Protel 99sE how to force autoroute on bottom layer

[weiwei2]

in Protel 99SE, auto routing PCB, how to force it to use only bottom layer for a particular component? (not the whole board)

i.e.

i want connection to a IC only at bottom layer and not top layer

i tried set rule, failed.

 

[joebazoka]

I have do this, but I can´t rmember well. Try this:
Before routing right click over PCB and choice Options/Routing Layers, then choice only Bottom Layer ant then proceed with routing. I don´t remember well. I expect be usefull. Regards.

 

[weiwei2]

joebazoka:

but enabling only bottom layer will cause whole board to be routed in bottom layer only. I want only certain component and region to be routed in bottom layer

 

[PsIoNiCs]

PCB directives

Place a PCB directive on the nets you want to restrict to the bottom layer. You'll find the function in the tool bar...

Place
...Directives
......PCB Layout

 

[weiwei2]

directive for nets? but then the whole net is bottom layer? how to just make the end of net on certain components (like IC) to be bottom layer?

 

[betanorm]

I simply put a rectangle drawn with lines on top layer. So autorouter can never pass over it. After autorouting I remove this rectangle. This may be the shortest way.

The second way is appliying rules and layers for each component, net or area... This may take more time for small projects...

 

[weiwei2]

PsIoNiCs:

i couldn't find the 'directive' .... can you help?

 

[weiwei2]

betanorm

your method works great. How nice ^_^

but i still want to learn the "conventional" way to do that too. How to set the rules? i actually fail to set it.

 

[amir81]

go to:
tools -> design rules -> routing tab -> routing layers -> ouble click on RoutingLayer -> for TOP LAYER in "LAYER ATTRIBUTES" choose not used.