On the printed circuit board is concerned, there are many ways to their classification, which classified according to the number of layers is most common.
1 single panel (Single-Sided Boards)
At the most basic PCB, components focused on one side, the other side of the wire is concentrated. Because the wire only in one side, the PCB is called a single panel (Single-sided).
In contrast, there are many single-panel limit (because only one side, and the path between the wires can not cross alone have to go around), when dealing with complex circuit often inadequate, is now rarely used in the design, unless the circuit is really very simple.
2 dual-panel (Double-Sided Boards)
This both sides of the wiring board. However, to use the wire on both sides, must be between the two sides have the proper electrical connections for the job. This circuit between a "bridge" called the pilot hole (via).
The guide hole in the PCB, holes filled or painted metal wire which can be connected to both sides. Because the double-sided single-panel area than twice as big, and because the wiring can be interleaved with each other (can go around the other side), it is more suitable for use in more complex than single-sided circuit.
3 MLB (Multi-Layer Boards)
Use a few pieces of double-sided plywood and put a layer of insulation after the sticky prison (laminated) between each board. Board represents the number of layers there are several layers separate wiring layers, layers are generally even, and contains the outermost layers.
Most motherboards are 4-8 layer structure, but it is technically possible to do nearly 100 layer PCB board.
For multilayer concerned, because the PCB layers are tightly integrated, generally less easy to see the actual number.
Double plate, the guide hole (via) easier to handle, just went through the whole board can be. But in terms of plywood, then a lot more complicated, such as some of them want to connect the line, then the use of vias may waste some space for other layers of the line, so buried vias (Buried vias) and blind holes (Blind vias) technology came into being because of which they only penetrate several layers, where the blind hole is connected with the surface layers of the internal PCB PCB, do not have to penetrate the entire board, and buried vias only connect the internal PCB, so just from surface is not apparent.
In multilayer PCB, the entire ground floor are directly connected to the power supply. Therefore, we classified the layers of signal layers (Signal), the power supply layer (Power) or the ground layer (Ground). If the PCB components require different power supply PCB usually have two or more of such power and the wire layer.
