Nigel: If you are washing the board after soldering I would recommend using a water soluble mask. We have used the Lackwerke Peters GmbH peelable vinyl mask in the past but have moved away from it. Using water soluble mask eliminates the labor intensity of removing the peelable style mask. Also depending on how the peelable is used, configured, applied and cured it doesn't always come off that easily. This is not aimed at the Peters mask but to peelables in general. We apply the temporary solder mask at the assembly level. Since we wash after soldering, water soluble masking materials are used. They are applied by imaged screen printing, localized liquid dispensing or taping depending on board design and volume of product. Screen printing is the most prevalent approach. I'm not sure why your board fabricator is hesitant to use the peelable unless they are not set up for doing imaged screening. However it's not a big leap from doing permanent mask to doing temporary mask. Perhaps they don't have enough customer requests for this to put in the process. I can understand why the fabricator may be hesitant to apply the water soluble mask. If the boards are nor packaged and/or stored correctly it can start to breakdown and also stick or brick together. Regards Michael Barmuta Staff engineer Fluke Corp. Everett WA 425-446-6076 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Burtt, Nigel Sent: Wednesday, January 03, 2007 7:44 AM To: [log in to unmask] Subject: Re: [TN] Temporary peelable solder masks Peter, I guess in part that is what I am asking. Do US assemblers more commonly use the in-house/DIY approach rather than have the PCBs supplied with the masking pre-applied to a supplied (gerber layer?) pattern. Alternatively I know that some use masking that is removed by a post-wave-solder cleaning process rather than peelable. Just surprised that what our suppliers seem to think is not a big problem to provide as a normal service is apparently not so readily available in USA... Or maybe it just depends who you ask! Cheers Nigel Burtt Production Engineering Manager Dolby Laboratories, Inc. - European HQ Email: mailto:[log in to unmask] Tel: +44 (0)1793 842132 [direct line with voicemail] Fax: +44 (0)1793 842101 -----Original Message----- From: Peter Swanson [mailto:[log in to unmask]] Sent: 03 January 2007 15:37 To: TechNet E-Mail Forum; Burtt, Nigel Subject: RE: [TN] Temporary peelable solder masks Nigel, You rightly draw the distinction between a) the types of temporary masks which are pre-applied by screen printing, usually by the pcb fabricator and b) the temporary masks which are dispensed on by the guys doing the assembly. They are different. Whilst it is obviously desirable to have this job done by your fab guy, as you pointed out, it isn't always straightforward. In particular, I remember a few years back when the process window on the screenable materials wasn't very wide, resulting in problems from under/over cure, removal, etc. Maybe the formulations are more robust today. It is possible to make the "in-house" dispensable types more appealing. Dispensing can be by fairly inexpensive robotics. Curing can be quick by heat or UV. Is this approach an option? Regards, Peter -------------------------------------------------------- Peter Swanson [log in to unmask] INTERTRONICS http://www.intertronics.co.uk Tel: +44 1865 842842 Oxfordshire, England INTERTRONICS is dedicated to providing quality material, consumable and equipment solutions to the high technology, high performance assembly industries, incorporating outstanding levels of technical support and customer service. Read our blog! http://www.intertronics.co.uk/blog/blog.htm -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of N Burtt Sent: 03 January 2007 09:27 To: [log in to unmask] Subject: [TN] Temporary peelable solder masks I'm being told that these are not widely used in USA, the common types used here in the UK (Peters and Electramask) not readily available, and they create packaging and shipping problems... thus US PCB suppliers reluctant to supply PCBs with peelable masking applied. Is this true? Now they are by no means a perfect solution to protecting holes on a PCB during wavesolder, but am not aware of another way of doing so in a no-clean RoHS process if fixturing can't do it. What do US PCB assemblers do if pre- applied peelable masking is really not viable? Other ideas? --------------------------------------------------- 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 847-615-7100 ext.2815 ----------------------------------------------------- ----------------------------------------- This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. --------------------------------------------------- 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 847-615-7100 ext.2815 ----------------------------------------------------- This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately. --------------------------------------------------- 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 847-615-7100 ext.2815 -----------------------------------------------------