Although there are many types of CBB capacitors, the CBB21 capacitor is definitely the most used one. What kind of capacitor is CBB21? Some users have burnt out when using CBB21 capacitors. What are the reasons for it to burn out? This article will explain it to you in detail.
What is the CBB21 capacitor?
In fact, CBB21 capacitors and CBB22 capacitors are the same capacitor, and some manufacturers like to print MPP words, they are the same type of capacitors, CBB21 capacitors use metallized polypropylene film non-inductive winding, flame-retardant epoxy powder packaging, Tinned copper lead out, with strong moisture resistance, good self-healing, high insulation, low loss and so on. Suitable for LED lights, ignition and high frequency circuits.
What are the reasons why the CBB21 capacitor burns out?
1.Bought low-quality capacitors
Now the cost of CBB21 capacitors produced by different manufacturers is actually very small. If the price of CBB21 capacitors you buy is obviously lower than the market average price, the possibility of buying inferior capacitors is very high. The materials used for this inferior capacitors are very poor. If the production process can be saved, the performance cannot be guaranteed, and the capacitor with too poor quality is definitely easy to burn out.
2.The working environment temperature is too high
Even a CBB21 capacitor with excellent quality is easy to burn out if the working environment temperature is too high. Generally, the temperature resistance of CBB21 capacitors is -40°C~105°C. Although it can withstand 105°C in theory, its working temperature is higher. High, the life of CBB21 capacitors is drastically reduced.
Generally, a qualified CBB21 capacitor burns out, which is basically caused by too high ambient temperature, such as being too close to an electronic component with a large heat generation (such as a MOS tube), or the entire circuit has a large heat dissipation, and the heat cannot be discharged smoothly. etc., are the core reasons for the damage of CBB21 capacitors.
Excessive operating temperature is one of the most common and most likely causes of CBB21 capacitor damage.
3.Improper selection of capacitors
For example, the current is too large, exceeding the working current of the CBB21 capacitor; the voltage in the circuit is too high, exceeding the rated working voltage of the CBB21 capacitor, etc. If the type is not selected properly, the CBB21 capacitor will be easily damaged during operation.
How to control the soldering temperature of CBB21?
CBB21 and CBB22 capacitors are the same capacitor. When using them, everyone generally knows its operating temperature. The upper limit of the normal CBB21 capacitor’s operating temperature is generally 105°C. The operating temperature of those inferior CBB21 capacitors that compete on price in the market The upper limit is 85°C (however, such low temperature-resistant CBB21 capacitors are rare), but when CBB21 is used for wave soldering on circuit boards, the test should not be too high, otherwise it is easy to burst and damage. The soldering temperature of CBB21 capacitors is How many?
The peak temperature of CBB21 capacitor wave soldering can be 275°C, and the immersion tin time is 3S-5S. High-quality CBB21 capacitors can meet this requirement.
Why does the CBB21 capacitor crack after wave soldering?
1.The wave soldering temperature is too high.
For example, the temperature of wave soldering exceeds 275°C, which exceeds the temperature tolerance limit of CBB21 capacitors, but experienced manufacturers seldom make such low-level mistakes.
2.Caused by wave soldering operation failure.
According to the actual use of customers, most of the wave soldering equipment is faulty during operation. For example, due to aging and setting problems of some wave soldering equipment, the conveyor belt may pause for a short time, and the pause time exceeds 3~5S, so It will also cause the CBB21 capacitor to burst due to overheating.
3.The quality of CBB21 is too poor.
This kind of situation is also rare, unless you choose the lowest price and worst quality CBB21 capacitors on the market, normal quality CBB21 capacitors, there will never be any damage caused by wave soldering.
