Bill, Bake the boards then test them. Follow that up with testing after 48 hrs in a 85% Rh chamber. That should result in interesting information! David A. Douthit Manager LoCan LLC Bill Higinbotham wrote: >We are using a multilayer FR4 board with 12 mils between layers and getting >breakdown between traces on different layers. The voltage is about 3500 V >peak. THis board should be good for 740 V/mil x 12 or 9 KV. I wonder if >it is excessive leakage due to moisture absorption? > >Bill > >Bill Higinbotham >RFL Electronics Inc. >E-mail : [log in to unmask] >Voice: 973.334.3100 Ext. 386 >Fax: 973.334.3863 > >--------------------------------------------------- >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 847-509-9700 ext.5315 >----------------------------------------------------- > > > > --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------