What is the difference between impedance PCB and non-impedance PCB?
PCB board impedance control technology is an important link in PCB production. Impedance-controlled PCB boards can ensure the quality of signal transmission, but the cost will be relatively high. Non-impedance boards are relatively cheap, but in high-speed signal transmission environments, the signal transmission quality may decrease.
1. Definition and principles of impedance PCB and non-impedance PCB
Impedance control technology refers to controlling the impedance of electronic signals through the wiring design and manufacturing process of PCB boards to minimize distortion and reflection of signals during transmission. The impedance board uses special materials and manufacturing processes to control parameters such as line width, distance, load, etc. to ensure the stability and accuracy of signal transmission. Non-impedance boards use general PCB manufacturing processes and do not pay attention to signal impedance control.
2. Advantages and Disadvantages of impedance PCB and non-impedance PCB
The main advantage of impedance plates is the high quality of signal transmission. The impedance-controlled PCB board can reduce signal distortion and reflection, and can also reduce signal interference and crosstalk, ensure that circuit noise is small, and improve signal transmission accuracy and stability. However, the cost of impedance control is relatively high, and the material and process requirements for PCB boards are also relatively high. In some special high-frequency and high-speed environments, impedance control may not fully meet the requirements. The main advantages of non-impedance boards are low production cost, simple production process and short manufacturing cycle. For some occasions where the transmission rate is not high and the circuit is simple, non-impedance boards can also meet the requirements. However, in some high-speed and high-frequency environments, non-impedance boards are prone to problems such as signal distortion, crosstalk, and noise, which will have a certain impact on the working stability and reliability of the circuit.
3. Applications of impedance PCB and non-impedance PCB
Impedance control technology is often used in high-speed signal transmission, high-frequency circuits, analog circuits and other fields. Usually in the design of high-speed AD, DA converters and high-speed digital signal processors, PCB boards using impedance control technology are required to ensure signal accuracy and stability. Non-impedance boards are usually used in some low-speed and low-frequency circuit designs, such as LED light bars, home appliance control boards, etc.
4. Manufacturing requirements and methods of impedance PCB and non-impedance PCB
The production of impedance-controlled PCB boards is highly demanding, requiring the use of high-precision manufacturing equipment and fine control of the materials and processes of the PCB boards. This can be achieved by using some high-impedance control design software and manufacturing processes. For example, during the design process, the upper and lower copper foils can be wired together to form a differential impedance. Use high dielectric constant dielectrics with controlled impedance greater than 1 such as FR4, ROGERS, etc. Non-impedance boards are relatively simple to make, and the process and material selection are also more flexible.
Impedance PCB and non-impedance PCB are suitable for different circuit design needs. Impedance PCB can ensure the quality of signal transmission in high-speed and high-frequency circuits, but the cost is relatively high. Non-impedance boards are suitable for the design of some low-frequency and low-speed circuits and have lower costs. Therefore, when selecting PCB board type, you need to make a reasonable choice based on the specific application environment and circuit design requirements.
