Re: gEDA-user: ready-made style classes

[Ales Hvezda <ahvezda@xxxxxxxxxxxxxx>]

[ Ales here, I'm reposting this since majordomo didn't recognize the
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-- Cut here --
Date: Fri, 21 Jan 2005 05:31:34 -0800
From: Stephen Meier <smeier@xxxxxxxxxxxxxxx>

Well my two comments are. line widths on critical traces (high speed 
clean analog for example) should be determined by the frequency of 
interest, the dialectric propertoies of the plastics and if there is a 
copper plane underneith them. In other words. Trace widths are one 
parameter that can easily be adjusted for setting the impedence of a trace.

Second, on that 900 pin bga I used 4 mil traces and vias with 10 mil 
diamater drill width and 18 mil copper pads.

So the values need to be project selectable.

What I would prefer is an extra tribute for these elements. For example,

current
 
    Line[592500 320950 593500 321950 2500 2000 0x00000020]

desire

    Line[592500 320950 593500 321950 2500 2000 0x00000020  1]

where the new value at the end of the line ;) represents that it is a 
member of a "premade class" and that if I adjust the perameters for that 
"premade class" all the lines, vias, what evers also get adjusted.

Steve Meier




Karel Kulhavy wrote:

>Hello
>
>I suggest for PCB that an entry "premade class", "ready made class" or
>something similar was added into the "Sizes menu"
>
>It would offer radio button "1"..."6" for construction classes 1 to 6.  It took
>me quite a time to "tune" my setting. They are currently
>
>After pressing the button one would press "OK" or Cancel and after OK it would
>ask him "do you really wish to overwrite all your current thickness settings
>with this new construction class"?
>
>	linewidth	via hole	via size	clearance	
>Signal	20		24		56		14
>Power	40		35		70		14
>Fat	80		50		90		14
>Skinny	12		24		56		14
>
>I have always been working in class 4 so unfortunately I can't offer
>these tuned settings for other classes.
>
>These settings looks like they don't present problems. It accounts even for the
>more picky fab houses I encountered (some permit 0.3/0.3, some 0.35/0.3
>space/copper). I have already designed 4 PCB's (Twister, I2C2P, Trinitrack, TX,
>Trinitrack and TX aren't released yet but are already in manufacture) with
>these settings.
>
>I think these "border conditions" are one of the things that make commercial
>packages attractive. Not always it's the code, often it's also the data that
>attract the customer.
>
>Clicking up particular class and then making subtle adjustments would be
>definitely more pleasing than thinking it all completely up.
>
>It should include the DRC constants too. For "my class 4" they are:
>Pcb.Bloat:      1378
>Pcb.minWid:     1182
>Pcb.Shrink:     400
>Pcb.minSlk:     800
>( http://ronja.twibright.com/editing.php )
>
>Cl<
>
>  
>