Using time-domain reflectometry to identify manufacturing information for a passive printed circuit board

摘要

A method uses time-domain reflectometry to measure a signal reflection delay in a conductive trace formed on a specific passive printed circuit board, and uses the measured signal reflection delay as an index into a table storing a predetermined association between signal reflection delay and passive printed circuit board manufacturing information, wherein the table includes a plurality of predetermined signal reflection delay values, and wherein each of the predetermined signal reflection delay values is associated with unique passive printed circuit board manufacturing information. During manufacturing of the passive printed circuit board, a hole is drilled through the passive printed circuit board so that the hole intersects with the conductive trace and divides the conductive trace into a proximal segment extending from the connector to the hole and a distal segment that is electrically isolated from the proximal segment by the hole.

主权项

1. A method for identifying manufacturing information about a passive printed circuit board, comprising:
providing a field-programmable gate array on an active printed circuit board, wherein the field-programmable gate array includes a time-domain reflectometry device to measure signal reflection delay; coupling the passive printed circuit board to the active printed circuit board through a connector, wherein the connector provides electronic communication between a conductive trace on the passive printed circuit board and the field-programmable gate array on the active printed circuit board; measuring a signal reflection delay in the conductive trace formed on the passive printed circuit board using the time-domain reflectometry device on the active printed circuit board; and identifying manufacturing information about the passive printed circuit board using the measured signal reflection delay as an index into a table storing a predetermined association between signal reflection delay and passive printed circuit board manufacturing information, wherein the table includes a plurality of predetermined signal reflection delay values, and wherein each of the predetermined signal reflection delay values is associated with passive printed circuit board manufacturing information.