What Are the Reasons for Using Multi-layer Circuit Boards in High-speed PCB Design?

Multi-layer circuit boards are recommended in high-speed PCB design. First of all, the multi-layer circuit board allocates the inner layer to the power and ground, so it has the following advantages:

1. The power supply is very stable;

2. The circuit impedance is greatly reduced;

3. The wiring length is greatly shortened.

In addition, from a cost point of view, when comparing the cost of the same area, although the cost of a multi-layer circuit board is higher than that of a single-layer circuit board, if other factors such as the miniaturization of the circuit board and the convenience of reducing noise are taken into account, the multi-layer circuit board The cost difference between circuit boards and single-layer circuit boards is not as high as expected. When simply calculating the area cost of the circuit board according to the data we know, the area of ​​the double-layer circuit board that can be purchased by the Japanese yen is about 462mm2, and the area of ​​the 4-layer circuit board is 26mm2, which means that the same circuit is designed, if 4 layers The use area of ​​the circuit board can be reduced to 1/2 of the double-layer board, so the cost is the same as that of the double-layer circuit board. Although multiple layers in batches will affect the cost per unit area of ​​the circuit board, there is still not a 4 times price difference. If a price difference of more than 4 times occurs, as long as you can try to reduce the use area of ​​the circuit board and try to reduce it to 1% of the double-layer board. /4 or less is fine.