Anyone else having multiple clearance issues with vias?

[kittmaster]

I have a high density two layer board and I can't get it to 100% because once again, UB will not take my settings as I direct it to. I'm using a 12 mil clearance for the nets settings, but I am setting the global properties with "use multiple clearances" option to tell the autorouter to use a 1 mil clearance around the vias annular ring.

The reason the router can't finish is that its TRIPLING MY CLEARANCE VALUES. I want the edge of the trace to have 12 mil clearance from any object, but its not routing it this way. I've included some screen shots......anyone else seeing this behavior and or what is the fix????????????

But if I select the via filter I can manually set it to 1 mil and the clearance view closes, but this doesn't do any good if the AUTOROUTER doesn't use this value, and hence the failure to 100%.....

Message Edited by kittmaster on 01-16-2008 11:16 PM

[lacy]

Here is the problem as I see it. You select Multi-clearance and set the spacing to vias at 1 mill. If you then goto to the spreadsheet under vias and look at trace clearance setting you will see it says to "Use Net Setting" Now goto to the net list editor and you will see the via clearance isn't set to 1 mil but some other number (in my test it was 11.5 mils). I tried changing it through the spreadsheet, but you can't get it to move from "Use Net Setting" as there are no other options. I even tried changing all of them to 1 mil and re-route, but it reset it to "Use Net Setting" each time.

Even though you tell it to use 1 mil in the Design Rules that is not being set in the net list editor nor updated to the spreadsheet. Unless there is a way to change the properties of the via clearance across all nets at the same time, it would appear to that you would have to go into the net list editor and manually do each net to get the proper clearance.

These are my observations and maybe that will help you come up with a solution. Right now I don't see an easy way around this.

[kittmaster]

Your mention of setting the vias via spreadsheet........i started with a blank trace design, components placed only. If you go to the vias section, there are NO data points in that area with no traces present. I'll attach my project here for you to see my starting point.

Since you've done part of the leg work, I'll try to change it in the netlist editor and see if I can try that process to at least get this board finished.......errr.. This has fairly high density.

Thanks for the other side view.......didn't think to use netlist editor since I'm a spreadsheet user .....;)

[kittmaster]

I found that adding all the nets to the using a group editor and using the clearances to vias to 1 mil, it accepts its all at once but the autorouter still keeps it 12 + 12 clearance........damn

[lacy]

I should have mentioned that I checked the vias in the spreadsheet after doing an autoroute. I thought maybe it might be changable within the spreadsheet somehow.

[kittmaster]

One of my iteration of this magically brought the via clearances field to the spreadsheet view but the autorouter tanked really bad. Went back to the archive file and tried the same steps, no via clearances in the spreadsheet now

[kittmaster]

Have you tried to route it there? How far does it get on your setup?

[lacy]

I spent over 2 hours last night trying various ideas, but everything I tried it only made it to 112 of 118 connections and just seemed to not be able to go any further. I will continue trying different ideas and let you know if I would happen to find something.

I know you shouldn't have to do this, but if it makes it to 112 of 118 have you tried to manually route the remaining connections?

[kittmaster]

Well I have considered it.......but I don't wanna.....;)

The way to get it to 100% is to adjust the via diameter to 46 diameter and drill to 32 in the main pcb section......so my vias are killing me

The reason I don't keep it that way is that the via pins I actually use to connect the board layers are 62 mil diameter press fit.

I could use wire and tact solder both sides, but 185+ vias..........neh.....I think not.....LOL.

Its all because the autorouter chokes on the multiple clearances......and also notice that the pcb to autorouter pass changes the shapes of the pads from square to round. While NI states that it doesn't matter......still something just "ain't right".......:(

[lacy]

I have still been experimenting on your board. I managed to get it to 116 of 118 by changing the number of rip-up trees to max in the autorouter setting and simultaniously grouping all the nets so the 1 mil spacing for vias will be correct.

Once consideration (which I probably already know won't be possible) is to maybe extend your board outline to give it more room to route. This is just a thougt as I am quickly running out of ideas.