Ceramics dielectric strength

The industrial ceramics produced by conventional sintering of 8-phase Si3N4 powders synthesized by SHS (Petrovskii et al, 1981) can be used as high-temperature articles with attractive dielectric properties (tan6=4.4 10 at/= 10 Hz, and dielectric strength, Ea=9.2 kV/mm). Also, silicon nitride powders with a relatively high a-phase content ( 80%) have been used for the production of advanced structural ceramics with good mechanical properties ([Pg.109]

Aluminum nitride has received attention as an alternative to Si02 dielectric layers in microelectronic circuits because of its high dielectric strength. Being a refractory ceramic with high thermal conductivity, AIN is useful for electronics packaging. There are also uses for AIN as a piezoelectric material because of its high surface acoustic wave velocity. 

The first disc capacitors used mica sheets. Mica has a very high dielectric strength (see Table 31.4) and can readily be cleaved into thin sheets. Disk capacitors are now made from BaTiOs-based compositions using traditional ceramic processing... 

Electrical parameters of interest for the ceramic substrates include volume resistivity, dielectric constant, dissipation factor, and dielectric strength... 

The electrical properties of ceramic substrates perform an important task in the operation of electronic circuits. Depending on the applications, the electrical parameters may be advantageous or detrimental to circuit function. Of most interest are the resistivity, the breakdown voltage or dielectric strength, and the dielectric properties, including the dielectric constant and the loss tangent. 

Ferrodielectric capacitors are shaped as tubes, monoliths, multilayers, or disks. They normally use ceramic dielectrics because of their high dielectric constants (1000 < s, < 30,000). However, the capacitance of a ferrodielectric ceramic capacitor is strongly dependent on the operating temperature, frequency, and voltage, where the effect of instability on the relative capacitance with respect to dielectric strength is demonstrated using two different e, values. These types are called non-linear capacitors and will be discussed briefly below. 

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