I used to spray coat resist back at Motorola.  I used to get 40,000
Angstroms to 60,000 Angstroms.  It may be worth experimenting with
simple small spray gun used fro spraying models.

 Bill Moffat

________________________________

From: [email protected] on behalf of Oakes Garrett
Sent: Fri 1/23/2009 10:23 AM
To: [email protected]; General MEMS discussion
Subject: Re: [mems-talk] Thick AZ-9260



Andrea,

By default, AZ9260 is a resist designed for a 6.0 - 8.0 =B5m coating =
thickness when spun between 3000 and 4000 rpm.  One can increase the =
thickness of a single pass coating by decreasing the casting rotational =
velocity but this will come at the expense of thickness control.  Film =
thickness of 50 =B5m might require coating the resist four times or =
more!

The best solution is to look for a resist which is designed for the =
needed thickness at 3000 rpm.  You can look at the XT and nXT resists =
from AZ-EM.  They have materials designed for the thickness range you =
desire and can be coated in only one or two passes.

Best Regards,
Garrett Oakes