BEAD probe give new life to in-circuit test

摘要

Prodrive, a European company based in the Netherlands, has traditionally used a test strategy that combines in-line automated inspection and functional test. However, for some time there has been some concerns about the functional test approach, due to its inherent complexity, cost and poor maintainability. Elfried Keers reports These concerns came to a head with a single board robotics controller that challenged the functional test approach. The board is large, greater than A3 in size, and combines digital processing with a full four-axis motion controller. The digital processing section incorporates high-speed processors, FPGAs and DSE The motion controller section incorporates high power motor control circuits. With 14 separate edge connectors to connect, just fixturing to the board under test during functional test was challenging. Functional test times were excessive and even with Built-in-Test that included Boundary Scan facilities the fault coverage was less than required.