HP board "gold recovery" garbage

William Donzelli wdonzelli at gmail.com
Thu Jan 24 11:02:43 CST 2019


Good, older MLCCs can be up to 3 or 4 percent Palladium by weight.
Modern-ish ones can be zero, but are often maybe 0.1 percent.

It adds up. Remember, Palladium is *heavy*, ceramic is not.

--
Will

On Thu, Jan 24, 2019 at 11:29 AM Jon Elson via cctalk
<cctalk at classiccmp.org> wrote:
>
> On 01/23/2019 08:20 PM, ED SHARPE via cctalk wrote:
> > I learn something  new  then... when   was  palladium used?   was it  around in  the  2100  hp  days or  was this   used  later?   and  I had not heard of  it?
> >
> If palladium was used, it was in VANISHINGLY small
> quantities.  Many circuit boards use palladium to seed the
> plating in the plated-through holes.  But, the amounts there
> are in the micrograms for a whole board.  I suspect if
> palladium was used in multilayer caps that it was used for
> the same purpose, a wash over the surface of the capacitor
> material, allow it to dry and then electroplate with the
> desired electrode material.  They'd probably use a couple
> milligrams at most on each layer of a capacitor sheet, which
> would eventually be cut up into hundreds of thousands of caps.
> Some high-value MLCs can have 20 layers or so, so that would
> be milligrams * 20 / 100,000.
> Not a hell of a lot of palladium would be in an entire board
> full of them.
>
> Jon


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