There is another problem with this rule If I am correct, it is indeed, a
hole clearance. But true clearance will be about 3 mils less, more or less,
because the holes are drilled oversize so that 1.5 mils of plating (1 oz)
will bring it back to the specified size. That is a conductive reduction
Your right. I keep forgetting that a pad on a plane layer is a void, so
that would be included in the clearnace.
Thanks,
Dave
At 04:20 PM 4/19/02 -0700, you wrote:
>The terminology for the clearance rule can be a bit confusing.
>
>The clearance you are specifying is not an expansion to clear
The terminology for the clearance rule can be a bit confusing.
The clearance you are specifying is not an expansion to clear a pad, it is
an expansion to clear the hole.
When you generate Gerbers, you do not get a pad with a clearance ring
around it on the planes, you get a void around the hol
Yes. This is how the Fab houses have historically spec'd expansions.
Brian
At 03:01 PM 4/19/02 -0700, you wrote:
>
>Has anyone noticed that you get exactly half the clearance you specify on a
>power plane clearance rule? In other words to get a 10 mil ring around a
>pad or via that does not c
David Palombo wrote:
> Has anyone noticed that you get exactly half the clearance you specify on a
> power plane clearance rule? In other words to get a 10 mil ring around a
> pad or via that does not connect to the plane, you have to specify a
> clearance of 20 mills.
Yup, some stuff works on
Has anyone noticed that you get exactly half the clearance you specify on a
power plane clearance rule? In other words to get a 10 mil ring around a
pad or via that does not connect to the plane, you have to specify a
clearance of 20 mills.
Dave
+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
>The clearance for an internal power plane depends on the accuracy of the
>plane alignment. 20 mils ahoould be sufficient, but check the spec with
>the pcb vendor.
If it's just a via, and no lead gets soldered, then direct connect. If
you're soldering a component lead in the hole (i.e. to-220
20mil is sufficient for soldering components without
having a soldermask, eg on selfetched pcb's.
Otherwise it can be lower.
Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
Tim Fifield wrote:
>
> oh, I just thought of another question...
>
> What is your (Protel user) preferred clea
oh, I just thought of another question...
What is your (Protel user) preferred clearance and connect style on the
power planes? A board I just finished had 20mil clearance and direct
connect. I'm wondering if 20mil is too much and if a relief connect would be
better.
Tim
* * * * * * * * * * * *
Thanks to all for the help!
Tim
-Original Message-
From: Abd ul-Rahman Lomax [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, November 21, 2001 11:23 PM
To: Protel EDA Forum
Subject: Re: [PEDA] Power Plane Clearance
At 04:19 PM 11/21/01 -0600, Jon Elson wrote:
>It seems Protel o
At 04:19 PM 11/21/01 -0600, Jon Elson wrote:
>It seems Protel only supports round pads on inner layers. Forcing a
>rectangular pad onto the inner layers results in this problem. I know
>of no way to get a rectangular clearance on a power plane layer. Protel
>can pour copper around rectangular p
I think what you are missing is that there really isn't a square pad on the
plane for which you need to generate a clearance. You are generating a
blowout around the hole. Plane clearances are normally expressed as a void
expansion around the hole.
If you mean that you have described a squar
Tim Fifield wrote:
> I have a few square thru-hole pads on a PCB, but when I set up a design rule
> to create a rectangle clearance on the GND plane it still produces a
> circular clearance so the corners of the pad are still touching the GND
> plane.
>
> Filter Kind is Pad Specification.
> Hole,
ssage-
From: Tim Fifield [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, November 21, 2001 5:05 PM
To: Protel EDA Form
Subject: [PEDA] Power Plane Clearance
I have a few square thru-hole pads on a PCB, but when I set up a design
rule
to create a rectangle clearance on the GND plane it still prod
I have a few square thru-hole pads on a PCB, but when I set up a design rule
to create a rectangle clearance on the GND plane it still produces a
circular clearance so the corners of the pad are still touching the GND
plane.
Filter Kind is Pad Specification.
Hole, XY dimensions match.
Rectangle b
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