Keyword: PCB assembly, printed circuit board, PCB test speed, PCB manufacturer
In printed circuit board testing, flying probe testing is widely used. Compared with needle bed testing machine, testing have no making fly needle bed (fixture), and the advantages of high density circuit can test, so making a few small batch sample proofing and PCB test speed, the prominent advantages of low cost. It's very practical for many small and medium-sized PCB manufacturer.
1, the structure characteristics
Flying probe tester is the traditional needle bed online tester is a kind of improved, it to replace the needle bed, with a probe on the x-y agencies equipped with high-speed mobile respectively 4 heads, a total of eight root test probes, minimum test gap is 0.2 mm. Work unit under test (UUT, the unit under test) through the belt or other UUT transmission system to the testing machine, and then fixed testing machine test probe contact pad (the test pad) and via hole (via), so as to test the unit under test (UUT) of a single element. Test probe by multiplexing (multiplexing) systems connected to the drive (signal generator, power supply, etc.) and sensor (digital multimeter, frequency counter, etc.) to test the components on the UUT. When a component is testing the other components on the UUT through the probe on the electric shielding to prevent interference. Flying probe tester can check the short circuit, open circuit and component values. On the flying probe test also used a camera to help find missing components. Use camera to check clear direction element shape, such as polar capacitor. As the probe location accuracy and repeatability to achieve the range of 5-15 microns, flying probe tester can be precise detection of UUT. Flying probe test resolved to see in the PCB assembly of ample existing problems: such as possible for as long as 4 to 6 weeks of test development cycle; Of fixture development costs about $10000 - $50000; Not economic to test small batch production. And not to quickly test prototype machines (prototype) assembly. Because has the close contact shielding ability of UUT and make new products to market faster (time - to - market), flying probe test is an invaluable resource. Also, because do not need to have experience in testing development engineers, the system also has the advantages such as save manpower, save time.
2, development and debugging
Flying probe tester programming easier and faster than traditional ICT system. GenRad company GRPILOT system, for example, the test developers will design engineer CAD data into usable files, this process takes 1-4 hours. And then the new file through the test program is running, generate a. IGE and the SPC file, add a directory. Then the software runs to produce need test UUT all files in the directory. Short circuit test type from the options page. Testing machine used on UUT reference point selection from the CAD information. UUT on a fixed platform. In software development, after the completion of the program was "turned into", in order to ensure the selection to the best possible test location. Then join the various components "protection" (component test isolation). A typical 1000 nodes of UUT test development of the time is 4 to 6 hours. In software development, and after the completion of the loading, start flying probe test process of a typical testing and debugging. Debug the next job is to test developers, is needed to obtain the best possible UUT test coverage. In the process of debugging, examine each element of fluctuation test limits, confirm the probe contact position and parts. Typical 1000 nodes of UUT debugging may take six to eight hours. Flying probe tester development easy and commissioning period is short, make the UUT test program development engineers of the test requirement is less. From CAD data and UUT ready to test between this period of time, allowing the flexibility of the maximum number of manufacturing processes.
3, advantages of overview
Flying probe testing advantages including: quick test development; Low cost test method; Fast conversion flexibility; And in the prototype stage for designers to provide rapid feedback. Therefore, compared with the traditional ICT, flying probe test required by reducing the total test time is enough to make up for the time. Use flying probe test system benefits outweigh the disadvantages. In the assembly process, for example, such a system to provide the received CAD file after a few hours you can start production. As a result, the prototype circuit boards in the assembly can be a few hours after the test, unlike the ICT, the high cost of test development process and fixture is likely to delay a few days, or even a few months. In addition, due to the set, programming, and testing of simple and rapid, and in fact generally technology assembler, rather than engineers, can test operation. Flying probe test also has flexibility, do a quick test process transformation and quick feedback. Also, because the flying probe test does not require fixture development costs, so it is a low-cost system can be placed in front of the typical test process. And because flying probe tester changes the low yield and fast conversion assembly test method, usually need a few Zhou Kaifa test now can get a few hours.
Speak so many advantages of the flying probe test, on the choice of specific still should according to their own some of the requirements to decide, if also selects the flying probe test batch of PCB will be slow. So the suitable is the best!
Source: //www.seekic.com
