Aluminum 3003-O vs. PCB Laminate FR-4

Compare Aluminum 3003-O vs. PCB Laminate FR-4 strength, stiffness, weight and thermal properties.

Mechanical	Aluminum 3003-O	PCB Laminate FR-4
Yield strength	40MPa1	not given (tensile used)
Ultimate tensile strength	110MPa1	246–385MPa2
Flexural strength	not sourced	531–621MPa2
Elongation at break	30%1	not sourced
Young's modulus (stiffness)	69GPa1	21.9–25.8GPa2
Density	2,730kg/m³1	1,920kg/m³342% lighter
Strength to weight	14.7kN·m/kg	164kN·m/kg11.2x higher
Stiffness to weight	25.3MN·m/kg2.03x higher	12.4MN·m/kg
Poisson's ratio	not sourced	0.171–0.1772
Shear modulus	not sourced	10.2GPa
Bulk modulus	not sourced	12.2GPa
Speed of sound	5,027m/s43% faster	3,525m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Aluminum 3003-O	PCB Laminate FR-4
Thermal conductivity	193W/m·K1483x more heat through a fin	0.4W/m·K2
Thermal expansion	23.2µm/m·K1	13–14µm/m·K2
100 mm part over a 50 °C swing	116µm growth	67.5µm growth1.72x less
Specific heat	not sourced	1,200–1,400J/kg·K3
Heats up and cools (diffusivity)	not sourced	0.16mm²/s
Thermal shock resistance	not sourced	324W/m
Melting point	melting range640–655°C1	not sourced
Glass transition	not sourced	180°C2
Max service temperature	not sourced	130°C2

Thermal conductivity against densityHigher and further left: spreads more heat for its weight

Thermal expansion against thermal conductivityLower and further right: warps less when heated

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Sources3 documents: Kaiser Aluminum, Isola, Park Electrochemical (Nelco)

Aluminum 3003-O: 3003-O (annealed) aluminium-manganese alloy, the heat-exchanger tube and brazing alloy, Kaiser Aluminum Tube & Pipe Alloy 3003 Technical Data (Rev. 05/06), typical properties; specific heat from the NIST cryogenic 3003-F fit at 293 K.
PCB Laminate FR-4: Isola 370HR FR-4 laminate (Polyclad PCL-FR-370HR, 180 C Tg multifunctional epoxy, E-glass fabric), copper removed; Isola data sheet Revision C, last updated April 15, 2021. Woven-glass laminate: the sheet gives in-plane values per weave direction (length / cross) and the Z-axis CTE separately; the solver is isotropic per material.

1
Alloy 3003 Tube & Pipe Technical Data, Rev. 05/06Kaiser Aluminumarchived copyAluminum 3003-O · Yield strength: typical, O, 0.0625 in specimenAluminum 3003-O · Ultimate tensile strength: typical, OAluminum 3003-O · Elongation at break: typical, O, in 4DAluminum 3003-O · Young's modulus (stiffness): typicalAluminum 3003-O · Density: nominal, 20 °CAluminum 3003-O · Thermal conductivity: typical, O, 20 °CAluminum 3003-O · Thermal expansion: typical, mean 20-100 °CAluminum 3003-O · Melting point: melting range
2
370HR Laminate and Prepreg Data SheetIsolaarchived copyPCB Laminate FR-4 · Ultimate tensile strength: typical, in-plane: cross direction .. length direction (ASTM D3039)PCB Laminate FR-4 · Flexural strength: typical: cross direction .. length direction (IPC-TM-650 2.4.4B)PCB Laminate FR-4 · Young's modulus (stiffness): typical, in-plane: cross direction .. length direction (ASTM D790-15e2)PCB Laminate FR-4 · Poisson's ratio: typical, in-plane: cross direction .. length directionPCB Laminate FR-4 · Thermal conductivity: typical (ASTM E1952); direction not stated by the sheetPCB Laminate FR-4 · Thermal expansion: typical, in-plane X/Y-axis, below Tg (IPC-TM-650 2.4.24C)PCB Laminate FR-4 · Glass transition: typical, DSC (IPC-TM-650 2.4.25C)PCB Laminate FR-4 · Max service temperature: UL Relative Thermal Index (UL 796)
3
N4000-6 Laminate Data Sheet (2006)Park Electrochemical (Nelco)archived copyPCB Laminate FR-4 · Density: typical, 50% resin content; another FR-4 producer: Park Nelco N4000-6 (high-Tg multifunctional epoxy), not Isola 370HRPCB Laminate FR-4 · Specific heat: typical (ASTM E1461); another FR-4 producer: Park Nelco N4000-6 (high-Tg multifunctional epoxy), not Isola 370HR

Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Questions

Mechanical

Is Aluminum 3003-O stronger than PCB Laminate FR-4?

PCB Laminate FR-4 is stronger: its tensile strength is 315 MPa against yield strength 40 MPa for Aluminum 3003-O (7.88x).

Which is lighter, Aluminum 3003-O or PCB Laminate FR-4?

PCB Laminate FR-4 is lighter: 1,920 kg/m³ against 2,730 kg/m³ for Aluminum 3003-O.

Which is stiffer, Aluminum 3003-O or PCB Laminate FR-4?

Aluminum 3003-O is stiffer: Young's modulus 69 GPa against 23.9 GPa for PCB Laminate FR-4, so the same part in Aluminum 3003-O deflects less under the same load.

Which is lighter for the same job, Aluminum 3003-O or PCB Laminate FR-4?

For the same stiffness or strength: Aluminum 3003-O is lighter for a stiff rod or tie (tension), stiff beam (bending); PCB Laminate FR-4 is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum 3003-O	PCB Laminate FR-4
Stiff rod or tie (tension)	lighter	2.03x heavier
Stiff beam (bending)	lighter	20% heavier
Stiff panel or plate	about equal	about equal
Strong rod or tie	11.2x heavier	lighter
Strong beam	5.63x heavier	lighter
Strong panel or plate	3.99x heavier	lighter

For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).

Thermal

Which conducts heat better, Aluminum 3003-O or PCB Laminate FR-4?

Aluminum 3003-O conducts heat better: 193 W/m·K against 0.4 W/m·K for PCB Laminate FR-4.

Which expands less with temperature?

PCB Laminate FR-4 expands less: 13.5 µm/m·K against 23.2 µm/m·K for Aluminum 3003-O.