Gold plated Alum Caps

[jeneje]

Hey All, before asking this i did a search for gold plated Alum. and did not find my answer. I De-Caped some cpus today and under the Alum. cap was gold plating. Not all had this but several did, the cpus were green fiber the small ones 1"x1".

I started my recovery by boiling in a lye solution to remove grease and such, now that i have them seperated, i am doing another boil in lye to remove any solder mask left, then i am going to wash and place in HCL overnite to remove the MLCC's.

Now to my question, the gold plating on the Alum. what process should i use. AR, AP, I am leaning towards the AP, not sure! If there is another search term please post and I will research it.

Thanks
Ken

edited for pic;

 

[maynman1751]

What you have pictured IS NOT aluminum. It's copper with, I believe, a tin coating. I'm not sure. I did some of these in HCl, to remove the solder, and it readily dissolves the surface coating, but the gold content was not even neglible. If the coating is tin, any gold would be 'locked up' by the tin (colloidal).

 

[jeneje]

What you have pictured IS NOT aluminum. It's copper with, I believe, a tin coating. I'm not sure. I did some of these in HCl, to remove the solder, and it readily dissolves the surface coating, but the gold content was not even neglible. If the coating is tin, any gold would be 'locked up' by the tin (colloidal).

Thanks maynman, better to focus on the pins.
Ken

edited; would not a mild HNO3 bath remove the gold as foils?

 

[ovidiuanghel]

The lye solution dissolve aluminium remaning only the gold foil and the solder but i know that this caps are from cooper. I saw aluminium caps only on AMD K6 cpu's.

 

[philddreamer]

I was running my sulphuric cell, and ran one of those and the nickle and gold were de-plated leaving the copper exposed.
Phil

 

[jeneje]

I was running my sulphuric cell, and ran one of those and the nickle and gold were de-plated leaving the copper exposed.
Phil

Thanks Phil, I thought a cell might work better after thinking about it for a while. I will try that instead of the HNO3.
Ken

 

[NoIdea]

It may not be what you are after, butt, if you ash then place them in a plastic tray (let them cool down first :mrgreen: ) dampen with dilute waste AP, Leaching acid, etc., and leave, you will see things start to happen, now, if you put some pins with them, then you can put them in a tumbler after washing, leaving damp, add some crushed ceramic CPU's, and bingo was his name oh.

The more i thing about it, one could call this process, the "Poor Mans AP" process. Just keep it damp with dilute HCl acid, let the air act like the Peroxide, you will be amazed. 8)

Good Luck.

Deano