Re: Gold plating the entire PCB

On Thu, 3 Apr 2008 06:41:02 -0700 (PDT), MooseFET <kensmith@xxxxxxxxx>
wrote:

On Apr 2, 10:56 am, qrk <SpamT...@xxxxxxxx> wrote:
On Tue, 01 Apr 2008 21:40:10 +0000, Guy Macon

<http://www.guymacon.com/> wrote:

qrk wrote:

It's the thickness of the gold layer. Supposedly, immersion gold layer
is thin enough (<1um) where its absorbed into the solder and not
enough to cause embrittlement.

...but only if the entire gold surface is wetted by solder.
This is not the case if you gold plating the entire PCB.

You're only worried about the part that gets soldered. Most boards,
these days use a soldermask to prevent solder from getting sucked off
the pad down the trace. If this is for a home made board without a
soldermask, then disregard everything I've said. What I'm spewing is
for commercially made boards.

Also, after the gold is dissolved, the solder has to wet
tin, not copper.

After the gold is dissolved, the solder is in contact with nickle
plated over the copper. Commercially plated boards have the copper
pads as the base material, nickle plating over the copper, then gold
plating over the nickle.


Oh-oh. I can't have that nickel in there. Does the same apply for
the solder getting down to the copper?

I don't know if immersion gold is possible over copper (no nickel).
You need to talk to your board supplier. As someone else mentioned,
they stripped the gold off their solder terminals. That seems like a
lot of work for pcb pads.
.

Relevant Pages

  • >>>> SOLDER COPPER <<<<
    ... How To Solder Copper Pipe ... How To Silver Solder Copper Pipe ... Time To Solder Copper Fittings ...
    (sci.fractals)
  • Re: Gold plating the entire PCB
    ... makes a nice chemically stable layer on top of the copper. ... cost more than the small amount of gold involved. ... gold that gets absorbed into the solder joint. ... EVERY PCB situation is ...
    (sci.electronics.design)
  • Re: Gold-PLated PCBs?
    ... Gold over nickel over copper? ... of exotic alloy for the solder? ... The only gold plating I've ever seen on a PCB has been edge ... They're usually gold over nickel over copper, ...
    (sci.electronics.design)
  • Re: Gold-PLated PCBs?
    ... Gold over nickel over copper? ... of exotic alloy for the solder? ... The only gold plating I've ever seen on a PCB has been edge ...
    (sci.electronics.design)
  • Re: Gold-PLated PCBs?
    ... of dollars for the design, deliverables are ten small PWBs), ... Gold over nickel over copper? ... of exotic alloy for the solder? ... The only gold plating I've ever seen on a PCB has been edge ...
    (sci.electronics.design)