Vintage pcbs recovery amounts

[eaglekeeper]

Leaching is also an option, but I am not familiar with types of ceramics on more modern MLCCs. And as long as I do not know the composition, it is hard to tell if it actually does work OK. For the old ones with titanate ceramics, it works decently. Alumina may be much more difficult to decompose, if even possible to decompose it by ordinary acids. As for the recovery of Pd out of the ceramics, AR works much better than straight nitric from my observations. But you firstly need to dissolve silver in nitric and then proceed with AR.

Awesome info, thanks

I figure since the Pd is layered between ceramics and not actually locked up in the ceramics, that a simple grinding would expose those layers to the acid, just my guess at this point.... when I get enough that I could get a measurable run I'll try it.

 

[macfixer01]

I've been super busy today but, I really appreciate your time with the response.

Yes, I'm sorry about that. After looking closer I noticed you maked the items with the color dots which I appreciate greatly. Is there a database somewhere with all this kinda information available? I have a few more boards if anyone feels gracious enough to help some more. Really, thank everyone for your all your help.

In that second group of (19) photos that you posted on Saturday November 5, there are several IBM boards. I don’t know if you were aware but the connectors on those actually contain karat gold pads bonded to the pins, which are better than plating. The white plastic shells over them can be pulled off, and the black ones are usually easier to bend on one side then will split lengthwise and fall off. The pins themselves are just soldered on the surface of the pads, and will come off the boards pretty easily with a heat gun. Some of those boards can contain several tantalum capacitors and often are types that are unique to IBM such as 3-pin and 4 pin varieties. They often contain a lot of MLCC’s and resistor networks also. I made up some photos awhile back too show the different types for them.