Hopefully my lil nugget of info will help..... FR-1-A low-grade version of FR-2. FR-2-A NEMA grade of Flame-Retardant industrial laminate having a substrate of paper and a resin binder of phenolic. It is suitable for printed circuit board laminate and cheaper than the woven glass fabrics such as FR-4. FR-4-A NEMA grade of Flame-Retardant industrial laminate having a substrate of woven-glass fabric and resin binder of epoxy. FR-4is the most common dielectric material used in the construction of PCBs. FR-6- Fire-Retardant glass-and-polyester substrate material for electronic circuits. Inexpensive; popular for automobile electronics. Those wanting to be really "Geeked" up...Hopefully this will give a little more insight: http://www.ilnorplex.com/quickref.htm Regards, Cal Communications Test Design, Inc. www.CTDI.com -----Original Message----- From: Jason W. Gregory [mailto:[log in to unmask]] Sent: Wednesday, September 10, 2003 12:10 PM To: [log in to unmask] Subject: Re: [TN] FR-4 Jim Right you are...."resistant". Maybe I'm retardant. Jason Gregory Jim Geer <Jgeer@PRIME-MEASU To: [log in to unmask] REMENT.COM> cc: Sent by: TechNet Subject: Re: [TN] FR-4 <[log in to unmask]> 09/10/2003 11:08 AM Please respond to "TechNet E-Mail Forum."; Please respond to Jim Geer --------------------------------------------------- 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 -----------------------------------------------------