Any designer or builder must implement PCB test method to achieve ultimate success. By testing the circuit board, you can minimize major problems, find small errors, save time and reduce the overall cost.
PCB testing is mainly used to alleviate the problems in the whole manufacturing process and the final production process. These types of tests can also be used on prototypes or small-scale assemblies, which helps to identify potential problems that may exist in the final product.
What is being tested in PCB testing
Various components of the circuit board can be tested in various PCB test methods.
Lamination
Lamination quality in PCB is a critical component. Use force or heat to test the peel resistance of laminates. Spalling can lead to major problems surrounding the final function of PCB.
copper plating
The copper coating of PCB board must be tested. PCB board is copper foil laminated on the board. The covering layer is conductive and should be tested in detail for quality, tensile strength and elongation.
Weldability
Solderability testing means analyzing the materials on the circuit board to ensure that other components can be firmly connected. If it is proved that the circuit board is not solderable, the designer cannot confidently connect other necessary components to the board. This test is performed using wetting.
Hole wall quality
Through the hole wall quality test, professionals can determine whether the hole wall will crack or delamination when using PCB. This test usually involves rapid temperature changes to evaluate PCB response to thermal stress environment.
Electric
In order for any PCB to work properly, it must have stable conductivity. The electrical test will determine this by passing the current with the minimum leakage through the circuit board.
environment
Because PCB usually works in humid climate, designers must carry out water absorption test on it. Before and after introducing PCB into wet environment, experts will weigh it. If the weight changes significantly, the PCB has failed.
Cleanliness
Finally, the PCB must be able to withstand all kinds of corrosion, humidity, dirt and other external factors while still operating normally. Experts will test PCB and its resistance to various potential environmental conditions, and analyze before and after each situation.
Flying needle test
Flying needle test, also known as fixture free online test, can be run without using any custom fixture. Its main advantage is that it can minimize the total cost of testing, but it is also very simple.
This test uses a fixture to fix the circuit board so that the test pins can move and analyze each point, all of which are controlled by software. It is widely used and can quickly and easily adapt to new circuit boards.
Automatic optical inspection (AOI)
AOI test will use one 2D camera to two 3D cameras to capture photos of PCB. Then, the program will compare these pictures with the detailed schematic diagram to find defects or mismatches.
AOI can be used to identify early problems to stop production and save time and money. However, experts will never rely entirely on AOI just because AOI cannot power up the circuit board and cannot test all part types.
X-ray examination
Technicians use X-ray inspection (Axi) to locate defects in solder connections, internal wiring, and barrel. With 2D and 3D Axi testing, designers can choose according to the plate at hand - although 3D testing is usually faster.
functional testing
The function test is very simple, because it only tests the function of the circuit. The function test is used at the end of the manufacturing plan. It connects with the PCB through the test probe point or edge connector to simulate the final environment of the PCB.
conclusion
PCB Fault Analysis and testing is critical to the success of any product using PCB. PCB performance test method, PCB component test method and PCB function test method are all methods to ensure the normal operation of your circuit board and materials
