Features of High Frequency High Speed Boards

With the development and construction of 5G communication, there is an increasing demand for high frequency high speed boards in the electronic equipment industry. What are the characteristics of high-frequency high-speed board?
2.1 material dielectric constant Dk and dielectric loss Df Speaking of high-frequency high-speed board, it is inevitable to talk about two concepts "dielectric constant - Dk" and "dielectric loss - Df". The dielectric layer of the PCB for high-speed digital signal transmission, not only plays the role of insulation between the conductors, more importantly, it plays the role of "characteristic impedance", but also affects the signal transmission speed, signal attenuation and heat generation.... The magnitude of the dielectric loss (Df) indicates the degree of attenuation of the signal transmission. This attenuation of signal transmission is often consumed by the generation of heat. With high frequency and high speed digital signal transmission, signal attenuation and heat dissipation are bound to increase rapidly with high frequency and high speed digital signal transmission. For high frequency and high speed digital signal transmission, the smaller the dielectric loss (Df) the better. In the development of high-speed products and high-frequency products, are required to plate the dielectric constant (Dk) and dielectric loss (Df) to the direction of smaller development. But high-frequency products and high-speed products still have some differences in the needs of the plate.
2.2 high-speed material characteristics of high-speed products pay more attention to the plate dielectric loss (Df). The grades of high-speed materials commonly used in the market are also divided according to the size of the dielectric loss (Df). (Different substrate materials are divided into conventional loss, medium loss, low loss, very low loss and ultra-low loss according to the dielectric loss of the substrate.) Five transmission signal losses correspond to the grade. 2.3 High-frequency material characteristics Compared with high-speed materials, high-frequency materials pay more attention to the size and variation of the material dielectric constant (Dk). High-frequency products are very sensitive to changes in the material dielectric constant (Dk). Therefore, the focus for high frequency materials is on the stability of the dielectric constant (Dk), as well as the material dielectric thickness, the temperature drift coefficient of the material and the stroboscopic properties of the material. The industry does not have a clear classification standard for high-frequency materials.
However, many PCB manufacturers roughly classify high-frequency boards according to the material's dielectric constant (Dk). Materials with the same dielectric constant (Dk) are considered similar and can be substituted for each other. There is also a customary division in the field of high-frequency materials, i.e. the materials are divided into PTFE and non-Teflon materials. This is closely related to the field of application of high frequency products. The current RF field can be divided into two parts. One is the frequencies below 6GHZ commonly used are 3.5GHZ, 2.7GHZ, 1.8GHZ. the main products are power amplifiers, antenna calibrators, arrays and other products. The other part is above 20GHZ millimeter wave field commonly used frequencies are 24GHZ, 66GHZ, 77GHZ, the main products for radar products. This is mainly because as the frequency increases, the stroboscopic effect of non-Teflon products, dielectric loss on signal transmission increases sharply, while PTFE material has better performance characteristics.