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PCBA Test Principle

Connect the test points on the PCBA board through the FCT test rack to form a complete path, connect the computer and burner, and upload the MCU programme, which will capture the user‘s input action (e.g. long-pressing the switch for 3 seconds), and then control the circuitry next to it (e.g. LEDs, etc., blinking) or drive the motor, etc. through the arithmetic calculation. By observing the voltage and current values between the test points on the FCT test stand, and verifying that these input and output actions are in accordance with the design, the test of the whole PCBA board is completed.

PCBA Test Rack

For large quantities of PCBA board processing must be tested, generally will be issued the corresponding test frame (English Fixture) to assist the efficient completion. The principle of the test frame is through the test thimble and PCB board test point connection, power on, so as to obtain the circuit voltage, current and other key data, and in the test frame of the display screen display, to achieve the purpose of rapid detection. Customers in the design of PCB board, engineers will consider its test programme, will be reserved PCB test points, and issued a professional test documents or test programme to the manufacturer. Our company can make PCBA test frame by ourselves (equipped with engraving machine and test frame assembly engineer).

Example: PCBA test programme for a foreign customer

PCBA test case PCBA test types are divided into the following:

ICT (In-Circuit Test) test: It is mainly to test the voltage/current data of the test point after the PCB circuit board is energised, and it does not involve the testing of functional keys or input/output.

FCT (Functional Test) Test: It is necessary to burn the written MCU programme into the programme IC through burner (e.g. ST-Link, JTAG) first, so as to achieve the corresponding functional test. For example, after pressing the key, the LED lights up; two keys are pressed at the same time to restore the factory settings and so on. Of course, all the functions of the test can be carried out, the PCB must be soldered OK and line conduction as a prerequisite, otherwise it can not be achieved.

Aging (Burn In Test) test: the program has been burned and FCT through the PCBA board, for a long time, periodic simulation of user input and output, in order to detect its durability and reliability of welding. Under special circumstances, the PCBA board also needs to be exposed to specific temperature and humidity environment.

PCBA testing is an essential and important part of the entire PCBA manufacturing supply chain, from the final data results to control the quality, in the standardised design and manufacturing management, PCBA testing is necessary to recommend the consideration and implementation.