Round PC Boards that say "Probe" "Testing" what is it?

[NobleMetalWorks]

Hello,

I have about 167 lbs of these boards, I have no idea what they are and some of them look like they might be a little work to process.

I have several boards, I am going to make a comment about a few, then just post pictures of the others.

This board when dropped on the ground, sounds like it's made out of metal, but upon breaking it in two that isn't the case at all. It has total gold foil (tested) that runs the entire length of the board, under the red coloring, on the front and back. I tried to take a picture of the leading edge to show the gold plating, but it didn't really turn out. There is also gold plating sandwiched in between the layers of PCB, this board is about a 1/8 inch thick and very heavy. The first picture is of the face of the board, second is of the broken edge I was trying to show gold foil, and the third are holes that go through the entire board, and are gold plated all the way through the hole, for what purpose I have no clue.

I have a lot of boards with these really fine metal wires going from the middle to the gold played leads. I haven't tested for gold yet, it's not like the normal gold color, but nor is it the color of copper, or any other metal I have ever seen. I am assuming it's some sort of alloyed gold.

This board has connectors all the way around the outside, but they are not connecters like I have seen before, except maybe very small versions of them on cell phones, or certain computers. I don't want to put all that plastic into solution, anyone know of a good way of getting the gold out of these?

This board has these thick see through chip sockets that are gold plate all the way through, not really sure what to do with them or how to extract all the gold out of the socket.

Leading edge, you can see the gold socket sideways.

Misc boards

 

[maynman1751]

Strange boards! I see one is marked Intel. Where did you get these.....what are they from? Are there any numbers on these you can search?

 

[NobleMetalWorks]

Strange boards! I see one is marked Intel. Where did you get these.....what are they from? Are there any numbers on these you can search?

Some do have numbers, I'm planning on googling them after I set up my hood and scrubber. I was hoping someone here would know, that's kinda why I posted the pictures. Someone did say they looked like semiconductor test boards, they do have words like "test only" or "Probe" etc. Very unusual boards, I have no idea other than that where they came from originally, I bought them from a small company that does recycling. I have 167 lbs of these, and another 150-200 lbs coming.

Since they are so thick I am going to attempt to defoil the entire board so that I don't have to try breaking them up, or sawing them (and loose gold in sawdust). I am going to fuse two sheets of poly together wide enough to accept the width of the boards and tall enough to accept the length, so that I can fully immerse the entire board into HCl or Caustic Lye whichever works better. That way I can put the board in, on end, without using tons of acid, or having a big plastic bin filled with acid open if you can picture what I am saying. So in other words the boards would be standing on end. Just need to dream up a way of retrieving the boards once defoiled, and leaving enough space to displace the HCl without it spilling over as the boards are lowered into the acid.

Anyone made something like this, or have a better idea? If I can avoid processing the boards by breaking them, there are some of them I would like to save because they look so unique, and maybe make a coffee table out of them, I live close to Silicon Valley, might be someone who would be interested in that type of thing.

 

[macfixer01]

These types of boards are used to interface automated testing machines to the actual silicon dies for testing during manufacture. Multiple chip dies would still be part of a large 6 or 12 inch round silicon wafer at this point for easier handling. Those dies that fail testing are remembered and automatically disposed of while the full wafer is being cut apart into the individual rectangular dies. After all a manufacturer wouldn't want to waste time and money finishing the whole chip packaging before finding out it wasn't going to work anyway. After the dies are cut apart they get mounted into whatever type of plastic or ceramic chip package they will end up in whether Flat Pack, DIP, BGA, PLCC, etc. Then they'd also have some sort of final testing after packaging in case of bad internal wire bonds or whatever other manufacturing mishap might occur.

So to reiterate, as far as the test probe board goes think of it as applying "bed of nails" testing concepts not to a whole circuit board but to just one tiny silicon die at a time. Possibly hundreds of tiny test probe tips are all kept precisely aligned and are laid down simultaneously, making temporary contact to multiple test points on the die without physically damaging it. With the functional electronic testing done the dies would either go into a scrap bin if bad, or get mounted into a chip package if good. Then they're final-tested by other automated test equipment that's set up to mate with the chip package's external pins.

By having multiple probe boards they can test many different types of chips without much switch-over time involved. Each probe board has the same contacts around the edges to mate with the test machine, but each board can also be customized in the center area to mate with a different type of device under test.

macfixer01

 

[NobleMetalWorks]

These types of boards are used to interface automated testing machines to the actual silicon dies for testing during manufacture. Multiple chip dies would still be part of a large 6 or 12 inch round silicon wafer at this point for easier handling. Those dies that fail testing are remembered and automatically disposed of while the full wafer is being cut apart into the individual rectangular dies. After all a manufacturer wouldn't want to waste time and money finishing the whole chip packaging before finding out it wasn't going to work anyway. After the dies are cut apart they get mounted into whatever type of plastic or ceramic chip package they will end up in whether Flat Pack, DIP, BGA, PLCC, etc. Then they'd also have some sort of final testing after packaging in case of bad internal wire bonds or whatever other manufacturing mishap might occur.

So to reiterate, as far as the test probe board goes think of it as applying "bed of nails" testing concepts not to a whole circuit board but to just one tiny silicon die at a time. Possibly hundreds of tiny test probe tips are all kept precisely aligned and are laid down simultaneously, making temporary contact to multiple test points on the die without physically damaging it. With the functional electronic testing done the dies would either go into a scrap bin if bad, or get mounted into a chip package if good. Then they're final-tested by other automated test equipment that's set up to mate with the chip package's external pins.

By having multiple probe boards they can test many different types of chips without much switch-over time involved. Each probe board has the same contacts around the edges to mate with the test machine, but each board can also be customized in the center area to mate with a different type of device under test.

macfixer01

Thanks for the detailed information. Makes them far more interesting, and now I sort of know what to look for, to find more of these boards. It's funny, I live very close to Silicon Valley, where you would expect to find these types of boards, but these particular boards came from a different state.

Again, I really appreciate the information, thank you very much, excellent job explaining what they are.