# Sheet Metal Sheer X THICK PCBs?



## NobleMetalWorks (Mar 30, 2012)

I have a lot of 160+ lbs of round PC boards about 1/4 inch thick, I have never personally seen PC board this thick. It's all from around 1990, and some of it has really heavy gold plate. A few of the pieces which are square, and about 24 inches by 14 inches have gold plate over the entire board, just under a red surface, I broke one in half, and can see the gold foil at the edges of the break. I don't want to try and use a table saw on these I figure the dust probably isn't good, and I really don't want to loose any gold in the saw dust or have to wear a respirator. So I am thinking about using a sheet metal sheer, but before I go trying it out I was wondering if anyone here has tried a sheet metal sheer before on PCB this thick?

Here is a picture of one of the boards.







If anyone has seen boards like this before, or processed these before, can you please let me know how you processed them? I would really appreciate it if someone has a better way than using a sheet metal sheer.

Thanks


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## Barren Realms 007 (Mar 30, 2012)

I would take one of the boards and use te acid peroxide process with an air bubbler and see if it will get the gold off and if it does I would process them that way. Why waste the labor cutting them up if you don't have to.


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## Photobacterium (Mar 30, 2012)

in case knowing the origin helps, that looks like a PCB from a piece of IC test equipment.

given access to normal shop equipment (bandsaw, shear, etc.) i would start with the bandsaw. obviously with carefulness to make sure that the fingers stay attached to the hands.


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## AztekShine (Mar 30, 2012)

I just want to say thanks for the picture and info. That is possabily the coolest board I have seen.


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## NobleMetalWorks (Mar 30, 2012)

AztekShine said:


> I just want to say thanks for the picture and info. That is possabily the coolest board I have seen.




That one is cool, but some other others are even more cool. When I get a chance, before I process them, I will take pictures of the most interesting ones. I was telling a friend of mine that some of them look so cool, that I was thinking about mounting them in shadow boxes and selling them on eBay. Almost a shame to process them.

I have aprox 100 of these, or just over 160lbs, and I am getting another 150-200 lbs more. I have no idea where they came from, when I originally saw them I thought the smaller ones (about 8") were boards that came out of old switches where the center rotated until the outside pins were positioned on the right gold lead on the board, but now I don't think so. Some have words like "probe" or strings of words like "for probe testing purposes only" and all seem to be made around the early to late 90s, wish a few exceptions being 2000, or 2001.

I'll take better pictures and post what they have etched on them, I would really like to know if anyone has seen these, and where they are from. Board thickness varies between about 1/8 inch to as much as 1/4 inch and some are as big as 24" round.


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## NobleMetalWorks (Mar 30, 2012)

Photobacterium said:


> in case knowing the origin helps, that looks like a PCB from a piece of IC test equipment.
> 
> given access to normal shop equipment (bandsaw, shear, etc.) i would start with the bandsaw. obviously with carefulness to make sure that the fingers stay attached to the hands.



I thought about using a band saw, zaw saw or a table saw, but I was a little concerned over the gold that would be lost in saw dust. I could probably recover it in sweeps, but it just seemed like too easy a way to loose some of the gold bearing material. That's why I thought the sheet metal sheer might work.

What type of testing equipment would round boards like these come out of? I got them from a small recycle company but I am totally at a loss as to what they are. They do have words like probe and test, etc, on them. I just can't figure out why they would be round unless in a switch of some sort. Totally at a loss.


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## element47 (Mar 30, 2012)

Do you see a manufacturer name on them anywhere? Teradyne? AMAT? (there are a dozen others) 

I agree, just throwing a wild guess out there, semiconductor test seems like a very strong possibility. 1/4" thick boards, these come from very, very high reliability (and cost) "somethings".


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## NobleMetalWorks (Mar 30, 2012)

I posted more pictures and information here.

I took those with my phone, I'll dig on the digital camera and take some of the words on the boards.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=13688


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