Help with White ceramic IC/ CPU

[Roj]

Hello everyon
I have had these white ceramic ICE/CPU for years now . They sealed with some type of dye and black sillicone .trying to figure out what would be best way to process them ( Nirtric bath first or AR ? ) my main problem os the protective layer on top sillicone/ some type or dye I have attached pics. Any tip or help will be really appreciated
Thank you

 

[g_axelsson]

Hi Roj and welcome to the forum

Nice scrap, looks like microwave circuit modules. I would love to refine that batch.

The first step is incineration, that will turn the protective epoxy and anything else organic that would create problems later on into ash. My next step would be to use HCl to eliminate tin and some other base metals. Then depending on what's left do another incineration and nitric bath or straight to AR and standard refining.

But if you don't have any experience with refining you should put it on the shelf for a while longer and study the forum, especially the library section. Hoke's book (links found in many members signatures) is also highly recommended to get up to speed with the language we use here.

And as always, run some smaller tests so you don't create a huge mess. A small mess is always easier to deal with.

Göran

 

[samuel-a]

Nice scrap... lots of hybrid circuits, would potentially yield some Pd as well.

 

[goldsilverpro]

I agree. Good stuff. On the circuit side, the traces appear (because the gold is dull) to be thick film, silk-screened, gold, which might be 15-30 times thicker than the gold on fingers or pins. I don't know what thickness the gold on the back is. I would guess it's pure gold plating about twice the thickness of finger gold. I would probably just use aqua regia.

 

[anachronism]

Yep I'd agree on the microwave part Goran. Possibly Nortel/Ericsson base station components. The gold on the back is thick plating usually on a copper substrate which can be quick thick and bonded to a Beryllium Oxide layer (the white stuff.) Pd yes - highly likely as the MLC are usually of the noble metal variety, and some traces and other components can be Pd bearing as well.

 

[Roj]

Thank you guys .its actually ceramic tho.

 

[anachronism]

Roj, those components have 1988-1991 date codes on them. BeO ceramic substrate was widely used for these components at this time and much later. It's white.

Not the best things to be incinerating.

 

[etack]

looks like the long pieces came out of thermal printers.

Eric

 

[Roj]

Keep getting error when i try to reply to the forum

 

[Roj]

FH diluted with isopropanol would that do the trick and remove sillicone ?

 

[Roj]

Under the black sillicone there is very fine gold bonding wires

 

[Roj]

Here is pic of it

 

[Roj]

Here we go

 

[FrugalRefiner]

Keep getting error when i try to reply to the forum

Make sure you don't try to use a percentage sign in your post. It's causing an error again. Noxx is working on it.

Dave

 

[patnor1011]

Take one piece and put it in acetone. It may soften that black epoxy down enough so you will be able to scrape it out. If that will work then you can incinerate just those black epoxy stripes.

 

[Roj]

Update .
First let me thank all of you , For tips and advises .
I did incinerate them first. and got one issue solved with the black sillicone . and tested couple pieces with AR it did dissolved the gold traces around the chip but it did not effect what so ever the middle part . As its still covered with almost looks like a layer of glass or some type of protected glue. Have no ide what is it .any tip will be appreciated as usual you guys a great help .
Thank you

 

[patnor1011]

Acetone.
And as it was mentioned by many people here it is not good idea to incinerate beryllium if you value your health/life.

 

[Roj]

I am amazed of the results. This was from the above ceramcis . Total was about 12lbs. Thank you again . Without this forum and amazing people here that share their knowledge helping others , I would not be able to do it .

 

[goldsilverpro]

$267 per pound. I'm not surprised. Thick film has always been one of the most lucrative items.

 

[Topher_osAUrus]

Very nice.