Re: electroless nickel for low rf attenuation?

Phil Hobbs wrote:
> Grant Kiehne wrote:
>
>
> > Grant
t?  Specifically:
> If you want low skin effect loss, you don't want nickel of any sort. 
> Gold, silver, and copper are the best things, with everything else a 
> distant also-ran.  Inside a cavity, electroless copper lasts a long 
> time.  It also tends to get smoother very rapidly as it gets thicker, 
> which is also important for low RF attenuation at high frequencies.


When plating be sure you're using a good process. If you plate too fast 
you'll get porous films that can have a conductivity less than 1/2 of 
bulk. This will lead to pure perfomance.  Gold is good in an wet 
atmosphere but if you don't need it use silver or copper. It will give 
you lower losses.

Depending on what you're plating to you may want to plate ~100 nm of Cr 
first for better adhesion.

We usually use a plating current per area density that falls in the 
med-range of recommended plating. It seems to give us the best results. 
If I was you I experiment and plate films on insulators and then measure 
the conductivity using a standard 4-point method. You'll need a 
nano-voltmeter and a constant current sourse for that. I would adjust 
the plating parameters until I got the highest conductivity.