I am trying to use a library foot print Package_DFN_QFN:QFN-56-1EP_7x7mm_P0.4mm_EP5.6x5.6mm and I can’t draw connections to it. The rat’s nest shows all the proper links from the net list and all other foot prints connect. Specifically, I am looking for the Arm RP2040 and this is the closet one. I can choose other QFN 56 foot prints and they work fine, but both 7X7 foot prints will not allow me to make a connection. What am I doing wrong? There are plenty of sample RP2040 foot prints on the net and I down loaded an example, but I have been unable to import any of them successfully…
The footprint seems to have 0.2mm pad / 0.2mm gap. If your netclass values for track width or clearance are larger than that, it won’t connect. Even those exact values may theoretically sometimes cause problems if there’s some tiny rounding error in internal calculations, so you can try with 1.9999 or something like that and see if it helps.
Check also the pad clearance value of the footprint; it should be 2.0mm or a bit smaller if it has been defined.
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That was the problem. It took a bit for me to realize that when I changed the foot print the base geometry changed because it was a smaller foot print. As you can see, I am a new to this program. It’s going to take some practice especially with respect to the symbol and foot print libraries…
Thanks for your help!!!
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