I’m having an issue when I use the DFN-14-1EP_3x3mm_P0.4mm_EP1.78x2.35mm footprint in my design. I have my minimum track spacing set to 0.2mm which is fine for assigning tracks to the pads on this device, but I get DRC rules about track near pad. The default is to just inherit the design rules. I set it to 0.15mm (which is the distance I measured between the pads) but I still get this error. I don’t want my traces closer than 0.2mm, but I can’t figure out how to get rid of all of these DRC errors other than creating a custom footprint with the pad width set to 0.2mm instead of the default of 0.25mm.
Ideally, the pad clearance and spacing should override the track clearance within the pad region. I ran into an issue with another footprint for a QFN where I had to change the corner pads to rounded to prevent DRC issues.
I may have to set it a bit smaller then. I set it to 0.15mm, which is what I calculated the distance to be. Oshpark’s spec says 6 mil (0.1524mm) but I imagine that 0.15mm works fine). I use 0.2mm for my minimum track width and spacing to be on the safe side. The TSSOP-14_4x5mm_P0.65mm footprint is tighter than this. In the interim, I created a custom footprint with narrower pads in the hope that that will work. Another footprint that gave me grief was the QFN-24-1EP_4x4MM_Pitch0.5mm footprint. I created a variant where the pads on the corners are rounded, i.e. pads 1, 6, 7, 12, 13, 18, 19 and 24.
