For general electronic products, FR4 epoxy glass fiber substrate is used, for use in higher ambient temperatures or for flexible circuit boards, polyimide fiberglass substrates are used, and for high-frequency circuits, PTFE fiberglass substrates are required; How to Choose PCB Materials and What Factors Should Be Considered? Electronic products with high heat dissipation requirements should use metal substrates.
(1) A substrate with a higher glass transition temperature (Tg) should be appropriately selected, and the Tg should be higher than the operating temperature of the circuit.
(2) The coefficient of thermal expansion (CTE) is required to be low. Due to the inconsistency of the thermal expansion coefficients in the X, Y, and thickness directions, it is easy to cause PCB soldering circuit board deformation, and in severe cases, the metalized holes may break and the components may be damaged.
(3) High heat resistance is required. Generally, PCB circuit boards are required to have a heat resistance of 250°C/50S.
(4) Good flatness is required. SMT PCB warpage requires 0.0075mm/mm.
(5) In terms of electrical performance, high-frequency circuits require materials with high dielectric constant and low dielectric loss. Insulation resistance, voltage strength, and arc resistance must meet product requirements.