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Gold Nickel Adhesion decreased due to oxide layer
January 12, 2006
I was wondering if anyone knows how to improve Au to Ni adhesion. I'm plating Au on top of Ni and there seems to be a 25A oxide layer that decreases my adhesion such that it fails the tape test.I'd like to either prevent the oxide from forming or remove it.
[name removed at request]
R&D Engineer - Minnesota, USA
First of three simultaneous responses -- January 13, 2006
How much time is there between Ni and Au? As you probably know, you can't let Ni plated parts sit in rinse tanks, they will passivate. Directly after Ni rinses you can use a Ni activator, rinse well and go directly into the gold. Be careful with choices of Ni activators, some contain high chlorides and you don't want to drag them into your gold bath. Good Luck!
Mark Bakerfellow plater - Syracuse, New York
Second of three simultaneous responses -- January 14, 2006
You start by doing a search of this web site. It has been talked about dozens of times.
Can you stand Hydrofluiric acid mixtures or fluoride containingacids?
- Navarre, Florida
Third of three simultaneous responses -- January 16, 2006
DEAR SIR YOU MAY DO THE FOLLOWING
1-GO FOR GOLD PLATING AS FAST AS POSSIBLE,WITHIN ONE TO TWO
MINUTES.
2-USE AN ACTIVATION TANK CONTAINING CYANIDE POTASSIUM,AND THE PART ON
THE NEGATIVE
GOOD LUCK
Cair Shishani
aircraft maintenance - Abu Dhabi, United Arab Emirates
First of two simultaneous responses -- January 16, 2006
I do not know what is your electroplating cycle after the Nickel Plate, Normally it is followed with an acid activate or cathodic activator,then a gold Strike before gold plate with drag-outs and rinses in between.
Hamilton Solidum
- Mays Landing, New Jersey, USA
Second of two simultaneous responses -- January 16, 2006
Dear Sir
Reduce Time delay from Ni>Au plating.Do Multiple DM water swills
in between.Introduce an activator dip prior to gold plating.Caution!
Consult your supplier before doing this.The ingredients of the
activator should be compatible with the gold bath sol'n. Introduce a
pure gold strike/Flash bath with minimum gold in the bath before the
main gold bath.
Regards
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T.K. Mohan plating process supplier Mumbai, India |
January 19, 2006
Thank you all for you comments.
Unfortunately, my process requires that I go through several steps
between the Nickel and Gold Plating. One of those steps happens to be
high temperature (over 300C) cure which is likely responsible for the
oxide layer growth. Since I can't change my process flow, or my
high-temperature cure, what can I do to remove the oxide layer after
it is formed? Anything besides HF?
Thanks!
[name removed at request]
R&D Engineer - Minnesota, USA
January 20, 2006
Is possible to use an inert atmosphere or reducing atmosphere during
heat treatment and cooling procedure to prevent oxide
formation.
Have you tried, acid Salts solution with ammonium bifluoride, Hot.
Check with your Nickel Solution supplier.
Good Luck,
Hamilton Solidum
- Mays Landing, New Jersey
January 20, 2006
Sir,
Immediately either go for an anodic cleaning after curing or better
introduce an anodic activator/dry salt.
regards
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T.K. Mohan plating process supplier Mumbai, India |