Dear Jim, I am interested to know where and how we can acquire the information for ammonium sulphate etching system is etching faster than that of ammonium chloride. ____________________________________________________________________________ ______ At 02:45 PM 1999/9/9 +0100, you wrote: >For the best undercut Cupric will etch slower than cuprammonium chloride. >It is possible to make cupric etch faster than cuprammonium chloride by increasing the acid normality,at the expense of undercut. >Cupric etch speed can also be increased by additions of sodium chloride but then your metal recovery guys don't want to know. >Note that cuprammonium sulphate is even faster than cuprammonium chloride. > >Jim Douglas >Kam Circuits > >############################################################## >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. >If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or >847-509-9700 ext.5365 >############################################################## > > Albert Mok ############################################################## 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. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################