AnsweredAssumed Answered

Guideance on Plane Thermal in Padstack Definition

Question asked by greg.hall on Feb 5, 2014
Latest reply on Feb 6, 2014 by clint.cote

We want to add on all our through hole padstacks a plane thermal pad. Thereby elimininating the need for the pcb designer to setup the plane definitions manually within the layout.

 

As is standard we have several through hole padstack with various sizes of top/bottom pad.

 

My question is that when I define my thermal pad does the overall size matter?

 

For example we have a padstack with a round 100thou pad and for a trial I have added a thermal pad which is only 65thou round (width 20thou, WebClear 10thou)

When I then bring this modified padstack onto my layout, the thermal ties appear to work fine.

 

This leads me to the conclusion at the moment that for the thermal pad the size of the pad does not matter, it could be 40thou and the thermal ties appear the same.

By not having the thermal pad defined as round 100thou what if any problems is this likely to cause going forward to gerbers and fabrication?

 

We currently use DxDesigner/Expedition 7.9.1 flow. Therefore is this a bug in this version or how this is supposed to work.

 

Any help and guidance as to what I should be specifing in our library would be of help.

Outcomes