I decided that I want to take the route of having complete control of my libraries meaning only having footprints that I brought down individually from snapeda or ultra say, from the digikey website. Symbols as well. Anyway all seemed OK until I tried to do a fill and then I noticed that my downloaded footprints for a few SMD caps have these extra rectangles on them that actually short the pads together. They also mess up the fill as well.I show two in my attached picture. The bottom one I fixed manually and it is now acting OK but the top one for a tantalum has a big rectangle around it and then one in the middle that shorts the two pads together. Other SMD footprints I downloaded the same way don’t have this problem. What is going on there, please?
Finally, if you have extra bandwidth, I notice very thin rounded ovals around SMD pads that seem to be top copper. What are they called?
SnapEDA doesn’t create tailored footprints for KiCad. They have some format from which they convert to KiCad, and it’s not always very good conversion. Especially the layers may go wrong. That’s what may have happened here. (Otherwise I have found them to be trustworthy, i.e. having correct dimensions for pads. I like SnapEDA.)
You gain nothing by dowloading from other source instead of using KiCad’s own libraries for standard package footprints. If you want to have “complete control”, you should just copy the needed footprints from KiCad’s library to your own and then modify them.
In any case and always inspect all footprints manually first before using them! Don’t trust anyone!
Thanks, I kind of surmised that these extra rectangles have some function but they are put in the wrong layer. I will probably take your advice but the reason I went the way I did was that just loading the system footprint library takes a long time and that’s annoying. Also it looks like there are a number of different versions of approximately the same thing. So I’d prefer footprints that have already been vetted against a specific part. In theory I wouldn’t have to wonder whether the footprint was some kind of compromise to fit kind of an average part. I wish I knew what that center rectangle was for since I removed it. Maybe it’s for gluing the part down? Perhaps I’ll take a look at the footprint itself in a text editor.
The Thin Ovals are clearance. Below is a snapshot from a card I am just finalising and since it is targeting 3oz I need 0.26mm clearance. I also have turned on the options to display this as I find it helpful.
Thanks Naib, doesn’t the fill algorithm manage clearance after you set it in the fill GUI? I don’t see these lines in the footprint files. There must be another pad clearance setting, perhaps in the board parameters. Obviously I have more reading to do but my original question was not that dumb. (So I think!)
