PCB board According to the circuit layer classification: Divided into single-sided Board, double panel and Multilayer board. The Common multilayer Board is 4 layer Board or 6 layer board, the complex multilayer board can reach more than 10 layers. It has the following three main categories:
Single panel: In the most basic PCB, the parts are concentrated in one side, the wire is concentrated on the other side. Because the wire only appears in one side, so this kind of PCB is called Single-sided Board (single-sided). Because the single panel in the design line has many stringent restrictions (because only one side, the wiring between the intersection and must be around the path alone), so only the early circuit to use this kind of board.
Double-sided board: This circuit board on both sides of the wiring, but to use the two sides of the wire, must be on both sides of the appropriate circuit to connect the line. The "bridge" between the circuits is called a guide hole (via). The guide hole is on the PCB, fills or spreads the metal the small hole, it may connect with the two sides the conductor. Because the area of the double-sided board is 1 time times larger than the single panel, and because the wiring can be interleaved (which can go around the other side), it is more suitable for use in a more complex circuit than a single panel.
Multilayer board: In order to increase the area that can be routed, multilayer board with more single or double-sided wiring board. Use a double-sided as the inner layer, two pieces of one-sided as the outer or two-sided for the inner layer, two-sided printed circuit board, through the positioning system and insulation bonding materials alternating together and conductive graphics according to the design requirements of the interconnection of the printed circuit boards become four-layer, six-layer printed circuit boards, also known as multilayer printed circuit boards. The number of layers on the board represents a few layers of separate wiring layers, usually with an even number and a two-tier outer layer. Most of the motherboard is 4 to 8 floors of the structure, but technically the theory can be nearly 100 layers of PCB board. Large supercomputers mostly use a fairly large number of mainframe boards, but because such computers can already be replaced with a cluster of common computers, the Super multilayer boards are not being used. Because the PCB in the various layers are closely combined, it is generally not easy to see the actual number, but if carefully observe the motherboard, still can be seen.
According to the soft and hard classification: divided into ordinary circuit board and flexible circuit board. PCB raw materials are copper clad laminate is the production of printed circuit board substrate materials. It is used to support various components, and to achieve their electrical connection or electrical insulation. The PCB is simply a sheet of integrated circuits and other electronic components. It almost appears in every electronic device.