PCB Libraries Forum : Rounded Rectangle Pad Shape https://www.PCBLibraries.com/forum/ Mon, 20 Apr 2026 18:56:02 +0000 Thu, 07 Dec 2023 11:36:59 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=1462 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[Rounded Rectangle Pad Shape : V23 &amp; the new V24 have IPC-7352...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13339.html#13339 Author: Tom H
Subject: 1462
Posted: 07 Dec 2023 at 11:36am

V23 & the new V24 have IPC-7352 footprint naming convention and an Option file that turns off the Fabrication and Assembly tolerances and updates all negative solder joint goals to 0.00. 

Note: All Option settings are user definable. 

]]> Thu, 07 Dec 2023 11:36:59 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13339.html#13339 <![CDATA[Rounded Rectangle Pad Shape : does PCB Footprint Expert -...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13338.html#13338 Author: eyoung
Subject: 1462
Posted: 07 Dec 2023 at 11:29am

does PCB Footprint Expert - for Allegro include the new additions and recommendations that have been released in IPC-7352?

Ive noticed in the sample files offered on the PCB Footprint Expert - for Allegro that none of the rectangular pads are rounded when opened up in Allegro 2022 17.4-2019 S038

Our company is considering a footprint/librarian program to help streamline our component creation process.


]]> Thu, 07 Dec 2023 11:29:14 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13338.html#13338 <![CDATA[Rounded Rectangle Pad Shape : All IPC documents regarding PCB...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13295.html#13295 Author: Tom H
Subject: 1462
Posted: 18 Oct 2023 at 9:17am

All IPC documents regarding PCB design and land patterns have been downgraded from "Standard" to "Guideline". 

All new Texas Instruments datasheets provide a recommended solder pattern and the pad patterns have 0.05 mm corner radius. 

You decide what settings work best for you. The current Footprint Expert default for Maximum Radius is 0.20 mm (not 0.25 mm) but you can change the Maximum value to anything you want. 

You can also change all pad shapes to be Oblong or Rectangle. Or some component families can have oblong and some rectangle. 

You need to make your own choices, but I would discuss this with an assembly shop because the pad shape affects that manufacturing process. 

]]> Wed, 18 Oct 2023 09:17:26 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13295.html#13295 <![CDATA[Rounded Rectangle Pad Shape : Our organization recently bought...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13294.html#13294 Author: eyoung
Subject: 1462
Posted: 18 Oct 2023 at 8:38am

Our organization recently bought the IPC standard 7352 and it does consider rounded rectangle pads advantageous espically for Pb-free soldering processes(relevant to us) in comparison with rectangular pads

I cant seem to find where it exactly states that rounded pads strengthens the solder joint, or where these values (below) were determined

  1. Corner Radius = 25% of Pad Width (pad width is the narrowest part of the SMD pad)
  2. Maximum Radius = 0.25 mm, so regardless of how wide the pad is the corner radius will never exceed 0.25 mm (10 mils)
  3. Radius Corner Round-off value is 0.01 mm

Im trying to justify our organization to move towards an update to our procedures to use rounded rectangle pads so that we are up to industry standard.
I want to be able to justify this change with a concrete IPC standard , if available. 
If so, could you point me to the exact one? Or maybe a study that demonstrates these claims.

I appreciate your time and attention on this very much

]]> Wed, 18 Oct 2023 08:38:50 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13294.html#13294 <![CDATA[Rounded Rectangle Pad Shape : CAD vendors created Rounded Rectangle...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13293.html#13293 Author: Tom H
Subject: 1462
Posted: 18 Oct 2023 at 8:25am

CAD vendors created Rounded Rectangle pad shape. 

Most component datasheets recommend rectangular pad shape. 

IPC recommends oblong pad shape. 

Rounded Rectangle was primarily intended for the pad shape to be similar to the paste mask stencil aperture opening which is created by a laser and has rounded corner openings. 



]]> Wed, 18 Oct 2023 08:25:08 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13293.html#13293 <![CDATA[Rounded Rectangle Pad Shape : Which IPC standard has these specific...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13292.html#13292 Author: eyoung
Subject: 1462
Posted: 18 Oct 2023 at 7:26am

Which IPC standard has these specific recommendations for rounded rectangles?
]]> Wed, 18 Oct 2023 07:26:23 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post13292.html#13292 <![CDATA[Rounded Rectangle Pad Shape : I suppose if there was ample solder...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post5976.html#5976 Author: AGONZ67
Subject: 1462
Posted: 24 Nov 2014 at 3:36pm

I suppose if there was ample solder that argument could be made. However in the example pictures it appears even with oblong pads there would not be enough solder to fully cover the pads. Six of one half a dozen of the other. Smile
]]> Mon, 24 Nov 2014 15:36:36 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post5976.html#5976 <![CDATA[Rounded Rectangle Pad Shape : Thanks, TomThis is all good...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post5973.html#5973 Author: 5not4
Subject: 1462
Posted: 24 Nov 2014 at 6:46am

Thanks, Tom

This is all good information.
]]> Mon, 24 Nov 2014 06:46:50 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post5973.html#5973 <![CDATA[Rounded Rectangle Pad Shape : I just got word from IPC that...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post5957.html#5957 Author: Tom H
Subject: 1462
Posted: 20 Nov 2014 at 6:22am

I just got word from IPC that "Rounded Rectangle" pad shape strengthens the solder joint.

This information will be published in the upcoming IPC-7351C standard.


]]> Thu, 20 Nov 2014 06:22:35 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post5957.html#5957 <![CDATA[Rounded Rectangle Pad Shape : Found the answer to #1. SM-782...]]> https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post5947.html#5947 Author: 5not4
Subject: 1462
Posted: 18 Nov 2014 at 10:45am

Found the answer to #1. SM-782 is the precursor to 7351 standard and no longer in print.
 
But I would still like to know where rounded rectangles stated to be preferred in the 7351.
]]> Tue, 18 Nov 2014 10:45:58 +0000 https://www.PCBLibraries.com/forum/rounded-rectangle-pad-shape_topic1462_post5947.html#5947