[SI-LIST] Re: Layout Cross Section
- From: Aubrey_Sparkman@xxxxxxxx
- To: cadpro2k@xxxxxxxxxx, si-list@xxxxxxxxxxxxx
- Date: Thu, 19 Feb 2004 12:36:09 -0600
Uri, Mitch,
You don't need to mess with your material.dat file; adding a layer of FR4
works. Before you do your testing, delete your interconn.iml file; you want
to make sure Allegro re-computes the parasitics. I opened a test board I
have, selected "DISPLAY/PARASITICS", and clicked on a trace on the top layer
and got:
57.113 ohms
36.207 nH
11.1 pF
0.633954 nS
I then removed the FR4 layer and did the "DISPLAY/PARASITICS" thing again:
64.334 ohms
36.2065 nH
8.74793 pF
0.562789 nS
To me this says everything changed about the right amount in the right
direction.
Aubrey Sparkman
Enterprise Engineering Signal Integrity Team
Dell, Inc.
Aubrey_Sparkman@xxxxxxxx
(512) 723-3592
> -----Original Message-----
> From: si-list-bounce@xxxxxxxxxxxxx
> [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Mitch S. Morey
> Sent: Thursday, February 19, 2004 10:48 AM
> To: si-list@xxxxxxxxxxxxx
> Subject: [SI-LIST] Re: Layout Cross Section
>
>
> Hi Uri,
>
> Before you get into material.dat file, and the parameters and
> what-not, I
> experimented with changing some variables in my stackup and
> the impedance
> DIDN'T change. I tried FR4 over top; conformal coat; etc; changed
> thicknesses; Dk and when I do DISPLAY/PARASITICS on my Clines nothing
> changes. Might be worth your time to experiment first. :)
>
> Mitch
> >
> > Hi !
> > Thanks for all answer me Kim, Mitch ( nice joke :) and Jeff.
> > Do you know what parameters of soldermask ?
> > Now I know that possible edit material.dat and now I need
> to do this.
> > Uri
> >
> > -----Original Message-----
> > From: Jeff Seeger [mailto:jseeger@xxxxxxxxxxxxxx]
> > Sent: Wednesday, February 18, 2004 8:38 PM
> > To: si-list@xxxxxxxxxxxxx
> > Subject: [SI-LIST] Re: Layout Cross Section
> >
> >
> > Uri Chaplianka wrote:
> >>
> >> snip <
>
>
>
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