Computer-generated layout of tracks on printed wiring board - involves broadening of tracks in conventionally plotted layout until single-track-width sepn. lines are available for tool programming

摘要

The PCB mfg. method involves scanning the layout of the printed wiring board in a program-controlled device with pixel size chosen to suit the track width. The data for all pixels pertaining to a track are stored and evaluated for selection of pixels which delineate the contour of the track. Sequences of pixels are overwritten or extended with an equidistant sequence until the breadth of one pixel separates adjacent tracks. A geometric program for the milling machine is worked out from the insulating track data corresp. to intertrack sepn. pixels. ADVANTAGE - Galvanically isolated tracks at min. spacing are guaranteed by programmed control of the milling machine with min. wastage.