AP solution for removing ic chips legs

[GoIdman]

Sure! Your help would be very appreciate, in the end your answers are supported by your huge experience, and I’m glad to be in this forum with people like you.
Yes, I would like to know how to process the IC’s after burning them…
I made enough mistakes, but i try to learn

I would go with Kurt on this one.

This is not an advice it is how I do IC chips.

I made a setup with an electric motor a reductor and a regular cast iron meat grinder (if you dont have a motor, use hand power it works as well....but I`m lazy so i`ll use motor power)). I use this setup to grind my IC`s after incineration. then use an old coffe grinder, it makes a fine powder, after that sieving and the whole shebang, after that sluce to wash away the carbon. When you have your concentrated washed material you could think about refining with whatever method you wish.

Don`t waste acid and create unnecessary waste, you`ll have issues with it later when you have to dispose it...

Be safe

Pete.

 

[joheleh]

I would go with Kurt on this one.

This is not an advice it is how I do IC chips.

I made a setup with an electric motor a reductor and a regular cast iron meat grinder (if you dont have a motor, use hand power it works as well....but I`m lazy so i`ll use motor power)). I use this setup to grind my IC`s after incineration. then use an old coffe grinder, it makes a fine powder, after that sieving and the whole shebang, after that sluce to wash away the carbon. When you have your concentrated washed material you could think about refining with whatever method you wish.

Don`t waste acid and create unnecessary waste, you`ll have issues with it later when you have to dispose it...

Be safe

Pete.

I’m proceeding to clean the material, collect and dispose the “wrong” AP solution, and incinerate.
As told me(and predicted) by Kurt, there is a good amount of copper passivation on the legs.
Cause of my approximation, and lack of study, it ended with a lot of unwanted(copper) base metal.
So I learned…
Now would be appreciated some directives on how to proceed after incineration.
I think about sieving the ic dust after incineration, eliminating the magnetic material with neodymium magnet, washing everything in a dilute nitric solution untill no reaction, and then process the remain via AR…
Let me know

 

[joheleh]

I’m proceeding to clean the material, collect and dispose the “wrong” AP solution, and incinerate.
As told me(and predicted) by Kurt, there is a good amount of copper passivation on the legs.
Cause of my approximation, and lack of study, it ended with a lot of unwanted(copper) base metal.
So I learned…
Now would be appreciated some directives on how to proceed after incineration.
I think about sieving the ic dust after incineration, eliminating the magnetic material with neodymium magnet, washing everything in a dilute nitric solution untill no reaction, and then process the remain via AR…
Let me know

And…I found a separated square ic, I want to condivide with you this video, where you can see the gold bonding wires. This is a clean one, I think it’s pretty representative about what inside, and what we are talking about “bonding wires”

 

[GoIdman]

Now would be appreciated some directives on how to proceed after incineration.
I think about sieving the ic dust after incineration, eliminating the magnetic material with neodymium magnet, washing everything ....
Let me know

After incineration you have to grind it somehow util you„ll get a very fine powder to work with...you know what options you have there but if you have a good blender (glass type with metal blade coupling and not plastic) it will do the trick.

You have to get rid of most of the carbon before even thinking about using nitric or aqua regia...so washing away the carbon can be done with plain water and 1-2 drop of washing liquid..

Read this thread from start to finish...it covers the process pretty well...

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=11827
Be safe

Pete

 

[Martijn]

Some general questions: Are you done incinerating, when there's carbon left?
Do you still need to grind incinerated material to let the bonding wires release from pins and dies? Or will sieving be enough to let these come apart?

 

[kurtak]

Sorry - have not had time to get back to this & it will be this weekend before I have time

Kurt

 

[kurtak]

Now would be appreciated some directives on how to proceed after incineration.

After incineration the next step is milling/grinding/crushing the chips

This is a very important step as it can make a BIG difference on the recovery you get from the chips

It needs to be said that you will not get 100 percent recovery from IC chips - that's because "some" gold will always be stuck to the silicon dies as well as "some" gold stuck to the Kovar &/or copper leads/wires

You need to "break" as much of that gold free from the silicon dies & Kovar &/or copper leads/wires as possible

So the more you mill them the more gold you will break free - do a really good job of milling should break free very close (plus/minus) 95% of the gold - do a poor job of milling & you may only break free (plus/minus) 80% of the gold

Therefore - ball milling is the very best method for breaking the gold free - a mortar & pestle is the least effective method

Some people suggest using a blender - & though a blender will do a better job then a mortar & pestle - not a lot better

Trust me - I have tried them ALL

Before I set up with ball milling I came up with a method that was very close to ball milling - if not as good as ball milling - but it is very labor intensive (so worked good on "small" batched)

I would first smash/crush the (incinerated) chips down in size (dry) with a mortar/pestle - which I would then wet - then I used a rolling pin to "grind" the living hell out of what came out of the mortar/pestle crushing --- pics of mortar/pestle & rolling pin provided

The rolling pin I used was made of a Teflon coated steel tube like this one

https://www.kohls.com/product/prd-3...p.ds&msclkid=4322e6660fe612d2d1f084e70513fa6a
The grinding with the rolling pin was done on top of a 1/4 inch (6.5 mm) thick piece of "tempered" glass about 3 foot by 2 1/2 foot (1 meter by 3/4 meter) on top of my work bench

The reason for doing the grinding on (thick tempered) glass is that when grinding the gold wont smear & stick to the glass - whereas grinding on a sheet of plate steel the gold will smear & stick to the steel plate

This method will break the gold free very close to as good as ball milling (if not as good)

You can mill about 4 - 5 kilos of chips in a day with this method

To clarify the steps of this process --------

1) Dry "crush" the chips in mortar/pestle - as breaking them down some first makes the "grinding" step go quicker/easier

2) get the "crushed material wet

3) put about a cup of the wetted material on the glass

4) Start running the rolling pin over it "grinding" it until the carbon is ground to a very fine powder - takes "about" 8 - 10 minutes per cup - it's going to spread out on the glass so you need to sweep it together several times & go back to grinding - other wise you wont get complete grinding of the carbon because the silicon dies & Kovar/copper wire will prevent the rolling pin from getting to the carbon for complete milling

In other words - sweeping it all back into a pile allows the silicon dies & Kovar/copper wires to provide more complete milling of the carbon - I use a window cleaning squeegee for this as well as for sweeping the material off the glass into a catch pan after grinding is complete

As I said - this method is rather labor intensive - but - outside of ball milling it will give you the best results of breaking the gold free from the silicon dies & Kovar/copper wires - by as much as 10 - 15% better results

Bottom line - the better/more complete the milling - the better the recovery

After milling - the next steps are separation by sifting &/or magnet which gets rid of some of the silicon some of the copper & most (if not all the Kovar) - which is a post for another day

Then after sifting/magnetic separation there is the step of separating (washing away) most of the carbon/ash

Once that is done you will have a concentrate you can leach for the gold

Kurt

 

[kurtak]

opps - forgot to post the pics of my mortar/pestle (for crushing) & the rolling pin I used (for grinding) before I went to ball milling

Kurt

 

[joheleh]

What about the non magnetic metals? It is the case to eliminate with the aid of a nitric bath the copper particles first? And then trough AR solution for gold?

 

[Geo]

I think you confused AP with CuCl2. As Shark said, the copper is necessary as a leachant. That is somewhat beside the point. As the others are trying to tell you that removing the leads from the outside of the body does nothing for the overall process. The leads left inside the body is the same metal. CuCl2 can be used to remove the excess copper left behind after milling and magnetic separation. It will not effect the silver other than create a little AgCl at the end of the process. You can use CuCl2 much like nitric leaching. Place the milled, screened material in a large beaker and add CuCl2 and an extra amount of fresh HCl and heat. Stir until the reaction starts to keep the material from settling and causing a hot spot on the bottom of the beaker possibly causing it to crack. I had a 5000ml beaker pop a perfectly round hole in the bottom about the size of a half dollar one time due to material swirling while stirring and formed a little mound in the center of the beaker. About the time the hotplate hit maximum, I heard a slight "tink" and all the solution drained into my catch pan.

 

[dpgold]

Why in the world are you wasting acid & creating acidic waste to dissolve the legs away on the outside of the chips ?

I ask because it makes NO sense to do this !!!

You are gaining NOTHING doing this other then creating UN-NEEDED chemical waste !!!

Why ?

Because the legs on the "outside" of the chip are only a "small" part of the lead frame that goes inside of the chips

SO - when you go to incinerate the chips - to get to the (gold) bond wires - you are still going to end up with MOST of that lead frame base metal in the carbon/ash after incineration

That means you still have to separate all the lead frame base metal "inside" the chips from the carbon/ash (after incineration) with a magnet &/or sifting

To put it in perspective --- the legs on the outside of the chips is only "about 10 - 15% of the lead frame - the other 85 - 90% of the lead frame is "inside" the chips

It makes absolutely NO sense to waste time - waste chemicals & create chemical waste to eliminate a VERY small part of the base metal --- when you "still" have to remove "the rest" of the lead frame from the carbon/ash after incineration anyway !!!

I don't know where you got this idea but it is a TOTAL waste of time & chems when you still have to remove the vast majority of those very same lead frames form the carbon/ash after incineration anyway

Kurt

it has been circulating on youtube mostly this idea that you get rid of the legs and you end up with less lead, apparently this is WRONG, is good that you clarified this. I am also looking into how I should go about processing a mix of IC CHIPS and this aspect was one which you clarified. If there is any separation of what you call frame it should be after the incineration otherwise you end up doing this twice. Can you give me some advice on how I should proceed after incineration? My biggest worry is the separation of silver, gold and other PM from the mix of IC chips. Any advice will be of great help.

 

[Martijn]

Can you give me some advice on how I should proceed after incineration?

:

https://goldrefiningforum.com/posts/326703/

 

[Shark]

it has been circulating on youtube mostly this idea that you get rid of the legs and you end up with less lead, apparently this is WRONG, is good that you clarified this. I am also looking into how I should go about processing a mix of IC CHIPS and this aspect was one which you clarified. If there is any separation of what you call frame it should be after the incineration otherwise you end up doing this twice. Can you give me some advice on how I should proceed after incineration? My biggest worry is the separation of silver, gold and other PM from the mix of IC chips. Any advice will be of great help.

I think where this comes from is the reuse of old solutions. Where old AP is used to remove the legs, or other base metals, before disposing of it. Struggling to make this sound reasonable here, but think of it as using every last drop of your acid before getting rid of it. I tried it several years ago and it was OK. Where i would drop chips in a fairly clean but little used AP that I would process when I had time or felt like it. Not when I needed them done anytime soon. Then I started getting 10 to 20 pounds of memory every week or two, and chips started piling up faster than I had AP to deal with them. Throw in another 50-100 floppy drives along with 100 plus CD ROM drives and often 20 to 50 pounds of sound and video cards. See where I'm going with this? The difference of whether I used AP or not amounted to nothing I could detect, and started following the don't use AP method. In my mind, AP is for fingers, and other gold plated boards. The left over solution can do a lot, particularly pins, if used right. If not, then there comes another mess often requested for help with.

To shorten the story, it is OK when your not in a rush. Otherwise the lead can be taken out of the refining process fairly easily.

 

[dpgold]

I think where this comes from is the reuse of old solutions. Where old AP is used to remove the legs, or other base metals, before disposing of it. Struggling to make this sound reasonable here, but think of it as using every last drop of your acid before getting rid of it. I tried it several years ago and it was OK. Where i would drop chips in a fairly clean but little used AP that I would process when I had time or felt like it. Not when I needed them done anytime soon. Then I started getting 10 to 20 pounds of memory every week or two, and chips started piling up faster than I had AP to deal with them. Throw in another 50-100 floppy drives along with 100 plus CD ROM drives and often 20 to 50 pounds of sound and video cards. See where I'm going with this? The difference of whether I used AP or not amounted to nothing I could detect, and started following the don't use AP method. In my mind, AP is for fingers, and other gold plated boards. The left over solution can do a lot, particularly pins, if used right. If not, then there comes another mess often requested for help with.

To shorten the story, it is OK when your not in a rush. Otherwise the lead can be taken out of the refining process fairly easily.

that makes sense, used AP is still very strong, even the second wash is impressive you could clean rusty steel apparently with it. Trying to figure out and understand the best method to process mixed IC chips. There will be a mix of values. I liked Geo's washing over and over method after incineration. Then it comes the metals separation and finally values separation.... Simple things could be difficult to understand sometimes. I found a site which explains chips construction and identification:
https://www.chipsetc.com/integrated-circuit-package-types.html

 

[Shark]

It is easy to get overwhelmed with this. Especially when dealing with electronics. If you stay after it, eventually it starts coming together better. Keep asking good questions and I am sure someone will give you a good answer. It just takes more time than YouTube makes out to be.

 

[NobleMetalsRecovery]

I would like to jump in here, and ask Kurt. How do you process IC chips?

I have 1/2 of a 5 gallon bucket of the ic chips from a bunch of ram memory which I recovered the gold from the fingers already.

All of the IC chips are already removed from the ram sticks as a result of how I recoved the gold on the fingers.

 

[dpgold]

It is easy to get overwhelmed with this. Especially when dealing with electronics. If you stay after it, eventually it starts coming together better. Keep asking good questions and I am sure someone will give you a good answer. It just takes more time than YouTube makes out to be.

is it ok to precipitate lead from the solution with sulphuric acid in AR or I should remove it all with AP?

 

[Shark]

For chips, I lean toward doing it in AR. For one reason, I developed the refining process my way because it incorporates lead removal even when I am sure there is no lead. My thinking goes back to when I first started with some very dirty buttons. To clean them up I started using additional steps and stopped assuming there was no lead or in some cases silver involved. I just started using the steps to target their removal and saw huge improvements in my buttons. This combined with the use of better equipment made for very nice buttons and has served me well for the amount of stuff I ran.

 

[dpgold]

For chips, I lean toward doing it in AR. For one reason, I developed the refining process my way because it incorporates lead removal even when I am sure there is no lead. My thinking goes back to when I first started with some very dirty buttons. To clean them up I started using additional steps and stopped assuming there was no lead or in some cases silver involved. I just started using the steps to target their removal and saw huge improvements in my buttons. This combined with the use of better equipment made for very nice buttons and has served me well for the amount of stuff I ran.

Do you mean AR after incineration and cleanup or after AP?

 

[Shark]

AR after incineration and clean up.

Kurt has a nice post on how he does his chips but I haven’t found it yet. I am sure he will when he gets time to see NobelMetals request.