AOI (Automatic Optical Inspection):
The machine automatically scans the PCB through the camera, collects images, compares the tested solder joints with the qualified parameters in the database, detects the defects on the PCB through image processing, and displays/marks the defects through the display or automatic signs for maintenance personnel to repair.
Using high-speed and high-precision visual processing technology to automatically detect various mounting errors and welding defects on PCB. The PCB board can range from fine-pitch high-density board to low-density large-size board, and can provide online inspection scheme to improve production efficiency and welding quality. By using AOI as a tool to reduce defects, we can find and eliminate errors in the early stage of assembly process to achieve good process control. Early detection of defects will avoid sending the bad board to the subsequent assembly stage, AOI will reduce the repair cost and avoid scrapping the unrepairable circuit board.
PCB board test stand:
It mainly includes: frame, which constitutes the main frame of the test frame and provides carriers for each unit; The needle board is provided with a plurality of test probes; The carrier plate is elastically installed on the upper end face of the needle plate, and is provided with a positioning groove for placing the PCB; A pressing plate, on which a plurality of pressing rods are arranged, is used for lowering the ballast plate and the PCB plate; The pressing mechanism is fixedly installed on the frame and comprises a quick clamp and a guide mechanism, and is used for realizing the up-and-down movement of the pressing plate; The utility model has the advantages of simple structure, accurate test and convenient use, and can solve the test problem of high-density circuit boards, thereby obviously improving the test accuracy and efficiency and greatly reducing the cost of manual test. At the same time, the modular architecture design improves the reuse rate of the test device, reduces the maintenance cost to a certain extent, and provides convenience for the later module upgrade.
Flying needle test:
The flying needle tester is an improvement on the traditional on-line tester for needle bed. It can replace the needle bed with probes. The X-Y mechanism is equipped with four, six or eight test probes that can move at high speed respectively, and the minimum test gap is 0.2 mm.. When working, the unit under test (UUT) is conveyed into the testing machine through a belt or other UUT conveying system, and then the probe of the testing machine is fixed to contact the test pad and the via, so as to test a single element of the unit under test (UUT). The test probe is connected to the driver (signal generator, power supply, etc.) and sensor (digital utility meter, frequency counter, etc.) through a multiplexing system to test the components on the UUT. When one component is being tested, other components on the UUT are electrically shielded by the probe to prevent reading interference.
Flying needle tester can check short circuit, open circuit and component value. A camera is also used in the flying needle test to help find the missing components. Use a camera to check the shape of components with clear direction, such as polar capacitance. With the positioning accuracy and repeatability of the probe reaching the range of 5-15 microns, the flying needle tester can accurately detect UUT.
Flying needle test has solved a lot of existing problems in PCB assembly: for example, the test and development cycle may be as long as 4-6 weeks; The development cost of fixture is about 10,000 -50,000 dollars; Can't economically test small batch production; And that assembly of a prototype cannot be teste quickly.
Flying needle testing is an invaluable production resource because of its ability to closely contact shielded UUT and the ability to bring new products time-to-market faster. In addition, because there is no need for experienced test and development engineers, the system also has the advantages of saving manpower and time.
