Programmable bed-of-nailstest access jigs.

摘要

Bed-of-nails test access jigs are commonly used to effect the required electrical connections between an electronic circuit constructed on a printed circuit board (PCB) and the automatic (electrical) test equipment (ATE) used to carry out their testing. "Fixed" bed-of-nails jigs have a number of disadvantages that can be overcome by the use of a programmable bed-of-nails jig, but the present-day programmable systems using apertured masks, or secondary pin frames, to set up a particular pin configuration, do not provide a good solution where the pin configuration has to be changed during the testing sequence.

The invention suggests a design employing individually-controlled pin control mechanisms such that from a total field of pins individual pins can be programmed to make contact with the PCB. It enables the pin actuating mechanism to fit into the space available by proposing the use of miniature clutch, or valve, mechanisms involving the utilisation of an electro rheological fluid. The inventive bed-of-nails device is thus one in which there are individual pin control mechanisms, functionally separate from the control means of any other pin, that utilise either the valve- or the clutch-forming abilities of an electro rheological fluid.