Hi Kris

    The information I have says that all electroplated film have
stress, but if you want a Gold filme without stress you can try an
electronless bath! I never used Au electronles bath, only Ni, but I
know they it exist and works well.

  Good look!!
  Best regards

  NH

>
> ---------- Forwarded message ----------
> From: kris 
> To: mems-talk@memsnet.org
> Date: Thu, 2 Aug 2007 21:24:05 -0700 (PDT)
> Subject: [mems-talk] Stress in Au electroplating
> Dear all,
>
> I am bonding (Au-Au thermocompression bonding)two
> different dies, one of them has electroplated Au on
> it. The sacrificial layer removal of one die results
> in the device release over the other die.
>
> I have seen lot of stress in the released structure. I
> was wondering if the the bonding temperature (400C) is
> the main reason for the residual stress in the
> electroplated Au??
>
> Can someone suggest me or provide a reference for the
> stress free or less residual stress Au electroplating.
>
> I am using sulphite bath from Technic, Inc. My plating
> setup is a typical beaker,electromagnetic stirrer,
> platinum mesh and 4" wafer. I am using pulsed power
> supply for the electroplating.