i think i hit the cpu jackpot

**jghilino** · 12-07-2012, 07:59 PM

Well with my trimming skills im thinking i can turn a 500% profit on them, ive been getting $100 pound for single sided solid plated and $200 for double sided solid plated. 1/3 of the board is double sided gold plated. Some of the rest is single sided. Im not a refiner so i dont know anything about recovery rates. I do know how to use a pair of tin snips though.

**NobleMetalWorks** · 12-07-2012, 08:21 PM

The gold plating is usually 22k and plating can be between 12-20 micro inches dependent upon when it was manufactured. If before 2002 it will be thicker gold plate, if it's after 2002 it's going to be closer to 12 micro inches.

So you first figure out the total square inches, and the aprox micro inch thickness and then input that information into a gold plating calculator like this:

Gold Plating Calculator

Then calculate for 22k and you will have your real value, or as close as you can get without actually refining it.

Believe it or not, once depopulated and the soldering mask is removed, that type of material is fairly inexpensive to recover, you would refine the same way you normally would refine Au, but the recovery process is fairly simple.

Scott

Scott

**JPete** · 12-21-2012, 06:36 AM

Originally Posted by NobleMetalWorks

The gold plating is usually 22k and plating can be between 12-20 micro inches dependent upon when it was manufactured. If before 2002 it will be thicker gold plate, if it's after 2002 it's going to be closer to 12 micro inches.

Scott

I am a printed circuit board designer. You are correct about the plating, as I used to specify to the manufacturer 12-25 micro inches of gold to be plated over nickel, on top of the copper. It was a complete immersion plating as opposed to selective areas. Meaning not just the exposed areas of pads, but all copper including under the soldermask. In other words, there may be gold on top of all the traces that are external, not just the chips. We never spec'd out how much nickel to put on though.