PCB Libraries Forum : QFN Pad Calculation Problem https://www.PCBLibraries.com/forum/ Tue, 21 Apr 2026 10:36:45 +0000 Thu, 08 Feb 2018 09:53:19 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=2294 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[QFN Pad Calculation Problem : The problem here is that you are...]]> https://www.PCBLibraries.com/forum/qfn-pad-calculation-problem_topic2294_post9448.html#9448 Author: Tom H
Subject: 2294
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. 

]]> Thu, 08 Feb 2018 09:53:19 +0000 https://www.PCBLibraries.com/forum/qfn-pad-calculation-problem_topic2294_post9448.html#9448 <![CDATA[QFN Pad Calculation Problem : Hi,when I try to generate a QFN...]]> https://www.PCBLibraries.com/forum/qfn-pad-calculation-problem_topic2294_post9446.html#9446 Author: robmeyer
Subject: 2294
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.


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