A new probing technique for high-speed/high-density printed circuit boards

Bullock in 1987 [Bull87] provided design-for-test (DFT) rules for probing printed circuit boards for in-circuit testing. Many of these rules stand in good stead even today. However, recent technical advances in operational board speed are leading some to believe that in-circuit testing cannot be performed on the high-speed sectors of boards soon to be designed. Due to the increasing usage of high-speed circuitry, there is worry in our industry that in-circuit testing is marginalized with no good substitute available. It is the purpose of This work to show how access can be maintained, even on highly dense gigabit logic boards.