You can try pulse plating, that will make smaller grains and reduce the
stress, something like current on for 25 milliseconds, then off for 15
milliseconds. Also make sure that the current is on when you go into the
bath.

Rick


-----Original Message-----
From: mems-talk-bounces+rmorrison=draper.com@memsnet.org
[mailto:mems-talk-bounces+rmorrison=draper.com@memsnet.org] On Behalf Of
Shree Narayanan
Sent: Tuesday, July 05, 2011 11:35 PM
To: mems-talk@memsnet.org
Subject: [mems-talk] Nickel electroplating stress issue

Hello All,

I am attempting to electroplate nickel of 100um thickness on Ti/Au seed
layer. I am using Technic Nickel Sulphamate RTU solution at 45C with
150rpm
magnetic stirring. The pH was monitored to be at 4 and the current
density
maintained at 70mA/cm2.

After 2 hours of plating, the stress is huge that it strips from the
pyrex
substrate. I have also added 1g/L saccharin but to no use. Can someone
give
me some pointers on how to tackle this stress issue.

A link to an optical image of the metal stripping out of the surface and
looking skywards:).

http://www.box.net/shared/nkp95tltba58382laydc

Thanks for your time.
Shree