The meaning and design principle of multilayer PCB

                       The meaning and design principle of multilayer PCB
Multilayer PCB have many advantages, such as high assembly density, small size, shorter circuit board wiring spacing,
faster signal transmission, and convenient wirinNowadays, there are more than 100 layers of circuit boards, four-layer
boards and Six-layer boards are the most common printed circuit boards.
 Multilayer PCB
Why are multilayer PCB basically having even-numbered layers?
In the process of design and production of multilayer boards, all levels need to be symmetrical. Asymmetry is likely to
cause distortion. In the production process, four-layer boards are easier to control than three-layer boards. The warpage
of four-layer boards can be controlled at 0.7%. Below (IPC600 standard), but when the size of the three-layer board is large,
the warpage will exceed this standard, and the warpage exceeding the standard will affect the subsequent chip processing
and product quality. Generally, multi-layer PCB design does not design odd-numbered layers. The difference in production
cost between the two is that the four-layer board has one more copper foil and bonding layer. The cost difference is not big.
When the board factory offers 3-4 layers as a grade Quotation, quotation is defined by an even number. For example, if you
design a 5-layer board, the other party will quote at the price of a 6-layer board. That is to say, the price you design for 3 layers
is the same as the price you design for 4 layers. So why not choose a four-layer board.
What are the layers of a multilayer PCB:
Multi-layer PCB is mainly composed of the following layers: Signal Layers Internal Planes, Mechanical Layers, Masks Layers,
Silkscreen Layers,System Layers. The signal layer is divided into top, middle, and bottom layers, which are mainly used to
assemble various components, or for wiring and soldering.