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 The mail list is run by SmartList v3.05 To unsubscribe from this list at any time, send a message to: [log in to unmask] with subject:unsubscribe and no text.