Circuit Board Substrate Differences And Their Respective Advantages

FR-4 (Glass fiber epoxy resin)
Features:
FR-4 is a glass fiber fabric reinforced epoxy resin with a medium dielectric constant (Dk 4.5-5.5), low dielectric loss (Df 0.02-0.03), high mechanical strength (bending strength ≥400 MPa), and UL94 V-0 flame retardancy.

Advantages:

Low cost: Material cost is 50%-70% lower than metal substrates, and it accounts for more than 80% of the consumer electronics market share.

Mature process: Compatible with multi-layer board design (4-16 layers), and supports through-hole and blind buried vias technology.

Heat resistance: Standard Tg value of 130-140℃, and high Tg FR-4 can reach above 170℃, adapting to lead-free welding process.

Application scenarios:
Main boards of mobile phones, computer motherboards, home appliance control boards, and other general electronic products

CEM Series (CEM-1/CEM-3)
Distinction:

CEM-1: Paper-based material epoxy, 30% lower cost than FR-4, but only supports single-sided boards, and has poor mechanical strength.

CEM-3: Glass mat reinforced, supports double-sided boards, with heat resistance close to FR-4, but slightly higher dielectric constant (Dk 4.7-5.4).

Applicable scenarios:
Low-end household appliance control boards (CEM-1), medium-end industrial control equipment (CEM-300)

Metal substrate (aluminum substrate/copper substrate)
Features:
Metal base material (aluminum/copper) combined with layer, thermal conductivity of 1.0-3.0 W/m·K (aluminum substrate) or 380 W/m·K (cop substrate), high mechanical strength (tensile strength ≥ 200 MPa).

Advantages:

Excellent heat dissipation: Heat is directly through the metal layer, with a heat dissipation efficiency that is 5-10 times higher than FR-4, suitable for high current scenarios above 100A5.

Resistant to deformation: The coefficient of thermal expansion (CTE) is close to that of the silicon chip (aluminum substrate 23 ppm℃), reducing thermal stress cracking.

Applicable scenarios:
LED lighting driver board, power module for new energy vehicles, industrial in

Ceramic substrate (alumina/aluminum nitride)
Features:
Alumina (Al₂O₃) thermal conductivity 4-28 W/m·K, aluminum nitride (AlN) thermal conductivity 170-230 W/m·K, dielectric constant 98 (alumina) or 8.8 (aluminum nitride).

Advantages:

High-frequency performance: low dielectric loss (D < 0.001), suitable for 5G millimeter wave and RF circuits.

High temperature resistance: operating temperature can reach 800℃alumina), suitable for extreme environments.

Application scenarios:
High-power RF modules (such as radar), aerospace electronics, high-power LED packaging.