Analyzing RAMs

[Romix]

I decided to analyze RAMs.

Did batch of Samsung with bga chips. Left them in HCl for few months, with all components and fingers there.
Solder gone in solution, copper begin to dissolve, ceramic capacitors survived.
Big mistake putting it all at once, should seperate first, cos later all components need to be washed from all the dirt swimming in solution, that's alot of water to evap. Alot easier doing them seperatly.
Ok, now all in seperate baggies, capacitors, resistors and chips. Collecting all solutions in different containers for further processing.

Doing it by brand. Not many models match, some with gold holes, some with out, just copper.

Did batch of Samsung with rectangle chips, most capacitors completely dissolved, can't see electrodes in solution. Few survived with purple ceramic and silver contacts. I'v got told that Palladium dissolves in HCl on air, but there is alot of stannous chloride in soulution, so it should precipitate out. Grey dirt migh be it.

Tonight seperated batch of Hinyx with squere chips, all in seperate beakers, chips, capacitors, and boards(left em with resistors), all in very dillute muriatic acid.

 

[Romix]

Washed fingers in HCl and H2O2, as needed it quick. and it's cheap and available.
Saved filtered sollution, you guys saying that gold dissolves in it at room temp.

 

[Romix]

Beaker with ceramic capacitors from Hinyx RAMs with bga chips.
2 hours standing in warm place.
Solution turned pinkish-purple, colour of potassium permanganate.
Ceramic dissolving, what cation colors solution this colour?

 

[Romix]

Maybe manganese?

 

[Romix]

Soaked MLLCs from boards with bga Elpida ICs.
Bubling, left it in worm place.

 

[Romix]

Soaked MLLCs from boards with squere Elpida ICs.
Bubling, left it in worm place.

Purple on third hour.

 

[Romix]

Soaked MLLCs from boards with squere Elpida ICs.
Bubling, left it in worm place.

Purple on third hour.

All brands with BGA chips are.

 

[Romix]

Hinyx, Elpida and MT stays purple.
Nanya on third day changed colour to green from purple, all ceramic dissolved, half etched electrodes swimming in solutions.

 

[Romix]

What plastic ICs made from?

 

[macfixer01]

What plastic ICs made from?

There doesn't seem to be much specific information on that, just that it's Epoxy. Maybe you could find more information in older manufacturer's chip data books? I have seen Youtube videos before on De-capping IC chips where they make a small hollow in the surface then dissolve the plastic using fuming nitric acid. Such as this one:

http://youtu.be/mT1FStxAVz4

Macfixer01

 

[johnny309]

What plastic ICs made from?

Your answer:

http://electroiq.com/blog/2005/08/materials-and-methods-for-ic-package-assemblies/

 

[Romix]

Ok, Capacitors from Hinyx BGA RAM, 2 months siting in dilute hcl, first month solution were purple, looked today and it's colourless, all ceramic dissolved, clean electrodes swimming in solution.

Elpida and MT purple first week, Nanya green. (MLLC)
What colors solution purple, maybe Nd in ceramic?

All resistors green too, what colors it green? maybe nickel contacts?


-----
Looked day after, colourless solution with Hinyx MLLC, changed colour to light green, nickel from electrodes begin to dissolve slowly on air.

 

[Romix]

There is a good procent of Bismuth in Samsung BGA RAM solder.

 

[johnny309]

Ok....you are doing in the wrong way.....
Why?
Because ....you wait 2 months.....with an acid( even dilute....vapors corodes .....)..... SMD resistors,the layer of Ag/Pd is in the "frit"(ecapsulated in glass and there acids have trouble to get to them).
You generated a lot of liquid waste product.
Melt it ....with the right flux....etc... then go acids......
And ,most important..... you forget your safety,yours and the people around you....the greed ...... study ,read,try to understand the complexity of aloys....and then.....you will be happy....why?: " BECAUSE" you will more educated and not endanger your life for penny.

 

[Romix]

Cheacked Hinyx today, few capacitors survived(they contain silver).
Rest dissolved, last time I looked, electrodes where there, today bit of grey dust on the bottom and few capacitors.

First 2 months solution where purple, that's ceramic dissolving. Don't know what cation colours it purple, not tested yet. Playing with Cu and Ni.
When all ceramic dissolved solution turned colourless. After acid began etching electrodes, changed colour to light green.
That's few drops of very dillute acid, very good!

 

[Romix]

Washed fingers in HCl and H2O2, as needed it quick. and it's cheap and available.
Saved filtered sollution, you guys saying that gold dissolves in it at room temp.

It does dissolve at room temp, recovers when stored for long time and on heating.