Every fabrication shop has a list of design rules that they provide to customers that detail the limitations of the manufacturing process. The specific numbers used will depend on the fabrication shop that you use as well as whether you are using their recommended process limits or their actual process limits. Remember that the closer that you get to the actual process limits, the more expensive your design will be to produce. Included in the rules are distances between traces, board edges, pads, etc…
You set the spacing between copper features in your design program and then have the software check your PCB layout against the numbers. This is the “Space Width” part of Trace and Space width. Remember that different copper weights have different trace and space minimums, so if you have thicker inner layers of copper, you’ll want to provide separate rules for those layers.
All of these values reference the minimum distance between two PCB features. Remember that PCB fabrication has some imperfections associated with it. If you take everything to the absolute manufacturing limits, then your board yield per panel will decrease.
Copper clearance isn’t the only concern. You also need to ensure that your minimum copper trace widths are met, there is a minimum size drill hole, minimum annular ring, etc… These are determined by the minimums provided by your design house.
Royal Circuit Solutions, Inc.
21 Hamilton Ct.
Hollister, CA 95023
Royal Flex Circuits, Inc.
Rigid-Flex and Flex Division
15505 Cornet St.
Santa Fe Springs, CA 90680
Get latest updates and offers.