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kender
Joined: 19 Jun 2005
Posts: 917
Helped: 68
Location: Stanford, SF Bay Peninsula, California, Earth, Solar System, Milky Way
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 12 May 2008 6:34 OrCAD Layout. Some vias and throughole pins don’t make... |
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... connections to ground plane
Colleagues,
In my layout some vias that are supposed to connect to the ground plane do actually connect and some don’t. I’ve never had this problem in the past.
- All vias use the same padstack
- Ground plane has no islands.
- No such problem with Vcc plane
- Auto->Refresh ->All doesn’t help
Attached is a screenshot of the layout.
I’ve noticed that “well behaved” vias are further away from other vias than the problematic ones. How can this problem be fixed?
I’m using OrCAD Layout Plus 10.5
- Nick
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Batke
Joined: 12 Nov 2001
Posts: 62
Location: PCB_LAND
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| 12 May 2008 11:17 Re: OrCAD Layout. Some vias and throughole pins don’t make. |
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| maybe via type isn't assigned to GND ?
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kender
Joined: 19 Jun 2005
Posts: 917
Helped: 68
Location: Stanford, SF Bay Peninsula, California, Earth, Solar System, Milky Way
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| 12 May 2008 22:48 Re: OrCAD Layout. Some vias and throughole pins don’t make. |
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| Batke wrote: |
| maybe via type isn't assigned to GND ? |
Maybe. I made my own padstack for all these vias, because the standard VIA1 padstack is too large. How would one assign a via type to GND?
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Batke
Joined: 12 Nov 2001
Posts: 62
Location: PCB_LAND
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| 13 May 2008 0:00 Re: OrCAD Layout. Some vias and throughole pins don’t make. |
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| view spreadsheet-nets, position on the GND net, right mouse button, assign via per net, check via.
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kender
Joined: 19 Jun 2005
Posts: 917
Helped: 68
Location: Stanford, SF Bay Peninsula, California, Earth, Solar System, Milky Way
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| 13 May 2008 1:00 OrCAD Layout. Some vias and throughole pins don’t make... |
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| I've decreased the "width" property of the copper pour the forms the ground plane from 50 to 10, and that solved the problem.
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Batke
Joined: 12 Nov 2001
Posts: 62
Location: PCB_LAND
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| 13 May 2008 9:22 Re: OrCAD Layout. Some vias and throughole pins don’t make. |
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good.
p.s always keep the polygon width between 4-12 mils.
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