Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

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PCB Laminate Materials

#7288

PCB Laminate Materials | 18 July, 2001

I reposted this in case the source became unsupported. [http://www.qsl.net/wb6tpu/si-list4/1316.html ]

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

#7291

PCB Laminate Materials | 18 July, 2001

I didn't wade thru all of the info you presented above, but your comment about ampacity of printed circuit boards brought to mind a copy of an article I keep in my files. Luckily I photocopied the whole page from the magazine and can actually tell you that it is from Printed Circuit Design, August 1997. In a Designer's Viewpoint column, he talks about designing PWB traces that can carry 20amps or more. He gives a chart that compares trace widths in 1/2 oz, 1 oz, and 2 oz copper to standard AWG values from 10-39. The article is by Claude J. Jodoin. He doesn't really mention the substrate used or deal with dielectric variations. I assume he used FR4.

Just my 1.28cents USD (I'm Canadian...)

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Charles A. Harper

#7293

PCB Laminate Materials | 18 July, 2001

Two more recent books are Electronic Packagind and Interconnection Handbook,Third Edition,2000; and High Performance Printed Circuit Boards,2000.I served as Editor for both.Charlie Harper PS to Dave Fish-Please contact me regarding two new books useful to the SMTnet Bookstore.

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