Materials / Compare
PCB Laminate FR-4 vs. Solder SAC305
Compare PCB Laminate FR-4 vs. Solder SAC305 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) | 22MPasourcetypical |
| Ultimate tensile strength | 246–385MPasourcetypical, in-plane: cross direction .. length direction (ASTM D3039) | 39.6MPasourcetypical |
| Flexural strength | 531–621MPasourcetypical: cross direction .. length direction (IPC-TM-650 2.4.4B) | not sourced |
| Elongation at break | not sourced | 49%sourcetypical |
| Young's modulus (stiffness) | 21.9–25.8GPasourcetypical, in-plane: cross direction .. length direction (ASTM D790-15e2) | 6.9GPasourcetypical, temperature and strain rate not stated |
| Density | 1,920kg/m³sourcetypical, 50% resin content; another FR-4 producer: Park Nelco N4000-6 (high-Tg multifunctional epoxy), not Isola 370HR | 7,350kg/m³sourcetypical |
| Strength to weight | 164kN·m/kg54.9x higher | 2.99kN·m/kg |
| Stiffness to weight | 12.4MN·m/kg13.2x higher | 0.939MN·m/kg |
| Poisson's ratio | 0.171–0.177sourcetypical, in-plane: cross direction .. length direction | 0.35sourcetypical |
| Shear modulus | 10.2GPa3.98x stiffer in shear | 2.56GPa |
| Bulk modulus | 12.2GPa | 7.67GPa |
| Speed of sound | 3,525m/s | 969m/s |
| Thermal | ||
| Thermal conductivity | 0.4W/m·Ksourcetypical (ASTM E1952); direction not stated by the sheet | 61W/m·Ksourcetypical, temperature not stated |
| Thermal expansion | 13–14µm/m·Ksourcetypical, in-plane X/Y-axis, below Tg (IPC-TM-650 2.4.24C) | 21.9µm/m·Ksourcemean, 20-100 °C (MacDermid Alpha) |
| 100 mm part over a 50 °C swing | 67.5µm growth1.62x less | 110µm 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 | 232J/kg·Ksourcetypical (MacDermid Alpha) |
| Heats up and cools (diffusivity) | 0.16mm²/s | 35.8mm²/s223x faster |
| Thermal shock resistance | 324W/m | 5,773W/m17.8x more resistant |
| Melting point | not sourced | 217–220°Csourcesolidus-liquidus |
| 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. | SAC305 (Sn96.5Ag3.0Cu0.5) solder alloy, bulk; Indium Corporation Indalloy 256 (SAC305) for Preforms product data sheet (Form No. 100346 R0, 2024), selected properties, test temperature not stated; expansion and specific heat from MacDermid Alpha VACULOY SAC TDS (06 September 2023). |
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 Solder SAC305?
PCB Laminate FR-4 is stronger: its tensile strength is 315 MPa against yield strength 22 MPa for Solder SAC305 (14.3x).
Which is lighter, PCB Laminate FR-4 or Solder SAC305?
PCB Laminate FR-4 is lighter: 1,920 kg/m³ against 7,350 kg/m³ for Solder SAC305.
Which is stiffer, PCB Laminate FR-4 or Solder SAC305?
PCB Laminate FR-4 is stiffer: Young's modulus 23.9 GPa against 6.9 GPa for Solder SAC305, 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 Solder SAC305?
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 | Solder SAC305 |
|---|---|---|
| Stiff rod or tie (tension) | lighter | 13.2x heavier |
| Stiff beam (bending) | lighter | 7.12x heavier |
| Stiff panel or plate | lighter | 5.79x heavier |
| Strong rod or tie | lighter | 54.9x heavier |
| Strong beam | lighter | 22.6x heavier |
| Strong panel or plate | lighter | 14.5x 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 Solder SAC305?
Solder SAC305 conducts heat better: 61 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 21.9 µm/m·K for Solder SAC305.