When generating a printed circuit board (PCB) layout, it’s a good idea to know the capabilities of your PCB fab house before you start. I’m ashamed, but I’ll admit that I recently finished routing a board with Altium Designer only to find out that I had created a layout which didn’t fall within acceptable manufacturing tolerances. I didn’t find this out until I tried to submit my design to PCBexpress.com (they’re pretty cheap and decent quality). It turns out that I had used a 5mil tolerance between traces instead of 6mils. Doh! After I had finished cursing myself up and down, however, I noticed that PCBexpress lists “Altium Designer 6″ and “Altium Designer 6 (With Sunstone DFM’s)” under the options for CAD software when you submit your design. That got me thinking. What are Sunstone DFM’s?

Sunstone Circuits is the actual fab house servicing PCBexpress.com. After hunting around on their website, I stumbled across this. Sunstone offers Design For Manufacture (DFM) rules for download for both Altium Designer and Eagle. In the zip file for Altium are two rule files and a set of instructions in a word document. The rule files are for single and double-sided boards, and multi-layer boards. Importing the appropriate rule file into the rule-set for an Altium PCB design establishes all the important layout rules to ensure your design gets manufactured the first time every time. Rules are set for things like trace width and spacing, via and hole size, thermal relief sizes for internal planes, solder mask tolerances, etc. This really beats trying to translate the manufacturing information on PCBexpress.com into working rules on my own, since apparently I’m not very good at it.