However, the coponent clearance rule is next to useless once
you start working with tightly packed boards. If you want to
place componnets so that their silkscreen borders overlap
(e.g. 0402s places side by side), you need to turn off the
component clearance rule - so you end up with the very dangerous
situation of requiring manual checking of each and every component
placement.

I've said this before (but I'll repeat it in the hope that someone
at Protel listens :-):

What is really needed is an extra layer defined as a physical
component outline layer. A clearance rule based on this layer would
ensure that components did not try to physically occupy the same
space. This rule would need to be combined with clearance rules that
would ensure minimum gap between a primitive entity (e.g. pad, or
a soldermask opening) and entities on the silkscreen layer (so that
one component's legend doesn't end up over a pad).

It is getting very rare, with the boards that I work on, that the
silkscreen overlay bears any resemblance to the actual component
outline - so using this as the rule to prevent component interference
is not useful.

Just my $0.02c

Cheers,

John Haddy


> -----Original Message-----
> From: Ian Wilson [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, 11 April 2001 10:00 AM
> To: Protel EDA Forum
> Subject: Re: [PEDA] Creating custom design rules?
> 
> 
> On 05:06 PM 10/04/2001 -0600, Gladieux, Jed said:
> >Does anyone know how to create new design rules.  For example, I 
> would like
> >to flag instances where component outlines on the silkscreen 
> layers overlap.
> >
> >
> >I got bit by this on a very busy board and wound up with 2 components
> >physically interfering with each other although pads/tracks were all OK.
> >
> >I'm currently using Protel98 but am planning to migrate to 99SE 
> as soon as I
> >get a chance.  Wasn't able to find anything in P98 Help.  Maybe I'll try
> >Protel's Knowledge Base, but in the meantime, it anyone knows 
> how to do this
> >I would appreciate any advice.
> >
> >TIA,
> >
> >Jed Gladieux
> 
> In P99SE you can set a rule for component clearance.  If you set 
> the Check 
> Mode to Full and the clearance of 0mil/mm you will get an 
> accurate check of 
> interference even for convoluted component outlines - assuming 
> your overlay 
> details are correct.
> 
> P98, from memory, does not have the full check mode and it 
> doesn't have the 
> same method of setting component clearance.  Anyway P99SE should 
> go someway 
> to trapping your problem.
> 
> Ian Wilson
> 
> 


* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* To post a message: mailto:[EMAIL PROTECTED]
*
* To join or leave this list visit:
* http://www.techservinc.com/protelusers/subscrib.html
*                      - or email -
* mailto:[EMAIL PROTECTED]?body=leave%20proteledaforum
*
* Contact the list manager:
* mailto:[EMAIL PROTECTED]
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Reply via email to