Implementing bead probe technology for in-circuit test: A case study

A major OEM implements bead probe technology on a new design to gain test access and coverage of high-speed circuits. Conventional probing techniques are incompatible with the density and speed requirements of the board. The experiences of a first implementation of bead probe technology are discussed here, including CAD issues at board layout, test fixture construction and debug, soldering process difficulties, and test probing problems during the ramp to high-volume production.