Hi Phil, I am just wondering how today`s PCB can be processed with DFSM ( dry film solder mask ) for several reasons: - DFSM is at least 2 mill thick , it means you might expect SM to be much more higher than the pads - It seems to me that ENIG and Immersion Tin chemistry will attack the DFSM and probably will contaminate quickly the chemistry. - what about resolution of DFSM which is usually far below lines/spaces present today ??? Best regards Edward Edward Szpruch Eltek Ltd P.O.Box 159 ; 49101 Petah Tikva Israel Tel ++972 3 9395050 , Fax ++972 3 9309581 e-mail [log in to unmask] > -----Original Message----- > From: DUTTON Phil [SMTP:[log in to unmask]] > Sent: ו ינואר 23 2004 2:54 > To: [log in to unmask] > Subject: Re: [TN] Why Dry film Solder Masks? > > I've recently specified dry film solder mask on a production board. > I normally ask for LPI. > The only reason being that I couldn't rely on LPI to reliably tent every > via. > The badly tented vias could not pick up solder and fill adequately to > comform to the Class 2 requirements, creating reliability concerns. > Ideally, I would like the vias filled and then tented with LPI, but our > fab shops here in Australia don't do the via filling. > > regards, > > Phil Dutton. > > -----Original Message----- > From: Steve Gregory [mailto:[log in to unmask]] > Sent: Thursday, 22 January 2004 11:47 AM > To: [log in to unmask] > Subject: [TN] Why Dry film Solder Masks? > > > 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 > ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------