pcb proofing, circuit board proofing, circuit board proofing] Multi-layer PCB is a comprehensive consideration. Sometimes the cable crossing needs to be changed to go through, and for high-speed
circuit boards, a complete reference plane and power plane are required. These need to increase the number of pcb layers!
For the most basic PCB, the components are concentrated on one side, and the wires are concentrated on the other side, because only one side can be wired, so we call this PCB a single panel. Both
sides of the dual panel can be wired, so the wiring area is twice as large as the single panel, suitable for use in more complex circuits.
For simple circuits such as radios, single or dual panel manufacturing is sufficient. However, with the development of electronic technology, the complexity of the circuit is greatly increased, the
electrical performance of the PCB is also put forward higher requirements, if you also use a single panel or double panel, the circuit volume will be very large, which also brings great difficulties to the
wiring, in addition, the electromagnetic interference between the lines is not good to deal with, so there is a multi-layer board (the number of layers represents several independent wiring layers, It’s
usually an even number).
Advantages of multi-layer pcb:
High assembly density, small volume; The connection between electronic components is shortened, and the signal transmission speed is increased; Easy wiring; For the high frequency circuit, the
ground layer is added to make the signal line form a constant low impedance to the ground; Good shielding effect. However, the more layers, the higher the cost, the longer the processing cycle, and
the more troublesome the quality detection.
Our common computer boards usually use four or six layers of boards, but now there are more than 100 layers of practical printed circuit boards. The difference between the six-layer board and the
four-layer board is that there are two more internal signal layers in the middle, that is, between the ground line layer and the power supply layer, which is thicker than the four-layer board.
The multilayer board is actually made of several etched single or double panels laminated and bonded. The double panel is easy to distinguish, looking at the light, except for the two sides of the line,
other places are transparent. For four – and six-layer boards, because of the PCB
The layers in the board are very tightly combined, and if there is a corresponding mark on the board, there is no good way to distinguish.