FR-4 - Wikipedia
`
`https://en.wikipedia.org/wiki/FR-4
`
`FR-4
`
`FR-4 (or FR4) is a NEMA grade designation for glass-reinforced epoxy laminate material. FR-4 is a composite material
`composed of woven fiberglass cloth with an epoxy resin binder that is flame resistant (self-extinguishing).
`
`"FR" stands for "flame retardant", and does not denote that the material complies with the standard UL94V-0 unless testing
`is performed to UL 94, Vertical Flame testing in Section 8 at a compliant lab. The designation FR-4 was created by NEMA in
`1968.
`
`FR-4 glass epoxy is a popular and versatile high-pressure thermoset plastic laminate grade with good strength to weight
`ratios. With near zero water absorption, FR-4 is most commonly used as an electrical insulator possessing considerable
`mechanical strength. The material is known to retain its high mechanical values and electrical insulating qualities in both
`dry and humid conditions. These attributes, along with good fabrication characteristics, lend utility to this grade for a wide
`variety of electrical and mechanical applications.
`
`Grade designations for glass epoxy laminates are: G-10, G-11, FR-4, FR-5 and FR-6. Of these, FR-4 is the grade most widely
`in use today. G-10, the predecessor to FR-4, lacks FR-4's self-extinguishing flammability characteristics. Hence, FR-4 has
`since replaced G-10 in most applications.
`
`FR-4 epoxy resin systems typically employ bromine, a halogen, to facilitate flame-resistant properties in FR-4 glass epoxy
`laminates. Some applications where thermal destruction of the material is a desirable trait will still use G-10 non flame
`resistant.
`
`Contents
`Properties
`Applications
`See also
`References
`Further reading
`
`Properties
`
`Which materials fall into the "FR-4" category is defined in the NEMA LI 1-1998 standard. Typical physical and electrical
`properties of FR-4 are as follows. The abbreviations LW (lengthwise, warp yarn direction) and CW (crosswise, fill yarn
`direction) refer to the conventional perpendicular fiber orientations in the XY plane of the board (in-plane). In terms of
`Cartesian coordinates, lengthwise is along the x-axis, crosswise is along the y-axis, and the z-axis is referred to as the
`through-plane direction. The values shown below are an example of a certain manufacturer's material. Another
`manufacturer's material will usually have slightly different values. Checking the actual values, for any particular material,
`from the manufacturer's datasheet, can be very important, for example in high frequency applications.
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`FR-4 - Wikipedia
`
`https://en.wikipedia.org/wiki/FR-4
`
`Parameter
`
`Specific gravity/density
`
`Water absorption
`
`Temperature index
`
`Thermal conductivity, through-plane
`
`Thermal conductivity, in-plane
`
`Rockwell hardness
`
`Bond strength
`
`Value
`1.850 g/cm3 (0.0668 lb/cu in)
`−0.125 in < 0.10%
`
`140 °C (284 °F)
`0.29 W/(m·K),[1] 0.343 W/(m·K)[2]
`0.81 W/(m·K),[1] 1.059 W/(m·K)[2]
`110 M scale
`
`> 1,000 kg (2,200 lb)
`
`Flexural strength (A; 0.125 in) – LW
`
`> 415 MPa (60,200 psi)
`
`Flexural strength (A; 0.125 in) – CW
`
`> 345 MPa (50,000 psi)
`
`> 50 kV
`
`> 50 kV
`
`20 MV/m
`
`4.4
`
`4.4
`
`0.017
`
`0.018
`3.9 – 4.7,[3] 4.4 @ 1 GHz (Supplier Isola) [4]
`0.02 – 0.03,[3] 0.030 @ 1 GHz[5][4]
`Can vary, but is over 120 °C
`3.5 ×106 psi (24 GPa)
`3.0 ×106 psi (21 GPa)
`1.4 × 10−5 K−1
`1.2 × 10−5 K−1
`7.0 × 10−5 K−1
`0.136
`
`0.118
`
`3602 m/s
`
`3369 m/s
`
`6.64 MRayl
`
`Dielectric breakdown (A)
`
`Dielectric breakdown (D48/50)
`
`Dielectric strength
`
`Relative permittivity (A)
`
`Relative permittivity (D24/23)
`
`Dissipation factor (A)
`
`Dissipation factor (D24/23)
`Dielectric Constant (εr)
`Loss Tangent (tanδ)
`
`Glass transition temperature
`
`Young's modulus – LW
`
`Young's modulus – CW
`
`Coefficient of thermal expansion – x-axis
`
`Coefficient of thermal expansion – y-axis
`
`Coefficient of thermal expansion – z-axis
`
`Poisson's ratio – LW
`
`Poisson's ratio – CW
`
`LW sound speed
`
`CW sound speed
`
`LW acoustic impedance
`
`where:
`
`LW
`
`CW
`
`PF
`
`Lengthwise
`
`Crosswise
`
`Perpendicular to laminate face
`
`Applications
`
`FR-4 is a common material for printed circuit boards (PCBs). A thin layer of copper foil is typically laminated to one or both
`sides of an FR-4 glass epoxy panel. These are commonly referred to as copper clad laminates. The copper thickness or
`copper weight can vary and so is specified separately.
`
`FR-4 is also used in the construction of relays, switches, standoffs, busbars, washers, arc shields, transformers and screw
`terminal strips.
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`2/28/2022, 9:44 PM
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`CX-0849
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`Page 2 of 3
`
`MASIMO 2064
`Apple v. Masimo
`IPR2022-01299
`
`

`

`FR-4 - Wikipedia
`
`https://en.wikipedia.org/wiki/FR-4
`
`See also
`FR-2
`Polyimide
`G10 (material)
`
`References
`1. Azar, Kaveh; Graebner, John E. (1996). "Experimental Determination of Thermal Conductivity of Printed Wiring Boards".
`Proceedings of the Twelfth IEEE SEMI-THERM Symposium: 169–182. doi:10.1109/STHERM.1996.545107 (https://doi.or
`g/10.1109%2FSTHERM.1996.545107).
`2. Sarvar, F.; Poole, N. J.; Witting, P. A. (1990). "PCB glass-fibre laminates: Thermal conductivity measurements and their
`effect on simulation". Journal of Electronic Materials. 19 (12): 1345–1350. doi:10.1007/bf02662823 (https://doi.org/10.10
`07%2Fbf02662823).
`3. "Using Pre-Emphasis and Equalization with Stratix GX" (https://datasheet.datasheetarchive.com/originals/library/Datash
`eets-SW6/DSASW00108149.pdf) (PDF). ALTERA Datasheet. Altera Corporation: 3. 2003.
`4. "HF Transmission" (https://datasheet.datasheetarchive.com/originals/library/Datasheet-02/DSA0019066.pdf) (PDF).
`Atmel Corporation. Atmel Corporation: 7. 2003.
`5. "PCB Layout Guidelines for Designing with Avago SFP+Transceivers" (https://datasheet.datasheetarchive.com/originals/
`library/Datasheet-080/DASF001217.pdf) (PDF). Avago Technologies. Avago Technologies: 2. 2005.
`
`Further reading
`Industrial Laminated Thermosetting Products (http://www.nema.org/Standards/Pages/Industrial-Laminated-Thermosettin
`g-Products.aspx). National Electrical Manufacturers Association (NEMA). 2012-02-01 [2011, 1998]. NEMA LI 1-1998
`(R2011).
`
`Retrieved from "https://en.wikipedia.org/w/index.php?title=FR-4&oldid=1045731451"
`
`This page was last edited on 22 September 2021, at 04:27 (UTC).
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`3 of 3
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`2/28/2022, 9:44 PM
`
`CX-0849
`
`Page 3 of 3
`
`MASIMO 2064
`Apple v. Masimo
`IPR2022-01299
`
`