srlaulis
Well-known member
Do you think it is possible to just put the entire green wafer, after the ap bath, into the hcl/cl in order to dissolve any gold that doesn't detach from the wafer?
Gold inside chips (black, flatpacks - not CPU)
- Thread starter patnor1011
- Start date
Help Support Gold Refining Forum:
Geo
Well-known member
unless you had a bucket full, you wouldnt get enough gold to to make a difference anyway. its best to collect the foils and process them. to try and do the entire base, you would wind up with more solution than you can deal with.
srlaulis
Well-known member
Thanks Geo!
There is a danger with putting multi-layer PCB:s (which the green bases are) into a gold solution.
It is very hard to remove all base metal inside the PCB:s, if you put it into a gold solution, gold will start to deposit inside the PCB when the solution comes into contact with the copper. Then you will probably lose more gold than what you get from the few foils on the surface. Only way to prevent losing more than you get is to start with a totally barren solution and remove the PCB:s before too much cements inside them.
I have done that error once when I ran two fiber CPU:s together with some ceramic CPU:s. I will provide pictures and a write up of it soon. The fiber bases is going to incineration and processing to get anything from the inside. I will not do that mistake again.
Better to take a sharp knife and just scrape off the foils on the surface and then wash it in a beaker with some water and a toothbrush. Collect the gold foils with solder masks and other dirt from the bottom and process them as usual.
Btw, incinerated black plastics is easily pulverized in ultrasound, and poured off as a cloudy fluid. The
bond wires, copper metal and silicon die is left very clean in the bottom of the beaker.
/Göran
It is very hard to remove all base metal inside the PCB:s, if you put it into a gold solution, gold will start to deposit inside the PCB when the solution comes into contact with the copper. Then you will probably lose more gold than what you get from the few foils on the surface. Only way to prevent losing more than you get is to start with a totally barren solution and remove the PCB:s before too much cements inside them.
I have done that error once when I ran two fiber CPU:s together with some ceramic CPU:s. I will provide pictures and a write up of it soon. The fiber bases is going to incineration and processing to get anything from the inside. I will not do that mistake again.
Better to take a sharp knife and just scrape off the foils on the surface and then wash it in a beaker with some water and a toothbrush. Collect the gold foils with solder masks and other dirt from the bottom and process them as usual.
Btw, incinerated black plastics is easily pulverized in ultrasound, and poured off as a cloudy fluid. The
bond wires, copper metal and silicon die is left very clean in the bottom of the beaker.
/Göran
srlaulis
Well-known member
Thanks for the advice, Goran! 
patnor1011
Well-known member
Göran what device do you use for that ultrasound treatment?
Hi Partnor, I'm just using a small cheap bench system for cleaning jewelry. I'm normally use it to clean mineral specimens from clay.
I don't know how it scales, I only tested one flatpack, incinerated with a small pocket-torch, but it was quite fast and the filler that remains after the incineration turned into suspended clay and could be poured off, I never needed to pan any gold threads.
Just add a drop of detergent before sonication to stop the gold to be carried away by the suface tension.
/Göran
I don't know how it scales, I only tested one flatpack, incinerated with a small pocket-torch, but it was quite fast and the filler that remains after the incineration turned into suspended clay and could be poured off, I never needed to pan any gold threads.
Just add a drop of detergent before sonication to stop the gold to be carried away by the suface tension.
/Göran
Some pictures from my microscope...
Just as a proof of concept I took half a chip (I've already broken it in half to look for bond wires) and incinerated it. Then I put it in a beaker with water and a drop of detergent into a small ultrasonic cleaner (effect 70W). There was an instant cloud and I left it on for circa 20 seconds. Then I gently poured off the silty water and found that I hadn't incinerated long enough, there were half of the black plastic still left.
Another turn under the mini-torch and then back into the beaker and sonication.
The second time I managed to burn off almost all carbon. The end result was a tangle of wires, some copper wires from traces from the base PCB that stuck to the black top when I ripped it off and the rest golden bond wires. (picture 3) With it was some small white sand-like particles that I suspect is melted glass fibers and some small pieces of charcoal from the incineration. To the right you could see a small piece of the plastics with some bond wires still attached.
Now I only have to invent the pocket incinerator and my fortune is made... small time! :lol:
/Göran
Just as a proof of concept I took half a chip (I've already broken it in half to look for bond wires) and incinerated it. Then I put it in a beaker with water and a drop of detergent into a small ultrasonic cleaner (effect 70W). There was an instant cloud and I left it on for circa 20 seconds. Then I gently poured off the silty water and found that I hadn't incinerated long enough, there were half of the black plastic still left.
Another turn under the mini-torch and then back into the beaker and sonication.
The second time I managed to burn off almost all carbon. The end result was a tangle of wires, some copper wires from traces from the base PCB that stuck to the black top when I ripped it off and the rest golden bond wires. (picture 3) With it was some small white sand-like particles that I suspect is melted glass fibers and some small pieces of charcoal from the incineration. To the right you could see a small piece of the plastics with some bond wires still attached.
Now I only have to invent the pocket incinerator and my fortune is made... small time! :lol:
/Göran
Check the auction sites for ultrasonic welder. I'm not talking about ebay or the like either, I mean local auction companies, I see them quite often and go between 2 and 5 hundred dollars. That's if you want a larger one.
I love the innovation that occurs on this forum.
May I also say that removing as much of the powders and plastics before trying to recover and refine the values is really important, I have rarely treated e scrap but have done large quantities of jewellers sweeps and to ensure a decent recovery they usually need treating twice at least due to the amount of powder that shields the values from the acids and the amount of pregnant solution also trapped in the powders which is also difficult to fully remove even using large vacuum filter beds and many rinses.
Metals only been dissolved makes loses less likely as you can see if any metals or values remain.
May I also say that removing as much of the powders and plastics before trying to recover and refine the values is really important, I have rarely treated e scrap but have done large quantities of jewellers sweeps and to ensure a decent recovery they usually need treating twice at least due to the amount of powder that shields the values from the acids and the amount of pregnant solution also trapped in the powders which is also difficult to fully remove even using large vacuum filter beds and many rinses.
Metals only been dissolved makes loses less likely as you can see if any metals or values remain.
NoIdea
Well-known member
patnor1011 said:
Evening All - try the good old trusted pyrolysis, all you end up with is aluminium, pretty much uneffected, and carbon.
For the larger ones, you can take the aluminium foil coil out of the can and unroll it to give wafe thin carbon and aluminium sheets.
I'll see if i can take a picture of a batch i did some time ago.
I was looking at utilizing the hydrogen produced then adding sodium hydroxide solution to the smaller ground up capacitors, another project festering. :roll:
Cheers
Deano
patnor1011
Well-known member
Thanks Deano will try that.
On another note, I got few email from people and we all got bit confused as what is what so here I put few pictures to show you what I mean and how I call different types of chips when we talk about them.
On another note, I got few email from people and we all got bit confused as what is what so here I put few pictures to show you what I mean and how I call different types of chips when we talk about them.
Attachments
patnor1011
Well-known member
Geo
Well-known member
patnor1011 said:
Pat, that is called a "flip chip". if i understand right, the only gold content is in the legs if its a plug in type. i dont know about any other PM inside. i incinerated 5 pounds of flip chip bases and never could recover any amount of gold from them.
samuel-a said:
Maybe the difference was in the plastic of the IC or the way I incinerated it. I think I described it quite detailed but if there are any details you feel I left out just ask.
I did the incineration at a quite high temperature, some of the exposed bond wires melted at the end as I used a small hand held torch (based on a cigarette lighter) when I heated the chip. I heated it until the ashed chip was glowing cherry red for a while to be sure to get all carbon out of it. As the first picture shows I didn't incinerated long enough at first, but after a prolonged heating I got nearly all carbon out of the chip and then it easily turned into suspended clay during sonication.
In the thread you linked to you talk about both pyrolyzed and incinerated chips. Was there any difference in how they reacted on the sonication? After sonication of the incinerated chips what colour did they have? If your chips came up black you didn't incinerate them long enough.
If I get some time I'll try to do some more tests, but as the first snow came yesterday this season of refining is almost at an end for me.
/Göran
patnor1011
Well-known member
Geo said:
The ones I do have are BGA type, I save them but I am in the dark if somebody ask me if they do have something inside. Rather not but I will try to experiment with couple to be sure.
samuel-a
Well-known member
- Joined
- Oct 7, 2009
- Messages
- 2,190
Thanks g_axelsson
I kinda figured there won't be much difference in what we did to the chips.
I\ve tryied that with fully incinirated and with only pyrolyzed RAM memory chips... suspended them in the bath with plastic mesh...
And nothing happend with both....
I suppose it has everything to do with the frequency... and i suspect when i tried that, it was too high.
Problem is, i don't have an ultrasonic to play with whenever i want to...
I kinda figured there won't be much difference in what we did to the chips.
I\ve tryied that with fully incinirated and with only pyrolyzed RAM memory chips... suspended them in the bath with plastic mesh...
And nothing happend with both....
I suppose it has everything to do with the frequency... and i suspect when i tried that, it was too high.
Problem is, i don't have an ultrasonic to play with whenever i want to...
NoIdea
Well-known member
samuel-a said:
Don't You??? I thought everyone had one. :mrgreen:
Ok, back to what im here for, pyrolyzed electrolytic caps.
The carbon foil in this lot did not stay intack like in previous runs but you can see what i mean by looking at the photo. The remaining aluminium pot weighted 7g and is 50mm long by 30mm in diameter for reference. The foil to the right is the aluminium foil that came out of it.
Next thing to do is put it through my smasher/basher/thrasher and see what sort of mess i end up with. 8)
Deano
Ooops, forgot the pic :roll:
