Just as a note, I have forgotten to "pull back" the planes on two different
designs over the past five years. Both times, I received the boards "as
drawn" with copper right up to the board edge. No flags were raised, and no
questions were asked. This is from a large, high-quality fabrication house
in the Midwestern US. They questioned other Gerber or design issues, but not
the plane to board edge clearance. In their defense, on both occasions these
were quick-turn orders (3 day). On the other hand, I have had other shops
call to ask if they could increase the clearance from what I already had
drawn. My point is that, yes, the majority of fabricators will question a
design with no clearance. However, I would not go to the point of taking it
completely for granted. Contact me off-line if you want the name of the
board shop that let the two designs go through with no clearance. Since it
was ultimately my own mistake and not theirs, I don't want to give the
impression that I'm passing the blame.

Mark Richards
CAD Designer
ON Semiconductor
Phone: 602.244.7267
Fax: 602.244.6716
Pager: 866.208.9913

----- Original Message -----
From: "Abd ul-Rahman Lomax" <[EMAIL PROTECTED]>
To: "Protel EDA Forum" <[EMAIL PROTECTED]>
Sent: Thursday, November 08, 2001 4:26 PM
Subject: Re: [PEDA] keepoutlayer and planes ??

> At 05:32 PM 11/8/01 -0500, Mike Reagan wrote:
> >you scare me man   thinking that you are design aircraft components and
> >know how to use the progam     I think you better fligt test it
> Knowing how to use the program is a convenience, not a necessity. The
> necessity is to know how to inspect the gerbers or films and the board
> Let me put it this way. If I want reliability of a pcb, I will prefer it
> be designed by someone who knows electronics and reliability issues, but
> who is a beginner with a piece of software he uses, than by one for whom
> the reverse is true.
> (I don't think Mr. Robison is designing "aircraft components." Last we
> spoke, he was designing equipment that might fly *on* a plane, but it does
> not *fly* the plane. If one of his boards fails, if I am correct, it will
> be a nuisance, not a disaster.)
> In my experience, boards for hi-rel usage (for me, it has been space
> flight) are reviewed through several different stages, at least. While it
> is obviously best and safest to get the board right in the first place
> (after all, there is a statistical possibility that the later safeguards
> could all fail), the knowledge that negative planes should not go to the
> board edge is widespread. As I mentioned previously, most board houses,
> perhaps all, will already create an edge clearance if you don't put one
> there and you don't clearly specify that you *don't* want one. They have
> been dealing with gerbers with no edge clearance for years, but they have
> probably never encountered a request for planes to go to the edge.
> Has anyone reading this received fabricated boards with no inner plane
> clearance? Was it from an established fabricator? (I'd be surprised if it
> *never* happened, but I would also be surprised if it was at all common.)
> Abdulrahman Lomax
> Easthampton, Massachusetts USA

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