Here are a couple real life reasons I have run into: Tenting of larger via holes without worry about unpolymerized LPI in the via, and the associated defect known as "anthills". The cost of changing the drawing to allow LPI, when Dry film was called out. The improper, yet still done, practice of using the soldermask as an insulation layer between a metal grounded component body and active traces running underneath. It worked last time, don't want to change any thing. The buyer who is placing the order has no authority to push back for design changes, or the design is so old, there is no one responsible for the design anymore. No way are you going to get the buyer to take responsibility for a product design change. George Franck Quality Assurance 703 295 2635 Steve Gregory <[log in to unmask] To: [log in to unmask] OM> cc: Sent by: TechNet Subject: [TN] Why Dry film Solder Masks? <[log in to unmask] > 01/21/2004 08:17 PM Please respond to "TechNet E-Mail Forum."; Please respond to SteveZeva Can anybody tell me why dry film solder masks are still specified? I don't want to hear; "Because they've always worked good..." But some clear, concise, reasons for specifying them... Vacuum at ICT is a dead deal, there are ways to deal with open via's with LPI's...Solder fill for via's is a dead deal...either you fill them, or you don't. So why dry-films? So many complications come up with dry film solder masks... Not only for the bare board manufacturer...but also for the assembler. Just a question...(for the DoD guys, especially) -Steve Gregory- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------