Design Guidelines  
 

A good design, including PCB layout and component selection, can make your product easier to manufacture and may reduce your cost. We prefer that you consult us early in the design process so that we can discuss potential manufacturing issues with your design. Together we can determine appropriate solutions. This page illustrates some basic guidelines that will eliminate the most commonly found problems during production. In addition, you can click on the links below for details on the types of files that are required for efficient import of your design data into our systems.
Files Needed for Production
Acceptable CAD Formats

Basic Guidelines
Fiducial marks are critical to aligning the PCB correctly for machine placement of surface-mount components. While we can handle a variety of fiducial types, the preferred mark should be a 35-mil diameter circular pad with 100-mil diameter solder mask relief. It is also preferable to have at least (2) fiducials that are placed as far apart as possible on the board, on either a horizontal or vertical line. If you are providing a separate solder paste image, be sure to include the fiducial marks on this image so the screen printer can align the solder paste screen with the board.

Keep all fiducials and components at least 50-mils away from the edge of the board (or else design in breakaway rails around board or panel of boards). Surface-mount components on boards that have parts on both sides should be placed at least 187-mils from board edges. Contact us to discuss exceptions to these limits that may apply to your specific board.

Even silkscreen on the PCB can cause manufacturing problems, if placed improperly. Keep silkscreen at least 15 mils from all pads.

Do not use silkscreen under low-profile, fine-pitch SMT parts (such as some resistor networks). The silkscreen could keep the component from sitting flat against the PCB.

To indicate component location use an outline box around the component instead of a line between the pads.


Example of a
good Fiducial
mark.
     
  This is an
example where
the silkscreen bar between SMT pads created problems during installation of components.
     
  Polarized components should have direction clearly marked on the board outside the footprint of the component .