Autorouting a 4 Layer Board

Thread Starter

sailmike

Joined Nov 11, 2013
147
I'm experimenting with 4 layer boards to teach myself how to do it. I'm using a board that was previously a 2 layer board for this. I set up the layers as [2:(1*2*15*16):15] and made layer 2 the VCC layer and layer 15 the GND layer then routed the board. The DRC check gave me a lot of layer setup errors, but I don't know what those errors are. I've attached a screenshot of one of them. I'm open to any tips.

I've no plans to send this board to a board house. I just wanted to see how small I could make this PCB.

Thanks,
Mike
 

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GopherT

Joined Nov 23, 2012
8,009
I'm experimenting with 4 layer boards to teach myself how to do it. I'm using a board that was previously a 2 layer board for this. I set up the layers as [2:(1*2*15*16):15] and made layer 2 the VCC layer and layer 15 the GND layer then routed the board. The DRC check gave me a lot of layer setup errors, but I don't know what those errors are. I've attached a screenshot of one of them. I'm open to any tips.

I've no plans to send this board to a board house. I just wanted to see how small I could make this PCB.

Thanks,
Mike
What software are you using? I haven't found a good one for even 2-layer boards. I friend who has access to several professional packages even says that hand adjustments are necessary. In general, auto-routing is a mess.
 

Thread Starter

sailmike

Joined Nov 11, 2013
147
Oh sorry, I forgot this isn't the Eagle forum. Eagle has worked very well for me so far. Autorouting has, so far, been a time saver. I just run the DRC and go over any errors, then send it off to a fab house.
 

John P

Joined Oct 14, 2008
2,025
As I've said more than once on threads about PCB layout software, I use FreePCB and I think it's very good--it's free with NO limits on size or component count, unlike some programs I've heard of. Until last summer, it could operate with the autorouter made available by Alfons Wirtz, but he felt that he needed to remove that from the Internet. That left me disappointed, but I just found that a freestanding version of the same program is available:
https://github.com/nikropht/FreeRouting

I've downloaded this, and it works just like before. And it's dead slow, just like before: if your board has any complexity at all, set the thing going last thing at night, and it'll be done in the morning. However, it's for 2-layer boards only, so it won't help in this case.
 

kubeek

Joined Sep 20, 2005
5,794
that via goes straight to a pad on the bottom side. Why on earth would you use an autorouter? Especially in eagle it is many times faster to route it all by yourself than to edit all those horrible traces.
 
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