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

[Tzoax]

Washing gold powder...



Drying gold powder...



Gold powder



Gold powder under microscope



Result:



Out of 196.1g of silicon dies i refined 0.16g of gold - that is 0.81g of gold / kg of silicon dies.

The result is slightly better then my previous test when i processed silicon dies directly to AR - 0.71g/kg.

One way or another - there is gold and yield is not that bad for silicon dies. Only difficulties are that silicon dies have large volume - so more acid will be needed and there is a lot of silver so knowing how to deal with silver / silver chloride is beneficial.

 

[niks neims]

That is some great info! Thank you, Tzoax!

Any idea about the Ag yield? about the same weight as Au (so - negligible value) or more?

 

[Tzoax]

That is some great info! Thank you, Tzoax!

Any idea about the Ag yield? about the same weight as Au (so - negligible value) or more?

I would say there is much more silver than gold in silicon dies (based on silver / silver chloride i could see) but i never tested the weight of silver due to much of work for such a small income. Next time i process silicon dies i will collect more of them and i will include silver yields as well, thanks for idea.

 

[Tzoax]

Finally i got some of medical equipment. In this test i will compare my previous results from PC's and compare it with medical equipment results - and see the difference in yields - are IC chips from medical equipment contains more of gold than from PC's?

I dismantled ultrasound boards from medical ultrasound - (Siemens Acuson Sequoia 512) and i classified the IC chips. I prepared this type of IC's model for test: Acuson 55471.









As i already tested this same package from PC's boards here: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=33&t=22951#p240808 ...i will compare a new results with it:

Total weight of chips - 576.5g
Number of chips - 109pcs
Avg weight by 1 chip - 5.288990826g
Gold recovered - 0.7g
Gold content per 1kg - 1.214224g
Gold content per 1 chip - 0.006422018g

 

[bvdsluis]

Hi Tzoax,
Your thread is amazing, a lot of information and inspiration. Almost every day I check the board and your thread. At this time I only collect base material like chips, fingers and pins. I live in Holland and everything is overregulated including e-waste and chemicals.

So the collecting of “raw material” is slow. I’m collecting for 3 years now but don’t have kilos of chips, fingers and pins. So it will take some time before I will start to recover and refine. In the meantime I study, study, study and make notes. I have for every material and process a document that I update with information I pick-up from this board. There are a lot of great posters with deep knowledge and you are one of them.

Thanks to people like you I keep motivated to continue collecting “raw material”.
In the meantime I make some small money with the leftovers like aluminum, steel, low grade boards (boards after cherry picking), copper and copper wires.

Thanks for sharing your recover and refine adventure with the board.

Bob

 

[Tzoax]

Hi Tzoax,
Your thread is amazing, a lot of information and inspiration. Almost every day I check the board and your thread. At this time I only collect base material like chips, fingers and pins. I live in Holland and everything is overregulated including e-waste and chemicals.

So the collecting of “raw material” is slow. I’m collecting for 3 years now but don’t have kilos of chips, fingers and pins. So it will take some time before I will start to recover and refine. In the meantime I study, study, study and make notes. I have for every material and process a document that I update with information I pick-up from this board. There are a lot of great posters with deep knowledge and you are one of them.

Thanks to people like you I keep motivated to continue collecting “raw material”.
In the meantime I make some small money with the leftovers like aluminum, steel, low grade boards (boards after cherry picking), copper and copper wires.

Thanks for sharing your recover and refine adventure with the board.

Bob

Bob, thank you very much - i am really glad to see that my "experimenting" with IC chips helps other people like you for better understanding of this huge topic.

People are generally greedy when it comes to gold refining - at least almost all people that i know personally. They are hiding their "secret recipes" for gold refining and their results. When i started to be interested in gold recovery it was impossible for me to find out any information about it...until i found this forum.

Gold recovery (for hobby) attracts many people...but it really requires certain personal attributes to be successful in it and to understand it which is also very important. It requires curiosity, intelligence, patience, skill, persistence, and of course a lot of time of studding. And not many people have it - so they give up eventually.

So whenever i learned something new thanks to other people here - it really gave me enlightenment feeling. My point is - sharing knowledge is priceless - especially in this huge field of gold recovery - it is a only way for deeper knowledge - which is a key thing here in my opinion.

I am sure there are other ways you can find some e-scrap...even if it is overregulated. If you have newer motherboards you can always make some replacement for older ones with PC services or individuals that are repairing them. That way you can change one newer motherboard for 2 or 3 older ones. Have you tried with ads?
I am repairing computers, so when i finish a job i always give opportunity to customer that he can pay me in some old e-scrap instead of money - and most people always have something that they not need.
Anyway, it is very small amount of material for 3 years of collecting - you should find some way to collect it faster. Do you have some pictures of material you collected so far?

Alex

 

[Tzoax]

While i was incinerating IC chips from ultrasound machine mentioned above i noticed very interesting thing - a whole lower surface of those IC's is gold plated. First i thought it was heat spreader but it seems it is just some thin gold coating. Does anyone know what is purpose of this layer?
I am not really sure it is really gold but for sure looks like it.







If it is gold - is there a way to recover it? Is it possible to separate it from the ash? While water rinsing - are those gold foils heavier than ash? Is it ENIG gold plating? Here is some questions so if anyone have some thoughts or experience with this problem (IC chips ashes with gold foils in it) please share it if you will.

This is picture of gold bonding wires, i managed to measure a length - it is about one mm. This package is QFP160 and it have 160 gold bonding wires per chip - or about 1.6cm of total length of gold bonding wires per chip. So i had 64 IC's - that is about 102cm of total lenght of gold bonding wires i am dealing in this batch - just for interesting fact.

 

[anachronism]

What do these chips look like before incineration?

 

[Tzoax]

What do these chips look like before incineration?

They are totally black - epoxy on both side. The plating is on bottom of IC chips - just beneath a very thin layer of epoxy - even after incinerating it is visible (without crushing).

 

[Tzoax]

I just saw - this gold? plating is on top side of IC chips - not on down side. So it is most likely related with markings on top surface of chips.

Anyway - this is how they look after first sieving, i will repeat incineration/sieving until all epoxy ash goes through the sieve. They are all non-magnetic.

 

[bvdsluis]

I am sure there are other ways you can find some e-scrap...even if it is overregulated. If you have newer motherboards you can always make some replacement for older ones with PC services or individuals that are repairing them. That way you can change one newer motherboard for 2 or 3 older ones. Have you tried with ads?
I am repairing computers, so when i finish a job i always give opportunity to customer that he can pay me in some old e-scrap instead of money - and most people always have something that they not need.
Anyway, it is very small amount of material for 3 years of collecting - you should find some way to collect it faster. Do you have some pictures of material you collected so far?

Alex

Hi Alex,

Thanks for your nice words and ideas. Guess what, I put an advert and just like that I got a response the same day. I got an offer to buy 160 VIA EPIA ML 8000 c3 800mhz boards (68 kilo) together with the power supply (224 kilo) for 50 euro. I have attached the motherboard image.

I see at least 2 gold tip chips (VIA CLE266 North Bridge and VIA VT8235 South Bridge) and an VIA C3™ EBGA processor 800 MHz Processor according to the specification I have found on the internet.
The North- and South Bridge are good candidates for a good yield, I’m not sure about the VIA C3 Processor. What do you think, is this a good buy? I believe the power supply (224 kilo) only will fetch 30 euro plus at the scrap yard.



Bob

 

[Tzoax]

I have just the same motherboard - the BGA processor with heatsink on top have gold bonding wires also, but i never tested how much. Most often there are several layers ob some kind of foils beneath the metal cap, i just take off epoxy (with gold bonding wires inside) and process it with other BGA's. And sometimes - with similar types of chips gold is in one of those foils i mentioned, and it is more often orange colored half transparent, and you can see gold bonding wires with naked eyes - i process these directly in AR with foils,

Those boards are small (Mini ATX format) but they are good - you have 3 BGA's and about 10 more reular IC's per board, I am paying them about 1.3 euros per piece. I usually take off BGA's and sell them for 0.8 euros,

So, roughly estimating - there is about 4g of black tops per board, so 160 motherboards will have about 640g of black tops - that is minimum 6.4g of gold - or 240 euros just from BGA;s. On your place i would take just BGA's and sell 160 boards without them for about 120 euros.

So yes, i think it is a perfect deal - buy them before someone else does.

You can test power supplies, i doubt they are all malfunctioned - and sell them for 5-10 euros per piece. You can test them with power supply tester - and with it you can check all voltages from power supply very fast,
I have one like this - it is cheap and does the job.



Alex

 

[Tzoax]

This is remaining material after third incineration/crushing/sieving. I removed the most of silicon dies and heat spreaders. Silicon dies are on the top left side of image, and heat spreaders on down left side. In a mix of remaining material i see a little more of unburned epoxy so i will repeat process once again.



Silicon die.



Heat spreaders are very light and look interesting under microscope.

 

[bvdsluis]

Those boards are small (Mini ATX format) but they are good - you have 3 BGA's and about 10 more reular IC's per board, I am paying them about 1.3 euros per piece. I usually take off BGA's and sell them for 0.8 euros,

So, roughly estimating - there is about 4g of black tops per board, so 160 motherboards will have about 640g of black tops - that is minimum 6.4g of gold - or 240 euros just from BGA;s. On your place i would take just BGA's and sell 160 boards without them for about 120 euros.

So yes, i think it is a perfect deal - buy them before someone else does.

Alex

Hi Alex,

Thanks a lot for your analyze and calculations I learn a lot from you.
I bought the 160 boards for 40 euros. The power supplies were gone. At your place you get a nice price for the boards without the BGS’s.

At my place I have 3 options:
If I sell the boards as is (including aluminum and battery) I receive 1 euro per kilo (68 kilo = 68 euro total).
If I remove the aluminum and battery I receive 2,80 euro per kilo (net 48 kilo = 134 euro total).
If I remove the BGA’s the boards will be low grade, 025 euro per kilo (net 48 kilo = 12 euro total)

So the best option is take the BGA’s and other chips and sell the boards as low grade. The gold in the BGA’s will bring the profit when I’m ready to process.

Thanks,

Bob

 

[Tzoax]

After another incineration, crushing and sieving - the residue was copper based legs. I decided to process them also. I never did that before when i made my tests - because i considered that there are very few of gold bonding wires left in there.



So i added about 100ml of fresh 16% HCl over copper legs and the solution was colored green immediately - Copper II chloride solution was formed. And it happened so fast because after incinerating IC's - all copper legs was oxidized - making copper oxide - which on contact with HCl produces copper II chloride right away.

I repeated decanting and adding fresh HCl two more times - when it seems the solution was saturated (settling down of copper I chloride white powder on the bottom of the beaker).



It was very fast reaction - i was very surprised how fast i was watching the copper is going into solution.



On my big surprise the whole process was over in a few hours. There was just a little more of copper wires undissolved - but very little of it. So final concentrate (just from legs) look like this:



So i took magnifying glasses and saw much more of gold bonding wires than i thought there will be. Those wires went 7-8 times of sieving before this...and still - there are considerable amount of them still with legs "residue".



So the bad news is that all my tests so far was wrong - there is considerable amount of more gold in all types of IC's i tested so far, so count on that. And the good news are that i learned a very important things and my results will be more accurate in the future because i will include kovar/copper legs into gold yields.

Now i will make concentrate out of ash and when i am done i will merge the concentrate from ash with concentrate from legs and get my first accurate result.

 

[cosmetal]

Tzoax wrote:
"And the good news are that i learned a very important things and my results will be more accurate in the future because i will include kovar/copper legs into gold yields."

Two questions, please:

1.) By "legs", I assume you are talking about that portion of the leadframe still encased within the unincinerated epoxy package as it appears you remove the exposed portions of the legs before incineration. Is this correct?
2.) If correct, what do you use (or how do you) remove the exposed portion of the legs prior to incineration? Grinding wheel, sander, nippers, etc.?

Thanks,
James

 

[Tzoax]

Tzoax wrote:
"And the good news are that i learned a very important things and my results will be more accurate in the future because i will include kovar/copper legs into gold yields."

Two questions, please:

1.) By "legs", I assume you are talking about that portion of the leadframe still encased within the unincinerated epoxy package as it appears you remove the exposed portions of the legs before incineration. Is this correct?
2.) If correct, what do you use (or how do you) remove the exposed portion of the legs prior to incineration? Grinding wheel, sander, nippers, etc.?

Thanks,
James

James, yes - i always remove the "legs" that are on outer side of (unincinerated) ic chps (one exception is the smallest types of IC's).

That helps me because that way i have less metals involved and no solder for further treatment, They are also taking less volume without legs and easier ti incinerate.

If IC chips have such a tiny legs like this QFP160 package (which i am processing now) - then i use scalpel - this one (still have couple more unused blades inside for replacement):



If legs are thick - then i bend them 2-3 times in two directions with hands - until they break off.

I am aware that i don't have to do this, and that there are other ways to remove legs like using CuCl2 - but old habits lasts long. I even used to wash them with water - just to be cleaner - i stopped doing that - so i am in a progress. :lol:

 

[Tzoax]

I am making concentrate out of ashes. After water rinsing i washed concentrate with HCl two times - and removed much of copper (source of copper - copper legs that went through the sieve).

This is bottom view of a beaker with concentrate:

 

[anachronism]

Excuse me for asking this but why dont you dissolve all the legs in HCL before you even begin the process?

 

[patnor1011]

Not possible to remove all. He cut out an exposed part like I used to do too. What remains is inside epoxy about 6-8 times longer than the exposed part and cant be easily removed before incineration.