In order to avoid thermally curing the top layer for
thick or ultra thick SU-8 with strong light source,
the on/off mutiple-time exposure are used.

If your illumination source is with low output, such
as 10mW/cm2 at i-line, you may continue exposure,
doesn't matter 200mJ/cm2 or 260mJ/cm2.

--- "Yue Mun Pun, Jeffrey"  wrote:

> Hi,
> I have heard on this forum that somebody mentioned
> that in exposing SU-8 we should not exceed 200mJ at
> a time.  I will be exposing SU-8 2150 at 260mJ,
> should I do it in 2 steps?