Functional circuit test system and method for printed circuit board assembly

Abstract

The invention provides a functional circuit test system for a printed circuit board assembly, and is used in the technical field of tests in printed circuit board assemblies. The system comprises an impedance test gauge head, a relay group, a travel switch, a self-locking control circuit and a switching circuit, wherein the travel switch and the self-locking control circuit are directly connected with the impedance test gauge head respectively; the self-locking control circuit is connected with the switching circuit which is connected with a functional circuit test module; the travel switch is connected with a probe group of a pressing tool, and is used for judging whether the tested printed circuit board assembly and the probe group of the pressing tool are well pressed or not; and the impedance test gauge head is used for measuring and judging whether a measured impedance value of the tested printed circuit board assembly is in a proper range or not, transmitting a test passing signal when the measured impedance value is in the proper range, and transmitting a control signal to the self-locking control circuit to enable the self-locking control circuit to enter a self-locked state to switch the test system to the functional circuit test module.

Description

technical field [0001] The invention relates to the technical field of circuit board testing, in particular to a functional testing system and method for measuring impedance of a mounted circuit board. Background technique [0002] In the mass production process of printed circuit board assembly (PCBA), due to the shortage of operators, production equipment and technology, it is very likely that the produced circuit board has some defects, which requires adding various A variety of test equipment or tools, so that the final factory-mounted circuit boards are completely consistent with the original design specifications and parameters. [0003] Functional Circuit Test (FCT) is an indispensable link in the circuit board testing process. Functional testing generally refers to providing a simulated operating environment for the target circuit board to make it work in various design states, thereby obtaining various states. To verify the function of the PCBA, that is, to load th...

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Problems solved by technology

[0004] For example, the artificial component test station in the stage before the functional test is to test the loading resistance of the circuit board and other components. This stage is mainly completed manually, and the test devices used generally include test fixtures, scanners, multimeters or oscilloscopes, etc. , but manual testing is usually inefficient, and the response time of test equipment such as multimeters and oscilloscopes is long. In addition, it is inevitable that some components of the circuit board will be missed or inaccurate, especially for surface mount technology ( Surface Mounted Technology (SMT technology) PCBA often has problems such as missing terminal resistors, empty soldering or wrong parts, and manual testing usually misses these situations, making it impossible to implement a fool-proof mechanism

[0005] If the component test in the previous stage is not perfect, it is usually difficult to find these problems in the functional test process of the overall PCBA in the latter stage after power-on

Therefore, in principle, it is required that the test process must first do a good job of component testing in the manual stage, then take out the tested PCBA from the fixture and put it into the fixture in the next stage, and then power on for automatic data collection, resulting in The entire test takes a long time and is inefficient. It is necessary to set up multiple sets of test equipment or sites to complete all functional tests, which is time-consuming and labor-intensive, and the cost of test equipment is also high. At the same time, the use of multiple sites or equipment requires a larger Production space, and a lot of energy will be invested in the maintenance of test equipment in the follow-up, which is not conducive to the production test of large-scale circuit boards

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