The failure factor of surface mount aluminum electrolytic capacitors is that the temperature rises during 

operation, and the electrolyte inside turns into steam and evaporates. Where there is loss, there will be

 depletion. Surface mount aluminum electrolytic capacitors will also have this outcome. Is the only factor 

causing the failure of surface mount aluminum electrolytic capacitors a problem with the electrolyte?

 No, the author has summarized the factors that cause the failure rate of surface mount aluminum electrolytic

 capacitors through multiple experiments and tests

1. Open the riot control valve:

The reasons for the general valve opening: during use, excessive voltage is applied, ripple current is too

 large, reverse voltage is applied, frequent charging and discharging occur, AC power is applied, and the 

operating temperature is too high. How do we know if the riot control valve is open?

We can see from its phenomenon that when an explosion-proof valve is opened, it usually shows an increase 

in internal pressure and temperature. Then we can use a multimeter to test whether the voltage of the surface 

mounted aluminum electrolytic capacitor is higher than the original standard, and we can know if the

 explosion-proof valve is open

2. Capacity reduction:

There are two reasons for the decrease in capacity of surface mount aluminum electrolytic capacitors. 

Firstly, the manufacturer may have cut corners, insufficient electrolyte, or defects in the quality of the

 electrolyte. Secondly, applying overvoltage, excessive ripple current, applying reverse voltage, frequent 

charging and discharging, applying alternating current, and using at high temperatures. How do we know 

that the capacity of surface mount aluminum electrolytic capacitors is decreasing? We can determine

 whether the anode foil capacity of the surface mounted aluminum electrolytic capacitor has decreased,

 whether the cathode foil capacity has decreased, and whether the electrolyte has dried up (the main 

reason).

3. Increased losses:

The increase in losses and the decrease in capacity are closely related, and their causes are similar

There are two reasons for this: firstly, the manufacturer is cutting corners, the electrolyte is insufficient, 

or there are quality defects in the electrolyte. Secondly, applying overvoltage, excessive ripple current, 

applying reverse voltage, frequent charging and discharging, applying alternating current, and using at

 high temperatures. Long usage time. We can determine whether the anode foil capacity of the surface

 mounted aluminum electrolytic capacitor has decreased, whether the cathode foil capacity has decreased, 

and whether the electrolyte has dried up (the main reason).

4. Leakage current phenomenon:

Deterioration of oxide film, invasion of chloride ions, reasons: manufacturing defects in oxide film, usage 

issues, application of overvoltage, excessive ripple current, application of reverse voltage, frequent charging 

and discharging, application of alternating current, high usage temperature, long-term use, use of halogen 

containing cleaning agents, use of adhesives, use of coating agents. These all have a certain impact on 

the failure rate of surface mount aluminum electrolytic capacitors during operation.

5. Short circuit:

Phenomenon: Deterioration of oxide film, damage to the insulation function of oxide film and electrolytic 

paper.

Reason: Manufacturing reasons, defects in oxide film, adhesion of metal particles, aluminum foil, lead burrs, 

usage reasons, lead subjected to abnormal external stress

6. Open circuit:

Phenomenon: Poor contact between the lead wire and aluminum foil, corrosion, and invasion of chloride 

ions.

Reason: Due to manufacturing reasons, the lead wire is not firmly riveted to the aluminum foil, and mechanical 

stress is applied. Reason for use, lead wire

Under abnormal external stress, the use of chloride ion cleaning agents, adhesives, and coating agents.

technical support:

Surface mount aluminum electrolytic capacitors are most commonly used in power filter circuits. When

 the input voltage changes or the load suddenly opens, the voltage at both ends of the filter capacitor

 will change accordingly. If the derating design is not carried out, it is likely to cause the capacitor to break 

down. In addition, the AC voltage coming in from the input terminal is not a sine wave voltage. Generally, 

the peak voltage of non sine waves is higher than that of sine waves, which can have a significant impact 

on the lifespan and reliability of capacitors. Therefore, during design and use, the operating voltage of 

electrolytic capacitors should be significantly reduced.

The magnitude of voltage reduction for electrolytic capacitors should be determined based on the reliability 

requirements of the entire machine and the specific circuit used for the capacitor. Generally, it can be

 divided into three levels, with the first level being 50% of the rated voltage; The second level is 60%; 

The third level is 70%. High voltage and large capacity capacitors should be selected with a larger derating 

amplitude. The larger the capacity of a capacitor, the larger the area of the oxide film, and the higher

 the probability of dielectric defects, resulting in lower reliability.

About Us

Guangdong Fulong Electronic Technology Co., Ltd. is a private high-tech enterprise specializing in the research and development, manufacturing, and sales of aluminum electrolytic capacitors, certified by IATF16949，ISO9001, ISO14001, and ISO45001. The company has a building area of 17000 square meters and more than 50 automated production lines; The total investment is 50 million yuan (RMB), with more than 100 employees, including more than 20 engineering and technical, quality management, and production management personnel. The annual production of capacitors (4 * 5.4~16 * 21.5) is about 400 million pieces; Our products are mainly sold to domestic and international markets, and we strive to promote our company's products globally.

Jiangxi Fulong Electronic Technology Co., Ltd. is a wholly-owned subsidiary of Guangdong Fulong Electronic Technology Co., Ltd. established in Hukou County, Jiangxi Province with a total investment of 500 million yuan. It has 50 fully automated production lines and an annual output of approximately 1.2 billion capacitors (4 * 5.4~16 * 21.5).

Fulong Group has an international professional core technology research and development team for aluminum electrolytic capacitors and a global sales network. Rich experience in the design, research and development, and production management of aluminum electrolytic capacitors. The R&D team follows the technical design theory of aluminum electrolytic capacitors, complies with international and domestic legal and regulatory requirements (RoHs), and adheres to the highest international quality standards

Fulong Group has high-quality and stable raw material supply partners, and key raw materials (such as aluminum foil, electrolytic paper, etc.) are selected from well-known Japanese and Korean companies (KJCC KDKNKK, etc.), ensuring reliable and stable advantages in product quality, environmental protection, safety, and energy conservation.

Fulong Group has a group of highly qualified professional technicians and management personnel who can produce various series of sheet aluminum electrolysis products according to customer requirements. The products include high-frequency low impedance, low leakage, wide temperature, extremely low impedance, non-polar, ultra long life, medium high voltage long life, high reliability and other new types of special requirements for surface mount products; At the same time, the company's products can withstand a soldering temperature of 260 ℃, meeting the lead-free reflow soldering technology required for SMT in the whole machine factory. All technical indicators of the products have reached or exceeded the international level of similar products.

While strengthening management and expanding operational scale, Fulong Group is also committed to improving its competitiveness and customer satisfaction, continuously and steadily increasing customer and social trust, continuously meeting market demand, further optimizing environmental management and expanding social contributions, and developing together with the electronics industry.

Guangdong Follon Electronic Technology Co., Ltd.

Jiangxi Follon Electronic Technology Co., Ltd.

Address: Building 3, South District, Haishan Science and Technology Park, Hukou County, Jiujiang City, Jiangxi Province

www.follon.com

Professional manufacturer of high-quality surface mount electrolytic capacitors