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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