PCB Testing Process

PCB testing includes the following:

Appearance Testing: Check the PCB surface for scratches, deformation, cracks, oxidation and other problems through visual observation, as well as whether the markings are clear, whether the position is correct, and whether the pads, sockets, connectors and other components are properly installed.

Dimensional Testing: Use gauges, microscopes and other tools to measure the size of the PCB to ensure that it meets the design requirements.

Electrical Performance Test: Check the electrical performance of PCB through contact test or non-contact test, including whether the circuit connection is normal, and whether the resistance, capacitance, inductance and other parameters between each circuit meet the design requirements.

Function Test: Gradually add external input and output signals to debug each part of the system to ensure that the system functions properly.

Reliability Test: Conduct small batch trial production, HALT experiment, environmental experiment, EMC experiment, thermal test, etc. to check the reliability and stability of PCB.

In the PCB testing process, the following points need to be noted:

Test Environment: Ensure that the test environment is clean, dust-free, non-interference, temperature and humidity are appropriate.

Test Equipment: Select the appropriate test equipment and tools to ensure its accuracy and reliability.

Test Procedures: Develop detailed test procedures, including test items, test methods, test steps, etc., to ensure the accuracy and consistency of the test.

Data Analysis: Analyze the test data in detail to evaluate the performance and quality of PCB.

Problem Solving: When encountering problems in the testing process, record and analyze the causes of the problems in a timely manner, and take appropriate measures to solve the problems.

Record Keeping: Save test records for subsequent review and analysis.

PCB testing process includes appearance inspection, size inspection, electrical performance testing, functional testing and reliability testing steps to ensure that the quality and performance of PCB meet the design requirements. In the testing process need to pay attention to the environment, equipment, procedures, data analysis and problem solving.

Characteristics of The PCB Test Process

The PCB testing process includes the following features:

Diversity: PCB  testing includes multiple aspects of detection, such as appearance, size, electrical performance, function and reliability, etc., for different test items need to use different test methods and tools.

High Precision Requirements: PCB testing requires high-precision test equipment and tools to ensure the accuracy and reliability of the test results.

High Degree of Automation: In order to improve the testing efficiency and accuracy, PCB testing is usually automated test equipment and methods to reduce human error and error.

Intelligent Data Analysis: Modern PCB test equipment is usually equipped with intelligent data analysis functions, which can automatically process and analyze the test data, and quickly arrive at the test results and fault diagnosis.

High Reliability Requirements: PCB test results are directly related to the quality and reliability of the product, so we need to take various measures to improve the reliability and stability of the test process.

Environmental Protection: PCB testing process needs to pay attention to environmental issues, such as reducing waste and harmful substances and emissions.

PCB testing  is characterized by diversity, high accuracy requirements, high degree of automation, intelligent data analysis, high reliability requirements and environmental protection, etc. It is necessary to take appropriate measures and methods in the testing process to ensure the accuracy and reliability of the test results.

PCB Testing Process Considerations

In the PCB testing process, the following points need to be noted:

Test Meter Internal Resistance: In measuring the integrated circuit pin DC voltage, should be used in the head of the internal resistance is greater than 20KΩ / V multimeter, otherwise there will be a large measurement error for some pin voltage.

Detect the PCB Board Test Meter Internal Resistance to Be Large: Measure the integrated circuit pin DC voltage, should be selected with the head internal resistance greater than 20KΩ / V multimeter, otherwise there will be a large measurement error for some pin voltage.

Avoid Testing Without An Isolation Transformer: It is strictly prohibited to test the PCB board without an isolation transformer with grounded test equipment to contact the base plate charged TV, audio, video and other equipment. It is strictly prohibited to use the shell has been grounded instrumentation to directly test the TV, audio and other equipment without power isolation transformer. Although general recorders have a power transformer, when contact with the more special, especially the output power or the nature of the power supply used to understand the nature of the TV or audio equipment, the first thing to find out whether the chassis is electrified, otherwise it is very easy and the base plate charged TV, audio and other equipment to cause a short circuit power supply, and integrated circuits, resulting in the further expansion of the fault.

Soldering Iron Insulation: Test PCB board should pay attention to the insulation of the soldering iron, do not allow the use of electric soldering iron welding, to confirm that the soldering iron is not electrified, it is best to ground the iron's shell, the MOS circuit should be more careful to be able to use the 6 ~ 8V low-voltage soldering iron is more secure.

Component Layout and Wiring: Before testing the PCB board to understand the integrated circuits and their related circuits work, inspection and repair of integrated circuits before the first to familiarize with the function of the integrated circuit used, the internal circuit, the main electrical parameters, the role of each pin and the pin's normal voltage, the waveform and the peripheral components that make up the circuit's operating principle.

Power Integrated Circuits Heat: Power integrated circuits should be good heat dissipation, not allowed to work without a heat sink and in a high-power state.

PCB testing process requires attention to many issues, the need for board manufacturers with advanced equipment and technical strength and strict quality management system to ensure that the production of circuit boards to meet customer requirements. At the same time, the design stage needs to take into account the performance and reliability requirements of the circuit, rational arrangement of component layout and wiring and other elements. In addition, attention also needs to be paid to environmental protection and safety measures and other aspects of the problem.