QFN Pad Calculation Problem

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   Hi,
when I try to generate a QFN with Version 2018.02 the Pads are to small, see picture. I also add the fpx to this post. uploads/870/QFN_error.fpx When I make D2 shorter (0.8mm) then the footprint looks good. Looks like the calculation takes the removed Pins also in it or something else is wrong.

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robmeyer Members Profile Send Private Message Find Members Posts Add to Buddy List Advanced User Joined: 04 Oct 2012 Status: Offline Points: 113	Post Options Post Reply Quote robmeyer Report Post Thanks(0) Quote Reply Topic: QFN Pad Calculation Problem Posted: 08 Feb 2018 at 4:58am
	Hi, when I try to generate a QFN with Version 2018.02 the Pads are to small, see picture. I also add the fpx to this post. uploads/870/QFN_error.fpx When I make D2 shorter (0.8mm) then the footprint looks good. Looks like the calculation takes the removed Pins also in it or something else is wrong.



Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5717	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 08 Feb 2018 at 9:53am
	The problem here is that you are using the QFN (Quad Flat No-Lead) component family to create a SON w/Tab (Small Outline No-Lead) footprint. Try using the SON with Tab and you'll get perfect results. There is no bugs or issues with V2018 Library Expert.
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