Research On PCB Test Method Based On Boundary Scan Technology

In modern electronic system, PCB is becoming more complicated and Multi-Layer–Board design is becoming more popular. In the mean time, with lots of surface-mounted component and BGA-package device in use, the number and density of pin on the chip are increasing ,which make it hard to soldering and assemble for chip and make it easy to go wrong .Under this background, test is becoming more and more important. The function of conventional probe-test technology is decreasing, while a new technology named boundary scan test solves this problem. Because of convenient fault location and simple logic control and high test efficiency, it receives approve and support in global test industry. After full research and mastering boundary scan principle, then through analysis of test type and methods of PCB,a boundary scan test system is developed based on parallel port.In order to communicate computer with PCB,a parallel port—JTAG port cable is designed and its access function is also realized. The software is developed on VC++6.0 with visual interface and object-oriented programming method,which can complete analysis of BSDL files and net list files and generation of boundary scan chain. On that basis, it completes test vectors generation according to test type and test vectors load and reading back the responding vectors. Finally, the software finishes the data analysis and results display.