Developing speed should be set by breakpoint. Developer pH does affect speed, however. If you are using a batch make-up, your best bet is to check breakpoint frequently, and adjust speed as required. If you use a feed and bleed replenisher system, pH can be tightly controlled (+\- .4) with ease. Then, breakpoint will be very stable, as will conveyor speed. Feed and bleed units are available from a variety of sources, and are fairly inexpensive (10 to 15K). Charting pH for SPC while using this type of unit will result in great CPK's. You will also be running a very consistent developing process. If you are trying to increase or decrease speed to match other units in an inline DES process, you may have to play with developer concentration. Check with your resist supplier before making any changes. Mark Dowding Multek Irvine [log in to unmask] or [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Photoresist developing Author: [log in to unmask] at INTERNET_GATEWAY Date: 7/3/96 3:14 PM Our process engineer for developing and I have been discussing ways to improve that process. He wants to see if developing solution pH can be used to set developer speed. Is this possible? Anyone else doing this? We also are looking for ways to use SPC to improve in this process. Anyone want to work with us or discuss this? Lou Hart Quality Assurance Compunetics 412-858-6117 . The mail list is run by SmartList v3.05 To unsubscribe from this list at any time, send a massage to: [log in to unmask] with subject:unsubscribe and no text. 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.