FreeLists / si-list / [SI-LIST] Er Variation

[Martyn Gaudion <martyn.gaudion@xxxxxxxxxxxxxxxxxxxx>]

Dear Aaron,

You may find you have more variation in
board fabricator process than you do due
to frequency.  As impedance only varies as
1/sq root Er.


Fine line structures (differential and coplanar) can be affected by
local glass / resin ratio variation:

www.polarinstruments.com/support/cits/AP139.html

IPC 2141 has some tables on typical variation with frequency, but I am not sure
how new the data is.


You can graph this using the Si6000b field solver
from Polar, a free demo is available for surface
microstrip from www.polarinstruments.com



Hope the above information is of
some assistance.

Kind regards
Martyn Gaudion
www.polarinstruments.com

------------------------------------------------------------------
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:
http://www.freelists.org/webpage/si-list

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

List archives are viewable at:     
                http://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