Actions
Forum Thread Details
  • Replies 7 replies
  • Subscribers 179 subscribers
  • Views 2239 views
  • Users 0 members are here
Related

How can I change the width of thermal ties

autodeskguest

By "thermal ties" I mean the copper that connects a pad to a copper pour.

I have a situation with a 0805 chip resistor:

  • the left pad is connected to an 8-mil trace coming into the pad and to an

8-mil trace exiting the pad.

  • the right pad connects to the GND polygon, with 3 16~18-mil traces. 

So this means that there is a LOT more copper on the right end of the

resistor.  I have read that in this type of situation when the board is

reflow soldered that the part can get pulled over to one pad and make poor

connection to the other pad, or that the part can "tombstone".  If what

I've read is correct, how do I make the copper (thermal) ties on the right

pad, narrower?  I played with DRC/Supply values, with no success.

 

BTW, I'd gladly post a pic of a portion of my board, but I don't know how

to save a portion of the board as a graphic.  I use EAGLE v5.6.0 and Win

XP/sp3.

-Dave Pollum

 

 

Parents

  • On Tue, 30 Jun 2009 23:40:27 +0200, "Ing. J.M. Rafetseder"

    <jrafetseder@hotmail.com> wrote:

     

    You can also change the width of the polygon, but this will affect all

    thermals

    r

     

    I should have mentioned, but the GND polygon width is 12 mils and the

    isolate value is 10 mils.  Well, if I place tRestrict wires around the GND

    pad, then I could use a small trace to connect the pad to the polygon, but

    that's a lot of work since I have to do this for 16 circuits.  I was hoping

    for a simpler way to do this.

    -Dave Pollum

     

Reply

  • On Tue, 30 Jun 2009 23:40:27 +0200, "Ing. J.M. Rafetseder"

    <jrafetseder@hotmail.com> wrote:

     

    You can also change the width of the polygon, but this will affect all

    thermals

    r

     

    I should have mentioned, but the GND polygon width is 12 mils and the

    isolate value is 10 mils.  Well, if I place tRestrict wires around the GND

    pad, then I could use a small trace to connect the pad to the polygon, but

    that's a lot of work since I have to do this for 16 circuits.  I was hoping

    for a simpler way to do this.

    -Dave Pollum

     

Children
No Data