Emily, I apologise as I didn't see your original question. However a realtime quality of etching I should think would be actual product measurements. Use a scope or other calibrated instrument to tell you if you are meeting the product spec after etch. Use SPC with this data. Most etchants as I see it are controlled fairly well with current controllers. There will be variation in the pH, Cu conc. etc. but nothing wild unless you have problems. The bottom line is the product. Are you getting what you should. Mike Doty -----Original Message----- From: Emily Tse [mailto:[log in to unmask]] Sent: Sunday, March 11, 2001 10:04 PM To: [log in to unmask] Subject: [TN] Quality of Etching Dear All, First of all, thanks for those who'd replied, it sure gave us some hints on some of the methods that are used for quality checking on etching process. For the quality of etching process, many of you have suggested cross section analysis and surface analysis such as SEM/EDX. One of the other suggestions is a passive way analysis on the quality of etching by evaluating the chemical properties (such as the Cu concentration) of etchant after the etching process. All of the above are some good ways to start, yet we wonder if there's any "real time" analysis on the etching quality? We're looking for some method that is simple enough to be carried out on the production floor, while actively controlled the etching process (instead of using the quality of the etchant AFTER the etching process) Any ideas? Looking forward for your reply! Sincerely, Emily Tse ______________________________________________ FREE Personalized Email at Mail.com Sign up at http://www.mail.com/?sr=signup ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- -----