Common Problems

Gerber File Problems

1. Missing Gerber Aperture List
   Some CAD programs generate a table for each layer. If your program is one of these make sure you send the table for each layer. PADS PCB and older ORCAD versions are two programs that usually require a table for each layer.
   
   
2. Missing one of the Gerber layers
   Ensure that you send a top and bottom layer for your two-sided boards.
   
   
3. Gerber RS274-X files that only contain the aperture definitions.
   Occasionally an incorrect setting will create a Gerber file containing only Dcode definitions and no X/Y locations - Open your Gerber file in a text edit program and check for X/Y locations following the last '%ADD' code.
   
   
4. Gerber layers that have been merged with silk screen layers.
   During the output stage the component outline/component text has been merged in with the Gerber top and or bottom layers.
   
   
5. Missing cut lines
   Make sure that the board outline is on at least one layer. Some programs use a mechanical or a keep out layer to store this outline.
   
   
6. Stale data
   Gerber data is much older than the drill file. Keep an eye on file creation dates and times. Depending on the speed of the computer that generated the data the worst case is twenty minutes between the Gerber data and the Drill data. Always generate Gerber and NC file sets in one session.
   
   
7. Zero Byte files
   A file name with out any contents, this is easy to spot with your directory management software. Be suspicious of file sizes under 1K and check them with a text edit program when they are under 1K in size.