High Dielectric Constant Ceramic Substrates

To meet the requirements of the commercial arena several proprietary and generic products have been introduced that offer some advantages over conventional fr 4 substrates.

High dielectric constant ceramic substrates.

Polymeric thin films with high dielectric constant low dielectric loss high dielectric strength excellent mechanical properties and thickness as small as possible are highly desired to fulfill the requirements in high energy density capacitors. The dielectric constant of ceramic filled ptfe substrates can be tuned from 3 to 10 and losses can be reduced by an order of magnitude by using different fillers and bonding materials. To this end the concept of external substrate perforation is applied to patch antennas in this paper. The term high κ dielectric refers to a material with a high dielectric constant κ kappa as compared to silicon dioxide high κ dielectrics are used in semiconductor manufacturing processes where they are usually used to replace a silicon dioxide gate dielectric or another dielectric layer of a device.

The terahertz thz dielectric constant ε r and dielectric loss tangent tan δ of the commercial ltcc materials ferro a6m and dupont 951 al 2 o 3 ceramic and single crystal aln and β si 3 n 4 ceramics were measured using a vector network analyzer vna over the frequency range of 140 220 ghz and a time domain spectrometer tds from 0 2 to 1 0 thz. The goal was to overcome the undesirable features of thick and high dielectric constant substrates for patch antennas without sacrificing any of the desired features. In general low dielectric constants i e polypropylene result in a fast substrate while large dielectric constants i e alumina result in a slow substrate. The implementation of high κ gate dielectrics is one of several strategies developed.

The use of the al 2 o 3 ceramic material substrate and its high dielectric constant made it possible to shrink the dimensions of the patch antenna. The dielectric loss tangent is defined by the angle between the capacitor s impedance vector and the negative reactive axis as illustrated in the diagram to the right. Dongrui wang zhi min dang in dielectric polymer materials for high density energy storage 2018. Our high dielectric ceramic substrates with superior thermal properties are used in filters isolators and monolithic ics mics contributing to the downsizing of microcircuits.

Dielectric ceramics and substrates are electrical insulators with dielectric strength dielectric constant and loss tangent values tailored for specific device or circuit applications. Finally the coefficient of thermal expansion of conventional ptfe substrates is high typically 180 to 205 ppm c depending on the dielectric constant of the substrates. The antenna was fabricated on 1 mm thick al 2 o 3 ceramic material with relative dielectric constant of 9 8 relative permeability of 1 and ideal loss tangent of 0 when modeled without any. The effect of tuning on dispersion in pcb substrate materials varies although the best materials manufacturers will have this data on hand for use by designers.