PCBA board performance test is a necessary test to ensure stable product performance after PCBA OEM is completed. According to the actual environment and purpose of product use, it is generally divided into withstand voltage test, insulation test, salt spray test, impedance test, vibration test, high temperature and high humidity test Test, welding strength thrust test. Below we will introduce in detail the performance tests of these 7 types of PCBA boards.
1. PCBA board voltage test
The purpose of the withstand voltage test is to detect the voltage withstand capability of the circuit board, and the equipment required is a "withstand voltage tester".
Test method: Connect the PCBA board to be tested to the tester, increase the voltage to 500V DS (direct current) at a speed of no higher than 100V/S, and maintain it for more than 30 seconds. If there is no fault in the circuit, it means the test has passed.
2. PCBA board leakage current test
The purpose of the leakage current test is to check whether the leakage current of the circuit board is within the requirements. The equipment required is a "leakage current tester".
Test method: Analog to the leakage current between the contactable part of the product and the two poles of the power supply under normal working conditions of the PCBA board and the circuit board at normal temperature. If the current is less than the design standard, it means the test has passed.
3. PCBA board salt spray test
The purpose of the salt spray test is to check the corrosion resistance of the circuit board. The equipment required is a "salt spray test machine"
Test method: First we need to prepare a salt solution. The preparation method is: use chemically pure sodium chloride and distilled water or deionized water with a resistivity of not less than 5000 ohms*CM, using 5% sodium chloride and 95% water. , after thorough mixing, a salt solution with a sodium chloride content of 5±1% is made. After the salt solution is prepared, spray continuously for 48 hours in a test site with a temperature of 35°C. The average spray volume per hour should reach 80CM square/10CM. After 48 hours, the functions of the product will be normal, and the appearance and structure will be normal. Indicates that the test passed.
4. PCBA board impedance test
The purpose of the impedance test is to check whether the circuit board circuit can operate normally. The equipment required is an "ohmmeter"
Test method: Connect the transmission line of the circuit board to the battery. If we measure the impedance in a shorter time than the reflection of the transmission line, we will get the "surge" impedance or characteristic impedance, but if we wait long enough until the energy After reflection and reception, it can be found that the impedance changes after measurement. Generally speaking, the impedance value will reach a stable limit value after bouncing up and down. If the limit value is within the specified range, it means the test has passed.
5. PCBA board vibration test
The purpose of the vibration test is to detect whether the circuit board can pass random vibration tests of different levels. The equipment required is a "vibration meter"
Test method: Fix the circuit board or packaged circuit board on the test bench, set the frequency to 20Hz, the three axes: X, Y, Z, the duration is one hour in each direction, a total of three hours, test After the test is completed, if the circuit board functions normally, has a normal appearance and structure, and no abnormalities such as loose welding or cracking of components are found, it means the test has passed.
6. High temperature and high humidity test
The purpose of the high temperature and high humidity test is to check the suitability of the circuit board under harsh conditions of high temperature and high humidity. The equipment required is a "constant temperature and humidity test chamber".
Test method: The PCBA board is in the working state of conduction at twice the rated voltage and rated load, and is placed in the test chamber in a working posture. Analogous to the temperature and humidity conditions during actual operation, if the temperature and humidity during actual operation are not clear, you can set The temperature is 70 ±2℃, the humidity is between 90-95%, and the test is continued for 8 hours. If the basic functions of the PCBA board are normal, and the appearance and structure are normal, it means the test has passed.
7. PCBA board welding strength thrust test
The purpose of the welding strength thrust test is to test whether the welding strength of the components meets the requirements. The equipment required is a "thrust meter"
Test method: Place the welded PCBA on the thrust gauge. Components of different specifications have different passing requirements. Generally, we will eliminate other components on the edge of the target component, then reset the instrument to zero and proceed at an angle of ≤30 degrees. Thrust test, check whether the components are desoldered, and record the value of the components desoldering.
The thrust standard of commonly used components is: 0402 specification components: 0.65Kgf, 0603 specification components: 1.20Kgf, 0805 specification components: 2.30Kgf, 1206 specification components: The thrust standard is: 3.00Kgf.
The above are 7 common PCBA board performance testing methods. You can choose different PCBA testing methods according to the actual situation of your product.