Printed circuit board is the core of any electronic product, so testing them is crucial to during manufacturing process to ensure they can work efficiently as designed. There are several requirements for PCB production testing such as international regulation certification rest safety compliance test.
In general, PCBs are tested at every stage of their production to ensure the effective quality flow though the whole process. This test is a choice for small custom PCB designer who use PCBs for their own use. But on the other hand, large scale manufactures incorporate testing as an individual part into their manufacturing processes. Fabricated boards are initially visually inspected by qualified technicians who can find errors about imperfect surface finish or board design. Boards then undergo secondary check for further inspection preferably under a precision microscope to ensure the integrity of the design.
After the physical inspection, the board is electrically inspected to ensure accurate design flow down to the production line. The continuity of traces are tested separately by transmitting a low voltage signal and then using a high-resolution voltmeter to measure the voltage drop. In order to make the PCB manufacturing test easier, designers add test points particularly for testing the functionality. These points are usually small solder pads that power the board's basic functions, such as the main power rail and signal source.
Some PCB manufacturing test use custom test jigs to test the functionality of PCB board. Designers design a separate circuit board for testing the fabricated PCB. These test jigs are connected to the important ports of the PCB and power the board. The perfect alignment of various test leads on the PCB measures the signals of each part to ensure perfect function. This method makes the test more time-saving.
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