The material selection of multi-layer PCB circuit boards directly affects their signal transmission performance, thermal management capability, and mechanical stability, and requires comprehensive optimization of electrical, thermal, and physical properties.

Core material composition
Copper clad laminate (CCL): As the basic material of multi-layer PCBs, it is composed of copper foil, resin, and glass fiber cloth, and is the key to determining the performance of the board.
Resin system: commonly used epoxy resin, with good adhesion and insulation properties; High performance resins such as polyimide can be selected for high-frequency scenarios.
Reinforcement material: Glass fiber cloth enhances rigidity and heat resistance, preventing warping and delamination.
Special substrate:
FR-4: The most widely used glass fiber reinforced epoxy resin material, with excellent electrical insulation, mechanical strength, and wet heat stability, and good economy.
High frequency sheet metal (such as Rogers RO3000 series): low dielectric constant (Dk), low loss factor, suitable for high-frequency applications such as radar and communication systems.
Metal substrate (aluminum/copper based): superior thermal conductivity, suitable for heat dissipation of high-power devices.
Ceramic substrates (such as Al ₂ O ∝, LTCC) have low thermal expansion coefficient and good thermal stability, and are used in high reliability fields such as aerospace and medical.

advantage
High density wiring: Implementing complex circuit layouts in a limited space to enhance integration.
Good signal integrity: reduces crosstalk through dedicated power supply/ground layer and supports high-speed signal transmission.
Strong electromagnetic compatibility: A shielding layer can be installed to reduce electromagnetic interference (EMI).
Excellent heat dissipation performance: heat can be effectively dissipated through metal core layers or thermal conductive vias.
Flexible design: Supports advanced design requirements such as multi-layer impedance control and BGA packaging adaptation.

shortcoming
High cost: The materials and processes are complex, and the price is significantly higher than that of single/double-sided panels.
Long manufacturing cycle: requiring multiple layers of pressing, drilling, electroplating and other processes, resulting in longer production time.
High design difficulty: requires professional EDA tools and experience, with high requirements for signal integrity and power integrity.
Difficulty in maintenance: The internal structure is complex, and it is difficult to locate and repair faults.
Heat dissipation challenge: Although heat dissipation structures can be designed, hotspots are still easily formed at high densities.