PCB Libraries Forum : Thermal Tab Vias https://www.PCBLibraries.com/forum/ Tue, 07 Apr 2026 06:23:07 +0000 Wed, 06 Nov 2013 15:17:20 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=1151 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[Thermal Tab Vias : Tom H wrote: I would not recommend...]]> https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4582.html#4582 Author: Mattylad
Subject: 1151
Posted: 06 Nov 2013 at 3:17pm

Originally posted by Tom H Tom H wrote:

I would not recommend that you put vias in Thermal Pads in the footprint.  


On the other hand, many others who lay out boards recognise that it is a very good suggestion to put them in the footprint itself.

If you add vias per PCB then it is easy to accidentally unroute them, when you move the component the vias do not move with it, if you forget to add the vias even worse etc.

So having the thermal vias in the centre of a heatsink pad as permanent features in a footprint that will always be there, not unrouted or forgotten can actually make the layout easier to do and trouble free. You should not remove them for routing - they are there for a purpose.

Thank you for adding this in FPD now, but what are the values referenced to?
Can you provide more information on how to do this? perhaps one of your nice videos?
]]> Wed, 06 Nov 2013 15:17:20 +0000 https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4582.html#4582 <![CDATA[Thermal Tab Vias : You can control the Thermal...]]> https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4527.html#4527 Author: Tom H
Subject: 1151
Posted: 25 Oct 2013 at 1:27pm

You can control the Thermal Pad Paste Mask % and you can turn that layer on to see the checkerboard pattern.
 
In FP Designer you can manually place the vias on a snap grid in-between the checkerboard patterns.
 
Interactive Graphic Editing will come some time in V2014.
 
]]> Fri, 25 Oct 2013 13:27:55 +0000 https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4527.html#4527 <![CDATA[Thermal Tab Vias : Thanks. The reason I want them...]]> https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4524.html#4524 Author: michaelhallin
Subject: 1151
Posted: 25 Oct 2013 at 6:33am

Thanks. The reason I want them in the footprint is that all my footprints also has paste mask defined, and I dont want paste in the vias. The paste mask pattern covers the via holes.

Are there any chance this will be implemented in the GUI?.
]]> Fri, 25 Oct 2013 06:33:16 +0000 https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4524.html#4524 <![CDATA[Thermal Tab Vias : Here is a Dual Row QFN that...]]> https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4523.html#4523 Author: Tom H
Subject: 1151
Posted: 25 Oct 2013 at 6:22am

Here is a Dual Row QFN that I built in FP Designer and imported the text file to insert the vias -
 
 
]]> Fri, 25 Oct 2013 06:22:22 +0000 https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4523.html#4523 <![CDATA[Thermal Tab Vias : I would not recommend that you...]]> https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4522.html#4522 Author: Tom H
Subject: 1151
Posted: 25 Oct 2013 at 6:14am

I would not recommend that you put vias in Thermal Pads in the footprint.
 
I would add vias in the PCB layout so you can move them around for routing inner layer traces or even remove some if they block routing.
 
However, if you do want to add vias to the thermal tab in the footprint, you can easily do this in the FP Designer.
 
I would create a .csv ASCII text file that looks like this and import it to add all the vias -
 
V1 -2.45 2.45
V2 -0.87 2.45
V3 0.87 2.45
V4 2.45 2.45
V5 -2.45 0.87
V6 -0.87 0.87
V7 0.87 0.87
V8 2.45 0.87
V9 -2.45 -0.87
V10 -0.87 -0.87
V11 0.87 -0.87
V12 2.45 -0.87
V13 -2.45 -2.45
V14 -0.87 -2.45
V15 0.87 -2.45
V16 2.45 -2.45
 
You can import a text file with coordinates to insert any specific pad stack.
  
]]> Fri, 25 Oct 2013 06:14:32 +0000 https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4522.html#4522 <![CDATA[Thermal Tab Vias : How can I create a number of vias...]]> https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4520.html#4520 Author: michaelhallin
Subject: 1151
Posted: 25 Oct 2013 at 1:33am

How can I create a number of vias in the thermal tab of a PowerSO36?

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00002294.pdf

]]> Fri, 25 Oct 2013 01:33:57 +0000 https://www.PCBLibraries.com/forum/thermal-tab-vias_topic1151_post4520.html#4520