The shell of tantalum electrolytic capacitors is marked with CA, but the symbol in the circuit is the same as that of other electrolytic capacitors. Compared with aluminum electrolytic capacitors, tantalum electrolytic capacitors have the following advantages.


Small volume

Because tantalum electrolytic capacitors are made of very fine tantalum powder, and the dielectric constant of the tantalum oxide film is higher than that of the alumina oxide film, the capacitance per unit volume of tantalum electrolytic capacitors is large.

Wide temperature range for use

Tantalum electrolytic capacitor in commonly can work normally at the temperature of -50 ℃~100 ℃. Although the aluminum electrolytic capacitor can also work in this range, its electrical performance is not as good as that of the tantalum electrolytic capacitor.

Long life, high insulation resistance, and small leakage current

Tantalum oxide film in tantalum electrolytic capacitors is not only corrosion resistant but also can maintain good performance for a long time.

Good impedance frequency

For capacitors with poor frequency characteristics, the capacitance will drop sharply and the loss (tg delta) will also rise sharply when the working frequency is high. However, solid tantalum electrolytic capacitors can operate above 50kHz. When the frequency of the tantalum electrolytic capacitor increases, the capacity will also decrease but by a small margin. The data show that the tantalum electrolytic capacitor capacity decreases by less than 20% at 10kHz, while the aluminum electrolytic capacitor capacity decreases by more than 40%.


High reliability

Tantalum oxide film has stable chemical properties. In addition, Ta2O5 anode substrate of tantalum can withstand strong acid and pressure, so it can use a liquid electrolyte with low resistivity of solid or acid. In this way, tantalum electrolytic capacitors have less loss than aluminum electrolytic capacitors and have good temperature stability.

Chip tantalum electrolytic capacitors are made of highly pure and extremely small homogeneous particles, which are characterized by small size, large capacity, and high frequency. In recent years, chip tantalum electrolytic capacitors have been widely used in mobile phones, DVDs and other consumer electronic products.

Please visit http://www.samaterials.com for more information.

How are Tantalum Capacitors used in Audio and Microphone Industry?

As tantalum capacitors have become more widely used in the market, their models and supply volumes have increased and prices have started to fall. Nowadays, aluminum electrolytic capacitors are replaced by tantalum capacitors in many industries. Of course, tantalum capacitors also have their own defects, such as not high enough pressure, which greatly limits its use area.

Tantalum is easily oxidized in the air. The tantalum capacitors made by using its oxide film as the medium have the function of repairing wound automatically, so they are durable and reliable. The tantalum oxide film is very thin, so the distance between two plates of tantalum capacitors is very close, and the reaction is very sensitive, so the charging and discharging speed is fast. These characteristics determine that tantalum capacitors are suitable for high-frequency, low-current and fast reactive circuits. Therefore, tantalum capacitors are widely used in satellites and other circuits requiring fast response and high reliability.

Tantalum capacitors are often used in advanced audio circuits, mainly high audio circuits, due to their high sensitivity and fast charge-discharge. As the loss of weak current to high audio is reduced, the relatively high pitch and sound quality are improved. In short, the tantalum capacitive microphone has the following advantages.

Capacitive Microphone
Capacitive Microphone

Broad frequency response

The vibrating membrane is the main component of the microphone which induces sound and converts it into the electrical signal, and the material and mechanism design of the vibrating film is an important factor to determine the sound quality of the microphone. The vibrating membrane of a capacitive microphone can be made of extremely thin material and the induced sound pressure is converted directly into an audio signal, so the bass of frequency response can extend to the ultra-low frequency below 10Hz, and the high tone can easily reach the ultrasonic waves of dozens of KHz, showing very broad frequency response characteristics.


Because there is no load on the diaphragm, the diaphragm can be designed in such a light and thin way that the frequency response is superior and the sensitivity is excellent. It can sense extremely weak sound waves, output the clearest, delicate and accurate original sound.

Fast transient response

In addition to the characteristics that determine the frequency response and sensitivity of the microphone, the ability of the vibrating membrane to react quickly to sound waves, namely the “instantaneous response” characteristic, is one of the most important factors that affect the microphone’s timbre. The speed of the instantaneous response of the microphone depends on the weight of the whole vibrating membrane. The lighter the vibrating membrane, and the faster the reaction speed. The extremely thin vibrating film of capacitive voice head has the extremely fast transient response, so it can show clear, energetic and accurate timbre.

Capacitor microphone

Resistance to fall and impact

In general, the use of microphones can be caused by accidental fall and collision. Since the capacitive head is made up of lighter plastic parts and a sturdy light metal case, the impact force on falling ground is small and the failure rate of damage is low.

Small size and lightweight

The capacitive microphone has the advantages of small volume, light weight, high sensitivity and superior frequency response due to its ultra-thin vibrating membrane, so it can be designed into subminiature microphones (commonly known as small bees and small ants) and widely used.

Please visit http://www.samaterials.com for more information.

Tantalum Capacitors VS Ceramic Capacitors

The function of capacitors is to remove the crosstalk of various high-frequency signals generated by the chip itself to other chips so that each chip module can work normally without interference. In the high frequency electronic oscillating circuit, the SMT capacitance and crystal oscillator together form an oscillating circuit to provide the required clock frequency. Its main chemical components are nickel and chromium, and the shape is filamentous, so it is called nickel-chromium wire.

Ceramic capacitors

Ceramic capacitors are made by high dielectric constant capacitor ceramics, which are extruded into tubes, wafers or disks as the medium. It is divided into two types: high-frequency porcelain medium and low-frequency porcelain medium. Low-frequency ceramic dielectric vessels are limited to those occasions where they are used as by-passes or dc insulation in circuits with lower operating frequencies, or where stability and loss requirements are not high. Such capacitors are not suitable for use in pulse circuits because they are vulnerable to breakdown by impulse voltage.

Ceramic Capacitors

Tantalum Capacitors

Tantalum capacitors are characterized by long life, high-temperature resistance, high accuracy and excellent performance of the high-frequency filter. Tantalum capacitors can generally withstand high temperature and voltage and are often used for high-frequency filtering. Ceramic capacitors look a bit like patch resistors, but they are smaller in capacity and more expensive than aluminum capacitors and have relatively low voltage and current resistance.

Compared with ceramic capacitors, tantalum capacitors on SMT are labeled with capacitance and pressure resistance, and the surface color is usually yellow and black. SMT aluminum electrolytic capacitors have a larger capacity than SMT tantalum capacitors, which is more commonly seen on the display card, with a capacity between 300 VPS F and 1,500 VPS F.

Tantalum Capacitors

The difference between tantalum capacitors and ceramic capacitors

They are made of different materials. As the name implies, tantalum capacitors use tantalum as the medium, while ceramic capacitors use ceramics as the medium. The capacitance of ceramic capacitors is much smaller than that of tantalum capacitors. Tantalum electrolytic capacitors can achieve a small capacitance, while the ceramic capacitor can hardly achieve the ideal performance when the capacitance is large.

Tantalum capacitors and ceramic capacitors also have different uses. Tantalum capacitors can be used as coupling, and the frequency range of such circuits as filter oscillatory bypass is large, while ceramic capacitors are mostly used in high-frequency circuits. Since tantalum capacitors are mainly made of tantalum, a very rare metal, so the capacitor grade tantalum powder is very expensive, while tantalum capacitors are sold at a high price and generally used only in high-end products that are not price-sensitive.

Multilayer ceramic capacitors are now the most widely used in almost all electronic products. In recent years, the capacity of ceramic capacitors has become larger and larger with the continuous progress of technology, and 47UF multi-layer ceramic capacitors have emerged. However, the large-capacity ceramic capacitors can only be made by a few big Japanese brands, so the price is still more expensive, which is similar to the price of tantalum capacitors.

Please visit http://www.samaterials.com for more information.

How to Select a Tantalum Capacitor?

What is a tantalum capacitor?

At present, the tantalum capacitor is still a kind of charge energy storage device with small volume but high capacity, and the amount of electric energy it can store depends on the thickness and area of the medium. The dielectric capacity of tantalum capacitor’s dielectric layer can reach 120KV/mm, and its relative dielectric constant is 27 times 10-12 farad/meter. Therefore, tantalum capacitors can withstand extremely high field strength in a very thin medium layer, which is the root cause of its small size but high capacity. Tantalum capacitors are not only used in military communications, aerospace and other fields, but also in industrial control, video equipment, communication instruments, electric vehicles, and other products.

Tantalum capacitors are mainly used for filtering, energy storage, and conversion, marking bypass, coupling, and decoupling and acting as the time constant elements. Pay attention to its performance characteristics in the application, and the correct use will help to give full play to its functions.


How to select appropriate tantalum capacitors?

To choose tantalum capacitors, the first problem is to choose encapsulation, voltage resistance, and capacitance. The capacity determines the size (encapsulation) of tantalum capacitors; on the contrary, what size determines what capacity and pressure tolerance can be achieved. According to the market, the most common problem is that engineers ignore this problem in the design process, and always want to achieve the desired parameters on the smallest device.

For example, the capacity of type A 10UF can be seen to have a withstand voltage of 4v6.3v10v20v, however, if you want to use 25V10UF, only the B type of tantalum capacitor can be used. In addition, since tantalum capacitors are used for derating, generally 70% of the capacitors need to be used, that is, the working voltage is 10V, which should be divided by 0.7. The capacitors can only be used with 16V withstand voltage.

How to purchase the original tantalum capacitors?

Due to the wide variety of electronic components and special uses, the current component market is full of fake products, dismantling and refurbishing products. The choice of a high-quality, long-term cooperation of the business is particularly important.


Currently, the world mainly has the following five brands of tantalum capacitors: AVX, KEMET, VISHAY, NEC, and NICHICON. Tantalum capacitors on the market are divided into two types: yellow tantalum and black tantalum. In simple terms, the black tantalum is produced by molding tantalum powder into shape, while the yellow tantalum is formed on the surface with polyoxide resin. Due to the production process, the internal space of black tantalum is not utilized most effectively, so the capacity of yellow tantalum is larger than that of black tantalum.

Please visit http://www.samaterials.com for more information.