WindowLESS Eproms - Gold & Silver

Thought that others might find this information interesting and/or helpful. Window type eproms usually have a sticker covering the silicon chip to prevent erasure. Additionally, looking at the end of the eprom an extra layer can be seen in the cross section. I believe it's generally accepted that this layer is the window covering material. Most of us are aware of these facts. However, recently while looking over a board I saw an eprom that had this extra layer but no window. So I decided it was time to find out what was going on here. I pulled the eprom placed it on a stable metal surface and tapped it with a hammer. The top layer of ceramic fell away and there was a beautiful gold "window"! I then went to my bucket of IC's/eproms and began searching. At the very bottom I found another eprom with no window but the same cross section. Tapped it a couple of times and there was a silver "window". Maybe all eproms are made with the gold or silver in the middle. I don't know and don't care. I do know that the extra opaque layer allows the eproms I was working with to split open nicely. I see no reason why these can not be included in a batch of window type for sell on eBay or to whom ever. Photo quality is a bit poor but it will suffice.

Two ceramic eproms with and w/o window.
http://i1305.photobucket.com/albums/...ps12a5b65c.jpg

Cross section - gold window
http://i1305.photobucket.com/albums/...pse278a8ff.jpg

Cross section - windowless. Had to reassemble for photo after splitting.
http://i1305.photobucket.com/albums/...ps9c9ee710.jpg

Windowless eprom after splitting.
http://i1305.photobucket.com/albums/...psbfb05aa6.jpg

Silver windowless eprom
http://i1305.photobucket.com/albums/...ps9a275e56.jpg

If you are planning on selling your ICs Proms and Eproms to people who are going to refine them, I wouldn't crack them open to show what's on the inside. Once you do, it's difficult to tell if it's an IC, Prom or Eprom and all the refiner has to go on is your word. And as we all know, when dealing with precious metals, everyone believes everyone else is attempting to rip them off.

On the inside of these chips, you could have gold, silver and/or palladium, that's right there is palladium in some of these as well. Also, sometimes the silver material you are looking at isn't silver or palladium at all, but tin.

So far as the legs are concerned, if they are silver, you can almost be sure they are tin and not silver. The reason why silver is used on the inside and not the outside is that silver oxidizes which affects it's ability to conduct electricity properly.

By cracking the Prom/Eprom/IC open, you run the risk of loosing the tiny little wire leads that are almost always some time of precious metal. Here are a few pictures of what I am talking about:

https://dl.dropbox.com/u/56505223/Ch...EPROM%2001.jpg

https://dl.dropbox.com/u/56505223/Chips/eprom2.jpg

https://dl.dropbox.com/u/56505223/Ch...SuperMacro.jpg

I really like this picture of a white ceramic Eprom with the wires showing through the window:

https://dl.dropbox.com/u/56505223/Chips/800px-Eprom.jpg

Also, the older Eproms/Proms/ICs are worth more because the precious metals were worth less, and the technology to deposit the precious metals was not nearly as advanced as it is today. So your white ceramic chips are generally the oldest. Here is a picture of some white ceramic chips:

Eproms:

https://dl.dropbox.com/u/56505223/Ch...2018.58.01.jpg

Proms:

https://dl.dropbox.com/u/56505223/Ch...2018.37.13.jpg

https://dl.dropbox.com/u/56505223/Ch...2018.54.21.jpg

Here is a picture of white Eproms, purple Eproms and Proms, Eproms are the ones with windows, UV light was used to erase them so they could be reprogrammed. Proms have no windows and the ICs are the smaller, skinnier purples ones on the left hand side. Purple ceramic is not as old as the white ceramic, but there is some crossover. Generally the white ones should be saved for collectors because they are worth more as collector pieces than they are for their precious metals.

https://dl.dropbox.com/u/56505223/Ch...2018.50.38.jpg

The newest Eproms, are generally grey or black. Here is a picture of a newer Eprom:

https://dl.dropbox.com/u/56505223/Ch...nent_eprom.jpg

The layer the OP is talking about is the oxide layer, it is weaker than the silicon, and also holds the channels the legs are set in. Like I said above, I wouldn't crack these open in order to sell them to refiners. I would keep them whole, and maybe only crack open one to show pictures of it so the person buying can see what's inside. You can buy a digital microscope to take pictures of the fine wires on the inside, if you are really industrious and plan on selling a lot of these.

And remember, just because it's silver in color does not mean it's silver, it could be palladium also. Palladium is sometimes used because it doesn't oxidize like silver.

I thought I would throw in a picture of some gold IC chips that were plated top, bottom and the legs as well. I sold these for $35 each which is far more than the gold content. If you look under the vintage computer section on ebay, you can get an idea of what chips you can sell for more than their scrap value. If you are pulling any of the older chips I would check this section of ebay first:

Vintage Computer in Other | eBay

And if you do a search for vintage Eproms this is what you might come up with:

vintage eproms | eBay

You can see the value on some of these is far more than what they might bring processing them, and you certainly wouldn't want to break off the eprom window. Here are some Proms:

vintage prom chips | eBay

Scott

Quote:

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Originally Posted by NobleMetalWorks

If you are planning on selling your ICs Proms and Eproms to people who are going to refine them, I wouldn't crack them open to show what's on the inside. Once you do, it's difficult to tell if it's an IC, Prom or Eprom and all the refiner has to go on is your word. And as we all know, when dealing with precious metals, everyone believes everyone else is attempting to rip them off.

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If my wording sounded as if I were advocating breaking them open, I apologize. My thinking was simply that others might want to know that there are chips out there as valuable as gold windows even though they do not have a window. Personally speaking, if I see ones that have the oxide layer in place, they're going in a different bucket from now on.

Quote:

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Originally Posted by Flinthills

If my wording sounded as if I were advocating breaking them open, I apologize. My thinking was simply that others might want to know that there are chips out there as valuable as gold windows even though they do not have a window. Personally speaking, if I see ones that have the oxide layer in place, they're going in a different bucket from now on.

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Naw, it didn't sound like you were advocating tearing them apart, actually I can appreciate the fact you were curious and industrious enough to break them open to see for yourself what value might be hidden inside. I say good job. A lot of my posts have to do with pointing out things from my point of view, as someone who refines and recovers precious metals, and how I purchase that type of material, and I do so in order to help people who collect, break down and sell that type of material make a fair profit.

I thought your post was informative enough that I took the time to do what I hope compliments it some with a little bit of what I know myself. And I hope someone else is able to expand more so maybe I can learn something I didn't know as well.

So please don't take what I posted as me thinking you were advocating removing the lids or breaking apart chips, I just wanted to suggest for others who might read your post, or mine, and think they might should break open all the chips, that they might be better served not doing so.

Excellent post by the way!

Scott

Excellent posts all around. Thanks for taking the time to photograph and post, as it furthered my education on these items.

edit: Now, can you tell me where I can find the Eprom tree these grow on?

How did you split it?

If you put the chip along it's side against something hard, and gently strike it with a hammer the tops tend to pop off. Also you can take two pair of vice grips, hold the bottom portion with one pair, and the very top portion with the second pair, twist and coax them apart like an oreo cookie. Or, you can even put them in a vice and slowly apply pressure, the top will eventually pop off. OR you can heat them up real hot, quench them in water and the tops tend to pop off.

The oxide layer between the silicon layers, is very fragile and will shatter or break with very little work or effort. You could probably drop it on it's side and it might pop off.

Scott

LOL, Thanks Scott. If it is one thing I love about people like you is that you give me more than one option in breaking something down, or more than one explanation of how to do something! Thank you!!

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Originally Posted by happyisthealero

LOL, Thanks Scott. If it is one thing I love about people like you is that you give me more than one option in breaking something down, or more than one explanation of how to do something! Thank you!!

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Anytime, there are probably a 100 other ways of doing it. I heard once someone looking at them in just the right way, and the top popping off.

Just kidding about that by the way...

Scott

Quote:

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Originally Posted by NobleMetalWorks

Anytime, there are probably a 100 other ways of doing it. I heard once someone looking at them in just the right way, and the top popping off.

Just kidding about that by the way...

Scott

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That was probably the wife's icy stare,,,8-l

Quote:

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Originally Posted by Mechanic688

That was probably the wife's icy stare,,,8-l

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It's not the icy stare I worry about I can always warm up after, it's the lasers that shoot from the eyes that concern me.

Scott

Pictures are great for someone like myself. I'm just started looking into "E" scraping, last night found a window eprom (Texas Instruments) in a old typewriter of all things. There was some nice copper sheeting in this old Olympia from West Germany!

Quote:

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Originally Posted by NobleMetalWorks

Anytime, there are probably a 100 other ways of doing it. I heard once someone looking at them in just the right way, and the top popping off.

Just kidding about that by the way...

Scott

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I heard that that's how Chuck Norris scraps chips.

Quote:

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Originally Posted by rawresale

I heard that that's how Chuck Norris scraps chips.

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Chuck Norris doesn't scrap chips, he just converts them directly to gold, silver and palladium.

Scott

Quote:

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Originally Posted by noblemetalworks

chuck norris doesn't scrap chips, he just converts them directly to gold, silver and palladium.

Scott

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this^

Quote:

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Originally Posted by happyisthealero

this^

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Chuck Norris doesnt dial the wrong number, YOU pick up the wrong phone!

Chuck Norris doesn't scrap electronics for precious metals, he creates nuclear fission with just the power of a thought, and turns plain air into whatever precious metals he desires!

Scott

Quote:

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Originally Posted by shendog

Chuck Norris doesnt dial the wrong number, YOU pick up the wrong phone!

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Huh?:-o

Who said anything about dialing? LOL

now what to do with the 17 pounds of silver windows and 3 pounds of gold windows ive accumulated

Quote:

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Originally Posted by shendog

edit: Now, can you tell me where I can find the Eprom tree these grow on?

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Wish I could but they are as elusive as the morel mushroom! And like the morel, will sometimes pop up in the most unlikely places!