Stuart ; I have just one answer. OSP coatings can't support oven reflow temperatures and the answer is the OSP is removed by the processing, I had problems in the past with a double pass board ( glue bottom side, solder top side ) and had insufficient fillet or not wetting at solder wave machine, due to OSP removal at the previous process ( solder reflow ) ,the solution were switch the boards to HASL finish. I hope this help ( at least first question !!! ) Jorge Dourado de Santana Maintenance / Process Engr Microtec - Brazil > -----Original Message----- > From: Stuart Korringa [SMTP:[log in to unmask]] > Sent: 22 de Fevereiro de 2000 10:45 > To: [log in to unmask] > Subject: [TN] Entek question > > TechNet, > > We have some SMT CCAs which we receive with Entek OSP coating. The > vias on > the PWB are not solder masked nor during assembly processing are they > screened > and pasted. After convection oven reflow, is there still some Entek on the > vias > or is the OSP removed by the processing? > > The CCAs are later conformally coated which puts down 1-5 mils of type AR > protection on the vias. However the vias underneath large QFPs do not get > conformally coated by the Nordson sprayer. Is there a reliability concern > here? > > Also, after 120 hours of humidity/temp cycling, the tin-lead pasted areas > exhibit some white residue while the non-solder masked and non-conformally > coated Entek areas appear fine. > > In anyone's experience, is there a long term issue for Class 3 goods? > > Stu Korringa > Smiths Industries > Grand Rapids, Mi > [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. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################