In a message dated 98-06-10 19:22:46 EDT, you write:

<< Is there chemistry available to remove oxidation
 from gold tips without compromising
 solderability?

 More specifically we have a costumer that has
 sent back some boards that have been stored
 for almost a year.  The gold tips are tarnished.
 The customer has requested that we rework the
 boards, without out buffing the gold out. >>

Chris:

Given the fact that Gold does not tarnish, it almost certain that the tarnish
you are seeing is from the Gold being porous, and the underlying Nickel has
oxidized, and that is what you are seeing.  Alternately the tarnish could be
from a metal that is co-deposited in the Gold, typically Cobalt.

I have a strong sense that a good acid cleaner, especially one containing
citric acid, should do the job nicely for you.  Alternately, a "simple" (you
should excuse the expression) dilute solution of either Sodium or Potassium
Cyanide in water, applied with a cotton swab should do the job.

If you want a sample of a citric acid based cleaner that should be more than
sufficient to cleaner a few thousand boards, give me a call.

And give my regards to Dr. Bratton.

Rudy Sedlak
RD Chemical Co.
Mountain View California
phone: 650-962-8004

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################