Gold on circuit boards

[SgtMaj]

Re: Gold on circuit boards

I have been an electrical engineer for 25 years and have never seen a circuit board with gold pads. Some hybrid assemblies I have worked with have gold pads but not circuit boards. There is not one reason to have a gold pad unless it used as a contact pad. Anything that needs to be soldered to a pad will never need to have a gold pad becuase typically, pads are copper and then tinned before part mounting. The only area to have gold is on connector surfaces because of oxidation issues with copper...that is it.

I'd wager you'd find plenty floating around in the space program (satellites, various instruments, etc)... that's just one application off the top of my head... Might find some in marine electronics, too... after all, gold is the thing to use when you're looking for corrosion resistance.

Why would anyone use gold for speaker wire? Gold has a higher resistivity than copper!

and at $2700 for 100 ft... I don't know why anyone would ever buy it. But I know at least one audio shop that sells it (or did a few years ago anyway, I think they have gone out of business now, but I'm not positive).

SgtMaj

 

[rwise]

Re: Gold on circuit boards

I don't believe I have ever heard of the TV guide channel deal. It sound very interesting though. Are these the cards that are used for watching TV on computers?

No it is a Devinchi card with a street value (at the time) of $10,000 U.S.D. per card. It is a mpeg incoder/decoder and complies wit FCC rule for broadcast. You local head end (like comcast/time warner/cox/dish network/direct tv/etc) use this computer to generate the TV Guide channel and broadcast it to the end user (you) you know the scrolly channel with all the advertisement!

As mentioned in my other thread (that I had locked), my uncle used to go to South America, and was supposed to be making another trip to go gold hunting, but this time it fell through. He has all the equipment to hunt with.

I have a gold pan and go to the mountains and pan from time to time, never really found anything though

 

[rwise]

Re: Gold on circuit boards

Yep I know there wouldn't be enough in those pictured below (in my other post) to even bother with. I believe the goof that advertised them on Ebay was trying to rip somebody off, just my opinion.

I don't believe I have ever heard of the TV guide channel deal. It sound very interesting though. Are these the cards that are used for watching TV on computers? If so I have only dealt with them one time, I installed one on my own computer, just so I could have the option to watch TV on the PC. I may be way off track .

If only I could get into gold hunting, I have even researched maps of areas here in Alabama, tried to contact a man that has personally been gold hunting around here and I never heard a reply from him. It'll half to stay a dream for now, I have bigger fish to fry.

As mentioned in my other thread (that I had locked), my uncle used to go to South America, and was supposed to be making another trip to go gold hunting, but this time it fell through. He has all the equipment to hunt with.

I have been an electrical engineer for 25 years and have never seen a circuit board with gold pads. Some hybrid assemblies I have worked with have gold pads but not circuit boards. There is not one reason to have a gold pad unless it used as a contact pad. Anything that needs to be soldered to a pad will never need to have a gold pad becuase typically, pads are copper and then tinned before part mounting. The only area to have gold is on connector surfaces because of oxidation issues with copper...that is it.

Why would anyone use gold for speaker wire? Gold has a higher resistivity than copper!

We obviously went to deferent schools

1. Platinum Highest conductivity
2. Gold next Highest conductivity
3. Silver next
4. Copper next in line and by far cheaper than the above!



All I can say is WOW

And we will have to agree to disagree!

 

[bruceb58]

Re: Gold on circuit boards

We obviously went to deferent schools

1. Platinum Highest conductivity
2. Gold next Highest conductivity
3. Silver next
4. Copper next in line and by far cheaper than the above!



All I can say is WOW

And we will have to agree to disagree!

Yes...we definitely went to different schools. Here is a table that proves my point:

http://environmentalchemistry.com/yogi/periodic/electrical.html

You think platinum is high conductivity?

1. Silver
2. Copper
3. Gold
4. Aluminum

 

[wildmaninal]

Re: Gold on circuit boards

Well I believe platinum is why all these people are collecting the catalytic converters for. My father sold 3 converters from these junk Honda civics for $80 a piece if I remember right. Some are going as high as $200 a piece, or were and people are buying these things to resell and make a profit. If I only had a salvage yard , I would have it made.

I had no idea that silver was the number 1 conductive.

I knew copper was one of the best conductive.

Was wondering where platinum came into play on the list.

Interesting link

 

[rwise]

Re: Gold on circuit boards

Yes...we definitely went to different schools. Here is a table that proves my point:

http://environmentalchemistry.com/yogi/periodic/electrical.html

You think platinum is high conductivity?

1. Silver
2. Copper
3. Gold
4. Aluminum

You are missing the point, this thread is not about the conductivity of gold verses coper (or platinum)! So you can continue filling the land fill with your old parts, and I will continue turning mine into cash!

 

[bruceb58]

Re: Gold on circuit boards

My point is that there is extremely little gold on circuit boards these days.

For the effort required to get the gold off the card, you could walk down the street and pick up a few aluminum cans and be better off.

 

[BoatBuoy]

Re: Gold on circuit boards

super high-end speaker wire is also made of gold... just as an FYI.

I've been in high-end audio a lot but I've never seen gold wire. I have seen many gold plated connectors. In fact, the connectors that I used on my speakers are gold plated. It prevents connector oxidation from impeding current flow. High end audio connects are usually oxygen-free copper. The super high-end are woven or braided cat-5 cable. There have been some experiments done with silver wire, some gold being used to fill the void areas between the silver micro-spheres. I've heard it produces some interesting sonics but no compelling benefits. Google Siltech.

 

[rwise]

Re: Gold on circuit boards

My point is that there is extremely little gold on circuit boards these days.

For the effort required to get the gold off the card, you could walk down the street and pick up a few aluminum cans and be better off.

Like I said you toss yours and I'll sell mine!

 

[v1_0]

Re: Gold on circuit boards

Like I said you toss yours and I'll sell mine!

How much do you get per board?

 

[rwise]

Re: Gold on circuit boards

Last I sold was 85 cents per pound, not bad for dead modems, sound cards, I/O cards, moma boards, dead ram and cpus, etc! And all I had to do was take them to his warehouse! Nothing to it let someone else do the dirty work for there share of the profit!

 

[bruceb58]

Re: Gold on circuit boards

Last I sold was 85 cents per pound, not bad for dead modems, sound cards, I/O cards, moma boards, dead ram and cpus, etc! And all I had to do was take them to his warehouse! Nothing to it let someone else do the dirty work for there share of the profit!

What is the name and address of the place that gives you $0.85/pound?

Most places that we use actually charge $0.20/pound to take it and that is a pretty low price.

 

[MrBigStuff]

Re: Gold on circuit boards

I have been an electrical engineer for 25 years and have never seen a circuit board with gold pads. Some hybrid assemblies I have worked with have gold pads but not circuit boards. There is not one reason to have a gold pad unless it used as a contact pad. Anything that needs to be soldered to a pad will never need to have a gold pad becuase typically, pads are copper and then tinned before part mounting. The only area to have gold is on connector surfaces because of oxidation issues with copper...that is it.

Why would anyone use gold for speaker wire? Gold has a higher resistivity than copper!

As mentioned some aerospace applications used gold plating when they realized there was a tin whisker issue for electronics on-orbit. That issue has long since been overcome and anyway, it would be very rare to run across SCRAP boards of this type.

Someone else also corrected the wire comment. It's the connectors only and it's done for the same reason the edge connectors are gold plated. What better place to inhibit oxidation than low level audio signals? Personally, I use the cheap tin plated ones myself

 

[rwise]

Re: Gold on circuit boards

What is the name and address of the place that gives you $0.85/pound?

Most places that we use actually charge $0.20/pound to take it and that is a pretty low price.

His name and cell phone number are posted above! If he does your state great! Last I talked to him he seen no point in the near future for a drop in price!

 

[SS MAYFLOAT]

Re: Gold on circuit boards

The boards I got that have the gold on them are from high end cash registers. The equipment in hospitals have lots of gold on their circuit boards as well.

If I had a camera, I would take a pic of these boards to prove that the circuit runners are indeed gold plated. The gold is there to prevent corrosion. Even the expoxy coated boards with tin alloy runners will still corrode under harsh conditions. Just because a person has not encounted such a board does not mean that they are not out there. I was surprised that I found these particular boards in the equipment that I was seperating for scrap.

 

[arboldt]

Re: Gold on circuit boards

I wish I knew of a place to recycle old electronics. I probably go too long between upgrades, so it'd take me years to come up with even a pound.

I remember touring a gold mine in the Black Hills (probably 45 -50 years ago), and seeing how many tons of ore they had to process to get even an ounce of gold, so even a miniscule amount on electronics boards would be cheaper to get, I'd think.

And then I think of photos of chemical wastelands in China where most electronic recycling is done, and the chemical pollution and environmental tragedies those poor people endure to recover anything of value.

I suspect a few hundred years from now, our landfills will be prime mining areas for all kinds of things.

There's gotta be a better way.

 

[MrBigStuff]

Re: Gold on circuit boards

The boards I got that have the gold on them are from high end cash registers. The equipment in hospitals have lots of gold on their circuit boards as well.

If I had a camera, I would take a pic of these boards to prove that the circuit runners are indeed gold plated. The gold is there to prevent corrosion. Even the expoxy coated boards with tin alloy runners will still corrode under harsh conditions. Just because a person has not encounted such a board does not mean that they are not out there. I was surprised that I found these particular boards in the equipment that I was seperating for scrap.

I would love to see a picture of the boards! I haven't seen everything but I have worked in design engineering for >28 years in both industrial and medical electronics. I have never seen a board with gold plated traces- yet. Some of my designs for industrial applications would easily surpass the medical in terms of environmental harshness. Conformal coating is going to be a lot cheaper method than gold plating and it's commonly used in very severe operating conditions where soldermasking or tinning is insufficient. Again, I would love to see the boards to understand why that choice was made.

One final thought- beryllium copper has a very close appearance to gold. It is typically used in contact/terminal applications. Are you sure the metal is gold and not some alloy of copper that is untinned?