I whole heartedly agree. Inspect the fabricator's cleaning and scrubbing techniques prior to mask application. That is where the trouble lies. Mask goes on like an adhesive and like an adhesive it needs a clean surface and, if possible, some texture to adhere to. CR Dave: The obvious answer is that the soldermask is not properly bonded to the board. The adhesive strength of the CM8 to the soldermask is nowhere near the bond strength of the mask to board. My first guess would be there is some type of surface contamination between to board and soldermask causing this. A couple of questions to better answer your question: 1. What type of soldermask is it? 2. Is it coming off the laminate, immersion silver or both? 3. If you apply the CM8, allow to cure and peel off without wavesolder does the same thing happen? 4. Is it possible that screw/nut/heatsink are fracturing the mask in some fashion causing it to lift? Regards Michael Barmuta Staff Engineer Fluke Corp. Everett WA 425-446-6076 -----Original Message----- From: Dave Chapman [mailto:[log in to unmask]] Sent: Friday, August 08, 2003 6:59 AM To: [log in to unmask] Subject: Re: [TN] The attack of the Peelable Mask -----Original Message----- From: Dave Chapman To: [log in to unmask] Subject: [TN] Peelable Solder Mask I am putting Chemtronics Chemask CM8 on a screw and nut securing a heatsink and when I peel it off after wave solder the board solder mask is coming off as well. The boards are Immersion Silver Finished. We have used the Chemask for hundreds of thousands of PCB's without this issue. What could be wrong? Dave Chapman --------------------------------------------------- Technet Mail List provided as a free 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/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 1.8e 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/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 1.8e 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/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 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- -----------------------------------------------------