Multilayer circuit board wiring method

Assuming that the frequency of the digital logic circuit reaches or perhaps exceeds 45MHZ~50MHZ, and the circuit operating above this frequency used to account for a certain amount of the entire electronic system (let's say 1/3), it is usually called a high frequency circuit (multilayer circuit board). High-frequency circuit board planning is a very messy planning process, and its wiring is critical to the overall planning!

The first move, high multilayer circuit board wiring

High-frequency circuits are often highly integrated, wiring density, the choice of multi-layer circuit board is necessary for wiring, but also to reduce interference is a useful wrist. In the PCBLayout stage, a reasonable selection of a certain number of layers of Printed Circuit Board scale, can fully apply the middle layer to set the shield, to better complete the proximity of grounding, and useful to reduce parasitic inductance and shorten the transmission length of the signal, together with a substantial reduction in signal interfering, etc., all these methods are beneficial to the reliability of high-frequency circuits. However, there is also a problem, the higher the number of layers of the circuit board, the more complicated the manufacturing process, the higher the unit cost, which requires us to suspend the PCBLayout, in addition to selecting the right number of layers of circuit boards, but also the need to suspend the planning of reasonable meta-equipment planning, and the use of the correct The wiring rules to complete the planning.

The second trick, high-speed electronic devices between the pins of the lead bend the less the better

High-frequency circuit wiring leads are best used in a straight line, the need for coloring, available 45-degree folding line or arc coloring, this plea in the low-frequency circuit is only used to advance the copper foil bonding strength, while in the high-frequency circuit, to meet this plea can reduce the emission of high-frequency signals and coupling between each other.

The third trick, high-frequency circuit equipment between the pins of the lead layer replacement the less the better

The so-called "interlayer replacement of the lead the less the better" refers to the process of connecting the components used in the hole (Via) the less the better. According to the side, a PCB vias can bring about 0.5pF dispersion capacitance, reduce the number of vias can significantly advance the speed and reduce the possibility of data errors.