Gold Embrittlement in solder joints

[status1]

Hello,
The basic question was answered in another closed thread but I just wanted to find out a little more detail about it

How exactly and why is solder used to remove the gold plating ?
What I mean is that since gold melts at much higher temperature than solder than why would the solder remove the gold ?
Is there something else going on like a chemical reaction ?
Maybe the correct word is leaching ?
But I still don't quite understand why would gold leach out in the solder. Does this work for other metals or just gold ?

I am taking the IPC 610 training and I asked the trainer about it but he did not know exactly how that happens
I know it sounds like a stupid question but I am just curious

 

[IRstuff]

Duh?

Does someone think that the gold plating is somehow bad? Can you really imagine doing this on every single solder joint?

Wouldn't this be a total waste of time and money? And wouldn't someone think that it might be more efficient to not have gold there in the first place, if all you're going to do is to remove it immediately prior to soldering?

TTFN

FAQ731-376

 

[status1]

I totally agree with the waste of money but I guess when you work for NASA price is not a factor
Where do you think those $700 hammers come from ?


Actually we did receive a small quantity of bds (not for NASA) that were plated with gold by accident and we ended up using it as is just soldering to it normally and haven't had any returns because of any joint failure

 

[IRstuff]

IPC610 allows for that, so long as you have documentation of no solder issues.

Frankly, it seems to be a perfectly stupid idea. Every additional second of heat on every joint is just increasing the probability of failure from other problems.

TTFN

FAQ731-376

 

[status1]

I agree but we can't do anything about it just follow the rules like a bunch of lemmings

 

[MacGyverS2000]

So your intent is to remove the gold plating from certain locations by applying solder and sucking it up? That's not going to work, not by a loooooong shot. You would need to apply/remove that solder several million (billion? trillion?) times to even come close to removing all of the gold. Doing it twice, you're just going to piss off the plating, not get rid of it.

You have three choices: 1) Don't put it there in the first place (masking is easy as pie during the plating process), 2) Remove it by chemical means (not ideal by a long shot, and messy, possibly dangerous/toxic), 3) Remove it by mechanical means (such as sandpaper tubes on a Dremel).


Dan - Owner

http://www.Hi-TecDesigns.com

 

[status1]

That's not my intent.
That is the instruction according to the IPC 610 standard
and the instructor

I understand your point and I have not removed any gold from any pc bd I was just trained on the IPC 610 so I was just curious about the process in theory only not in reality.

 

[richardgb]

"I understand your point and I have not removed any gold from any pc bd I was just trained on the IPC 610 so I was just curious about the process in theory only not in reality."


There is no real gold out there any place in industry.
Real gold is in gold nuggets only. Close to 100% gold.

Jewelry gold and industrial (watch cases etc.)are a tin-copper alloy with only a trace of real gold in it.
The gold content is less than 1/1000 of one percent even in
gold bullion coins.

Specific gravity of tin can be increased to match that of gold by melting the tin and letting it cool down on air--repeatedly. I am ready to do that experiment here at home and have a way to check specific gravity as well.

I learned this from God (who now wants to be called Voynich)
at age 4, looking at my real tin soldiers I was playing with.

So, now I want to prove it to myself.

I own a few gold nuggets purchased from ebay, they look like crap, not shiny like gold, but that proves they really are gold.


So, you are really not dealing with gold at all, but with compressed tin at 99 % or so. That golden tin has similar qualities to real gold, and its usefulness has been established.

Since you don't believe this, there is no point in writing any more than this.


Voynich (psychic reading)

 

[btrueblood]

"Since you don't believe this, there is no point in writing any more than this."

But what about the cold fusion possibilities?

 

[IRstuff]

It's indeed so disappointing that the IPC would be so bamboozled into thinking there was actual gold on their PC boards:

http://www.ipc.org/4.0_Knowledge/4.1_Standards/6012B-Amendment-1(12-06).pdf

TTFN

FAQ731-376

 

[analogkid2digitalman]

Wow! So my tin jewelery I mail in that safe and secure envelope to "Cash for Gold" is going to be a heck of a deal!

-AK2DM

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"It's the questions that drive us"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

[IRstuff]

Let me know how that works out for you ;-)

TTFN

FAQ731-376

 

[status1]

Looks like we are getting a little bit off the subject
I was only asking about the gold plating on pc boards
I was not referring to jewelery or any other gold

I found another good link that explains the type of plating
and it's many uses

http://en.wikipedia.org/wiki/Gold_plating

 

[IRstuff]

Actually, the IPC link I posted has some very detailed data on the layer construction; it would probably be quite educational.

TTFN

FAQ731-376