1. Basic requirements of safety regulations for electronic components.

Generally speaking, when evaluating electronic component products, its safety performance should be considered from the following aspects:

1. Withstand voltage (electric strength) - prevent electric shock injury.

2. Insulation resistance - prevent electric shock injury.

3. Grounding resistance - prevent electric shock injury.

4. Leakage current - prevent electric shock injury.

5. Electromagnetic compatibility - (EMS and EMI)

6. Fire prevention - fire hazard.

7. Mechanical structure - prevent damage, burns, etc. caused by mechanical structure defects.

8. Energy shock - prevent fire or arc burn caused by high current.

9. Other special requirements.


2、 Test requirements for electronic components.

1 withstand voltage test.

The bearing capacity of the insulation system under abnormal high voltage is mainly considered. Products with working voltage less than 50V generally do not undergo withstand voltage test, so III electrical appliances generally do not need withstand voltage test. Take American UL certification as an example:

Voltage setting.

The withstand voltage is generally related to the rated voltage of the product. The commonly used calculation formula is:

(1) AC: 1000V + 2 * rated working voltage.

(2) DC: (1000V + 2 * rated working voltage) * 1.4.

The above is the ordinary insulation test voltage. In case of double insulation, the test voltage is twice that of ordinary. If the calculation result is not an integer multiple of 100, take the large one instead of the small one.

For example, the rated working voltage is 220V, and the ordinary insulation test voltage is:

Communication: 10002 * 220 = 1440v. At this time, the test voltage should be 1500V instead of rounding.

(2) Set the leakage current.

It is generally set to 5 ~ 10mA, and the maximum is no more than 100mA. According to the different requirements of different industries, for example, the leakage current of medical devices is generally 1mA.

(3) Set the test time.

The general test setting is 1 minute. We can consider shortening the production line and changing it to 1 second. When shortening the test time, a higher test voltage should be used. According to UL regulations, the following relationships can be converted:

*1.2 AC (1000V + 2 * rated working voltage).

*1.4 * 1.2 DC (1000V + 2 * rated working voltage).

The IEC test parameters are different. For specific parameters, please refer to the voltage value of electrical strength withstand voltage test in part X of this manual.

2. Grounding resistance test.

The ability of insulation collapse or charge leakage during normal operation of the product is mainly considered. This is a protective measure, which is not considered in products without grounding.

The smaller the grounding resistance is required, the better. Generally, the single grounding resistance shall not be greater than 0.10hm, the total system grounding resistance shall not be greater than 40hm, and the continuous resistance between system grounding shall not be greater than 0.010hm.

Generally speaking, if the withstand voltage test passes, the insulation resistance test will also pass, but if the insulation resistance test passes, it does not mean that the withstand voltage test will also pass.

In the case of mass production, the production line generally needs to conduct 100% withstand voltage test. Insulation resistance, leakage current and grounding resistance are only carried out during random inspection or introduction of new products.

3. Electromagnetic compatibility test.

There are many EMC test items, and the general requirements are:

a. Conducted interference and anti-interference.

b. Radiation interference and anti-interference.

c. Antistatic

d. Lightning resistance

e. Anti surge or voltage mutation, etc.

EMC mainly includes EMS and EMI. Although not all certification bodies have requirements, many countries list them as mandatory items and independently carry out EMC certification EMC certification

EMC includes two requirements: on the one hand, the electromagnetic interference of the equipment to the environment during normal operation shall not exceed a certain limit (EMI); On the other hand, the equipment has certain immunity to electromagnetic interference in the environment, that is, electromagnetic sensitivity (EMS).

4. Fire resistance and flame retardancy

For the combustion evaluation of electronic products, the world mainly adopts the American UL94 combustion test standard, that is, the glue used must pass the corresponding flame retardant grade test requirements.

The combustion test of plastics and insulating materials is generally evaluated according to UL94, which can be divided into three categories according to the material form of products, and slightly different test methods are adopted.


2、 Certification of key electronic components.

Generally speaking, the following components require safety regulation certificates, and they are also safety critical components. Plastic shell. Nameplate;

PCB board Fuse;

Varistor The discharge tube;

Inductive transformer;

Optocoupler X capacitance Y capacitance;

Socket. wire rod;

silica gel. Heat shrinkable tube Sleeve PVC sheet;

Fan relay. Switch Temperature switch.

Electrical coupler Connectors, etc.

Safety regulation component is the key component controlled by safety regulation certification authority. Generally speaking, they need to be certified by relevant countries. Without certification, other products cannot be used. At the same time, if these safety regulation components change, they must apply to the safety regulation certification authority for filing. It can only be used after obtaining approval and approval. Sometimes it is necessary to resend samples for testing. After passing the test, it can be officially used.