Rick, The best method to eliminate shorts is to perform "root causes analysis". In other words identify where the short occurred. There are three primary tools used today: CAM Design Analysis, Automatic Optical Inspection, and Electrical Test. These may be obvious but are the best tools today to ensure high yields. A Design Analysis program can verify netlists and summarize design spacing values. An optical inspection systems can optically compare the bare board against the orignal design and highlight in-process defects. This tool can be used throughout the process to inspect: the master phototool, the working photo- tool, the developed resist image, and the post etch panel. As the final gateway, electrical test is used to prevent any board with a short being sent to a customer. Using these tools can help eliminate defects only if corrective action is taken to eliminate the cause of the defect. George Murray Gerber Systems Rick wrote: > I have been tasked to eliminate the defect of shorts on PWB's. Other than the > obvious etch defects, what are some causes of shorts that other companies have > seen ? Could the raw material be part of the problem ? Could the defect be > "buried via" related ? I would appreciate any inputs or thoughts on the > subject. > > Thanks in advance, > > Rick Haynes > Process Engineer > Texas Instruments > e-mail [log in to unmask] > phone 512/250-7823 > >