SDRAM chips and other memory chips like those

Paige · Apr 29, 2007

If you were to cruch SDRAM (?) memory chips and those like them into dust and them recovered whatever is inside of them, would you have anything which was worth the effort?

I know stripping the gold from the edge would have some worth, but what about is in those chips?

lazersteve · Apr 29, 2007

Paige,

You've asked another excellent question. In an effort to answer your question I have inadvertently discovered an interesting fact that was unknown to me. I've always known the black integrated circuits (ICs) contained silver, gold, and pgms. I've never processed any because of the required crushing and assumed minimal yields. Today you have provided me with some new information.

I decided to run a few ICs thru a heavy duty paper shredder (Fellows Model PS-80). This shredder is mean, it can shred up to 12 sheets of paper at one time. Anyway, I started feeding ICs from various boards into it to get an idea of just what was in them. I shredded about a pound of them into bits about 1/8 across and smaller. I looked down into the bin and noticed something unusal. One of the IC pieces was attached to a small circuit board (?). This is very unusual for plastic pak ICs. What makes this one of those eureka moments is that the circuit board had gold traces all over it!. Luckily the gold traces still had a chunk of the plastic package attached to it and I saw a portion of the manufactures logo. I immeadiately recognized the logo and searched out several other IC's from the same manufacturer.

Here's what I discovered:

This is a photo of one of the source ICs and another which went thru the shredder (I cleared the bin and shredded a single IC for the photo). So it looks like these IC do still have surprises inside for us scrap hounds. I've decided to check several individual types of the same generation of IC to determine if any others have this kind of hidden treasure inside. I'll keep the forum posted. The chip in the picture comes from an old 14.4 ISA Modem. It just so happens that I bought over three hundred pounds of these modems from a guy on ebay last year!

I'll post a follow up when I get some average yields for this type of scrap.

Cheers,

Steve

goldsilverpro · Apr 29, 2007

That part really was loaded. Do I see a hybrid circuit in there? Do you think the shredder will hold up? It sure did a perfect job on the part. I bet it was really noisy.

lazersteve · Apr 29, 2007

goldsilverpro said:
I bet it was really noisy

My wife said she thought a giant rat was upstairs chewing thru the wall. She was out front doing yard work!

Steve

goldsilverpro · Apr 29, 2007

I'm still laughing.

lazersteve · Apr 29, 2007

goldsilverpro said:
Do I see a hybrid circuit in there?

Chris,

You are correct. This is one oddball IC configuration. Typically hybrids are mounted in an exposed state or sealed in a single in-line package (SIP). I never knew they put hybrids in plastic quad packs! I've been hands on in the electronics industry for nearly 20 years and have never seen this type of configuration. I'm hoping to find more surprises like this one in my scrap pile. The most unique aspect of this little bugger is that the gold looks to be plated onto the substrate directly. I also can make out a perimeter of what appears to be Pd or Ag on the ground plane. Definitely a great find! Thanks Paige ! :wink:

Steve

goldsilverpro · Apr 29, 2007

Is the hybrid a thin film (shiny metals) or thick film (matte) circuit.

lazersteve · Apr 29, 2007

It appears to be a copper ground plane with a silver or palladium perimeter. On this is a small fiber circuit board with the gold traces. Very unusual for 1995. The core is mounted on the ground plane and has gold wire interconnects to the internal circuit board.

mike.fortin · May 1, 2007

Steve--I read your post with photo about putting ICs thru a heavy duty paper shredder (Fellows Model PS-80). Have you ever found any shredder which would reduce monitor housings to more manageable pieces for disposal? You or anyone use a wood chipper do the job? Thanks. Mike Fortin

lazersteve · May 1, 2007

Mike,

I just take mine to the dump when I get a truck load.

Never tried using a chipper.

Steve

lazersteve · May 4, 2007

Hello Everyone,

I started rounding up some of my modem chips that are the hybrid types as pictured above. I did a few controlled crushings with a sledge hammer to get a better look at what I was dealing with in these chips. Here's what I found:

I started pulling the chips from the modems and managed to gather over two pounds of them in less than 10 minutes.

If anyone else finds chips of similar construction please post pictures along with the type of chip and part number on the chip.

From the looks of these things they are going to put out gold, silver, and possibly even palladium.

Thanks,

Steve

zauggart · Mar 17, 2008

hi there
i just took apart a chip that says rockwell 93 and it too is the same inside as the rockwell 95 in the pic above
thanks
Ian

silversaddle1 · Mar 20, 2008

Hey guys, I too just did a Rockwell chip and found the gold board too. Here's a quick way to open them up. Place them in a vise, on edge, not flat, and turn them until they break. The three I did popped right open and the gold was right there for the takin!

Thanks!

Scott2357 · Mar 28, 2008

Newbie here.

Did I miss the yield report somewhere?

Also, I've been looking for average yield for CPUs, etc. Can someone point me to the data?

Thanks.

alpha1 · May 1, 2008

Hello, guys.
What I found is that all Rockwell modem chips which are about 2 mm thick have such gold.
I crushed a few chips from 14,4Kbps to 33,6Kbps.

Harold_V · May 2, 2008

lazersteve said:
goldsilverpro said:

I also can make out a perimeter of what appears to be Pd or Ag on the ground plane. Definitely a great find! Thanks Paige ! :wink:

Steve

Click to expand...

Yet another example of why e scrap is processed by incineration and furnace by the "big boys". What better way to extract all the values? It's a damned shame a safe method isn't devised that would allow home refiners to incinerate this stuff. It could spell the difference between spinning one's wheels and making a decent profit.

Harold

Rag and Bone · May 2, 2008

"It's a damned shame a safe method isn't devised that would allow home refiners to incinerate this stuff"

I hear ya brother! I would be happy with a few cubic feet of incinerator space and proper fume scrubbing and filter to catch values.

flankdrive04 · Jun 11, 2008

goldsilverpro said:
That part really was loaded. Do I see a hybrid circuit in there? Do you think the shredder will hold up? It sure did a perfect job on the part. I bet it was really noisy.

NICE!!

GeeDub · Feb 8, 2009

I have been thinking for years, about getting one of Keene's centrifugal crushers for chips:

http://www.keeneeng.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=RC1&Category_Code=RC

Anyone out there ever try this thing?

wop1969 · Apr 1, 2009

I have been exploring chips and have some good findings.
The first pic is the rockwell 95, and once more full of gold.
the second one and third chips have gold on the copper traces but only one one side so dont let it fool you if you see copper on a trace when a chip is first opened.

SDRAM chips and other memory chips like those

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