Dummy layers to get 4-layer rules in DRC?

Questions about the BatchPCB service

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KreAture
Posts: 158
Joined: Thu Apr 24, 2008 2:57 pm

Dummy layers to get 4-layer rules in DRC?

Post by KreAture » Sun Feb 12, 2012 7:05 am

Can you fake two layers extra in the datafiles to get 4-layer rules?
My design requires the tolerances of 4-layer but my free cad soft can only do 2-layers.
There should be a checkbox in the order to select designrules...

While one is at it, a checkbox to expedite the order would save you some emails too.

KreAture
Posts: 158
Joined: Thu Apr 24, 2008 2:57 pm

Re: Dummy layers to get 4-layer rules in DRC?

Post by KreAture » Sun Feb 12, 2012 8:11 am

To ansver my own question.
To fool the DRC-bot into using 4-layer rules, add two empty.g2 and empty.g3 containing the following:

Code: Select all

G75*
G70*
%OFA0B0*%
%FSLAX24Y24*%
%IPPOS*%
%LPD*%
%AMOC8*
5,1,8,0,0,1.08239X$1,22.5*
%
%ADD10R,0.0236X0.0354*%
%ADD11C,0.0071*%
%ADD12R,0.0248X0.0500*%
%ADD13R,0.0500X0.0248*%
%ADD14C,0.0118*%
%ADD15R,0.0984X0.0984*%
%ADD16C,0.0060*%
%ADD17C,0.0250*%
%ADD18R,0.0000X0.0000*%
%ADD19C,0.0189*%
%ADD20C,0.0094*%
%ADD21R,0.0512X0.0591*%
%ADD22C,0.0080*%
%ADD23C,0.0100*%
%ADD24C,0.0150*%
%ADD25C,0.0065*%
M02*
Note, there is a bug in the DRC-bot making it fail pads even though they are abowe the limits. Even abowe 8/8.
It seems to only affect very small pads where rounding of the pad corners cause the remaining straight to be shorter than 6 mils
The workaround for me was to make these pads square.
Last edited by KreAture on Sun Feb 12, 2012 3:26 pm, edited 1 time in total.

skimask
Support Volunteer
Posts: 1244
Joined: Sun Nov 09, 2008 2:11 am
Location: Minot, N.D.

Re: Dummy layers to get 4-layer rules in DRC?

Post by skimask » Sun Feb 12, 2012 3:00 pm

Won't that method going to really jack up the price of your board?
Wouldn't it be a LOT cheaper to just add a handful of square inches to the board to fit the fatter traces?
I ignore "one post wonders".

KreAture
Posts: 158
Joined: Thu Apr 24, 2008 2:57 pm

Re: Dummy layers to get 4-layer rules in DRC?

Post by KreAture » Sun Feb 12, 2012 3:09 pm

The board is $8 instead of $2.5 and I don't really mind as the alternative is my other supplier at $200.
My other supplier would give me 5 panels of 90 boards pr panel in 5 days though. I just don't need $200 worth of junk if they don't work...

Also, I actually may need to go 4-layer so then the layers will come by themselves. Routing is tight...
Pic of my board attached...
Attachments
krefly_v1.15_bottom.png

evanrich
Posts: 42
Joined: Thu Jan 27, 2011 8:46 pm

Re: Dummy layers to get 4-layer rules in DRC?

Post by evanrich » Fri May 18, 2012 9:54 am

KreAture wrote:The board is $8 instead of $2.5 and I don't really mind as the alternative is my other supplier at $200.
My other supplier would give me 5 panels of 90 boards pr panel in 5 days though. I just don't need $200 worth of junk if they don't work...

Also, I actually may need to go 4-layer so then the layers will come by themselves. Routing is tight...
Pic of my board attached...

Off topic, but what program did you use for the 3d model?

KreAture
Posts: 158
Joined: Thu Apr 24, 2008 2:57 pm

Re: Dummy layers to get 4-layer rules in DRC?

Post by KreAture » Fri May 18, 2012 10:35 am

Latest version of Eagle CAD can export to Google Scetch UP with the script EagleUP (downloaded seperately).
This gives you a model with all objects seperate so they can be edited and modified, even textured.

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