PCBA circuit board performance test is PCBA processing after the completion of the necessary test to ensure stable product performance, according to the actual use of the product environment and purpose, generally divided into pressure test, insulation test, salt spray test, impedance test, vibration test, high temperature and humidity test, welding strength thrust test. The following is a detailed introduction to the performance test of these 7 kinds of PCBA circuit boards.
1. Pressure test
The purpose of withstand voltage test is to test the circuit board withstand voltage ability, need to use the equipment is "withstand voltage tester".
Test method: connect the PCBA circuit board that needs to be tested to the tester, increase the voltage to 500V DS (direct current) at the speed of no more than 100V/S, and keep it for more than 30 seconds. If the circuit has no fault, it represents that the test is passed.
2. Leakage current test
The purpose of leakage current test is to check whether the leakage current of the circuit board is within the requirements. The equipment needed is "leakage current tester".
Test method: Simulate the leakage current between the contact part of the product and the two poles of the power supply under the normal working condition of the PCBA circuit board and the normal temperature of the circuit board. If the current is less than the design standard, the test is passed.
3. Salt spray test
The purpose of the salt spray test is to check the corrosion resistance of the circuit board. The equipment needed is a "salt spray tester".
Test method: first of all, we need to configure salt solution, configuration method is: made of chemical pure sodium chloride and resistivity of not less than 5000 ohm *CM distilled water or deionized water, with 5% sodium chloride and 95% water, after full mixing, sodium chloride content of 5±1% salt solution. After the salt solution is configured, spray continuously for 48 hours in the test place with the temperature of 35℃, and the average spray volume per hour should reach 80CM square /10CM. After 48 hours, the product has normal functions and normal appearance and structure, which means that the test has passed.
4. Impedance test
The purpose of impedance test is to check whether the circuit board line can work properly, the equipment needed is the "ohmmeter".
Test method: Will be connected to the transmission line and battery of the circuit board, if we are in a shorter time than transmission lines reflect the measured impedance, get the "surge" impedance or characteristic impedance, but if you wait long enough until the energy reflected back and received after, can be found by measuring the impedance change, in general, the impedance value would reach a stable after bounce up and down limit, If the limit value is within the specified range, the test passes.
5. Vibration test
The purpose of the vibration test is to detect whether the circuit board can pass the random vibration test of different levels. The equipment needed is the "vibration meter".
Test method: the circuit board or packaged good circuit board fixed on the test bench, set 20 hz frequency, axial: X, Y, Z three axial, lasts an hour in each direction, a total of three hours, after the test, circuit board function is normal, normal appearance, structure, no loose components welding, cracks and other abnormal represents the test pass.
6. High temperature and high humidity test
The purpose of high temperature and high humidity test is to check the applicability of the circuit board under the harsh conditions of high temperature and high humidity. The equipment needed is "constant temperature and humidity test box".
Test method: The PCBA circuit board is in the rated voltage conduction, rated load working state, in the working attitude into the test box, simulate the actual working temperature and humidity, if the actual working temperature and humidity is not clear, the temperature and humidity can be set between 70±2℃, 90-95%, continuous work for 8 hours, if the PCBA circuit board basic function is normal, If the appearance and structure are normal, the test has passed.
7. Welding strength thrust test
The purpose of welding strength thrust test is to test whether the welding strength of components meets the requirements. The equipment needed is "thrust meter".
Test method: place the welding good PCBA circuit board on the thrust meter, different specifications of the different components have passed the requirements, usually we will eliminate the target components on the edge of the other components, and then the instrument zero, at 30 degrees or less thrust test, check whether the component is to take off the welding, and record components desoldering.
The thrust standard of commonly used components is 0.65kGF for 0402 components, 1.20kGF for 0603 components, 2.30kGF for 0805 components, and 3.00kGF for 1206 components.
