Gold inside chips (black, flatpacks - not CPU)

[patnor1011]

I reacted to Crowking - I posted pictures about what I think he is dealing with.
I generally consider every black square chip with more than 8 legs as flatpack and I separate them in 2 categories. Well that is just my method. All thin ones with thin legs like the ones on RAM sticks are in one, thick ones with thick legs are in second category. Black parts from north and south bridges (ball grid array) chips are cream for me as they do not contain metallic parts inside only some of them like that ATI pictured do have that heat sink type of metal attached. They are easier to process. Lately I started to remove Si wafer from inside as it is harder to grind and when it is in small pieces grinding become harder. It is easier to remove that right after pyrolysis before I start to grind burned chip housing.

Chips pictured with square heatsink well they are BGA type chips they usually do have some monolIthics attached and I do not process them yet. I just toss them in a box and I will decide later what to do with them, they maybe end up on ebay - I do not see much value inside but I may be wrong.

 

[patnor1011]

Tomorrow I will try to make some pictures of concentrates (material after initial pyrolysis and grinding and washing with water).
1. will be just black top parts from n/s bridges
2. will be from all other flatpacks
3. same as No2 but with Si wafers removed prior grinding

I always do it like this: burn / grind / water wash / dry / grind again / water wash / hot Nitric wash / AR
I remove all magnetic pins after first grind and most of non magnetic too by using sieve. Whatever non magnetic is left is usually dissolved in hot Nitric wash later.

*edited pictures added

 

[EPhantom]

Hello, I'm new to the forums and to refining/recycling of electrical components. I am currently just starting to collect parts and probably won't get into refining for a year or two. One thing that confuses me about this topic is the definition of "Flatpack". It appears that everyone is being selective of which ICs they include in this category for gold recovery (primarily computer ICs in specific locations), but at the same time nobody has actually said that not all ICs have gold. So... is a "Flatpack" a specific type of Integrated Circuit, or do all ICs have gold in them and I am just misunderstanding?

I mean, could I take an op-amp from a speaker system, or a 555 timer from some random circuits and expect there to be gold in it?

 

[patnor1011]

Maybe and maybe not. That is why I collect any chip with more than 8 legs. I have found gold in chips with pins on two sides too, generally consensus here is that we call (or at least me in this thread) flatpack all black chips with more than 8 pins.
I separate them in 3 cat similar like Geo is doing:
1. low yield - rectangular chips with legs/pins on two sides, eprom like plastic/resin type (less than 1g/kg)
2. middle yield - all square and rectangular with pins on all 4 sides and 2 sides pin chips from ram (1-4g/kg)
3. high yield - black top parts from south and north bridge BGA type chips from motherboards and video cards (5+g/kg)

I have just processed about everything I had but I might find some and I will try to take few pictures.

 

[patnor1011]

Small IC Chips, 6 legs - three on each side. I thought a waste of time to collect from boards or floor, well gold is where you find it...

 

[joem]

Hey Patrik
Did you get some pictures of your low, middle, and high grade?

 

[patnor1011]

No Joe, but I can do some in next 2-3 days. Little bit busy in work and on my last project. I recently processed nice lot of southbridge BGA IC chipsets (flatpacks) for one member. It was 1336 g precisely (2.94lb)
I did that like I wrote in by eBook but slightly changed my method and at the end I produced nice healthy 7,1 g little beauty, which was sent to owner.
Enjoy pictures.

hmmm we really need to come to some conclusion on how to call different type of IC chips :|

 

[oldgeek]

Pat,
I have been following your work on this for a long time , and I have to give you credit, you are a MAJOR contributor to this forum. Thanks for all of the information, and hard work.

I have a question on yields. In your last post, you processed 1336g of (mostly) southbridge type BGAs for a recovery of 7.1g
Did that include both parts of that type of chip? I know you process the tops, and the bottoms separately. Is that correct? Do you have any yield figures for recovery of the tops only?

Oh yeah, Are you gonna tell us how you tweaked your process? :wink:

Thanks,
Scotty

 

[patnor1011]

Well thanks
If major contributor then perhaps in this thread and this particular process - that is what I can agree with. :lol:
My number of posts show that many times I talked when I should be quiet but I am trying to stay cool and do not react to everything.
Yes, yield is 7.1g from 1336g of whole IC chips, top and bottom part. From my observation I can say that bottom part with visible plating will not be more than 5% of all gold recovered. I mean it is so little that perhaps it will be wiser to list it on eBay than actually try to recover that gold. I was trying to recover gold as foils to have final weight from this bottom part but I must admit that I resigned trying to leach it out as foil when it was in Nitric for 5 days and about 30% of foils still attached. At that point I just put all that in AR.

I do have about pound of s/n bridges so I may do some additional math where I will try to find out what % of that 1336g was top and bottom part so in that way you can get answer about yield from top part only.

 

[oldgeek]

I have been collecting this type of chip quite a while now, I separate them as I get them. The tops go in one bag, and the bottoms go in another bag. So far I have 260g of tops, and 330g of bottoms, which equals 590g total. I am sure the results of weights of the tops verses bottoms could vary GREATLY depending on the way the chips are removed from the boards, and how much solder came along with the chip. I remove mine mechanically, and a lot of solder usually comes off with them. I also noticed that most of the top layer of fiber sticks to the top part when the chips are separated.
I will just keep on collecting them until i am ready to try your process out.

I have also been thinking about processing the resulting ashes with a flux/collector in a smelting setup and pouring the lot in a cone mold. (I don't have a furnace though)

 

[Geo]

The gold foils on the green base will come off and stay stuck to the top if you just rip them off leaving the green bottom virtually worthless. The best way to separate the top and bottom is to heat the top (not the green base) until the top pops loose. You will see it when it happens. Until I started using a heat gun, I just layed them with the top down on my single electric burner until the green base popped up.

 

[acpeacemaker]

Cheers
-Andrew

 

[patnor1011]

I try not to mix them, or separate to 4 types at least.
This is just my sorting from my experience:
1. low yield black rectangular eprom like type with thick legs on two sides /usually older boards/
2. middle yield - all other square or rectangular type with legs on 2 or 4 sides
3. middle to good - ram stick chips /older thick or new thin with legs on 2 sides/
4. holy grail - s/n bridge BGA IC chips /only those with black plastic square part on top of green fibre part, NOT whole green type with small silicon chip and capacitors on top/

 

[Laitinen Marco]

Hello! Im new and from Sweden.
Thanks all for a great forum!
And thanks Patnor for this thread, very inspiring.

How do you take away the last non magnetic parts in goldpan? Do you pan it out?

I did burn the chips then crush them then washed with water then used magnet, then I tried to pan...
Have never pan before and the thing I use is not really a gold pan, so now I am stuck with a small pile
With small copper parts and hopefully some gold in but not sure how to get concentrate like in your
pictures whitout losing my gold.

Thanks again / Marco.L

Sorry for my bad English

 

[xALmoN]

So where do those with the small silicon chip go? I'll do a quick sorting when I pull off more chips tomorrow. I haven't depopulated any ram so far, so ram chips should go in another corner too?

 

[patnor1011]

Marco,
Nitric acid will sort them out in no time. When panning be very careful. Some wires are very very small and can be carried away with mud. I use Acid when I do have say about 5% of concentrate still in pan. That will dissolve small non magnetic pins and then panning is again easier. If you do have a lot of broken silicon dies (centre pieces) in your concentrate - they look like broken glass this is again hard to pan out without losing values just proceed to AR (after you did dissolve pins in Nitric).

 

[patnor1011]

So where do those with the small silicon chip go? I'll do a quick sorting when i pull off more chips tomorrow. I havent depopulated any ram so far, so ram chips should go in another corner too?

To the skip they go... :lol:
No, really I was joking. I do not think they do contain much of value apart of some dots of gold plating on top and something in capacitors. I do not know about anyone who processed sizeable load in some way and report any values in them. I do have about a pound of them which I may try to process or I am willing to donate to some skilled member to try to perform some recovery in order to know if there is anything inside. I will see if I will have time to try to do something with them but at this moment I just put them aside.

 

[Laitinen Marco]

Ok, I will use nitric, I found the broken silicon dies a little bit easier to pan because they was not as heavy as the rest
of the material, but I probably lost some gold, I should have used nitric a bit earlier I think, the gold wires is much
smaller then one can believe, hard for me to see what is gold and what is not due to the lack of experience,

Thank you very much Patnor / Marco

 

[xALmoN]

Would probably need to figure a way to shred it along with the silicon chip and see how things go from there.

 

[acpeacemaker]

I use a very durable plastic container. Putting the silicon chips in a handful at a time. Then cover with water. Then I use the butt end of a 12 steel punch or "awl" as mortar and pestle. The water keeps all the pieces from going everywhere. Then pan the remaining wires that were still attached to the chips. From the rest of the remains I have found Ag and Pd.