# Ram only gold plated on unpopulated side ?



## kernels (May 24, 2016)

Hello from rainy New Zealand guys . . . Was hoping for a bit more advice . . .

I've been taking a second look at the ram modules left over from my gold-plated-fingers harvest. This particular module is only populated on one side of the board and the un-populated side has the pads gold plated. Like this pic showing both sides of the same module:




So, after turning to Hoke for some advice, I decided to boil a piece of the board in some Hydrochloric acid to remove the left-over solder. All good so far. 

I left the board boiling for a bit, keeping an eye on the gold plated side to make sure there was no effect from the boiling acid. After a while I removed the board and wiped the black residue from the pads. The result is that I have ended up with one side that is still gold plated and looking good and the other side appears to be just copper ? This is surprising since I would have expected the entire board to be gold plated before any components were fitted. 

Any advice ? Am I doing something wrong or is it just that only the 'left over' pads were somehow plated ? 

Pics of the two sides post acid are below:


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## kernels (May 24, 2016)




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## kernels (May 24, 2016)




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## nickvc (May 25, 2016)

It's possible the black residue you wiped off was the gold.


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## kernels (May 25, 2016)

nickvc said:


> It's possible the black residue you wiped off was the gold.



This is an excellent question, not sure why the gold would dissolve with the solder though, but seems like a logical train of thought.

Can anyone tell me whether boiling hydrochloric acid has any reaction with gold ?


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## nickvc (May 25, 2016)

In chemistry we are taught gold is inert in HCl, this is true until you add an oxidiser and if you leave it open to absorb oxygen, AP, it will start to dissolve base metals and a little gold until it has enough base metals to cement the gold back out, possibly the black powder you wiped off. 
Incinerate the wipe and dissolve in AR or whatever method you prefer and test with stannous and you will get your answer as to whether that was gold or not.


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## patnor1011 (May 25, 2016)

What Nick said. 
That gold plating is flash plating and solder simply kind of dissolve it and mix with it so gold end up mixed up in blob of solder. Then you boil it in acid and you will get it as tiny amount of dark/black powder. So you perhaps did not dissolved gold but there is so little it goes off as powder and that powder is so dirty it appears dark/black. Not really worth chasing after, acids and energy used will cost you more than you will be able to recover.


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## kernels (May 25, 2016)

patnor1011 said:


> What Nick said.
> That gold plating is flash plating and solder simply kind of dissolve it and mix with it so gold end up mixed up in blob of solder. Then you boil it in acid and you will get it as tiny amount of dark/black powder. So you perhaps did not dissolved gold but there is so little it goes off as powder and that powder is so dirty it appears dark/black. Not really worth chasing after, acids and energy used will cost you more than you will be able to recover.



Thank you Patnor, sounds like you are on the money here. My real objective was to remove the solder so that I could process the boards with my regular AP solution without the possible added complexity of lead / tin in the mix. Is there a better way to prepare these boards for processing ?


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## nickvc (May 25, 2016)

Throw the wipe in with your old filters, it's your gold at the end of the day.


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## patnor1011 (May 25, 2016)

Some people here remove green mask and try to recover tiny bit of plating sometimes present on some areas under green mask. I am not believer. While there is indeed gold present on some boards it is so little it would not warrant to bear cost associated with doing so. Perhaps I may be inclined if it would be some ancient board or military one but certainly not RAM stick. I am also not on friendly terms with hot lye bath and I try to avoid potential dangerous situation as much as I can. I believe that there is a beauty in simple things. 

Put them in AP as they are or use cyanide based leach. There is one available and while I do not have personal experience with it yet I am in contact with person who does use it and do have interesting results. I plan to test it on various samples even RAM like you do have but even that I am ready to go with all reagents, chemicals and samples ready I do have to wait due to my recent health complications. Stay tuned I will post as much results as I can in the next 3-4 weeks.


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## Anonymous (May 25, 2016)

I think people need to be very careful bandying figures like 1g per Kg around in all fairness because then it becomes expected. The range is frankly enormous.


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## nickvc (May 25, 2016)

Jon I'm with you on that point, some may only get 1/2 a gram others 1/3 of a gram, in some cases it pays to sell as is and let others worry about the yield, very few home refiners will ever get all the values because of the many processes needed to recover them and the loses incurred can outway what you would get paid for them as is, the same as cats why refine them when you can sell them for more than you can recover.


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## kernels (May 25, 2016)

Hi guys, maybe there has been some miscommunication, I'm not trying to remove the solder mask, have never found there to be anything other than copper under the solder mask of cheap-ish boards. I'm only trying to get rid of solder so that the boards can just be processed with the rest of the fingers in AP without the complications of lead and tin. 

I can't seem to find a tutorial or thread that covers what to do with boards once you have removed the components to strip the lead and tin selectively. Was hoping the boiling in HCl would do it, but that appears to have some other pitfalls ! Do you guys just AP the boards with solder still on ?


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## patnor1011 (May 25, 2016)

Yes.


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## Barren Realms 007 (May 25, 2016)

kernels said:


> Hi guys, maybe there has been some miscommunication, I'm not trying to remove the solder mask, have never found there to be anything other than copper under the solder mask of cheap-ish boards. I'm only trying to get rid of solder so that the boards can just be processed with the rest of the fingers in AP without the complications of lead and tin.
> 
> I can't seem to find a tutorial or thread that covers what to do with boards once you have removed the components to strip the lead and tin selectively. Was hoping the boiling in HCl would do it, but that appears to have some other pitfalls ! Do you guys just AP the boards with solder still on ?



You might not have run into it but you need to be aware that under the solder mask of some older gold fingered smaller RAM sticks there is gold plating.


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## kernels (May 25, 2016)

patnor1011 said:


> Yes.



Billiant  Thanks, that is what I was hoping. Will still run them separate from 'clean' items like fingers, but that will definitely make my life easier.


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## kernels (May 25, 2016)

Barren Realms 007 said:


> kernels said:
> 
> 
> > Hi guys, maybe there has been some miscommunication, I'm not trying to remove the solder mask, have never found there to be anything other than copper under the solder mask of cheap-ish boards. I'm only trying to get rid of solder so that the boards can just be processed with the rest of the fingers in AP without the complications of lead and tin.
> ...



Thanks, will definitely check them out.


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## g_axelsson (May 25, 2016)

What Patnor said!

Molten solder dissolves gold quite easily. The thin gold flash is only there as a protection against oxidation so the cards will be easy to solder. When the solder is dissolved (via HCl or in copper chloride) the gold will form a fine mud (probably black) that settles on the bottom after some time.

And a bit off topic, some boards that actually are worth going after the plating under the solder mask is boards from HP equipment from the 1970-1985 era. They made some beautiful boards with fully gold plated wires and solder mask only on one side. If you have seen one you will know what I'm talking about. They don't make them like that any longer.

Göran


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## kernels (May 25, 2016)

g_axelsson said:


> What Patnor said!
> 
> Molten solder dissolves gold quite easily. The thin gold flash is only there as a protection against oxidation so the cards will be easy to solder. When the solder is dissolved (via HCl or in copper chloride) the gold will form a fine mud (probably black) that settles on the bottom after some time.
> 
> ...



Great, thank you for the advie  When you just get started with this game the amount of things that are not as you would expect is huge!


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## modtheworld44 (May 26, 2016)

spaceships said:


> I think people need to be very careful bandying figures like 1g per Kg around in all fairness because then it becomes expected. The range is frankly enormous.



spaceships

I agree that bandying figures around is not a good practice,it gives false hope to newbies and other members alike that have not done a big enough batch to get a true result.I run a 21 pound batch of the fully depopulated ram sticks about 3 years ago and only got 0.2grams from it.This was about a year after I had started my own yield data base.



modtheworld44


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## kernels (May 26, 2016)

modtheworld44 said:


> spaceships said:
> 
> 
> > I think people need to be very careful bandying figures like 1g per Kg around in all fairness because then it becomes expected. The range is frankly enormous.
> ...



Wow, that is terrible ! Do you by any chance have some guidance in your database about the yield from the memory chips from RAM sticks ?


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## Anonymous (May 26, 2016)

Giving yield information out when it's hard earned commercially isn't something that many people will do. To learn that yield information costs many thousands of dollars. It's one thing to share stuff like I and others do when you're refining particular types of processors or maybe fingers but much of the other yield information cannot be treated that way as it compromises a companies trading.

I certainly would never disclose certain information as it would ruin a commercial advantage and I hope that people would understand that. Especially as that commercial advantage involves feeding my family. 8) 8) 

Excuse my candour however I am sure you would expect nothing less from me. 

Jon


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## patnor1011 (May 27, 2016)

Search forum. Read as much as you can. Many people posted their results. One point you need to remember is that mixed lots with many different types of IC will have different results. Difference is very large as there is simply way too many of different types. If you do have large lots try to separate them in different categories. I do use at least 3 with IC from RAM sticks. RAM with thin IC with legs on 2 sides, RAM with thick IC with legs on 2 sides and RAM IC with no legs - BGA type. Even separated as that they do tend to have various results every time I do them as there is simply zillion of types of IC. 
If you search forum you will find threads like this, which may answer some of your question. 
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=33&t=22951


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## kernels (May 27, 2016)

Thanks Patnor and Spaceships, I can understand your reluctance to share information that was paid for with lots of money and time. I guess I'm going to have to learn the hard way !


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## g_axelsson (Jun 4, 2016)

g_axelsson said:


> And a bit off topic, some boards that actually are worth going after the plating under the solder mask is boards from HP equipment from the 1970-1985 era. They made some beautiful boards with fully gold plated wires and solder mask only on one side. If you have seen one you will know what I'm talking about. They don't make them like that any longer.


This is what I'm talking about...


Göran


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## kernels (Jun 4, 2016)

Hi Göran, very cool! The plating looks like quite a dark color on that photo. Is it just the lighting / camera, or is it a different karat of gold or just thicker plating ? I picked up a couple of more modern boards from a scrap guy recently. I believe they are out of a mobile phone tower, also fully gold plated top and bottom, will upload a pic tomorrow. Haven't decided how I will deal with them yet, so just have them sitting in my pile at the moment.


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## g_axelsson (Jun 4, 2016)

On these cards the plating is thick and with a mirror finish. Really hard to take a picture that shows the gold.

Modern cards could have a lot of golden surfaces but are usually made with gold flash. When dissolving the copper on a gold flash card the gold breaks down in small flakes. When dissolving the copper on the HP cards the gold comes off in large sections.

Göran


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## kernels (Jun 9, 2016)

Hi Göran, a bit late, but here are some pictures of the boards I got:







The color is not great in the photo, but they look pretty great to the naked eye. I should have put something for scale, but the larger board is about the size of a A4 paper


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## patnor1011 (Jun 9, 2016)

Take a pencil with rubber at the end. Have a go on them and you will see that you will be able to "erase" this plating with ease. That is what flash plating look like. If you will not be able to erase plating it may be slightly better. Plating like this may break to powder when in AP, hardly foils like we see coming off fingers. This kind of plating is for shielding purposes where plating on fingers need to be thicker as they are designed for repeated insertion in slots.


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## kernels (Jun 9, 2016)

Hi Patnor, will give that a try. To the inexperienced those boards look fantastic, but I guess they may end up not being all that good!


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## razvanflorin (Jul 2, 2016)

kernels said:


> Hi Patnor, will give that a try. To the inexperienced those boards look fantastic, but I guess they may end up not being all that good!


Did you have tryed something ? any idea of the yield ? 
I Have got about 300 kg of those boards :mrgreen:


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## kernels (Jul 3, 2016)

razvanflorin said:


> kernels said:
> 
> 
> > Hi Patnor, will give that a try. To the inexperienced those boards look fantastic, but I guess they may end up not being all that good!
> ...



Hi there, yes, ran those boards recently and results were extremely disappointing. I ended with such a small amount of powder that I didn't even bother to melt and weigh, I estimate 0.2 or so gram for the two boards plus a couple of smaller gold flashed boards. I have ended up deciding that gold 'flash' on boards is not worth the effort or waste acid. 

I would still recommend maybe running 2kg of your boards and just confirming for yourself what you will get.


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## razvanflorin (Jul 3, 2016)

Thanks.. But what about the flatpacks and integrated chips that come from ?


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