JOSH, Attempts to answer your question were written below. On Oct 4, 11:19am, [log in to unmask] wrote: > Subject: [TECHNET] Developing question > Recently, I heard of a dry film photoresist developer system that uses sodium > hydroxide as a pH stabilizer. Apparently, the system doses the developer > sump with carbonate based on a panel counter, and sodium hydroxide based on > solution pH. The sodium hydroxide is used straight out of the drum, probably > at around 40 % strength. I'm told this controls pH in a very tight range, > and reduces consumption of carbonate. > > I have some questions regarding a system of this type. > > 1. What would the advantage be of using both chemicals? Cost savings don't > seem to be too likely, since you are replacing one chemical with another. ANSWER: YOU CAN MAINTAIN TIGHTER pH CONTROL ON THE DEVELOPER SOLUTION ( CONSISTENT BREAKPOINT), LESS BAIL-OUT ( REDUCED WASTE AND CHEMICAL COST), INITIAL COST WOULD BE MUCH LESS THAN CONVENTIONAL FEED & BLEED SYSTEM. > > 2. What are the potential dangers of using sodium hydroxide in a developer? ANSWER: AT THIS POINT I HAVEN'T SEEN ANY. WORSE CASE SCENARIO, YOU CAN FLOOD THE SUMP WITH HYDROXIDE( IF THE pH PROBE OR PUMP IS DEFECTIVE) WHICH MAY STRIP THE RESIST OR LEAD TO RESIST BREAKDOWN. > What effects could it have on photoresist? ANSWER: SAME AS ABLOVE. > > 3. Does the addition of sodium hydroxide cause bicarbonate to be converted > to carbonate? ANSWER: YES, KOH OR NaOH WHEN ADDED TO THE DEVELOPER SOLUTION WILL CONVERT BICARBONATE BACK TO ACTIVE CARBONATE. > > 4. How many people are using this type of system in production? ANSWER: WE HAVE IT IN OUR I/L DEVELOPER & PLANNING TO CONVERT OUR O/L DEVELOPER INTO THE SYSTEM SOME TIME THIS YEAR. > > Thank you in advance for your assistance. > > ############################################################## > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c > ############################################################## > To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: > To subscribe: SUBSCRIBE TECHNET <your full name> > To unsubscribe: SIGNOFF TECHNET > ############################################################## > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. > For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 > ############################################################## > >-- End of excerpt from [log in to unmask] ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################