Alterate to Gold plating

Don't worry, it is not really going up, it's the dollar going down

martin

On pcb's? It's microinches thick, so still doesn't cost much.

John

Martin,

This should help:

Bob

And we still have gold in California! There's a new gold rush brewing.

The price of rice has doubled in the last few years. We grow lots of rice here.

John

Yes, you can invest in USO (US oil) which is up about 50% last year. Or silver (SLV), or other commodities. But they will all probably fall at the same time.

-Bill

The alternatives generally cost more and work less well. Gold can be put on very thin and still do its job so you don't end up using enough to really matter.

Lately, I've been looking again at gold plating the entire PCB. It makes a nice chemically stable layer on top of the copper. With the price of copper these days, changes are the copper on the PCB will cost more than the small amount of gold involved.

:With the price of Gold close to $1k/oz has anyone looked for alternatives? : :Cheers :

In the early 90's I was required to do a plating job on split center pins for DC jacks commonly found in small appliances such as modems cordless phones etc. Gold was out of the question because it was too soft and would wear off with expected high usage. The best alternative was Rhodium which is much harder, resists corrosion and performs well electrically.

It looks nice too.

Best regards, Spehro Pefhany

That sounds like the stuff.

When combined with the usual barrier layer,

Are there any alternatives to copper on PCBs?

Aluminum was tried for a while for house wiring. I think it would work but there seems to be a long tail on the learning curve.

It's also more expensive than gold by almost an order of magnitude!

$9,060/oz vs. a mere 931 for gold.

Historically it tracks about 8:1 according to Wikipedia.

Rhodium is used in high temperature thermocouples (something like

Best regards, Spehro Pefhany

Yes, gold does look sexy, but...beware of the purple plague, most especially at the negative end of electrolytics. Creates nice powdery un-connections.

Aluminum has a real nice electromigration and mechanomigration propensity that does not help...

Ever try to solder to aluminum?

Nowadays the standard "gold plating" on pcb pads, called "immersion gold", is a roughly 100 micro-inch electroless nickel plating finished with 8-10 uin of gold. It looks good, doesn't tarnish easily, and solders beautifully. It's very flat, so is good for fine-pitch and BGA parts. The tiny amount of gold dissolves in the solder when the board is reflowed, so the joint is basically solder onto nickel.

John

Aluminum would be big trouble on PCBs for the same sort of reasons as it is in house wiring. It isn't soft enough, it corrodes to make a nonconductive material and it has more resistance.

You can buy solder than works on some types of aluminum. It doesn't work at all on other alloys.

I don't see where the OP referred to PCB pads...

JF