Dummy layers to get 4-layer rules in DRC?

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1

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.

2

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:

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.

3

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?

4

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…

5

KreAture:
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?

6

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.