Unpopulated solder boards

[zamistro]

I picked up some PCBs with no parts on them. Appear to be manf. recently. They have printed traces that appear to be silver because they are somewhat tarnished. Is there enough silver to be worth recovering? I did use the search and didn't find excactly what I was looking for. I'm having trouble posting pix. Please click.

http://img101.imageshack.us/i/059i.jpg/
http://img714.imageshack.us/i/060xp.jpg/
http://img3.imageshack.us/i/062w.jpg/

 

[samuel-a]

They look like gold from here...

Those are usually flash plated with gold at about 4-7 microinch thick...
Try to use an eraser from the back of a pencil, and you'll see that the gold is beeing removed....

I would not bother my self trying to recover PM's from them. better sell them.
Though they are good to learn and expirience the AP method...

Good Luck

 

[goldsilverpro]

They look like tin plating or lead-tin solder plating to me.

 

[dtectr]

these appear to be cell phone blanks(?) the areas in the red squares are usually Au plated, but most of the values, according to those that process them regularly, is in the components, rather than the boards themselves.
though i am surprised that the edges are not plated, as well. Is it possible that these boards failed, & were discarded before plating was completed?
just my dos centavos.

 

[Geld Konig]

Hi Zamistro,
These are, certainly, 4 cell phone board together. And the red local are Au palted. Once, I visited a board manufacter ( factory) and I saw that the boards are jointed one to other to plate the apropriated local ( contacts like a piano). These boards are put in electrochemical solution ( a solution Au with CN- ). So,the gold is deposited in determined place on the boards.

 

[zamistro]

Thanks one and all for the replies. They are rejects from a place that makes GPS trackers for dogs. Some are gold flashed but they look different from this one. My pictures don't show the 'tarnish' as I had hoped. GSP in your experience are all modern boards like this just tin and/or lead solder? Do some have silver or is that a thing of the past?

 

[g_axelsson]

Silver and gold plate is not a thing of the past. With new environmental regulations lead is banned from most electronics and it isn't that easy to plate with only tin. Silver plate or gold flash is common in new products but the amounts are tiny. The boards are plated/flashed after the solder mask is put on. Only the solder pads are plated.

The board I designed last month came back from the factory with silver plated solder pads.

/Göran