Bottom part of N/S chips - how to do them?

[Wingedcloud]

Hello everyone,

I'm currently looking for a way to process the bottom part of N/S chips, presented in the picture.

I looked around the forum for a whilem, but only came across ways to process the ceramic top of these chips. But considering I see the gold in these, and take I will come across a large quantity of them, I'm very interested in learning to recover the gold from them.

From everything I have seen until now, I have come to these thoughts:

- Running in nitric acid: will create a mess because under these chips there's tin from solders and will create a mess and will not get me closer to the gold.

- Running in HCl to remove tin: As far as I have read, tin removal with HCl is very time-consuming. However, after removing tin, i could then use AR to get the gold seen in the chips.

- Running in AP: don't know for sure if it is the right method to employ.

- Incinerating, washing and AR: dont have much experience or the ways to incinerate properly so don't think it is the right process to me.

- Running in straight AR: will the tin be an issue if i just go for good ol' AR to dissolve the gold?

I hope someone can shed a light on this subject, from personal experience.

Best regards,
Winged

 

[patnor1011]

AP is the way to go. That solder you do see do contain some gold too.
There is way too much of tin involved to even try to use nitric or AR on them, not to mention that they are low yield - 0.7g/kg (-when considered how many you need to a kilo, there are about 5 kilogram of them in that bucket)

Gold you see on them is plating on copper. I tried to peel plated traces off but that is time consuming if you do have larger quantity. If tou decide to peel gold plated parts off them they can be processed in Nitric, then AR.

However I am not going to even attempt to do this with what I accumulated over some time and to be honest I have no idea what to do with my stash perhaps I will sell them.

 

[Wingedcloud]

Thanks for you reply Patnor

I'll definitely go for AP on them, then.

Will wait for more replies before doing so, however ^^

Kind regards,
Winged.

PS: Patnor, if you have time, can you please check the PM i sent you, regarding gold from IC's ? Thanks !

 

[patnor1011]

I do not have any pm from you.

 

[mls26cwru]

on some of them, if you take a pair of pliers and grab a corner, bend it all the way back and one of the layers will separate so you can peel the two halve apart like two ply toilet paper...the ones that separate i throw in AP, the others with the solder... i haven't decided what to do with them yet, but i am thinking about asking boardsort about them, maybe to see if they can have them tested ore something.

 

[patnor1011]

I sent sample of that solder to have it tested. Test result is in my big thread.

 

[Wingedcloud]

I do not have any pm from you.

My mistake. I mistaken you for another member

Winged