# Silicon waffers between CPU and heatsink



## Romix (Sep 17, 2014)

Hello Dear forum members 
Is there anything precious on wafers?


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## Claudie (Sep 17, 2014)

To my knowledge, there are no values to the Silicone wafer, but some of the thermal paste used contains Silver.


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## MarcoP (Sep 17, 2014)

Claudie said:


> To my knowledge, there are no values to the Silicone wafer, but some of the thermal paste used contains Silver.


I've read that P4s do, don't recall the source tho.


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## Claudie (Sep 17, 2014)

I may be misunderstanding. Are you referring to the Al heat sink that sits on top of a CPU or the metal heat spreader that is connected to some processors like the P4?


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## MarcoP (Sep 17, 2014)

Heat spreader attached to the CPU.


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## MarcoP (Sep 17, 2014)

Source: http://m.youtube.com/watch?v=uVGgw5DiNyw


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## Claudie (Sep 17, 2014)

Okay, I misunderstood the question. 
Yes there is Silver in the gray paste but many of the P4's I think have Gold braze under them. They come apart harder then the ones with the Silver thermal compound.

You should read this thread to know more about it: http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=45&t=17250

EDIT: To add link & correct mistake.


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## MarcoP (Sep 17, 2014)

It happen I read this today but they are talking about solder and yet not sure if the solder contains Indium, or the solder was made by Indium Corp. of America with 1% Ag content. Will have to read it all again, thanks.


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## Romix (Sep 18, 2014)

Claudie said:


> I may be misunderstanding. Are you referring to the Al heat sink that sits on top of a CPU or the metal heat spreader that is connected to some processors like the P4?


Yes.
Im talking about silicon wafer between cpu and heat-sink. 
I heard that wafers in chips contains Pd. 

Refining heat sink is a good idea, and its easy.
Boil it in hcl, you be left with pure copper. that's worth 4£ per KG. 
Filter of all the gold bits that's left and black sticky tin oxides. 
Don't throw tin oxides away, save it up, it can be recovered back to metal by heating it in H2. And later used in testing or recovering.
You left with pure nickel chloride solution. Crystallise it to NiCl2·6H2O (it's 4 times heavier then metal Nickel)
Can be sold on chemistry forum... 2 - 3 £ per LB.


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## Romix (Sep 29, 2014)

Same processes for all other bits on the boards.
Most need to be crashed first. 
It's worth saving up.


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## shmandi (Sep 30, 2014)

Silicon waffers between CPU and heatsink? Silicon waffer is actually CPU, the heart of it. Better post photo, so we know what you are refering to.


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## Romix (Oct 2, 2014)

I tried boiling 10 heat-sinks in hcl, and about 50 gramm of nickel plated copper crimps. 
Plate from crimps came off in first 2 - 3 minutes. 
Plate on heat - sink is insoluble. That means it's not nickel? What else it can be?


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## Romix (Oct 2, 2014)

Flame tested solution for Ni ions. 
Result bluish-green flame.


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## Barren Realms 007 (Oct 2, 2014)

Romix said:


> I tried boiling 10 heat-sinks in hcl, and about 50 gramm of nickel plated copper crimps.
> Plate from crimps came off in first 2 - 3 minutes.
> Plate on heat - sink is insoluble. That means it's not nickel? What else it can be?



If you are talking about the heat sinks from P4-I7 CPU's it takes an extended soak in hot HCL to remove the plating but it will come off with time and patience.


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## Romix (Oct 2, 2014)

Also there's white precipitate in NiCl2 solution. 
Any ideas, what is it?


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## Romix (Oct 2, 2014)

Barren Realms 007 said:


> Romix said:
> 
> 
> > I tried boiling 10 heat-sinks in hcl, and about 50 gramm of nickel plated copper crimps.
> ...


2 hours boiling them, plate not coming off!


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## Barren Realms 007 (Oct 2, 2014)

Romix said:


> Barren Realms 007 said:
> 
> 
> > Romix said:
> ...



The last batch I ran filled a 4L beaker 3/4 full. They were on the heat for a day and a half. Time and patience.


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## Romix (Oct 2, 2014)

Plate almost came off.


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## MarcoP (Oct 2, 2014)

shmandi said:


> Silicon waffers between CPU and heatsink? Silicon waffer is actually CPU, the heart of it. Better post photo, so we know what you are refering to.


As far I could understand he refers the fiber board as the CPU so I believe he was meant to say "the silicon wafer between the fiber board and the heat sink".
My notes were talking about the silver based thermal paste between the wafer and the heat sink found only in P4s but I'm still unsure if the chip contains values thus some research could put some light on it.


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