[SI-LIST] Re: Conductor loss reduction at High Frequency
- From: olaney@xxxxxxxx
- To: kgrhoads@xxxxxxxxxxxx
- Date: Wed, 29 Aug 2007 14:13:33 -0700
"silver tarnishes easily"
So does copper, which is why standard PWB practice is to either plate
over it or solder mask it or both. Silver flash would need solder mask.
I don't think the HT semiconductors etch very well, being ceramic and
all, but if you go for the 4 Kelvin metal ones, lead traces would melt
when you tried to solder. Niobium-Tin costs more, but maybe it's more
amenable to a multilayer process. What are your other suggestions?
Orin
On Wed, 29 Aug 2007 20:55:33 +0000 "Kevin G. Rhoads"
<kgrhoads@xxxxxxxxxxxx> writes:
> >Silver is best, as is well known, but only about 4-5% better than
> copper.
>
> Unless you can afford to chill to superconducting; but the high temp
>
> superconductors are all ceramics and don't plate well, and even
> liquid
> nitrogen temps are expensive to achieve.
>
> As for the metallic superconductors, liquid helium temps are MUCH
> more expensive, and it is hard to get semiconductors that are happy
> at those temps.
>
> SO, yes, silver plate is the best you can ordinarily do for HF
> conductors,
> and can but you a little if the plating depth is greater than a skin
> depth
> or three -- but silver tarnishes easily, and you are more likely to
> get
> better bang for your buck by concentrating on other kinds of loss
> that
> are more readily controlled.
> ------------------------------------------------------------------
> 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 technical documents are available at:
> http://www.si-list.net
>
> 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
>
>
>
>
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
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:
