Materials / Compare
PCB Laminate FR-4 vs. Plastic TPU
Compare PCB Laminate FR-4 vs. Plastic TPU 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) | 23.7MPasourcetypical, stress at break |
| Flexural strength | 531–621MPasourcetypical: cross direction .. length direction (IPC-TM-650 2.4.4B) | 4.1MPasourcetypical |
| Elongation at break | not sourced | not sourced |
| Young's modulus (stiffness) | 21.9–25.8GPasourcetypical, in-plane: cross direction .. length direction (ASTM D790-15e2) | 0.067GPasourcetypical |
| Density | 1,920kg/m³sourcetypical, 50% resin content; another FR-4 producer: Park Nelco N4000-6 (high-Tg multifunctional epoxy), not Isola 370HR | 1,220kg/m³sourcetypical |
| Strength to weight | 164kN·m/kg8.46x higher | 19.4kN·m/kg |
| Stiffness to weight | 12.4MN·m/kg226x higher | 0.0549MN·m/kg |
| 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 | 234m/s |
| Thermal | ||
| Thermal conductivity | 0.4W/m·Ksourcetypical (ASTM E1952); direction not stated by the sheet | not sourced |
| Thermal expansion | 13–14µm/m·Ksourcetypical, in-plane X/Y-axis, below Tg (IPC-TM-650 2.4.24C) | not sourced |
| 100 mm part over a 50 °C swing | 67.5µm growth | not sourced |
| 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 | not sourced |
| Heats up and cools (diffusivity) | 0.16mm²/s | not sourced |
| Thermal shock resistance | 324W/m | not sourced |
| Melting point | not sourced | 217°Csourcetypical |
| Glass transition | 180°Csourcetypical, DSC (IPC-TM-650 2.4.25C) | not sourced |
| Max service temperature | 130°CsourceUL Relative Thermal Index (UL 796) | 50.3°CsourceHDT 0.455 MPa (printed specimens) |
| 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. | Ultimaker TPU 95A, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS (file v5.00), April 29, 2022. |
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.
Plastic TPU is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is PCB Laminate FR-4 stronger than Plastic TPU?
PCB Laminate FR-4 is stronger: its tensile strength is 315 MPa against 23.7 MPa for Plastic TPU (13.3x).
Which is lighter, PCB Laminate FR-4 or Plastic TPU?
Plastic TPU is lighter: 1,220 kg/m³ against 1,920 kg/m³ for PCB Laminate FR-4.
Which is stiffer, PCB Laminate FR-4 or Plastic TPU?
PCB Laminate FR-4 is stiffer: Young's modulus 23.9 GPa against 0.067 GPa for Plastic TPU, 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 TPU?
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 TPU |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 226x heavier |
| Stiff beam (bending) | lighter | 12x heavier |
| Stiff panel or plate | lighter | 4.5x heavier |
| Strong rod or tie | lighter | 8.46x heavier |
| Strong beam | lighter | 3.57x heavier |
| Strong panel or plate | lighter | 2.32x 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).