Re: [PROTEL EDA USERS]: Design rule vias under smd constraint

[Abd ul-Rahman Lomax <marjan@vom.com>]

<x-flowed>
At 02:47 PM 9/6/00 -0500, Nicholas Cobb wrote:
>How come the design rule for vias under SMD constraint says in its
>description that it "specifies whether vias can be placed under SMD pads
>during autorouting", but when you add a rule it says that the rule is not
>followed by the autorouter?

As pointed out, the autorouter is not the latest and greatest. It will not 
place a via under an SMD pad. But you can, yourself, accidentally, and the 
DRC rule will detect that so you can fix it. Or you can allow it (which is 
the default).

It will be a better day for us when the autorouter respects this and other 
rules, such as the acute angle constraint. It would be sufficient for many 
purposes to have a good clean-up routine, which should be a lot easier than 
totally revamping the autorouter. I don't know which way Protel will go, 
though I am sure that in the long run we will see a shiny new autorouter, 
something to give Specctra a run. I doubt that the Protel router will ever 
be better than the contemporary version of Specctra, simply because of the 
vast difference in price. It is as to price vs. performance that Protel has 
a very good chance. It could already be said that Protel is the winner in 
this area.

marjan@vom.com
Abdulrahman Lomax
P.O. Box 690
El Verano, CA 95433



</x-flowed>