At 13:12 18.09.01 -0700, you wrote:
>Abd ul-Rahman or others,
>         if I read his description correctly he is trying to do a plated
>mounting hole with additional vias within the diameter of the larger pad for
>the plated thru-hole. I am guess that he is trying to make this as a
>component for simple re-use.
>         The reasoning that I have heard behind doing this is to make the
>plated through hole more reliable. The reliability is greater when the screw
>may wear away or break the mounting hole plated barrel. The copper top and
>bottom is still connected via the plated vias. This is also a common
>practice in high freq. microwave applications where ground must be
>maintained as ground by repetitive via stitching, every 50 - 100 mils in
>some cases.
>         I have similar structures in my library but they do not work as
>fluidly as I would like so I have waiting for other responses to find out if
>there is a better way myself.

I have created such things, I call them "mounting holes". Its a part with 
seven pads, a large in the centre and six around it. They numbered from 1 
to 7. Then I have a associated schematic symbol with seven overlapping pins 
(all at the same location).
Voila, just place as many parts on the schematic as you need, and the 
mounting holes will show up on the pcb and there are no drc problems at all.

Edi


>Brad Velander,
>Lead PCB Designer,
>Norsat International Inc.,
>#300 - 4401 Still Creek Dr.,
>Burnaby, B.C., V5C 6G9.
>Tel. (604) 292-9089 direct
>Fax (604) 292-9010
>website www.norsat.com
>
>
> > -----Original Message-----
> > From: Abd ul-Rahman Lomax [mailto:[EMAIL PROTECTED]]
> > Sent: Tuesday, September 18, 2001 3:52 PM
> > To: Protel EDA Forum
> > Subject: Re: [PEDA] Pad with multiple holes surrounding it.
> >
> >
> > At 02:22 PM 9/18/01 -0500, Ted Tontis wrote:
> > >I believe he is trying to put supporting holes around the
> > top of the PTH.
> >
> > I'd like to know what a "supporting hole" is, since holes
> > remove physical
> > support.
> >
> > Holes placed for additional ground connection would be likely
> > to make only
> > a negligible contribution under most circumstances; the pad,
> > if it goes to
> > a ground plane or copper pour, should be made direct-connect
> > unless it is
> > to be soldered. Holes surrounding a central hole going to a plane may
> > remove connection to the inner hole unless they are direct-connect.
> >
> > A .125 hole direct-connect to a ground plane is equivalent to a trace
> > almost a half-inch wide for a distance of perhaps 30 mils at most.
> >
><SNIP>
> >
> > [EMAIL PROTECTED]
> > Abdulrahman Lomax
> > Easthampton, Massachusetts USA

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* To post a message: mailto:[EMAIL PROTECTED]
*
* To leave this list visit:
* http://www.techservinc.com/protelusers/leave.html
*
* Contact the list manager:
* mailto:[EMAIL PROTECTED]
*
* Forum Guidelines Rules:
* http://www.techservinc.com/protelusers/forumrules.html
*
* Browse or Search previous postings:
* http://www.mail-archive.com/proteledaforum@techservinc.com
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Reply via email to