Eagle DRC clearance error on L1 footprint.

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Matt
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Eagle DRC clearance error on L1 footprint.

Postby Matt » Sat Mar 19, 2011 3:43 am

Hey Guys,

I have just started using eagle and I am getting a lot of clearance errors on the pads in footprints. I downloaded a .dru file for the standard PCB from PCB Cart but this does not seem to help. Any ideas.

Matt
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Bianco
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Joined: Thu Dec 10, 2009 6:56 pm

Postby Bianco » Sat Mar 19, 2011 11:18 am

I suggest to take measurements of the pad clearance and pad width and compare them with the technology you use at PCBCart http://www.pcbcart.com/cart.php?page=ca ... andard_pcb

I want to warn you that i wasn't satisfied with the silkscreen on the standard tech (two years ago). ( http://www.silentdiscoproject.net/weblo ... eup_01.jpg )
The silkscreen was messed up at places with traces going under the silkscreen.
Besides that they have been messing with my support tickets, they promised faster delivery in a support ticket. This ticket disappeared. I made a new ticket about why that ticket was gone and also that one got deleted.
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Folknology
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Postby Folknology » Sat Mar 19, 2011 12:41 pm

What L1 footprint (and package) are you using and what are the clearance settings in your DRC.
Matt
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Postby Matt » Sat Mar 19, 2011 11:44 pm

Most of the values are 8 mil as you can see below. Most of the problems go away if I reduce the padpad distance to 4mil. What settings do you use.
I also get the problem in a LAN8710A footprint.
I think the footprint for the L1 I used was the one from sparkfun library or from the minimalist board by rp181. Perhaps I should PM him.

mdWireWire = 8mil
mdWirePad = 8mil
mdWireVia = 8mil
mdPadPad = 8mil
mdPadVia = 8mil
mdViaVia = 8mil
mdSmdPad = 8mil
mdSmdVia = 8mil
mdSmdSmd = 8mil
mdViaViaSameLayer = 8mil
mnLayersViaInSmd = 2
mdCopperDimension = 20mil
mdDrill = 8mil
mdSmdStop = 0mil
msWidth = 8mil
msDrill = 0.4mm
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Folknology
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Postby Folknology » Sun Mar 20, 2011 11:57 am

Most of the values are 8 mil as you can see below. Most of the problems go away if I reduce the padpad distance to 4mil. What settings do you use.
To be honest this is probably a Cadsoft support issue, but it sounds like you clearance settings are too large for these sort of packages. Are you using a DRC file from the PCB supplier or are you setting up the DRC yourself?

The L1-64 package/footprint isn't that unusual and should be fine with most PCB house rules/spacings etc. The L1-128 however has pads that are 0.4mm spacing rather than the more common 0.5mm and could give you issues with some suppliers. Although looking at PCBCart's capabilities it looks as though they should not have any problems with even the L1-128 package.

Your issues appear to be your DRC settings not the footprints/library. I notice that PCBCart accept Eagle board files in addition to Gerbers, so they will likely have a DRC file that they use to check designs before production, maybe it would be worth requesting this directly from them as it would make your life easier and guarantee that you meet their capabilities.

regards
Al

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