It is recommended to use multi-layer circuit boards in high-speed PCB design. Firstly, multi-layer circuit boards allocate inner layers specifically for power and ground, thus having the following advantages:

1. The power supply is very stable;

2. The circuit impedance is significantly reduced;

3. The wiring length has been significantly reduced.

In addition, from a cost perspective, when comparing costs for the same area, although the cost of multi-layer circuit boards is higher than that of single-layer circuit boards, if other factors such as miniaturization of circuit boards and convenience in reducing noise are taken into account, the cost difference between multi-layer circuit boards and single-layer circuit boards is not as high as expected. When calculating the area cost of a circuit board based solely on the data we know, the daily available area of a double-layer circuit board is about 462mm2, and a 4-layer circuit board is 26mm2. This means that if the usage area of a 4-layer circuit board can be reduced to half of that of a double-layer board, the cost will be the same as that of a double-layer circuit board. Although batch production of multiple layers may affect the unit area cost of the circuit board, there is not yet a price difference of four times. If a price difference of more than four times occurs, as long as efforts are made to reduce the usable area of the circuit board and reduce it to less than 1/4 of the double-layer board, it is sufficient.