DF (Dissipation Factor)：The DF, also known as the loss tangent, is an important parameter that characterizes the energy loss in a material. While the dissipation factor does play a role in determining the performance of PCBs, it is not the sole factor that directly determines their overall performance.
In high-frequency applications, low-loss dielectric materials are preferred to minimize signal attenuation and maintain signal integrity. The dissipation factor is an indicator of the energy lost as heat during signal transmission, and materials with lower dissipation factors generally exhibit lower signal loss. However, it is important to note that other factors, such as the dielectric constant, thermal stability, and consistency of the material, also significantly impact the performance of high-frequency PCBs.
The selection of materials for high-frequency PCBs involves considering multiple parameters, including the dissipation factor, dielectric constant, thermal stability, and mechanical properties. It is a balanced approach that takes into account the specific requirements of the application and the desired performance characteristics.
Therefore, while the dissipation factor is an important parameter, it is not the sole determinant of PCB performance. The overall performance of high-frequency PCBs relies on a combination of factors, including the choice of materials, proper design techniques, impedance control, signal integrity management, and thermal considerations.
Coefficient of Thermal Expansion: The coefficient of thermal expansion should closely match that of copper foil in order to prevent separation of the copper foil during thermal cycling.
DK (Dielectric Constant): The DK of the material, which represents its ability to store charge, should be low and sufficiently stable. A lower DK is generally preferred as high DK can lead to signal propagation delays.
Good Thermal Resistance, Chemical Resistance, Impact Resistance, and Peel Strength: These properties are crucial for high-frequency PCBs to withstand thermal stress, resist chemical corrosion, withstand mechanical impact, and maintain strong adhesion between layers.
The thermal expansion coefficient of the high-frequency PCB should closely match that of the copper foil to ensure that the performance of the PCB is not affected during thermal cycling. High-frequency PCBs exhibit excellent heat resistance, chemical resistance, impact resistance and peel strength.
