Materials / Compare
PCB Laminate FR-4 vs. Plastic PMMA
Compare PCB Laminate FR-4 vs. Plastic PMMA strength, stiffness, weight and thermal properties.
| Try it on a partA sample part 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) | 80MPasourcetypical, 23 °C |
| Compressive strength | not sourced | 110MPasourcecompressive yield stress, typical |
| Flexural strength | 531–621MPasourcetypical: cross direction .. length direction (IPC-TM-650 2.4.4B) | 115MPasourcetypical |
| Elongation at break | not sourced | 5.5%sourcetypical |
| Young's modulus (stiffness) | 21.9–25.8GPasourcetypical, in-plane: cross direction .. length direction (ASTM D790-15e2) | 3.3GPasourcetypical, short-term |
| Density | 1,920kg/m³sourcetypical, 50% resin content; another FR-4 producer: Park Nelco N4000-6 (high-Tg multifunctional epoxy), not Isola 370HR | 1,190kg/m³sourcetypical |
| Strength to weight | 164kN·m/kg2.44x higher | 67.2kN·m/kg |
| Stiffness to weight | 12.4MN·m/kg4.48x higher | 2.77MN·m/kg |
| Poisson's ratio | 0.171–0.177sourcetypical, in-plane: cross direction .. length direction | 0.37sourcetypical |
| Shear modulus | 10.2GPa8.44x stiffer in shear | 1.2GPa |
| Bulk modulus | 12.2GPa | 4.23GPa |
| Speed of sound | 3,525m/s | 1,665m/s |
| Thermal | ||
| Thermal conductivity | 0.4W/m·Ksourcetypical (ASTM E1952); direction not stated by the sheet | 0.19W/m·Ksourcetypical |
| Thermal expansion | 13–14µm/m·Ksourcetypical, in-plane X/Y-axis, below Tg (IPC-TM-650 2.4.24C) | 70µm/m·Ksource0-50 °C |
| 100 mm part over a 50 °C swing | 67.5µm growth5.19x less | 350µm growth |
| 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 | 1,470J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | 0.16mm²/s48% faster | 0.109mm²/s |
| Thermal shock resistance | 324W/m7.8x more resistant | 41.5W/m |
| Glass transition | 180°Csourcetypical, DSC (IPC-TM-650 2.4.25C) | not sourced |
| Max service temperature | 130°CsourceUL Relative Thermal Index (UL 796) | 80°Csourcemax. permanent service temperature |
| 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. | Röhm PLEXIGLAS GS 0F00 cast acrylic sheet, typical values at 23 °C / 50 % RH (Röhm Technical Information Ref. No. 211-1) |
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 Plastic PMMA?
PCB Laminate FR-4 is stronger: its tensile strength is 315 MPa against 80 MPa for Plastic PMMA (3.94x).
Which is lighter, PCB Laminate FR-4 or Plastic PMMA?
Plastic PMMA is lighter: 1,190 kg/m³ against 1,920 kg/m³ for PCB Laminate FR-4.
Which is stiffer, PCB Laminate FR-4 or Plastic PMMA?
PCB Laminate FR-4 is stiffer: Young's modulus 23.9 GPa against 3.3 GPa for Plastic PMMA, so the same part in PCB Laminate FR-4 deflects less under the same load.
Which is lighter for the same job, PCB Laminate FR-4 or Plastic PMMA?
For the same stiffness or strength: PCB Laminate FR-4 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.
| Part that must be | PCB Laminate FR-4 | Plastic PMMA |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 4.48x heavier |
| Stiff beam (bending) | lighter | 1.67x heavier |
| Stiff panel or plate | lighter | 20% heavier |
| Strong rod or tie | lighter | 2.44x heavier |
| Strong beam | lighter | 1.55x heavier |
| Strong panel or plate | lighter | 23% heavier |
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).
Which conducts heat better, PCB Laminate FR-4 or Plastic PMMA?
PCB Laminate FR-4 conducts heat better: 0.4 W/m·K against 0.19 W/m·K for Plastic PMMA.
Which expands less with temperature?
PCB Laminate FR-4 expands less: 13.5 µm/m·K against 70 µm/m·K for Plastic PMMA.