I was hoping that someone out there would know what the markings on this board indicate. I have no idea what the individual chips were for, but one appears to be damaged, so they discarded the entire board. The owner of the boards believes that the "Au 0.237" indicates a 23.7k purity. He also believes that the "total 1.115" indicates that it contains 1.115 troy oz of gold. I must adimit that it looks quite rich. The rings around the holes appear to be solid gold. I have considered melting part of it down in a crucible in my kiln, if they were solid 24k gold i would expect them to melt and bead up. Any observations/comments would be appreciated.
Super high grade boards
- Thread starter Deldaddio
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patnor1011
Well-known member
Deldaddio said:
total 1.115 SF
SF :idea: silver face, solder flux..... zillion possibilities but miles away from t.oz don't you think?
It looks like rejects without any smd so I would scratch some of that in test plate and test, test, test. You can start with some of HNO3. I would say that there cant be oz of gold. I saw gold filled watch cases but not circuit boards...
MMFJ
Well-known member
1 square inch = 0.00694444444 square feetDeldaddio said:
A little math here (and boy, am I rusty...!)
If each square is 3" and you have 6 x 4, then you have 72 square inches of "painted" surface on the board.
72 x 0.00694444444 square feet = ~ .5 inches - which is what your board tells you has been manufactured.
The markings are more of an engineering/quality control for a manufacturing process. The board looks newly etched (pre-cut) for some small circuits. The Au is gold, but it is simply plating, like everything else.
Of course, that is my opinion and that, plus about $3 will get you a cup of coffee just about anywhere.....
By using the dimensions you gave, making a few screen measurements with a ruler, and making a few assumptions (I assumed the 3x3 squares to be 25% gold plated), I would estimate between 80 and 100 square inches of gold plated area. If the gold thickness is 30 microinches, there would be from $40 to $50 worth of gold on the board.
In order to contain a total of 1.115 TO, the gold plating would be about 850 microinches thick. In the history of the world, there has never been a circuit board plated that thick with gold. Probably, not even one plated 1/4 that thick. 30 microinches is probably more than adequate for that application and it is very possible that's it's even thinner. Also realize that the gold on boards is never solid. It is always plated. Also realize that these manufacturers don't waste gold. If 30 (or, 10) microinches is all they need, that's all they'll use. Also realize that electronic manufacturers never express gold plating purity in karats. It's always in percentage. Karats are for jewelry. Finally, if the board manufacturer printed, on the board, the total weight of gold on the board, it would be the only time in history that that was ever done. The owner is dreaming.
With medium hard pressure, on a small area of the border of the board, use a pencil eraser and see how many strokes it takes to erase the gold. Stop when you first see the white nickel. You need good light and have to watch very carefully to see this. I doubt if it would take more than about 10-15 back and forth strokes, probably less. This doesn't really tell you much, but you'll see that it is very thin.
In order to contain a total of 1.115 TO, the gold plating would be about 850 microinches thick. In the history of the world, there has never been a circuit board plated that thick with gold. Probably, not even one plated 1/4 that thick. 30 microinches is probably more than adequate for that application and it is very possible that's it's even thinner. Also realize that the gold on boards is never solid. It is always plated. Also realize that these manufacturers don't waste gold. If 30 (or, 10) microinches is all they need, that's all they'll use. Also realize that electronic manufacturers never express gold plating purity in karats. It's always in percentage. Karats are for jewelry. Finally, if the board manufacturer printed, on the board, the total weight of gold on the board, it would be the only time in history that that was ever done. The owner is dreaming.
With medium hard pressure, on a small area of the border of the board, use a pencil eraser and see how many strokes it takes to erase the gold. Stop when you first see the white nickel. You need good light and have to watch very carefully to see this. I doubt if it would take more than about 10-15 back and forth strokes, probably less. This doesn't really tell you much, but you'll see that it is very thin.
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Anonymous
Guest
You can take this to the bank Deldaddio,If there was I would have run across it by now.rusty said:
The markings are more indicative of E-crap,not Escrap.I have seen thousands of newer boards on ebay,that have similar markings.Usually this is for one simple reason,to get the buyer excited.It's not your fault,(unless you were the one that had it manufactured),it is just a tactic in the new gold game.It has been going on for several years now.I have personally caught 2 seperate individuals on ebay that were purposely having material made,so they could sell it on ebay as "Escrap"......knowing full well the yields were virtually nothing.There are 2 manufacturers not too far from where I live,that will manufacture a PCB to any specs you desire,as long as you purchase in quantity.....and yes that includes flash plating.That is exactly what this appears to be.A board,made to look like something it is not.
I could be wrong,but that's what it looks like to me.
Geo
Well-known member
another assumption would be instead of 1.115 troy ounce, theres 1.115 grams which is what i would have thought to be a more realistic number.
patnor1011
Well-known member
I don't think it is possible to know weight of gold electroplated on board. Only if board is custom made and weighted before plating and after plating is done but that is something I never heard about.
macfixer01
Well-known member
Smaller circuit board designs are normally "Panelized" before photoresist masks are produced for etching boards. That means multiple copies of a small board are laid out to fit on a standard sized panel their machinery is set up to work with. So they would produce full panels at a time, laminate any additional internal layers if applicable, and run them through plating. Finally they'd be cut apart and drilled using CNC machinery directed by data files also generated from the same PCB layout software.
With all commercial circuit board layout being done on computers these last many years it makes possible time and hair saving miracles like auto-routing of traces, but also the collection of many usually irrelevant details like the total length of all traces on the board if it was so desired. The computer already holds all the material data, component and pad spacing information, and design specs, so it's no extra work to the operator to extract it and even print it out on the panel itself.
I think all it's saying is that the total area of coverage left on the board Top+Bottom is 1.115 Square Feet. To the left it also itemized that the Top layer's area was 0.567 Square Feet and the Bottom layer's area was 0.548 Square Feet, which once again totals up to 1.115 Square Feet. From the dark shadows it looks like this is a (relatively simple) multi-layered circuit board. The other text in question relates to layer 1 which seems to be an internal ground plane layer and says it has an area of 0.237 Square Feet. Since it doesn't have the contact metal area around the edges that the Top and Bottom layers do, and would have to leave clearance around all non-grounded plated through holes, it's area would be smaller than the Top or Bottom layer. Well that's my theory anyway.
macfixer01
With all commercial circuit board layout being done on computers these last many years it makes possible time and hair saving miracles like auto-routing of traces, but also the collection of many usually irrelevant details like the total length of all traces on the board if it was so desired. The computer already holds all the material data, component and pad spacing information, and design specs, so it's no extra work to the operator to extract it and even print it out on the panel itself.
I think all it's saying is that the total area of coverage left on the board Top+Bottom is 1.115 Square Feet. To the left it also itemized that the Top layer's area was 0.567 Square Feet and the Bottom layer's area was 0.548 Square Feet, which once again totals up to 1.115 Square Feet. From the dark shadows it looks like this is a (relatively simple) multi-layered circuit board. The other text in question relates to layer 1 which seems to be an internal ground plane layer and says it has an area of 0.237 Square Feet. Since it doesn't have the contact metal area around the edges that the Top and Bottom layers do, and would have to leave clearance around all non-grounded plated through holes, it's area would be smaller than the Top or Bottom layer. Well that's my theory anyway.
macfixer01
The whole board would have been layered in the material then etched, to be able to say exactly how much Gold is left after etching would be near on impossible.
I have experience in designing and etching my own PCB's if i had the choice of making them out of almost pure gold then i certainly would not be leaving precious Gold on the edge of the PCB like that unless i was going to reclaim it for myself after trimming the boards, but if the boards were for me then i wouldn't need to advertise their plating properties etc...
I have experience in designing and etching my own PCB's if i had the choice of making them out of almost pure gold then i certainly would not be leaving precious Gold on the edge of the PCB like that unless i was going to reclaim it for myself after trimming the boards, but if the boards were for me then i wouldn't need to advertise their plating properties etc...
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Anonymous
Guest
Trust me when I say....there is NOTHING on that board,or any other printed circuit board,that is "solid" gold.I am not trying to discourage you....but you need to realize that,just like many others have already told you,there is NO reason to use excess gold on anything in the computer industry.I have been doing this a long time,and I have found very few items that had gold on them,when it was not a necessity,and those items came from R&D equipment from the navy.
Besides,if you put that board "in a flame" you are going to have more smoke than you know what to do with.
Besides,if you put that board "in a flame" you are going to have more smoke than you know what to do with.
jimdoc
Well-known member
Deldaddio said:
Your neighbors will love that.
Jim
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Anonymous
Guest
Lol.jimdoc said:
