![]() ![]() This can help assure the board designer that the PCBA will have maximum test coverage, without worrying for possible structural defects of the board. It will be very cost-effective if manufacturers can consider if their PCBA has proper design for boundary scan tests during the prototype design stage, before the board is actually assembled. Boundary scan can be used as part of the test strategy from the prototype stage, right to new product introduction (NPI) and production run stages to achieve the highest test coverage at every stage of the PCBA process, and at the same time lower the cost of test implementation.įigure 2: Boundary Scan on devices and interconnect test implementation Hence the printed circuit board assembly (PCBA) test strategy should start at the design stage of the board to ensure that maximum coverage is achieved during testing. The success of boundary scan lies with the proper design of the board and verification of boundary scan at the early stage of the board design to ensure success during production implementation. Boundary scan also has the capability to execute other tests, as defined in the BSDL (Boundary Scan Description Language), including private instructions which support internal functions of a boundary scan device, such as built-in self-test (BIST). Boundary scan usage has also expanded to include testing of non-boundary scan digital device such as DDR and programming digital devices such as flash, EEPROM and serial peripheral interface (SPI) devices. When these device pins are connected to other boundary scan devices, it will allow connectivity testing of each device.īoundary scan has become an important limited access solution for PCBAs. These boundary scan cells allow control and observation of what happens at each input and output pin of the boundary device. ![]() A boundary scan device is designed with shift registers known as boundary scan cells that are placed between pins of the devices and the internal logic (see Figure 2). Repair Station (ICT and FT) – To repair the PCBA that failed during ICT and FT stage.ĭesign for Test: Introduce Boundary Scan Test at Prototype Phaseīoundary scan or 1149.1 is an IEEE Standard that defines the test access port and boundary scan architecture of digital integrated circuits to allowed testing of devices in a PCBA.The defects are presented in a block of functions. Functional Test (FT) – PCBA is powered to enable checking of the functionality of the board.Common defects arising from manufacturing faults include open, shorts, and wrong components. ![]()
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