Views:38 Author:Site Editor Publish Time: 2021-08-31 Origin:Site
The custom pcb assembly test refers to the electrical continuity of the PCBA circuit board mounted with electronic components and the detection based on the input and output values.
Why do custom pcb assembly testing?
In the design of PCB circuit boards, there are numerical relationships such as voltage and current between different test points. However, the process flow of printed circuit board assembly production and processing is very complicated, including many important processes such as PCB board manufacturing process, component procurement and inspection, SMT patch assembly, DIP plug-in, PCBA testing, etc. During the production process, there may be Various problems arise from improper equipment or operation, so it is necessary to use professional test equipment or manual operation of a multimeter to test the test points to verify whether the actual PCBA board meets the design requirements and ensure that each product does not have quality problems.
The custom printed circuit board assembly test is a key step to ensure the quality of production and delivery. FCT test fixtures are made according to the test points, procedures and test steps designed by the customer, and then the PCBA board is placed on the FCT test rack to complete the test.
Prototype printed circuit board assembly test principle
Connect the test points on the PCBA board through the FCT test frame to form a complete path, connect the computer and the burner, and upload the MCU program. The MCU program will capture the user's input actions (such as long pressing the switch for 3 seconds), and control the on and off of the side circuit (such as LED flashing) or drive the motor to rotate through calculations. By observing the voltage and current values between the test points on the FCT test frame, and verifying whether these input and output actions are consistent with the design, the test of the entire PCBA board is completed.
Custom pcb assembly test type:
The custom pcb assembly test mainly includes five forms: ICT test, FCT test, aging test, fatigue test, and harsh environment test.
The ICT (In-Circuit Test) test mainly includes circuit continuity, voltage and current values, fluctuation curves, amplitude, noise, etc., and does not involve function keys or input and output tests.
For FCT (Functional Test) testing, you need to first burn the prepared microcontroller (MCU) program into the program IC through a burner (such as ST-Link, JTAG) to simulate the function of the entire PCBA board, such as after pressing a button , The LED light is on; press the two buttons at the same time to restore the factory settings and so on. So as to find out the problems in the hardware and software, and equip with necessary patch processing production jigs and test racks.
Burn in test (Burn In Test) is mainly to perform long-term and periodic simulation of user input and output on PCBA boards that have been programmed and FCT passed to test their durability and welding reliability. Only after the aging test can electronic products be sold in batches.
The fatigue test is mainly to sample the PCBA board, and perform high-frequency and long-term operation of the function, observe whether there is failure, and judge the probability of failure in the test, so as to feed back the working performance of the PCBA board in the electronic product.
The test in harsh environments is mainly to expose the custom pcb assembly board to extreme temperature, humidity, drop, splashing, and vibration, and obtain the test results of random samples, thereby inferring the reliability of the entire PCBA board batch product.