Doug - IPC 4101 was first published in 1997, so it is not possible that it was the originating standard (UL 746E has been around for decades), though it does contain specification or several materials, some of which are cross-referenced to NEMA and MIL types.
I looked into the NEMA connection a bit and found a standard reference for industrial laminates dating back to 1927. For further reading, refer to NEMA LI1, which provides a large cross-reference of standards (ASTM, IEC, NEMA, MIL, UL). The TOC and scope of LI1 is available free to download at http://www.nema.org/stds/li1.cfm See Subclause 1.4 of LI1 (Page 9 of 9 of the above download) for the antiquity I mention above, in spite of being small a number of standards available at the time. It may be interesting to read references for IEC standards on the subject, if anyone knows them or doesn't mind taking a little time to look into it. Regards, Peter L. Tarver, PE [email protected] > -----Original Message----- > From: POWELL, DOUG [mailto:[email protected]] > Sent: Wednesday, June 01, 2005 9:24 AM > To: [email protected] > Subject: RE: PCB inner plane spacing for high pot > withstand > > > The originating standard is IPC 4104 > > > > -doug > > > > -----Original Message----- > From: Peter L. Tarver > [mailto:[email protected]] > Sent: Wednesday, June 01, 2005 9:23 AM > To: POWELL, DOUG > Subject: RE: PCB inner plane spacing for high pot > withstand > > > All - > > I recall that UL 746E contains a set of tables that define > the minimum properties set for generic ANSI grade > materials, > such as FR-x and G-x, XP ... > > I also recall that these tables may have been derived from > an ASTM standard, though I'm not certain of the > originating > standard. Greg Galuccio might recall more > clearly, if he's > still around. > > IPC might have a similar set of tables in a standard. > > These tables can be used in establishing a minimum set of > criteria for interlayer electric strength per mil for a > given cured industrial laminate. > > > Regards, > > Peter L. Tarver, PE > [email protected] > > > -----Original Message----- > From: POWELL, DOUG > Sent: Tuesday, May 31, 2005 3:01 PM > > > Chris, > > <deletia> > > While it is true that laminate manufacturers will have > differing information on dielectric withstand of cured > layers. I have found that for FR-4 using > 500V/mil for base > material and 350V/mil for prepreg material is quite > adequate. > > -doug This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
