I expect you will get a lot of responses like that. Soldermask is not a reliable insulator. And to point out the other variable: does the arcing come from the body of the part? Is its insulation changing or unreliable (too)? Ahne -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Hogg, Blair K. Sent: Thursday, 05 July, 2007 08:37 To: [log in to unmask] Subject: [TN] Soldermask Thickness We switched PC board suppliers for one of our products a while back and have started having hipot issues with components that are connected to main 110VAC input voltage arcing through the soldermask to tracks underneath at 1200V hipot voltage. I'm pretty sure I'll get a few responses that say that we shouldn't be using the soldermask as an insulator, however, since the change in supplier seems to coincide with the onset of problems, I've been asked to evaluate the soldermask thickness as a potential contributor to the problems. I would some recommendations on how to measure the thickness of the soldermask. Thanks, Blair ******************************************************************* This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept for the presence of computer viruses. www.Hubbell.com - Hubbell Incorporated --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 -----------------------------------------------------