PCB Board FR-4, 2 copper planes vs. Plastic PETG

Compare PCB Board FR-4, 2 copper planes vs. Plastic PETG strength, stiffness, weight and thermal properties.

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PCB Board FR-4, 2 copper planesComposite

Mechanical
Try it on a partA sample part to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD
Yield strength	not given (tensile used)	46.2MPasourcetypical
Ultimate tensile strength	246–385MPasourcethe bare laminate's (fr4-370hr), in-plane: cross direction .. length direction (ASTM D3039)	46.2MPasourcetypical, peak stress (= stress at yield)
Flexural strength	not sourced	78.9MPasourcetypical
Elongation at break	not sourced	7.6%sourcetypical
Young's modulus (stiffness)	21.9–25.8GPasourcethe bare laminate's (fr4-370hr), in-plane: cross direction .. length direction (ASTM D790-15e2); the copper planes are left out	1.94GPasourcetypical
Density	not sourced	1,270kg/m³sourcetypical
Strength to weight	not sourced	36.4kN·m/kg
Stiffness to weight	not sourced	1.53MN·m/kg
Poisson's ratio	0.171–0.177sourcethe bare laminate's (fr4-370hr), in-plane: cross direction .. length direction	not sourced
Shear modulus	10.2GPa	not sourced
Bulk modulus	12.2GPa	not sourced
Speed of sound	not sourced	1,236m/s
Thermal
Thermal conductivity	not sourced	0.21W/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical
Thermal expansion	13–14µm/m·Ksourcethe bare laminate's (fr4-370hr), in-plane X/Y-axis, below Tg (IPC-TM-650 2.4.24C)	51µm/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical
100 mm part over a 50 °C swing	67.5µm growth3.78x less	255µm growth
Specific heat	not sourced	1,300J/kg·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), DSC at 60 °C (lowest temperature listed)
Heats up and cools (diffusivity)	not sourced	0.127mm²/s
Thermal shock resistance	not sourced	not sourced
Glass transition	not sourced	77.4°Csourcetypical
Max service temperature	not sourced	76.2°CsourceHDT 0.455 MPa (printed specimens)
Values for	A whole circuit board read as one orthotropic plate: the JEDEC high-K thermal test board (JESD51-7, "2s2p"), 0.062 in (1.575 mm) thick with two internal solid copper planes 0.0014 in (1 oz) thick, as Texas Instruments SZZA017A Table 1 gives it. Copper C110 and the Isola 370HR laminate from this library; the layers conduct in parallel along the board and in series through it (boardStackup.ts). Its two 0.0028 in trace layers cover little of the board and are left out; vias are ignored. Mechanical values are the bare laminate's.	Ultimaker PETG, 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 v1.00, 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 PETG is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Is PCB Board FR-4, 2 copper planes stronger than Plastic PETG?

PCB Board FR-4, 2 copper planes is stronger: its tensile strength is 315 MPa against yield strength 46.2 MPa for Plastic PETG (6.83x).

Which is stiffer, PCB Board FR-4, 2 copper planes or Plastic PETG?

PCB Board FR-4, 2 copper planes is stiffer: Young's modulus 23.9 GPa against 1.94 GPa for Plastic PETG, so the same part in PCB Board FR-4, 2 copper planes deflects less under the same load.

Which expands less with temperature?

PCB Board FR-4, 2 copper planes expands less: 13.5 µm/m·K against 51 µm/m·K for Plastic PETG.

Among 73 materials

Stiffness against density

Strength against density