Re: Gold-PLated PCBs?

On Sat, 24 Feb 2007 04:06:10 GMT, Rich Grise <rich@xxxxxxxxxxx> wrote:

On Fri, 23 Feb 2007 10:07:49 +0000, me wrote:
Robert Baer wrote:

Gold looks sexy, but can cause rather expensive problems.

Assuming no cost constraints (customer paying thousands
of dollars for the design, deliverables are ten small PWBs),
no Rohs requirement, and a normal office environment, which
would you choose? Gold over nickel over copper? Some sort
of exotic alloy for the solder? Or good old copper traces
and 63/47 solder?

The only gold plating I've ever seen on a PCB has been edge
connectors. Of course, they plug into sockets with gold-plated
contacts. They're usually gold over nickel over copper, but
the rest of the board is usually tinned and has solder mask.


It was common for old Tek and HP gear, roughly 1970 vintage, to have
pcb's with heavy gold plating everywhere, ususlly with no solder mask.
Nowadays, you see gold flash over nickel on high-density BGA boards,
or on boards that will be used with lead-free solder. We fabbed a few
boards like this recently... they looked like jewelry.

John

.

Relevant Pages

  • Gold plating the entire PCB
    ... makes a nice chemically stable layer on top of the copper. ... occurred at the interface between solder balls and PCB pads. ... "ENIG (electroless nickel and immersion gold) plating applies ...
    (sci.electronics.design)
  • 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. ... I was not considering nickel under the gold. ... When eutectic 63% Sn - 37% Pb solder is ...
    (sci.electronics.design)
  • Re: American PCB fabs defaulting to lead-free
    ... they work fine using normal leaded solder. ... The downside is you have a possibility of tin whiskers ... Gold plating is bad, as it is a flash of electroless gold deposits a ... over nickel which is plated over the copper traces. ...
    (sci.electronics.design)
  • 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)
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