PCB Libraries Forum : how to use PTH reference calculator https://www.PCBLibraries.com/forum/ Tue, 07 Apr 2026 12:39:43 +0000 Thu, 05 Nov 2015 09:54:56 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=1788 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[how to use PTH reference calculator : Thank you! ]]> https://www.PCBLibraries.com/forum/how-to-use-pth-reference-calculator_topic1788_post7320.html#7320 Author: fishoutofwater
Subject: 1788
Posted: 05 Nov 2015 at 9:54am

Thank you!]]> Thu, 05 Nov 2015 09:54:56 +0000 https://www.PCBLibraries.com/forum/how-to-use-pth-reference-calculator_topic1788_post7320.html#7320 <![CDATA[how to use PTH reference calculator : 1. Yes, WRT lead diameter or diagonal...]]> https://www.PCBLibraries.com/forum/how-to-use-pth-reference-calculator_topic1788_post7319.html#7319 Author: Jeff.M
Subject: 1788
Posted: 05 Nov 2015 at 9:40am

1. Yes, WRT lead diameter or diagonal if not round.
2. Yes, Minimum Annular Ring will never be less than this value.
3. Thermal ID over Hole defines the inner clearance, Thermal OD is the outer clearance.  The clearance is bridged by the spokes.
4. Thermal OD and Anti-pad are equal.
5. Thermal OD to Hole ratio allows the OD to increase in proportion to the hole.
6. Spoke width is calculated as a (percent of the thermal OD) / 4. 75% is the default.
]]> Thu, 05 Nov 2015 09:40:33 +0000 https://www.PCBLibraries.com/forum/how-to-use-pth-reference-calculator_topic1788_post7319.html#7319 <![CDATA[how to use PTH reference calculator : Hello again,I have a few more...]]> https://www.PCBLibraries.com/forum/how-to-use-pth-reference-calculator_topic1788_post7314.html#7314 Author: fishoutofwater
Subject: 1788
Posted: 04 Nov 2015 at 1:35pm

Hello again, 


I have a few more basic question, regarding the PTH reference calculator:

1. Hole over Lead - this refers to how much larger the hole diameter should be, WRT lead diameter?

2. Minimum Annular Ring - this refers to the minimum pad-hole width, irrespective of the Pad-to-Hole ratio?

3. Thermal ID over Hole - this refers to the min distance between a hole and a plane it passes through, but does not want to connect to?

4. What is the difference between the pad on layer3 (thermal pad) and the antipad on layer4, other than that the antipad is bigger?

5. Thermal OD to Hole ratio - why do we need to specify this? Isn't both the Thermal OD and Hole diameter already specified previously?

6. Spoke width - why is it specified as 75?


Thank you very much.
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