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I'm using Eagle for a PCB project. Referring to the image below , you can see that Eagle insists on placing thermal reliefs on IC pins that have been grounded. The problem with this is that the they will actually allow for more thermal dissipation by having added these 'spokes'.

Is there any method for editing these thermal reliefs such that adjacent pins are not directly connected to one another? Essentially, how do I remove the thermal relief 'spokes' such that there is only one that is grounded.

How do I edit the thermal reliefs around pins?

enter image description here

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  • \$\begingroup\$ Maybe add a rectangle with higher ranking and some nonexisting bus, preventing it from generating these spokes there? Messy workaround, but I can't think of other way to do it. \$\endgroup\$ – Wesley Lee Dec 1 '16 at 23:08
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    \$\begingroup\$ I don't understand what you think the problem is. What is wrong with what you show? Your statement of "they will actually allow for more thermal dissipation by having added these 'spokes'" makes no sense. Neither does "how do I remove the thermal relief 'spokes' such that there is only one that is grounded". Fix the gibberish or be closed. \$\endgroup\$ – Olin Lathrop Dec 1 '16 at 23:37
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    \$\begingroup\$ @Teague -- I think he's not getting why the extra thermal dissipation is a problem in your design. \$\endgroup\$ – ThreePhaseEel Dec 2 '16 at 0:18
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    \$\begingroup\$ The quite normal connections shown should not interfere with any sound method of soldering. If you are trying to use a tiny iron tip with conventional heating, that might be your mistake - use reflow or hot air, or a large tip that spans several pins but has good heat transfer, or a fancy RF or whatever heated tiny tip, etc. \$\endgroup\$ – Chris Stratton Dec 2 '16 at 2:30
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    \$\begingroup\$ Oh, so you want less thermal connection between the pads and the plane? If so, you need to make that clear. It would also help to explain why. There are definitely ways to do this, but your question needs to make sense first. \$\endgroup\$ – Olin Lathrop Dec 2 '16 at 11:31
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It's not the thermal relief causing those connections, it's your ground plane. Just keep it away from areas where you don't want it.

You can either draw the ground plane polygon(s) to avoid the area, or put a rectangle over it in the 'Restrict' layer.

enter image description here

ETA: Eagle version 6.0 and above has the option of using a polygon with 'cutout' pour instead, which avoids potential DRC errors in the restricted area. Thanks to Tom Carpenter for pointing this out.

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  • \$\begingroup\$ If you put a restrict layer over the pads you will get lots of DRC errors because the pad copper is within the restrict area. Instead a cut-out polygon should be used. \$\endgroup\$ – Tom Carpenter Dec 3 '16 at 11:34
  • \$\begingroup\$ @Tom Carpenter good idea! (I have just been turning off 'check restrict' in DRC). I see that Cutout polygon was introduced in Eagle version 6... \$\endgroup\$ – Bruce Abbott Dec 3 '16 at 17:36

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