Re: [SI-LIST] : Bends in PCB Traces (renamed from MECL System Design Handbook)

About this list Date view Thread view Subject view Author view

From: Scott McMorrow (scott@vasthorizons.com)
Date: Tue May 22 2001 - 11:54:35 PDT


Ray,

Here is a copy.
Thanks for checking out the list server earlier.

scott and gus

Ray Anderson wrote:

> Scott-
>
> Could you please include me on your mailing of the report ?
> Thanks!
>
> -Ray Anderson
> Sun Microsystems Inc.
>
> >
> >All,
> >
> >Gus Panella of Molex and I have collaborated on some test structures and
> >measurements of right angle bends which would be appropriate
> >to share with the list at this time.
> >
> >We are prepared to share a report containing data, measurements and
> >observations with anyone willing to contact us directly via email.
> >The report is titled:
> >
> >
> >" Impedance Discontinuties of Right Angle Bends"
> >
> >
> >Gus and I included these structures on a board we co-designed
> >6 months ago for some advanced characterization work.
> >All of our trace bends were created with circular arcs, in order to
> >totally eliminate the loss at corners. "Just for fun" we placed other
> >test structures on the board to see what the difference might be.
> >Because of the recent discussions of bends on the si-list, Gus has
> >just gotten around to making some measurements of these structures.
> >We have both agreed that sharing this data makes good sense at this
> >time.
> >
> >To give you some background, the board was fabricated with
> >state-of-the-art traces, materials and manufacturing processes.
> >The traces measured are of asymmetric stripline construction for
> >precise impedance control to 50 ohms. They are 12.5 mils wide and
> >built on Rogers 4003 substrate material and designed to propagate
> >signals at bandwidths greater than 10 GHz with low loss.
> >
> >Here is a summary of the results:
> >
> >1) We can measure the effects of corners with a "slow" TDR.
> >2) We can correlate this data to the available microwave literature.
> >3) We can make recommendations on when corner effects are
> >important and when they are not.
> >4) We can quantify the effects of radius corners vs. square corners
> >vs. angled corners.
> >5) We can tell you where to best place corners in your designs.
> >6) We believe that these results are valid for all corners used
> >on 50 ohm traces.
> >
> >Again, if you would like a copy of our preliminary report, please
> >contact Gus or myself. We will send it out later today.
> >
> >regards,
> >
> >Gus and Scott
> >
> >
> >--
> >Gus Panella
> >Molex
> >databits@earthlink.net
> >
> >Scott McMorrow
> >Principal Engineer
> >SiQual, Signal Quality Engineering
> >18735 SW Boones Ferry Road
> >Tualatin, OR 97062-3090
> >(503) 885-1231
> >http://www.siqual.com
> >
> >
> >
> >**** To unsubscribe from si-list or si-list-digest: send e-mail to
> >majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
> >si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
> >si-list archives are accessible at http://www.qsl.net/wb6tpu
> >****
> >

--
Scott McMorrow
Principal Engineer
SiQual, Signal Quality Engineering
18735 SW Boones Ferry Road
Tualatin, OR  97062-3090
(503) 885-1231
http://www.siqual.com



About this list Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : Thu Jun 21 2001 - 10:12:04 PDT