Sal: If I'm reading your post correctly this is showing up on a Sn/Pb board not SMOBC. If that is the case and you are using mechanical screening such as a DP10 which applies higher squeegee pressures than hand screening, then what your seeing is not unusual.Take a close look at the residual soldermask and see if it has a dot pattern and spacing the same as the mesh in your screen printer. I have seen this on LPI's from many different suppliers. The mask forms a "compression bond" to the surface of the Sn/Pb when screened and will not release during development. We worked with our suppler in the formulation and formulation processing steps to solve the problem. Regards Michael Barmuta Staff Engineer Fluke Corp. Everett Wa 425-356-6076 On Tue, 26 May 1998 11:33:56 -0700 Modular Components National, Inc. wrote: > From: Modular Components National, Inc. <[log in to unmask]> > Date: Tue, 26 May 1998 11:33:56 -0700 > Subject: [TN] Liquid Photo Image Soldermask > To: [log in to unmask] > > To All > We are using RONASCREEN OPSR 5600 HARDENER & RONASCREEN 5600 > OPSR 5600 CODE 2D-AU SOLDERMASK. The problem that we are having is after we > screen the board and tack cure the board at 160 F for 30 min. We then > expose the board then develop the board. Upon inspection of the board on > the developed areas we have found small little areas of soldermask all over > them if we try to develope them again they will not come off. Has anyone > come across this before if so, how did you fix it? > Last thing the the areas have Tin Lead on them. > > > > THANK FOR ANY IMPUT > SAL MITICHI > Modular Components National, Inc. > 2302 Industry Court > Forest Hill, MD 2150 > PH (410) 879-6553 > Fax (410) 838-7629 > > ################################################################ > TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 > ################################################################ > ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################