[SI-LIST] : Information on FR-4 and other PCB dielectric materials

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From: jrbarnes@lexmark.com
Date: Wed Apr 12 2000 - 06:24:34 PDT


TIA,
For the last nine months I have been researching the ampacity (safe
current-carrying capacity) of printed circuit board (PCB) traces and planes as a
side project to my "normal" work. The most complete, up-to-date source of
information on that I have found on PCB dielectrics is IPC-4101,
Specification for Base Materials for Rigid and Multilayer Printed Boards. You
can order it through the IPC Bookstore at http://www.ipc.org/

Some books with a lot of information on PCB dielectrics are:
* Handbook of Electronic Packaging (Charles A. Harper, McGraw-Hill, 1969)
* Handbook of Wiring, Cabling, and Interconnecting for Electronics (Charles A.
Harper, McGraw-Hill, 1972)
* Printed Circuits Handbook 3rd ed (Clyde F. Coombs, Jr., McGraw-Hill, 1988)
* Multilayer and Flexible Circuits (Clyde F. Coombs, Jr., McGraw-Hill, 1990)

The Dynacircuits Material Specifications for Printed Circuit Boards Sliderule
(dated 1985) has the following
information on common PCB dielectrics:
* Phenolic paper XXXP GE 11571 4.1 permittivity 740V/mil 30C Tg max 125C
operating
* Phenolic paper FR-2 GE 11800 4.2 permittivity 700V/mil 60C Tg max 105C
operating
* Epoxy CEM-1 GE 65M62 4.2 permittivity 550V/mil 70C Tg max 130C operating
* Epoxy CEM-3 GE 65M78 4.0 permittivity 550V/mil 120C Tg max 130C operating
* Epoxy FR-3 GE 65M41 4.3 permittivity 700V/mil 60C Tg max 105C operating
* Epoxy FR-4 GE 65M38 4.9 permittivity 500V/mil 120C Tg max 130C operating
* Polyester glass FR-6 Cincinnati Milacron Cimclad 4.2 permittivity 500V/mil
65C
    Tg max 130C operating
* Polyester glass CRM-5 Cincinnati Milacron Milclad 4.2 permittivity 500V/mil
65C
   Tg max 130C operating

If you are on a hurry, MIL-S-13949H and its slash sheets probably have the
information you are looking for. Go to
http://astimage.daps.dla.mil/quicksearch/ and search for document ID =
MIL-S-13949. You will need to relate the
material designations to the dielectrics you are interested in as follows--
laminate designation xy or xyz where:
* x = reinforment material:
   - A = woven aramid
   - B = nonwoven aramid
   - C = nonwoven polyester
   - G = woven E-glass
   - N = nonwoven E-glass
   - Q = woven quartz
   - S = woven S-2 glass
* y = resin:
   - B = epoxy, non-flame resistant, hot strength retention
   - C = cyanate ester, flame retardant
   - F = epoxy, flame resistant
   - H = epoxy, flame resistant, hot strength retention
   - I = polyimide, high temperature
   - M = epoxy, flame resistant
   - P = polytetraflouroethylene, flame resistant
   - R = polytetraflouroethylene, flame resistant, for microwave applications
   - T = polytetraflouroethylene, flame resistant
   - X = polytetraflouroethylene, flame resistant, for microwave applications
   - Y = polytetraflouroethylene, flame resistant, for microwave applications
* z = special consideration:
   - G = natural color F resin with 150-200C glass transition temperature
   - J = natural color I resin with 200-250C glass transition temperature
   - K = natural color F resin with 110-150C glass transition temperature
   - L = natural color I resin with > 250C flass transition temperature
   - M = coloring agent or opacifier added to F resin with 110-150C glass
          transition temperature
   - N = natural color of resin
   - P = coloring agent or opacifier added to resin
   - T = natural color F resin blended with nonepoxy resins for high
          temperature integrity, with 170-220C glass transition temperature

From the Handbook of Electronic Packaging (Charles A. Harper, McGraw-Hill, 1969)

NEMA grade MIL spec Maximum service temperature
XX PBG 250F paper & >=45% by weight phenolic
XXP PGB 250C paper & >=45% by weight phenolic
XXX PBE paper & >=58% by weight phenolic
XXXP PBE-P paper & >=58% by weight phenolic
XXXPC PBE-P 250F paper & >=58% by weight phenolic
FR-2 PBE-P paper & >=58% by weight phenolic
FR-3 PEE paper & epoxy
FR-4 GEE glass & epoxy
FR-5 GEB glass & epoxy
G-2 glass & phenolic
N-1 NPG 165F
G-5 GMG 300F glass & melamine
G-7 GSG 350F glass & silicone
G-9 GME glass & melamine
G-10 GEE 250F glass & epoxy
G-11 GEB 300F glass & epoxy

                                   John Barnes Advisory Engineer
                                   Lexmark International

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