Yep, as would say your gran-granfather.
Inge

----- Original Message ----- 
From: "John Maxwell" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, March 19, 2007 5:06 PM
Subject: Re: [TN] "Greenish colour on traces"


> Ingemar,
> We must also remember that nickel is  magnetic as well increasing its 
> impedance at high frequencies. That is a reason that many GHz passive 
> components do not use a nickel barrier on their terminations.
>
> John maxwell
>
>
>>That's something else! You did not tell what purpose. It's right, for
>>some multiGHZ bands, where low losses are wanted, we don't use nickel
>>plating because it's higher resistivity. Some nickel platings can have
>>10 times higher losses than Copper and Gold! In these cases, we use just
>>copper (no plating at all)if it's possible in environmental point of
>>view, or we use tinned copper lines. So, silver over copper is
>>theoretically right. And metallurgically spoken, silver on copper has
>>been used for centuries. What I don't understand is why add gold. Maybe
>>to avoid silver tarnish, if the package is not hermetic.
>>Resistivity microOhm x cm :
>>
>>Electronic solder       17-20
>>Pure Tin                9-11
>>Electroless nickel      50-100
>>Electrolytic nickel      8-10
>>Electrolytic Gold        2.5
>>Copper lines             1.8
>>Electrolytic Silver      1.6
>>
>>When you look at the above table, you will understand why Silver.
>>
>>Inge
>>
>
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