PCB Libraries Forum : Thermal Pad and Paste Mask Apertures https://www.PCBLibraries.com/forum/ Mon, 20 Apr 2026 17:48:48 +0000 Thu, 05 Mar 2026 07:39:00 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=3622 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[Thermal Pad and Paste Mask Apertures : All the Texas Instruments footprints...]]> https://www.PCBLibraries.com/forum/thermal-pad-and-paste-mask-apertures_topic3622_post14475.html#14475 Author: Tom H
Subject: 3622
Posted: 05 Mar 2026 at 7:39am

All the Texas Instruments footprints on www.pcblibraries.com/POD that have thermal pads, have the exact checkerboard pattern dimensions and spacing as their datasheets provide. Including 0.05 mm corner radius. 

These parts include QFN, SON, QFP, SOP, PSON, PQFN, DPAK with thermal pads. There are approximately 40,000 TI footprints with thermal pads on the Parts on Demand cloud database. 

The only way to accomplish this is to build the footprint using the calculator and setup all the TI package and footprint dimensions and save to FPX for the 3D STEP model. 

Then move the footprint to FP Designer for customizing the paste mask apertures in the thermal pad stack. Then save to FPX as the real footprint. 

Rename the Calculator footprint and Physical Description to match the FP Designer data. 

Output to CAD the FP Designer footprint footprint first. Then open the Calculator footprint and create the 3D STEP only and overwrite the FP Designer 3D STEP model. 

Then import into your CAD tool and you'll get the perfect mfr. recommended pattern with a high-quality 3D STEP model. 

]]> Thu, 05 Mar 2026 07:39:00 +0000 https://www.PCBLibraries.com/forum/thermal-pad-and-paste-mask-apertures_topic3622_post14475.html#14475 <![CDATA[Thermal Pad and Paste Mask Apertures : If a bottom pad of a QFN for example,...]]> https://www.PCBLibraries.com/forum/thermal-pad-and-paste-mask-apertures_topic3622_post14474.html#14474 Author: pcbfreedomcad
Subject: 3622
Posted: 05 Mar 2026 at 3:19am

If a bottom pad of a QFN for example, has multiple paste mask openings generated from PCB Libraries, do these openings need to have rounded corners, or do the fabricators handle the issue with 90 degree corners on stencil openings automatically?

I know the bottom pad itself can have rounded corners.
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