What is Internal Signal Layers
Internal signal layers are specific layers within a multi-layer printed circuit board that are dedicated to carrying electrical signals. These layers are positioned between the core and outer layers of the PCB stackup. Unlike other layers, such as the top and bottom layers, internal signal layers are designed specifically for routing and transmitting signals between different components and parts of the PCB.
Using internal signal layers allows for higher component density, enabling more complex circuitry to be accommodated within a smaller space. Additionally, internal signal layers provide additional routing channels, facilitating the efficient transmission of signals across the PCB.
It is important to follow high-speed PCB routing guidelines to ensure proper functionality and performance when working with internal signal layers. This includes considerations such as impedance control for high-speed signals or RF routing, the placement of ground (GND) planes on specific layers for shielding and decoupling, and using proper vias for signal return paths and grounding.