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Re: PCI PCB physical characteristics
- To: "PCI-SIG, Mail List" <pci-sig@znyx.com>
- Subject: Re: PCI PCB physical characteristics
- From: "Ingraham, Andrew" <Andrew.Ingraham@hp.com>
- Date: Mon, 22 Jul 2002 16:58:31 -0400
- Resent-Date: Mon, 22 Jul 2002 14:08:13 -0700
- Resent-From: pci-sig@znyx.com
- Resent-Message-ID: <esFVoB.A.FKE.FLHP9@electra>
- Resent-Sender: pci-sig-request@znyx.com
- Thread-Index: AcIxoO7LiCQnsVbjQYKo12T1NDBT/QAH16HJ
- Thread-Topic: PCI PCB physical characteristics
> Exists some specification about the physical characteristics of a PCI PCB?
> If it is not thus, which would be the material, surface finish and copper weight on to outer layers more recommendable?
For regular PCI, the only characteristics in the PCI Specification are for characteristic impedance, and signal velocity; and only for plug-in cards. System boards (motherboards) have no explicit specification.
Board dielectric material directly affects signal velocity.
Board material plus physical dimensions (layer thickness, trace width, and to a lesser degree copper weight) affect characteristic impedance.
The PCI-X Specification does include a few examples of physical dimensions to get the right electrical characteristics. But the PCI Specification doesn't.
Regards,
Andy