PCB Classification

PCB Classification

Knowledge

Classification and Applications of Printed Circuit Boards (PCBs)

Printed circuit boards (PCBs), as the core components of electronic devices, can be systematically classified based on different characteristics and application scenarios as follows:

Classification by Conductive Layer Count

  1. Single-Sided PCB
    The most basic type of PCB, featuring a single copper layer with components mounted on one side and conductive traces on the other. It is simple in structure and low-cost, primarily used in early electronics and simple circuit designs.
  2. Double-Sided PCB
    Utilizes copper layers on both sides, with electrical connections between layers achieved through plated through-holes (PTHs). Compared to single-sided PCBs, they offer higher wiring density and design flexibility, making them the most widely used PCB type today.
  3. Multilayer PCB
    Consists of three or more conductive layers, bonded together with insulating dielectric materials and interconnected through vias. Multilayer PCBs enable complex circuit designs, meeting the high integration demands of modern electronics.

Classification by Substrate Material

  • Rigid PCB
    Manufactured using inflexible, sturdy base materials, including:
  • FR-4 (fiberglass epoxy)
  • Paper-based substrates
  • Composite substrates
  • Ceramic substrates
  • Metal-core substrates
  • Thermoplastic substrates
    Widely used in computers, communication equipment, industrial controls, and more.
  • Flexible PCB
    Made with bendable insulating substrates, allowing for folding, rolling, and bending. Ideal for portable electronics such as smartphones and tablets.
  • Rigid-Flex PCB
    Combines rigid and flexible sections, providing structural support while allowing bending, making them suitable for 3D assembly applications.

Specialized Functional PCBs

  • Metal-Core PCB (MCPCB)
    Composed of a metal base, insulating layer, and circuit layer, offering superior heat dissipation. Mainly used in high-heat applications like LED displays/lighting and automotive electronics.
  • Heavy Copper PCB (≥3 oz copper thickness)
    Features:
  • High current/voltage handling
  • Excellent thermal performance
  • Demanding manufacturing processes
    Applications: Industrial power supplies, medical equipment, military electronics, etc.
  • High-Frequency PCB
    Characteristics:
  • Low dielectric constant materials
  • Strict signal integrity requirements
  • High-precision fabrication
    Applications: Communication base stations, satellite systems, radar, etc.
  • High-Speed PCB
    Features:
  • Low-loss dielectric materials
  • Precise impedance control
  • Minimal insertion loss
    Applications: Networking equipment, servers, data storage systems, etc.

Advanced Multilayer PCB Technologies

  • HDI (High-Density Interconnect) PCB
    Technical Features:
  • Microvia technology (laser drilling)
  • Sequential lamination
  • Ultra-high wiring density
    Applications: Smartphones, automotive electronics, aerospace, etc.
  • IC Substrate PCB
    Functional Features:
  • Direct chip mounting
  • High pin-count design
  • Miniaturized packaging
    Applications: Memory chips, processors, sensors, and other semiconductor devices.

With advancements in electronics, PCBs continue to evolve toward higher layer counts, greater precision, and increased density. Emerging PCB technologies are driving innovation in electronic product development.