Stack-up refers to the arrangement of copper layers and insulating layers that make up a PCB prior to board layout design.It defines the structure of the board, including the number of layers, the thickness of the layers, and the materials used. The stackup plays a crucial role in determining the electrical performance, mechanical stability, and manufacturability of the PCB.
- Signal Layers: These are the layers where the actual electrical traces are routed. They carry the signals between components.
- Power and Ground Planes: Dedicated layers for power and ground connections. They help in reducing noise and providing a stable reference voltage for the signal layers.
- Prepreg Layers: These are thin layers of fiberglass impregnated with resin, used to bond the copper layers together. They also provide insulation between conductive layers.
- Core Layers: These are thicker, rigid layers of fiberglass and resin with copper on both sides. They form the central part of the PCB stackup.
- Dielectric Materials: These are insulating layers between the conductive layers, affecting the impedance and signal integrity.
- Signal Integrity: Proper stackup design helps maintain signal integrity by controlling impedance and reducing crosstalk.
- Electromagnetic Compatibility (EMC): A nice stackup minimizes electromagnetic interference (EMI) and ensures the board meets EMC standards.
- Thermal Management: The stackup affects the thermal performance, helping to manage heat dissipation.
- Mechanical Strength: The stackup contributes to the overall mechanical strength and rigidity of the PCB.
- 2-Layer Stackup: Consists of two layers (top and bottom), typically used in simpler designs.
- 4-Layer Stackup: Includes two signal layers and two planes (power and ground), common in more complex designs.
- Multi-Layer Stackup: Involves more than four layers, with multiple signal, power, and ground planes, used in high-density and high-speed designs.
Choosing the right stackup is an important for achieving the desired electrical performance and reliability of the PCB.
