Processing films from newer DDR2 memory chips

[electrocycle44]

Hello everyone!

I have been working to depopulate some of the memory I have sitting around, and after taking off some of the newer memory chips from DDR2 memory (mounted directly instead of with legs) I decided to throw a couple of them in the mortar and pestle to see what they looked like inside. I've read a lot here on the forum about processing IC's and how the gold connecting wires are usually not visible. After doing just a bit of crushing with the mortar, I am finding out that most of these newer chips seem to have a visible line of gold running up the middle of the chip/green film.

The original plan was to incinerate all the chips going along with the processes discussed in other posts, but I'm wondering if it would be easier to process these chips separately and then incinerate the leftover material to catch any hidden values. Would a short soak in HCL remove any leftover solder and possibly clean up any of the black plastic? After that wash and place in AP to separate the gold wires/foils from the plastic wafer?

I don't want to reinvent the wheel at all but this would be something I could do now while I wait to build a furnace in the next couple of years.

Thanks for any advice!!

Pic1 http://imgur.com/a35P7BH

Pic2 http://imgur.com/8Zmqz36

 

[jason_recliner]

Hi electrocycle44
I read your post with interest, as I have just started to depopulate RAM myself. Note that while I have been reading on it about six months but have not yet processed any further than trimming boards for chips and fingers.

I will assume you've seen Patnor's guide at http://goldrefiningforum.com/phpBB3/viewtopic.php?f=52&t=11827&start=40

Like you, I too considered tossing all my RAM modules into HCl to get rid of the legs and tin. Maybe float off a few extra foils. But this would be a waste; there's unwanted metal inside the chips too. So you'd have to do it again. Once incinerated, you'll be able to get pretty much all of the gold out. Whereas if you try to mechanically pulverise them while the resin is intact, you'll need more work for a poorer result. Especially if you are planning to incinerate them later anyway.

HCl won't degrade the black resin.

To my mind, Patnor's method for RAM still appears the best. So far. No one has a monopoly on ideas or the ultimate method. You might come up with something awesome. If you do, please share! But you will most likely do that if you start by following where others have already tread. Your good ideas will sprout from there.

Also you don't need a full furnace, just a briquette BBQ should do. Not having one, I'm going to try a steel pan in a wood fire.

Good luck!

 

[patnor1011]

What you see is like fingers. Places where bonding wires were connected from Si die in the middle to film. Grind that centre piece of carbon and you will see your wires. Quite a few IC use similar structure, sometimes you will see that it look like square piece of cloth. Wires are located in the middle part of IC.

 

[electrocycle44]

Thanks for the clarification, I was going to keep the crushed material to recover the bonding wires from - I think what I'll do on these as a test is clean the rest of the carbon off the 'mini fingers' and clip them with a small scissors, then throw them in the next batch of AP I do. If I can keep it to a very clean cut I should not pollute the AP with tin from the solder.

I know I wouldn't want to do this for 100's of chips but it will be a nice little experiment for now.

 

[patnor1011]

You will likely need 100's to be able to see any gold from these mini fingers.