How to make Eagle autorouter prefer the bottom layer?

[asafsmilan]

Hi, I'm doing my first steps with Eagle and I would like to know how do I make the autorouter to prefer the bottom layer over the top layer and build as much as possible traces on the bottom layer before adding traces to the top layer?

[mtl_asm · Accepted solution]

Before you start the auto router you can click this ">>" button which lets you adjust the cost weights. SO if you want it to prefer bottom, just increase the cost of top (and other layers if you have more than 2 layers). The more you increase teh cost of other layers, the more it will prefer the bottom. Depending on how many optimizations you are attempting you will have to add teh costs on those tabs too. 

[RichardHammerl · Accepted solution]

Hi @asafsmilan 

I suggest to set the layer costs for Top layer to 99. It might be helpful, if you choose no preferred direction ( * ) for the bottom layer then.

Regards,

[asafsmilan]

Thank you very much!