The copper diffuses into the gold

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Nik Dee
Sent: Saturday, February 03, 2007 4:19 PM
To: mems-talk@memsnet.org
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?

Nik Dee