[SI-LIST] PCB manufactures control impedance report!

From: "Avi Hayun" <avi.hayun@xxxxxxxxxxxxxx>
To: <si-list@xxxxxxxxxxxxx>
Date: Sun, 30 Mar 2003 19:40:31 +0200

Hi all,

I have question regarding the PCB manufactures control impedance report.
I have notice that in the impedance test report graph (ohms via inch)
they are using mask in order to get out the results. Looking at the
graph, at the beginning (0-2.5 inch) the impedance is lower (falling)
and at the end point is higher (growing up) from the required impedance
(its look worse in differential measurement graph).

I understand that the phenomenon at the beginning is because of the
measuring equipment that they are using? And that the phenomenon at end
it's the end point of the trace that they are measuring. 

So, my question is assuming that I using 1GHZ signal with 200PS tr/tf
dose the impedance measurement at point of 2.5 inch is satisfy? What
shall be the minimal and the maximum distance (in inch) of the
measurements (mask)? 

 

Thanks in advance,

Avi Hayun.

 

 


------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List archives are viewable at:     
                //www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu

[SI-LIST] PCB manufactures control impedance report!

Other related posts: