Gold inside chips (black, flatpacks - not CPU)
- Thread starter patnor1011
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Geo
Well-known member
the silica chip itself contains precious metals, but it would take a long time to collect enough to process. the chip is a tiny circuit board in itself with layers of metal and silica. the circuits are imprinted into the metal like taking a picture.the metal is so thin that photons is all thats needed to vaporize it.each layer is printed like a stack of photo copies.
patnor1011
Well-known member
Maybe I used wrong term. I meant silicone die, center piece in any IC chip. It is not wafer like solar cell but Si piece loaded with tiny micro components.
Geo
Well-known member
breaking the chips would yield no more than processing them whole. they would have to be milled extremely fine to recover what was inside.
I don't think you will find any large amounts of precious metals in the silicon dies. The usual material for connecting the components is aluminum. Some more fancy processes uses tungsten via plugs and copper interconnections, but I'm quite sure that gold is only used for plating of the connection points for the bonding wire if they use gold.patnor1011 said:
Before doing too much job, take one or a few dies that have already been leached in AR and crush, treat with AR and test with stannous. Then you know if it's worth doing a bigger batch or not.
Göran
patnor1011
Well-known member
That exactly is the plan for next week. :idea:
patnor1011
Well-known member
I looked into this stuff a little bit now, and it seems that they have very little need for gold in these "flip chips". There's some plating that is used to make the contact between the silicon and the copper traces on the wafer's underlying board. The solder which connects them are called bumps, and the solder composition is a bit of a mystery. It can be several things; lead-tin, tin silver tin-gold (5%), and pure gold in some cases, but in any case looking underneath a silicon wafer just now whatever it is made of, it's not going to be much. Hopefully these rotten chips fall out of favour. 
Geo said:
patnor1011
Well-known member
Time to ebay my pile then. To let somebody else to figure out what to do with them. :mrgreen:
Yeah, Patnor, I have a bunch of motherboards with pga flip chip processors and two bga flip chips, and looking at them a few days ago these boards looked good and nicely populated to me, but now I know better.
Anyway, I've sort of skimmed over a lot of escrap related stuff here before, and just recently started giving some of this stuff a more thorough read, and I must give my commendations to you Partnor, to Sam and to Geo, for your work on board components processing, yields etc. Sorry if I missed anyone who's made contributions in this area. It's amazing to think of how far the forum's knowledge has come since the start!
Anyway, I've sort of skimmed over a lot of escrap related stuff here before, and just recently started giving some of this stuff a more thorough read, and I must give my commendations to you Partnor, to Sam and to Geo, for your work on board components processing, yields etc. Sorry if I missed anyone who's made contributions in this area. It's amazing to think of how far the forum's knowledge has come since the start!
patnor1011
Well-known member
I got mail from member asking me something so I replied but I think it will be good to post it here too as it may help some other members too.
Email:
Hi. I downloaded & read your incineration PDF. I was wondering how much coal you used to consume the 7kg you started with? I can get some coal, which I believe will burn hotter & last longer than charcoal, but I've never personally burned coal so I don't know how much to use.
My reply:
It is really hard to say. It probably depend on where you going to do it. Some people do have heating systems based on some stove or burner using coal, here I guess it will take shorter time and less fuel but it will need to be done in some closed steel container with few small holes to allow gas to escape.
I did it in regular size open fire place like people do have in living rooms. I am guessing right now but say it had space like cube 50 cm x 50 cm and is deep probably like 50 cm as-well.
In there I put probably about 1-2 kilograms of coal - well it can be seen on my pictures that will show you how much I used.
If you want to know total amount it depend on many things. I now do them only few pieces at a time. I mean that if there is few pieces on tray and in fire they burn properly and faster on the contrary of putting there full bowl or too much of them on tray like one on another. I now prefer single layer of them. That will make them to burn properly, they become white and very soft-crumbling that enable me to separate center Si piece and sieve out powder with wires and separate pins.
If you put them in fire in container where they are stacked one on another then those in middle will not burn properly and will require additional crushing.
I will estimate that I spent about one bag of coal which is 40 kilograms in here.
I will suggest that if you cut them off boards with knife then proceed to incinerating but if yopu just desoldered them and they do have legs still on them then if you have source of cheap HCl then soak them in warm HCl to dissolve as much of legs as possible. They do not contain any values, most if not all PM are locked in center of IC so dissolving legs will work for you to speed up later recovery from incinerated material. (less base metals with values to deal with).
Regards Pat.
Email:
Hi. I downloaded & read your incineration PDF. I was wondering how much coal you used to consume the 7kg you started with? I can get some coal, which I believe will burn hotter & last longer than charcoal, but I've never personally burned coal so I don't know how much to use.
My reply:
It is really hard to say. It probably depend on where you going to do it. Some people do have heating systems based on some stove or burner using coal, here I guess it will take shorter time and less fuel but it will need to be done in some closed steel container with few small holes to allow gas to escape.
I did it in regular size open fire place like people do have in living rooms. I am guessing right now but say it had space like cube 50 cm x 50 cm and is deep probably like 50 cm as-well.
In there I put probably about 1-2 kilograms of coal - well it can be seen on my pictures that will show you how much I used.
If you want to know total amount it depend on many things. I now do them only few pieces at a time. I mean that if there is few pieces on tray and in fire they burn properly and faster on the contrary of putting there full bowl or too much of them on tray like one on another. I now prefer single layer of them. That will make them to burn properly, they become white and very soft-crumbling that enable me to separate center Si piece and sieve out powder with wires and separate pins.
If you put them in fire in container where they are stacked one on another then those in middle will not burn properly and will require additional crushing.
I will estimate that I spent about one bag of coal which is 40 kilograms in here.
I will suggest that if you cut them off boards with knife then proceed to incinerating but if yopu just desoldered them and they do have legs still on them then if you have source of cheap HCl then soak them in warm HCl to dissolve as much of legs as possible. They do not contain any values, most if not all PM are locked in center of IC so dissolving legs will work for you to speed up later recovery from incinerated material. (less base metals with values to deal with).
Regards Pat.
patnor1011
Well-known member
Good. Few thoughts. While it is wise to open mixer outside as that fine powder is very bad to breathe I do recommend to do sieving outside too. For the very same reasons.
I used similar device but blades become dull very fast and you will have to sharpen them often. Also some IC contain large piece of metal as heatsink which may jam and burn engine of mixer or break actual body of mixer. I abandoned this method long time ago. Now, as I explained in previous post I use extra time when incinerating so all of IC are white when cooled and crumble in fingers. Like sand so I do not need to employ additional measures for crushing.
Be sure that you check your sieve very closely. Some, mainly longer bonding wires like to stuck in there and need to be removed.
I used similar device but blades become dull very fast and you will have to sharpen them often. Also some IC contain large piece of metal as heatsink which may jam and burn engine of mixer or break actual body of mixer. I abandoned this method long time ago. Now, as I explained in previous post I use extra time when incinerating so all of IC are white when cooled and crumble in fingers. Like sand so I do not need to employ additional measures for crushing.
Be sure that you check your sieve very closely. Some, mainly longer bonding wires like to stuck in there and need to be removed.
patnor1011
Well-known member
rewalston
Well-known member
Look beautiful Pat, so S/N bridge and RAM chips are the only real ones worth going after on the boards? None of the other flatpacks?
Rusty
Rusty
Geo
Well-known member
Rusty, they are not worth the time. you can send them to me and ill happily pay the shipping. :mrgreen: seriously, all quads or flatpaks should have precious metals. almost all will have gold bonding wires. when the weather finally breaks here, i intend on doing a start to finish video on flatpak chips.
rewalston
Well-known member
Geo said:
:lol: Right now the only RAM chips I have are from RAM that has gold plating. The others I cut the fingers and toss in a box. I've been pulling all flatpacks and tossing them in a box as well. I have a cat litter bucket (roughly 15 lbs) with boards and what not that appear to have gold plating that I'm going to run through an HCl bath to remove solder and then strip the mask followed by AP. Just need someplace to work on it.
Rusty
patnor1011
Well-known member
I do save and process all of them with exception of eprom like IC. They are saved too but I do not have intention to process them, I may try to eBay them later on.
I did only RAM chips this time as I am trying to find out approximate yields of different types. I am so far convinced (all my test batches proved) that s/n bridge type run at least 5 g of Au from kilogram.
I am now close to have number for RAM IC (thin & thick).
The rest of IC I like to separate to thin and thick type and those two then to small and big size.
I did only RAM chips this time as I am trying to find out approximate yields of different types. I am so far convinced (all my test batches proved) that s/n bridge type run at least 5 g of Au from kilogram.
I am now close to have number for RAM IC (thin & thick).
The rest of IC I like to separate to thin and thick type and those two then to small and big size.
