Ceramic Cpu's

[goaldspektre]

Having a problem doing an HCl/peroxide dissolve with 25 lbs of ceramics.It seems that one of the metals in kovar is plating to all the gold surfaces and won't dissolve.I was thinking maybe the iron in kovar is causing the nickle to cement to the gold surfaces?Anyone else ever had this problem?Also the HCl is dissolving the ceramics and may be using up the acid before it can work on the metals?

 

[samuel-a]

Ceramics are impervious to mineral acids and bases with only few exceptions.

Have you tried heating the AP solution?

 

[patnor1011]

How long do you have them in solution? AP can take days to dissolve pins in CPU. I think he is observing what I saw too. When you put CPU in solution after some while pins appears to be rusty or covered with something. All it takes is just wait some time as I did. At the end I had nice golden hollow foils.

 

[Geo]

the tin in the solder dissolves first because it is lower on the reactivity scale, then it plates back out onto the gold making it look like that.

 

[goaldspektre]

It's been 2 months and the ceramics aren't impervious!

 

[Geo]

i just processed a little over a pound of ceramic IC packages in poor mans AR and it worked fantastic,this will be the process i use for IC's and cpu's from now on.

 

[qst42know]

AP is best for copper alloys and it can be rejuvenated.

Iron from kovar possibly saturated your solution and depleted the ability to dissolve more.

Test with stannous then replace the acid.

Are you using heat?

And. Double check the definition of impervious.

 

[goaldspektre]

I've used heat to no avail,perhaps it's time for nitric.

 

[Dr. Poe]

A metal that plates to the surface of gold without the aid of a dc current? Sounds like osmium or iridium.

 

[samuel-a]

It's been 2 months and the ceramics aren't impervious!

Well.. now you owe us a picture. :shock:
And better explain what you are processing and how...

 

[Harold_V]

A metal that plates to the surface of gold without the aid of a dc current? Sounds like osmium or iridium.

I was scratching my head with that comment, too. Makes me wonder if, maybe, gold is being dissolved and the surface witnessed is what's beneath the gold?

If that's the case, can't imagine why the gold remains in solution with base metal present.

A real mystery :!:

Harold

 

[patnor1011]

He is processing 25 pounds.
How much of HCl did you use to make AP? Maybe it is really acid saturation. I never had a problem but I have used (and reused) about 5-6 litres of AP dissolving less than a kilo of them at a time.

 

[goaldspektre]

Well 42know I looked up smart ass remarks and there was a picture of you right there in the dictionary.Do not ever try to give me a lesson in English!I know what impervious means .That said it's 6 lbs of 496's ,8lbs of Cyrix and 11lbs of Pentium MMX etc...

 

[goaldspektre]

Same here Patnor , I have no idea why this is happening.Done this process before and had no problems?

 

[Palladium]

So if he was being a smart ass being one in return makes your behavior any different in what way?

Think i'll leave this one to Harold.

 

[Harold_V]

Well 42know I looked up smart ass remarks and there was a picture of you right there in the dictionary.Do not ever try to give me a lesson in English!I know what impervious means .That said it's 6 lbs of 496's ,8lbs of Cyrix and 11lbs of Pentium MMX etc...

Your comment is not acceptable on this forum. I advise you to retract your statement.

If you can't say something positive, with manners, don't post.

Do not escalate. It will be expensive if you do.

Harold

 

[samuel-a]

We were all trying to help you...
I guess we'll stop now... i know i will.

Good luck solving your own problems.

 

[qst42know]

A metal that plates to the surface of gold without the aid of a dc current? Sounds like osmium or iridium.

He has reached the saturation point of his acid without dissolving all the iron in the kovar alloy. Any metals that were briefly in solution (nickel, cobalt and a trace of gold) are cementing to the remaining iron, but I don't expect ceramic CPU's contain any platinum group metals.

AP is a copper chloride process efficient on fingers but is a slow troublesome choice for iron alloys.

 

[goaldspektre]

I agree,i'm pretty sure the iron is causing the other base metals to cement out of the solution as well.No harm no foul on my comment,my apologies.

 

[goaldspektre]

Finally refined the lot and got 21 grams gold.I figured out it was silver cementing to the remaining iron(thanks quest , it made me think) I incinerated the lot and used nitric on the remaining pins and foils, after that I dissolved in AR and dropped the gold with smb.I re-refined the powder with hcl-cl and did the washes as per Harolds instructions.Now to do the lids in my sulphuric cell