Hey Shay,
  what i suggest is to add less proportion of acid to solution.
  hope this will help?
  regards
imran ali

  From: "Shay Kaplan" 
To: "'General MEMS discussion'" 
Date: Sun, 4 Feb 2007 08:49:30 +0200
Subject: RE: [mems-talk] Copper plating

The copper diffuses into the gold

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Nik Dee
Sent: Saturday, February 03, 2007 4:19 PM
To: [email protected]
Subject: [mems-talk] Copper plating

Hi guys, I am currently using a Copper plating solution (Water, Copper
Sulphate, Sulphuric Acid, NaCl and CUbath copper brightener) on gold seed
layer. I try to keep the plating rate to 30mA / cm2. I have noticed
sometimes that the copper plated on the seed surface is not bright enough
and it gets a pink colour. Do you have any idea what the reason for that
might be?