Materials / Compare
PCB Laminate FR-4 vs. Plywood
Compare PCB Laminate FR-4 vs. Plywood strength, stiffness, weight and thermal properties.
| Try it on a partA panel to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | not given (tensile used) | not given (tensile used) |
| Ultimate tensile strength | 246–385MPasourcetypical, in-plane: cross direction .. length direction (ASTM D3039) | 41.4MPasourcemodulus of rupture (no direct tensile value) |
| Flexural strength | 531–621MPasourcetypical: cross direction .. length direction (IPC-TM-650 2.4.4B) | 41.4MPasourcestatic bending MOR (Douglas-fir); range 33.72-42.61 across species |
| Elongation at break | not sourced | not sourced |
| Young's modulus (stiffness) | 21.9–25.8GPasourcetypical, in-plane: cross direction .. length direction (ASTM D790-15e2) | 7.45GPasourcestatic bending MOE of the panel (Douglas-fir); range 6.96-8.55 across species |
| Density | 1,920kg/m³sourcetypical, 50% resin content; another FR-4 producer: Park Nelco N4000-6 (high-Tg multifunctional epoxy), not Isola 370HR | not sourced |
| Strength to weight | 164kN·m/kg | not sourced |
| Stiffness to weight | 12.4MN·m/kg | not sourced |
| Poisson's ratio | 0.171–0.177sourcetypical, in-plane: cross direction .. length direction | not sourced |
| Shear modulus | 10.2GPa | not sourced |
| Bulk modulus | 12.2GPa | not sourced |
| Speed of sound | 3,525m/s | not sourced |
| Thermal | ||
| Thermal conductivity | 0.4W/m·Ksourcetypical (ASTM E1952); direction not stated by the sheet | 0.12W/m·KsourceAPA-recommended design value (Douglas-fir plywood), as reported by FPL/ORNL |
| Thermal expansion | 13–14µm/m·Ksourcetypical, in-plane X/Y-axis, below Tg (IPC-TM-650 2.4.24C) | 3.1–4.5µm/m·Ksourcebase material: solid wood parallel to grain, ovendry, range across species |
| 100 mm part over a 50 °C swing | 67.5µm growth | 19µm growth3.55x less |
| Specific heat | 1,200–1,400J/kg·Ksourcetypical (ASTM E1461); another FR-4 producer: Park Nelco N4000-6 (high-Tg multifunctional epoxy), not Isola 370HR | 1,700J/kg·Ksourcebase material: solid wood (all species), 12% MC, 27 C |
| Heats up and cools (diffusivity) | 0.16mm²/s | not sourced |
| Thermal shock resistance | 324W/m | not sourced |
| Glass transition | 180°Csourcetypical, DSC (IPC-TM-650 2.4.25C) | not sourced |
| Max service temperature | 130°CsourceUL Relative Thermal Index (UL 796) | not sourced |
| Values for | 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. | Douglas-fir plywood sheathing (construction plywood per PS 1), static bending properties from USDA FPL Wood Handbook FPL-GTR-282 Ch. 12 Table 12-2 (Biblis 2000) |
Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Is PCB Laminate FR-4 stronger than Plywood?
PCB Laminate FR-4 is stronger: its tensile strength is 315 MPa against 41.4 MPa for Plywood (7.62x).
Which is stiffer, PCB Laminate FR-4 or Plywood?
PCB Laminate FR-4 is stiffer: Young's modulus 23.9 GPa against 7.45 GPa for Plywood, so the same part in PCB Laminate FR-4 deflects less under the same load.
Which conducts heat better, PCB Laminate FR-4 or Plywood?
PCB Laminate FR-4 conducts heat better: 0.4 W/m·K against 0.12 W/m·K for Plywood.
Which expands less with temperature?
Plywood expands less: 3.8 µm/m·K against 13.5 µm/m·K for PCB Laminate FR-4.