How to conduct PCBA test?
Polychlorinated biphenyls (PCBs) are an important ticket to success in the market in the era of product quality Any high-quality product must be continuously ground and tested until its shape is perfect In the electronic product industry, PCB testing is the most critical quality control link in the entire manufacturing process, which determines that the products manufactured by PCBs fully meet the standards
PCBs test type
1. ICT (online tester) test
SMT science and technology quality inspector tests the circuit's on-off, voltage and current values, fluctuation curve, amplitude, noise, etc. High measurement accuracy and clear instructions on detected problems are a means of standard testing.
2. FCT (functional circuit test) test
FCT refers to providing analog operating environment (excitation and load) for test target boards, burning IC programs, analogizing the functions of the whole PCB board, finding hardware and software problems, and providing necessary patch manufacturing tools and test racks.
3. Fatigue test
The quality inspector of the SMT chip manufacturer of the PCB board manufacturer samples the PCB board during the entire production process and conducts high-frequency test on the functions. The test shall be maintained for a long time to observe whether there is a failure, and the failure probability shall be judged synchronously during the test to echo the working efficiency of PCB plates in electronic products.
4. Aging test
Smt quality inspectors let PCB boards and electronic products be powered on for a long time, keep them working, and observe whether there is any fault, so that electronic products can be sold in batches after aging test.
5. Testing under harsh environment
It refers to the process of intensifying experiments, analogizing various factors related to aging in the actual use conditions of products, exposing PCBs to extreme humidity, temperature, drop, splash and vibration, and obtaining the test results of random samples, so as to infer the reliability of the whole batch of PCBs.
Test methods for polychlorinated biphenyls
1. Manual test
Direct visual inspection confirms that components are installed on PCB by visual inspection and comparison.
2. Automatic Optical Inspection (AOI)
Also known as automatic visual testing, it is performed by special detectors and used to check the polarity of components before and after reflow.
3. Flying needle test
The progress in machine speed, accuracy and reliability, together with the current requirements for rapid conversion of prototypes and low yield manufacturing and fixture free testing systems, make flypin testing the best choice.
4. Function test
There are two types of functional tests: final product test and thermal analogy. The test method of specific PCB or unit must be completed by special equipment.
Manufacturing Defect Analysis (MDA)
Advantages: low initial cost, high output, easy for subsequent diagnosis, fast and complete short circuit and open circuit test.
Disadvantages: It is impossible to conduct functional test, usually there is no test coverage instruction, fixture must be used, and the test cost is high.
Polychlorinated biphenyl test equipment
1. ICT online tester
ICT is an automatic online tester, which has a wide range of applications and simple operation. ICT automatic on-line detector is mainly used for production process control. It can measure resistance, capacitance, inductance and integrated circuit. It is especially suitable for detecting open circuit, short circuit, component damage, accurate fault location and convenient maintenance.
2. FCT function tester
The analog operating environment, such as excitation and load, can point to the PCB board to obtain various state parameters of the board to detect whether the functional parameters of the board meet the design requirements. The items of FCT function test include voltage, current, power, power factor, frequency, duty cycle, brightness and color, character recognition, voice recognition, temperature measurement, pressure measurement, motion control, flash memory, EEPROM burning, etc.
3. Aging tester
It refers to the process of intensifying the experiment to simulate various factors involved in the actual use conditions of aging products. Long term power on test can be carried out on PCB boards based on electronic products to simulate the use of customers, and input/output tests can be carried out to ensure their efficiency meets the market demand.