Photo-imageable seems to be the most common, but there are the other types around as well, and what I'm trying to find out is why would a designer choose one type over another - are there any guidelines on which type to select for particular sorts of applications or particular sorts of substrate materials, and having chosen one, how does said designer determine how thick it should be? It's not left to the PCB fabricator, is it? I've heard enough to know that too thick a resist layer can affect solderability among other things, while too thin a layer reduces its effectiveness. Put it another way - if I don't specify a resist and resist thickness, how do I gain confidence that my PCB fabricator has chosen to put the right thickness of the right resist on my boards? Any ideas? Best regards Pete Paul Klasek <PaulK@ResMed To: "[log in to unmask]" <[log in to unmask]> .com.au> cc: Subject: RE: [TN] Which Solder Mask 05/29/01 01:33 PM Thought it was bit fuzzy . Photo-I is the way, watch for undercure (too fast process) on UV, BLISTERS THAN . Common enough when fab's are stressed . paul -----Original Message----- From: [log in to unmask] [mailto:[log in to unmask]] Sent: Tuesday, May 29, 2001 3:05 PM To: Paul Klasek Subject: RE: [TN] Which Solder Mask Thanks, Paul, but maybe I need to clarify what I'm after a bit - I'm talking about the actual caoting that PCB fabricators put on boards to cover external tracking, etc., the photo-imageable, dry film, UV cureable type resist layer. Pete Duncan Paul Klasek <PaulK@ResMed To: "'TechNet E-Mail Forum.'" <[log in to unmask]>, .com.au> "[log in to unmask]" <[log in to unmask]> cc: 05/29/01 Subject: RE: [TN] Which Solder Mask 06:17 AM Multicore's "Spot Stik" latex used to behave well, easy peel afterwards, not the usual dentistry . That is, for the resist. paul -----Original Message----- From: <Peter George Duncan> [mailto:[log in to unmask]] Sent: Monday, May 28, 2001 3:39 PM To: [log in to unmask] Subject: [TN] Which Solder Mask 'Afternoon, All, Today I need your help to find a good guide on how to select solder mask/resist materials and how to determine what thickness should be specified for particular applications. Immediately I need to know recommendations for 0.063" thick, 10 layer FR4 HASL finished VME conduction-cooled boards of 15 mil track spacing for military application. Boards will be Convection Reflow Soldered with Kester 63/37 solder and 331 flux. Anything else you need to know? I'm from a manufacturing background and have never needed to know this level of detail before. However, I am now involved with helping a bunch of design engineers who have even less idea than I do about this sort of thing than I have. I have had a go at the Web trying various terms and key words, but get absolutely nothing useful back at all, so I'm hoping our TechNet Goldmine/Delphi Oracle can succeed where the WWW has failed me. TIA, Pete Duncan ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------