Keywords: Express PCB, High Speed PCB

There is a point regarding the definition of high-speed PCBs: a high-speed PCB is a circuit board that consists of digital circuit speed at or above 45 to 50MHZ, and for more than one-third of the entire systems is accounted by digital circuit signals. But this definition of high-speed PCB is not fully correct. In case you take it for granted, and when you are doing a PCB project whose maximum signal speed reaches 49.9MHz, you will feel relaxed as this is not a high-speed PCB and keep moving on. At last, the PCB fails, the delivery has to delay, and you miss the expected bonus.

There is not any particular type of definition for high-speed PCBs. You will find that back in the 1960s when there was the development of digital electronics, the signal speed was low, and PCB design could be done without much effort. Later on, there was an increase in speed in digital circuit signal and engineers found that traditional PCB designing doesn’t work for these high-speed circuits; as a result, they optimized the circuit design and used specific PCB base materials. For these high-speed circuits, the PCBs developed are referred to as high-speed PCBs. But for speed-speed values, no specific signal speed value is defined.

 Know Whether High-Speed PCBs and High-Frequency PCBs are the same or not?

The meaning of high speed and high frequency is different but Express PCB and high-frequency PCBs are the same printed circuit boards. The sine wave is the carrier of modulated signals. A high-speed circuit indicates that in a short period the voltage rises or drops, and a high-frequency circuit says that the circuit cycle is short (frequency is the reciprocal of the period).

The cycle shortens when the signal frequency rises. In the cycle, the time for the signal to rise and drop needs to be short to make sure that there is enough time for the signal to maintain stability. This ultimately leads to high speed. In different words, high-frequency PCBs are also high-speed PCBs.

There is no such exact distinction between High Speed PCB and high-frequency PCBs. Even you will find that their base materials are the same.