My results of specific types of IC chips, flatpacks and BGA

[Tzoax]

Washing gold powder...



Drying gold powder...



Result...



0.14g of gold out of 14.31g (12 pieces) Intel 324-pin BGA chips.

14.31 / 0.14 = 1000 / x
x = 1000 * 0.14 / 14.31
x = 9.78

Yield: 9.78g/kg

12 / 0.14 = 1 / x
x = 1 * 0.14 / 12
x = 0.0116

1 piece of IC chip: 0.0116g of gold

That is a lower yield than i was hoping....but still it is not that bad.

 

[Dr.xyz]

That yield was expected, it's logical to assume that one solder ball equals one bond wire and southbridge chips have 1.5x less balls. Also die size is smaller, so bond wires should be slightly shorter.

 

[Tzoax]

That yield was expected, it's logical to assume that one solder ball equals one bond wire and southbridge chips have 1.5x less balls. Also die size is smaller, so bond wires should be slightly shorter.

Sure...i was hoping that gold bonding wires would be more thicker - it is also an important factor - and a little harder to assume.

Some interesting ratios...

 

[Dr.xyz]

Also would be logical to expect thinner wires, not thicker. They carry same signals, and shorter wires can be made thinner and still have the same resistance as longer thicker wire.

 

[Tzoax]

Also would be logical to expect thinner wires, not thicker. They carry same signals, and shorter wires can be made thinner and still have the same resistance as longer thicker wire.

This is bottom view of NVidia GeForce4 BGA chip that i tested earlier.



It have about 702 solder balls (if i counted it right - i couldn't find anywhere data about it on internet)

Results of test: 0.0108g of gold per chip.

That is 0.0108 / 702 = 1.538e-5g of gold per one gold bonding wire.

So...comparing with 3.600e-5g and 5.477e-5g of gold used per one gold bonding wire result is surprisingly low - 1.538e-5g.

Could your assumptions/logic may be implemented even for this type of BGA? That would help a lot. Thanks in advance.
https://goldrefiningforum.com/phpBB3/viewtopic.php?f=33&t=22951&start=330#p289895

 

[Tzoax]

I always wondered how much of gold are in ceramic resonators.

I have never processed them separately. They are very lightweight and hard to collect some decent amount for testing gold content.

I have about 12g of them. Do you think making a test with such small sample is a good idea?

 

[niks neims]

I have about 12g of them. Do you think making a test with such small sample is a good idea?

YES! Love your thread, man!

 

[Tzoax]

I have about 12g of them. Do you think making a test with such small sample is a good idea?

YES! Love your thread, man!

I just found some more of it - now i have 26.1g of them... Ok - i will test them.

I will process them straight to AR (just like ceramic CPU's).

 

[mls26cwru]

I would advise against an initial AR leach... you have a decent amount of tin and the caps are steal... and on the inside there is a good amount of silver.

I would suggest HCl leach followed by a Nitric leach (with a good rinse in between obviously). Then AR when all the silver is gone... And the gold yield is decent per pound... around the 0.75g/lb if I recall correctly. I would have to dig through my numbers though.

M

 

[archeonist]

I have about 12g of them. Do you think making a test with such small sample is a good idea?

YES! Love your thread, man!

Yes! Very good idea!! I am collecting those for a while now, I suspect a good amount of gold in them.

 

[Tzoax]

I would advise against an initial AR leach... you have a decent amount of tin and the caps are steal... and on the inside there is a good amount of silver.

I would suggest HCl leach followed by a Nitric leach (with a good rinse in between obviously). Then AR when all the silver is gone... And the gold yield is decent per pound... around the 0.75g/lb if I recall correctly. I would have to dig through my numbers though.

M

Mike, thank you for advice and for sharing your results. I always processed them together with other similar components (hybrid ceramic IC's etc) straight in AR and never had a problem with tin (metastannic in AR/ filtering) or silver.

I thought that the source of silver in ceramic resonators is in thin foil (quartz resonator)- and i thought that it is very very small amount of silver that could not cause any problem relating with silver (partially dissolved in AR or AgCl) in AR.

On this picture parts of gold bonding wires could be seen behind quartz resonator.


There are many of different packages of ceramic crystal resonators. Here are some types...



So, i opened few pieces to peek inside and see some gold bonding wires...





Plus - i think that good amount of gold would come from gold braze used to seal the steel cap.
Also, i saw some tiny MLCC's in some of the packages...so i am still considering Mike's advice...

For sure - i will make HCl leach as Mike said - prior anything - it will take out the most of tin out.

But...i am still thinking about next step - straight to AR or like Mike advices - washing/nitric/filtering/AR...

This is why is hard for me to decide which way to choose:
In case of using HCl leach followed by a Nitric leach - i think that good rinsing would not be enough to rinse all HCl and some of gold could went to solution after adding nitric - so maybe incineration is a better option (after water rinsing).
After nitric leach - small gold particles/powder from braze and gold plating would be free and after filtering that solution i will have a filter paper with small gold particles/powder that should be incinerated again / or the whole filter paper could be added to AR solution later.
In other words - i am afraid that using this method - i could lose gold somewhere between those steps...maybe when incinerating - some of fine gold powder could be blown to the air or something like that....

Anyway - i am still thinking. And i will process it like most of experienced members would advice. Mike, thank you - your advice is taken. Does anyone else thinks it is a better way than going straight to AR based on your experience with ceramic resonators?

Alex

 

[cosmetal]

"Does anyone else thinks it is a better way than going straight to AR based on your experience with ceramic resonators?"

I certainly am no expert at ceramic resonators as I only "discovered" their gold content in June 2018: https://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=26993

That being said, I am still a firm believer that in any type of design or methodology, that "less is more". No doubt that you will experience sample loss if you follow HCl leach > wash or incinerate > HNO3 leach > AR finish. But would that loss be greater than any loss that could be experienced with a straight to AR process with the potential of Ag/Sn struggles? Who knows? And being so small and few, it would be very hard to do two separate process experiments.

I vote for straight to AR. But, I would "crack" the little buggers first with a small ball peen hammer for faster AR processing.

Peace,
James

 

[Tzoax]

"Does anyone else thinks it is a better way than going straight to AR based on your experience with ceramic resonators?"

I certainly am no expert at ceramic resonators as I only "discovered" their gold content in June 2018: https://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=26993

That being said, I am still a firm believer that in any type of design or methodology, that "less is more". No doubt that you will experience sample loss if you follow HCl leach > wash or incinerate > HNO3 leach > AR finish. But would that loss be greater than any loss that could be experienced with a straight to AR process with the potential of Ag/Sn struggles? Who knows? And being so small and few, it would be very hard to do two separate process experiments.

I vote for straight to AR. But, I would "crack" the little buggers first with a small ball peen hammer for faster AR processing.

Peace,
James

Great images James... wish i have USB microscope - if Santa doesn't bring me one - it will be the first thing in the next year for me - to buy one. So far- i was using cellphone camera plus magnifying glasses.



In my experience i never had problem when processing them altogether with some other ceramics straight to AR.

And steel caps were dissolving pretty fast in AR as i remember - even without crushing ceramics.

Tin will not be a problem - first thing i do will be a simmer boil with HCl until the tin dissolves and i will decant solution.

Thank you for advices James.
I am planning to process ceramic resonators in about 24 hours from now - so until then - there is some time to think more about it - so any comment is welcome - anyway - one way or another - the cat will be skinned tomorrow... and i am looking forward to see results!

 

[mls26cwru]

I guess with a small sample size, you would be okay with straight AR... i did a bit more than a pound and a half. Tin was definitely an issue, and there was enough silver to be a neucance in my test run... enough to cover material. Since it's a small amount, i think you would be okay.

 

[zoltan]

If somebody want to refine ram chips, here is my finding. The chip with small epoxy area from the bottom its mostly flip chip technology. And the ram chips with larger epoxy area have gold bond wiring. If i am wrong, please forgive me. I just want to save yours hand. Sorry for my English.

 

[kurtak]

If somebody want to refine ram chips, here is my finding. The chip with small epoxy area from the bottom its mostly flip chip technology. And the ram chips with larger epoxy area have gold bond wiring. If i am wrong, please forgive me. I just want to save yours hand. Sorry for my English.

:lol: :lol: :lol: Sorry but a just have to laugh because I read this post right after posting this

:arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=34&p=291651#p291651

Kurt

 

[Tzoax]

Just a quick update with images....i will write details when i finish everything...still working on it...
Great idea Kurt! But those are VERY rare RAM sticks...i would need some time to collect them for test.

Start material...

After hot HCl...the most of tin is gone...

AR stage - reaction sterted....

 

[Tzoax]

This is residue...

 

[Tzoax]

Braze foils floating - they look nice.



After all of metals dissolved i neutralized solution and decanted it to another beaker so solution cools down and all silver chloride is settled down.

*Because silver is dissolved in AR solution - adding water will make AgCl immediately. So because i used some water to rinse beaker - i will wait for AgCl to completely settle down - then i will continue.

 

[zoltan]

To Kurtak, these (no gold wires) are from tv board and have epoxy top.