[SI-LIST] Problem with Ni plated transmission line
- From: Daniel Kuchta <kuchta@xxxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Fri, 14 Mar 2003 09:58:01 -0500
I have run into an unexpected problem with a Ni plated transmission line.
I have fabricated 2 types of 100 Ohm differential transmission lines on a
flex circuit.
They are both approximately 3mil width and 3 mil space. The substrate is
3mil Dupont Pyralux.
The metallurgy on one pair is 1/2oz copper covered with PSR9000 solder
mask.
The metallurgy on the other pair is 1/2 oz copper plated with 100u in
Electroless Ni and 10u in Electroless Au.
The plated line is not covered with solder mask.
The expected result was that the plated line would have higher bandwidth
since the solder mask has a loss tangent of 0.02.
The measured result is 20GHz for the covered lines and 7 GHz for the plated
lines!
The plated lines appear to suffer from high conductor losses.
The dc resistance of the lines is also different: 0.5 Ohm for the unplated
and 1.1 Ohm for the plated.
Does anyone have a similar experience with plated transmission lines?
Does anyone have an explanation for this effect?
Thanks
Daniel M. Kuchta
IBM T. J. Watson Research Center
1101 Kitchawan Rd. Rt. 134
Yorktown Heights NY 10598
914-945-1531 (voice)
914-945-4134 (fax)
kuchta@xxxxxxxxxx
------------------------------------------------------------------
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
Other related posts:
