Precautions for use of aluminum electrolytic capacitors
Please note the following when using aluminum electrolytic capacitors.
Aluminum electrolytic capacitors in carrying the following load, will cause its characteristics deteriorated dramatically.
* Reverse voltage
* The voltage exceeds the rated value
* The ripple current exceeds the rated value
* Rapid charge and discharge
At this point, the capacitor may produce a lot of heat, the internal pressure rise, resulting in the pressure valve open, the internal gas jet, leakage, etc.
In some cases, with the capacitor damage will be combustible concurrency, may lead to explosion and fire.
A circuit design considerations
1 Please confirm the use of the environment and the assembly environment, based on the product catalog and specifications specified in the capacitor rated performance within the scope of use.
Aluminum electrolytic capacitors have polarity.
Please do not load reverse voltage or AC voltage. If the installation of the polarity reversed, may lead to the circuit in the initial state of short circuit, pressure valve action and other damage. For polarity, please check the dimensions of each page in the product catalog or specification sheet and the markings of the product body.
Select the bipolar capacitor when the aluminum electrolytic capacitor is used in a circuit with polarity reversal. But the bipolar capacitor can not be used in the AC circuit.
3 load voltage
Please do not load too much voltage (over the rated voltage).
Although the surge voltage exceeds the rated voltage, but there are restrictions, can not guarantee long-term use.
4 ripple current
Please do not load extra current (current exceeding the rated ripple current).
When applying excessive ripple current, there will be a large internal heat
* Life is shorter
* Pressure valve action
* Caused by short circuit failure and other damage occurred.
The frequency of the rated ripple current is limited. When used outside the specified frequency, to control
Multiplied by the value of the frequency correction coefficient specified by each series.
5 use temperature
Please do not use it at high temperature (temperature above working temperature).
If the working temperature is exceeded, the life of the capacitor will be shortened and the pressure valve will be damaged.
In addition, if the temperature of the aluminum electrolytic capacitor is set to be low, the life may be prolonged.
When designing a circuit, use a capacitor that matches the life of the device.
Please note that the results calculated using the presumed life formula are not guaranteed values. When designing the life of the machine, select a capacitor with sufficient margin relative to the inferred value.
7 charge and discharge
General capacitors should not be used in the rapid charge and discharge circuit.
If the voltage difference between the use of large charge and discharge circuit, or short cycle and repeated rapid charge
Discharge circuit, may lead to reduced capacitance, internal heat and other damage.
8 Fault mode of the capacitor
Aluminum electrolytic capacitors are parts of the service life, in general, there will be open-type friction failure.
Product and the use of different conditions sometimes lead to pressure valve movements and other failures.
9 insulation of the capacitor
Capacitors in the following circumstances, with the circuit to be completely isolated.
* Aluminum electrolytic capacitor between the housing and the cathode terminal and between the anode terminal and the circuit type
* Aluminum electrolytic capacitor substrate Self-standing type connectionless (strength-enhanced) terminal and other (anode and cathode) terminals and circuit board
10 Capacitor use environment
Please do not use the capacitor in the following environment.
① direct splashing water, salt water, oil or in the exposed state of the environment
② sun direct exposure to the environment
③ environment filled with toxic gases (hydrogen sulfide, sulfurous acid, nitrous acid, chlorine and its compounds, bromine and its compounds, ammonia, etc.)
④ ozone, ultraviolet radiation and radiation environment
⑤ vibration or shock conditions beyond the scope of the product catalog or specification range of excessive environment
11 capacitor configuration
① aluminum electrolytic capacitors using flammable organic solvents as the main coal-based conductive electrolyte and flammable electrolytic paper. When the electrolyte leaked to the printed circuit board, it will corrode the circuit board, resulting in short circuit between the circuit board, and even smoke, fire,
Therefore, please confirm the following contents after the design.
* Align the capacitor spacing and the hole spacing of the printed circuit board
* Wiring or circuit does not extend over the pressure valve section of the capacitor.
* If the pressure valve part of the capacitor contacts the printed wiring board edge, open the vent of the pressure valve according to the position of the pressure valve.
* Do not circuit wiring under the sealing part of the capacitor. If the capacitor is attached
Near wiring, please ensure that the line spacing in 1mm (if it is 2mm) or more.
* Do not place hot parts on the periphery of the capacitor and on the back of the printed circuit board (below the capacitor).
* When installing capacitors on both sides of the printed wiring board, pay attention to the bottom of the capacitor when designing
There may be excess substrate holes or through-holes for surface connection.
* When assembling capacitors on both sides of the printed wiring board, the mounting parts of the capacitor main body must not have wiring lines.
② The patch pattern of the printed wiring board for the chip type capacitor should be designed according to the size recommended by the catalog and specification.
① With the temperature and frequency changes, the electrical characteristics of the capacitor will change. Please design the circuit after confirming this change.
② When two capacitors are connected in parallel, the circuit design should consider the current balance.
③ When two capacitors are connected in series, consider the voltage balance and insert the capacitor
Parallel voltage divider.
B. Installation Notes
1) when assembled
① have been assembled and assembled through the electric capacitor do not re-use. Except for regular checks
Electrical performance when the capacitor removed, the other can not be used again.
② The capacitor may generate regenerative voltage. In this case, discharge it by a resistance of about 1 kΩ.
③ long-term storage, the capacitor leakage current may increase. In this case, connect the capacitor in series with a resistor of about 1kΩ and apply a voltage of 1 second for the rated DC voltage.
(4) Check the capacitor's rated size (static capacity and rated voltage) before installation.
⑤ Please check the polarity of the capacitor before installation.
⑥ Do not use capacitors that fall on the floor or the like.
⑦ Do not deform the capacitor when installing.
⑧ Make sure that the terminal spacing of the capacitor and the hole of the printed wiring board are aligned
⑨ can not apply to the capacitor product catalog or specification manual above the mechanical strength
The force. Automatic assembly machine in the adsorption, assembly and position alignment, or cutting the terminal
When it is possible to produce stress, please note its impact.
2) welding heat resistance when welding
(1) When using soldering iron, please confirm the following.
* Welding conditions (temperature, time) must meet the scope specified in the catalog or specification.
* The lead terminals are required because the terminal spacing and the hole spacing of the printed wiring board do not correspond
For machining, the terminal is machined before welding. Be careful not to apply pressure to the capacitor body.
* Do not let the tip of the soldering iron touch the main body of the capacitor.
(2) When reflowing is performed, check the following.
* The welding conditions (preheating, reflow temperature, time) must not exceed the range specified in the catalog or specification.
* When using infrared heaters, depending on the color and material of the capacitor, the absorption rate of the infrared rays is different. Please note the degree of heating.
* The number of times of reflow of aluminum electrolytic capacitors is specified in the catalog or specification.
* When installing a body aluminum electrolytic capacitor on a double-sided printed wiring board, please note that there is no circuit wiring for the mounting parts of the capacitor main body.
③ Do not use the chip capacitors that have been installed after they are removed.
④ In addition to patch type, please note that other types are not reflow soldering.
3) after welding treatment
Printed wiring board after welding treatment Note that the following mechanical stress can not be applied.
① The capacitor body can not be tilted, fell to the ground or twisted.
② can not grasp the main handling of the capacitor circuit board.
③ Do not allow other objects to crash into the capacitor. In addition, when the printed wiring board is placed in an overlapping manner, the printed wiring board or other parts can not be brought into contact with the capacitor.
④ The printed circuit board with the capacitor installed can not be dropped.
4) substrate cleaning
① The capacitor can not be cleaned with the following cleaning agent.
* Halogen Solvent → Capacitor produces electrical contact to cause malfunction
* Alkaline solvent → Aluminum shell corrosion (dissolved)
* Terpenes, petroleum solvents → Sealing rubber aging
* Xylene → Sealing rubber aging
* Acetone → mark disappears
If it is necessary to clean, be sure to use a guaranteed capacitor for cleaning,
And remain within the scope specified in the catalog and specifications. Please pay special attention
Ultrasonic cleaning conditions.
(2) When cleaning the aluminum electrolytic capacitor with cleaning and cleaning, please check the following.
... Please carry out the pollution management of the cleaning agent (conductivity, pH, specific gravity, water content, etc.).
After cleaning, do not keep in the cleaning solution or sealed container. In addition, please
With a hot air (working upper limit temperature below) blowing more than 10 minutes to fully dry,
Avoid cleaning of printed wiring boards and electrolytic capacitors.
C Maintenance Check Note
1) Please periodically check the capacitors used in industrial equipment.
2) Please check the following regularly.
① appearance (pressure valve action, leakage, etc.) whether the obvious abnormalities.
② electrical performance (leakage current, static capacity, loss tangent value and product catalog or delivery specifications specified in the project)
When the above contents are abnormal, please confirm the specifications of the capacitor and replace it with proper handling.
1. With a certain size of the capacitor, in order to reduce the pressure of the installation of a pressure valve. When the gas valve overflows during the operation of the pressure valve of the capacitor used in the equipment, disconnect the power supply of the equipment or unplug the power cord from the socket.
2. When the pressure valve of the capacitor moves, it will spray more than 100 ℃ high temperature gas, please do not close the face. In case of accidental gas into the eyes, or when inhaled, please immediately wash your eyes with water, mouthwash. When sticking to the skin, rinse with soap.
E. custody conditions
1. Do not store the capacitor in a high temperature and humidity environment. Please keep the environment at room temperature 5 ~ 35 ℃, humidity below 75%.
Storage period, in principle, within 3 years after manufacturing.
2. Please try to keep it in packaged state.
3. Please keep in the following environment.
① splashing water, high temperature and humidity and condensation of the environment
② splash oil, or filled with gas oil composition of the environment
③ splashing salt, filled with salt environment
④ full of acidic toxic gases (hydrogen sulfide, sulfurous acid, nitrous acid, chlorine, bromine, bromine
⑤ full of ammonia and other alkaline toxic gas environment
⑥ acidic and alkaline solvent environment
⑦ direct sunlight, ozone, ultraviolet radiation and radiation environment.
⑧ can not be kept in the capacitor by the vibration, the impact of the environment
When discarding capacitors, please hand over to a professional industrial waste treatment plant for incineration or landfill.
Incineration, please use high temperature burning (800 ℃ above). Low temperature incineration, will produce halogen gas and other harmful gases.
In addition, in order to prevent the capacitor from exploding, burn it on the capacitor or after it is fully crushed.
G. About RoHS Rules
1. comply with the relevant provisions of the EU RoHS Directive 2011/65 / EU requirements of the relevant hazardous substances,
2. Juju every year in accordance with the latest EU RoHS directive testing, both inside and outside the product packaging are marked RoHS
H. REACH requirements
* According to the contents of RIP3.8TGD (Technical Guidance Document: 2008/5/26), the electronic components manufactured by our company are "unintentional products" and therefore do not apply to Article 7 (1) of the European REACH Rules.
* Due to the SVHC (Highly Concerned Substances) list, it is published by the European Chemical Organization (ECHA). We will organize and build information on the relevant substances in the SVHC waiting list in our products. Institutional inspection.