Would it be possible to stencil print, or dispense dots of an appropriate epoxy paste to form small mechanical stand offs only at the location of the offending PTH components? Best regards, Leo Leo M. Higgins III, Ph.D. Sr. Vice President, Engg and Technology ASAT, Inc. 13809 Research Blvd., Suite 635 Austin, Texas 78750 office phone 512-249-4758 mobile 512-423-2002 [log in to unmask] www.asat.com -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Phil Nutting Sent: Wednesday, August 15, 2007 9:59 AM To: [log in to unmask] Subject: [TN] Solder mask as an insulator Let me start with, I know that we should not rely on the LPI solder mask as an insulator. So I need recommendations for a simple and cost effective solution. Problem parameters; 0.062 thick FR-4 with 2 oz copper and LPI mask. PTH components laying on traces that go under the parts. PTH parts are shorting to the traces. Our fab house is against adding a second layer of LPI mask. On face value a second layer sounds good and easy, but I know there are issues too long to list. Short of raising the components above the board, applying an insulator under the components or a new board layout is there a better way of preventing this shorting problem? Thanks in advance. Phil Nutting Design for Manufacturing Engineer Kaiser Systems, Inc. 126 Sohier Road Beverly, MA 01915 voice: 978-922-9300 x1310 fax: 978-922-8374 e-mail: [log in to unmask] www.kaisersystems.com --------------------------------------------------- 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 -----------------------------------------------------