PCBA , it is after put the components on PCB，also can say that PCB plus assembly of electronic components process. However, each PCBA part needs to undergo PCB testing and PCBA testing to verify the functions of the circuit board, verify whether the PCB and PCBA meet the design requirements, and ensure that each product does not have quality problems.

The test principle of PCB:
Electrically test the PCB through the metal needle plate on the specific test frame, mainly to test the conductivity of the PCB and whether there is an open or short circuit.

The test principle of PCBA：

Connect the test points on the PCBA part through a specific test frame to form a complete path, connect the computer and the burner, and upload the MCU program. The MCU program will capture after arithmetic control the side circuit. Obtain typical values such as voltage and current values of the test circuit through the test frame, so as to observe whether the tested circuit is conducting normally, and verify whether these input and output actions are consistent with the design, so as to complete the test of the entire PCBA part.