Actions
Forum Thread Details
  • State Not Answered
  • Replies 5 replies
  • Subscribers 178 subscribers
  • Views 517 views
  • Users 0 members are here
Related

Automatically generated traces between PTH and pour, how can I make them bigger?

Former Member

I am concerned that the traces that are automatically generated between plated through holes and a ground pour are too thin.  Say I have two plated through holes to connect to the positive and negative supply from a battery. I can choose a 50mil trace from the positive, but I have no control over the size of those tiny little traces generated with the ground pour. If the pour surrounds the PTH it is connected by four little traces, but if the pour only borders one side of the PTH you only get one tiny little trace.  Can you use the wire tool to draw a 50mil trace from a PTH into the pour or will the software freak out when the gerbers are generated?

 

What size are those little traces anyway, and how many amps can they carry? Where can I adjust their size?

 

Cheers all. Matt.

  • 0

    From the manual

     

    "The width of the thermal connectors is calculated as the half of the

    pad's

    drill diameter. The width has to be in the limits of a minimum of the wire

    width and a maximum of twice the wire width of the polygon."

     

    So increase the polygon wire width to make them larger

     

    HTH

    Warren

     

     

    --

    Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

     

  • 0

    Me again.

     

    I have discovered that you can un-check the thermals box in the wire/polygon properties but that makes every PTH solid to ground.  I want thermals on all the GND PTH except for two which carry large current.  I would fill in the gaps with the wire tool and paint in some copper in the top layer but I have read that manufactureres dont like that.  Is that true?

     

    cheers again.

  • 0 in reply to autodeskguest

    Hi Warren. Thx for the reply.  My problem is that what ever parameter you specify in the properties window will be translated to every PTH connected to the pour.  I want all my PTHs to be thermals except for two which I want to be solid.  Any suggestions for how I would go about that?

     

    Cheers

     

    Matt

  • 0 in reply to Former Member

    On 08.06.2015 07:12, Matthew Findlow wrote:

    Me again.

     

    I have discovered that you can un-check the thermals box in the

    wire/polygon properties but that makes every PTH solid to ground.  I

    want thermals on all the GND PTH except for two which carry large

    current.  I would fill in the gaps with the wire tool and paint in some

    copper in the top layer but I have read that manufactureres dont like

    that.  Is that true?

     

    For pads, you can turn on/off thermals individually (goto properties,

    find the checkbox). I use non thermal pads for mounting holes thats

    going to be connected to gnd/shield.

     

    So the solution could be to make those special holes as a component. Its

    sounds like the right thing to do if we're talking about battery terminals.

     

     

     

  • 0 in reply to Former Member

    On 08/06/15 06:46, Matthew Findlow wrote:

    Hi Warren. Thx for the reply.  My problem is that what ever parameter

    you specify in the properties window will be translated to every PTH

    connected to the pour.  I want all my PTHs to be thermals except for two

    which I want to be solid.  Any suggestions for how I would go about

    that?

     

    First off, are these actual PTH for component legs? If so, the thermals

    are extremely useful and not recommended to be omitted. If not, use vias.

     

    That said, if you connect an explicit trace to the pad then that trace

    can be any width you like. If the pad is a high power one from a

    component leg, then I'd expect you to want to do that before you ever

    start thinking about flood filling. After all, you need to route your

    primary power rails sensibly and not just hope they'll get connected

    round the houses. If the trace is wider than the thermal diameter you

    won't get a thermal.