Method for determining drill target locations in a multilayer board panel

In order to correct for misregistration of solder pads in multilayer board (MLB) panels and determine drill target locations through vertical stacks of the solder pads, a fixture is prepared with fixture holes arranged in a pattern that corresponds with the locations of fiducial pads that are located on the MLB panel. The fixture has tooling pins that engage with tooling holes in the MLB panel to hold the MLB panel in an absolute position relative to the fixture. An x-ray inspection system views the superimposed image of a selected fixture hole and a corresponding fiducial pad that is visible within the boundary of the fixture hole. A software routine is then used to compute the offset between the fixture hole and the fiducial pad. The process is then repeated for the remaining sample of fixture holes and fiducial pads. The results are then fitted and then sent to a drilling machine to determine a position for the drilled holes in the MLB panel that compensates for the misregistration of the solder pads.