What is Internal Layer
An internal layer is the copper layers that are situated between the top and bottom layers of a PCB, facilitating the routing of electrical signals between various components and layers of the board.
The internal layers, also known as inner layers, can vary in number depending on the specific design requirements of the PCB. They are typically connected to the outer layers through vias, which can be either blind vias or buried vias. These connections enable the seamless flow of electrical connections throughout the PCB.
The internal layers are crucial in determining the functionality and performance of the PCB. They can include conductive patterns or ground planes, further enhancing the electrical capabilities of the board. The thickness and copper weight of the internal layers can be predefined for standard constructions, but they can also be customized to meet specific design needs.