The first item I would recommend is to convert your batch developer
to a feed and bleed system. (You will use more chemistry, but you will
a much improved product).  This will require that you buy a dosing
system and pH controller, these items will be somewhat spendy (probably
around 20K for the whole setup) You should talk with your resist vendor
and let them make recommendations.  If you do not want to convert to feed
and bleed, batch systems can be monitored using SPC.  As you load the
developer you need to monitor three things
	1. Solutiuon pH
	2. Loading (sq, ft developed resist in solution)
	3. conveyor speed that produces good product
The first two are relatively easy to monitor and document the third
requires that you inspect product after develop and determine whether
you are getting good or bad results at that conveyor speed and solution
pH.  What you should be able to come up with is an x,y graph of solution
pH versus conveyor speed. The conveyor speed will need to decrease
as the pH falls (bath becomes loaded with developed resist) in order
to allow for good developing.  Again batch developing is not recommended,
but if you don^t want to spend the bucks and your engineer has
some time you can probably make batch developing work.  Of course,
your resist vendor will probably do most of the work for you.

Hope this helps,
Josh Moody
Process Engineer
Merix Corp.
Forest Grove, OR

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