if one was to use a hole for mounting the PCB to a fixture, they might put
plated through holes around the mounting hole for reinforcement. The extra
copper in the vias around the hole would support more pressure in that area.
I have never implemented this in a design, but I have seen articles on it.
Regards,
Ted
-----Original Message-----
From: Abd ul-Rahman Lomax [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, September 18, 2001 5:52 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.
In any case, if the original questioner will tell us in more detail not
only what he wants but why he wants it, we'll have a better idea of what
recommendations to make.
When a way of doing a thing is not easy in a program like Protel, it is a
clue (but certainly not a proof) that perhaps the thing is not a good idea.
There are, obviously, exceptions; but it is much more common to see that
the thing cannot be done easily because the users did not want it, and the
users did not want it because it was not a good idea.
So I'm just trying to find out what is the case here.
[EMAIL PROTECTED]
Abdulrahman Lomax
Easthampton, Massachusetts USA
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