Dielectric Constant of Commonly Used Polymer Plastics

The transmission speed of the signal in the 5G era will also be much faster than that of the 4G signal, which requires the material to have a small interference with the signal and a small dielectric constant to ensure that the transmission of big data is not interfered with. So what is the dielectric constant, the dielectric constant of various materials and how much? Medium in the applied electric field will produce induced charge and weaken the electric field, the medium of the electric field reduction and the original applied electric field (in a vacuum) of the ratio of the relative permittivity (relative permittivity or dielectric constant), also known as the induced electric rate, and frequency-related. The dielectric constant is the product of the relative permittivity and the absolute permittivity in vacuum. If a material with a high dielectric constant is placed in an electric field, the strength of the field decreases appreciably within the dielectric. The relative permittivity of an ideal conductor (metal) is infinity.

According to the dielectric constant of the substance can be judged by the polarity of the polymer material. Usually, the relative permittivity greater than 3.6 of the material for polar substances; relative permittivity in the range of 2.8 ~ 3.6 of the material for weakly polar substances; relative permittivity less than 2.8 for non-polar substances.

Similarly, we based on the polarity of polymer materials can also be roughly inferred material dielectric constant size, more polar groups, high dielectric constant, less polar groups dielectric constant is small.

The following is the size of the dielectric constant of common materials:

At present, we are discussing more 5G engineering plastics, mainly divided into thin film products (LCP, PI, etc. used in circuit boards, antennas), and structural parts (injection molding), such as low dielectric LCP, PBT, PPO, PPS and so on. Selection of materials to meet both low dielectric constant and mechanical properties, chemical properties, electrical properties and other factors. The dielectric constant of modified plastics is related to the molecular structure of the base material, as well as the dielectric constant of the reinforcement/filler material.