Got it bro.. thanx for your precious time. Now I am processing sata and ide pins.
BGA chips Bottom part and Pin Less Proccesors Processing
- Thread starter avigp193
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There are "NO" Silver in AR.Leave i understand it's very small yeild but silver content was high in that and I messed up with that too. Leave this thread.
That might be a part of the "scum" you filtered out, though unlikely since modern electronic has little Silver in those parts.
Please stop this until you understand what is happening, now you are going to go from one issue to another.
If you just jump from batch to batch without understanding your current issues,
you will just end up here asking questions to the same issues again.
Answer my questions please.
How did you use Sulfamic acid?
How did you mix/use your AR?
I just added
About 20 m sulfamic acid
Taking your initial reaction where you used Nitric and added HCl.
How much AR did you use then?
1 mole excess Nitric or Nitrous acid needs 1 mole Sulfamic the decompose.
this means 63 grams of Nitric needs 97 grams of Sulfamic to fully decompose.
And it needs to be hot.
That would be for the powders.
So at that 20 ml might do depending on concentration.
What temperature was the solution and what happened when you added the Sulfamic?
patnor1011
Well-known member
Nope.
It has abundance of copper wire it may seem like gold but it is not. Gold bonding wire is so thin you will have hard time to see it with naked eye. Also it is super short rarely over 1-2mm and located close to silicone die in a center of a chip. There are no gold bonding wires in green fiber part of BGA IC.
There is silver in large enough quantity to be dissolved by the aqua regia. Warm, or even room temp aqua regia will hold a significant amount of silver. This is why we chill and filter AR prior to dropping gold. It's in the 1-2g/liter range.
The amount of gold is miniscule. The base only has plating. The bond wires you saw that you thought were gold were likely actually copper traces that were pulled off from the fiber backing.
The only gold in the BGA bottoms is the plating on the surface of the top, as well as the plating on the pads. The plating on the pads is usually dissolved into the solder. This will be recoverable in a really large quantity (10+ lbs), but in small amounts, not really.
The amount of gold is miniscule. The base only has plating. The bond wires you saw that you thought were gold were likely actually copper traces that were pulled off from the fiber backing.
The only gold in the BGA bottoms is the plating on the surface of the top, as well as the plating on the pads. The plating on the pads is usually dissolved into the solder. This will be recoverable in a really large quantity (10+ lbs), but in small amounts, not really.
I think he's maybe referring to the gold plated traces that partially stay on the fiber board after you remove the epoxy tops...?
The Metastannic acid was probably from any solder balls that may have still been attached to the BGA's. Metastannic acid takes forever to filter out. To avoid Metastannic acid you can soak your BGA's in hydrochloric acid until the solder balls are gone, then you can go to incineration of the chips......removing the solder balls this way also creates stannous chloride, it's not high quality...but it still works. The black powder material that will be left over from the solder balls could be Silver and/or Antimony...(maybe a very very tiny amount of gold).
The majority of the gold in the bases is actually in the solder balls. Recovering it is the difficult part. If you have more time than anything, scraping the tin balls is the best way. Soaking in HCl will seem to work, but you'll coat everything in chlorides. They are extremely difficult to get rid of. The gold that will be released will also be soaked in chlorides, and burning it will send it up the stack with the smoke.
Thanxz for your precious time guys!
As per your opinions I guess there were no bonding wires with the base and yeild was so low that's y I am neglecting this and storing that in my storage as waste acid.
patnor1011
Well-known member
Yes, I once had a piece of tin scanned with niton and as far as I remember it had 2.2g of gold in a kilogram. This was just solder balls from BGA melted together. That scan result is somewhere on this forum I tried to look for it but no luck
Curious if that mix could have been used directly in a cupel allowing for size and volume of course.Yes, I once had a piece of tin scanned with niton and as far as I remember it had 2.2g of gold in a kilogram. This was just solder balls from BGA melted together. That scan result is somewhere on this forum I tried to look for it but no luck
My thoughts exactly. I am collecting solder balls, and used solder for some time, from various BGA`s to check if by cupelling, some gold, silver can be recovered and in what quantity. I did not cupel anything from that material, just collecting it.
patnor1011
Well-known member
Dunno but I should have about 3 kilo of that tin somewhere in my hoard
