Dielectric ceramic material for multilayer ceramic capacitor with high temperature insulation performance

Abstract

The invention discloses a composition and a preparation method of a dielectric ceramic material for a multilayer ceramic capacitor with high temperature insulation performance. The composition comprises a main component of BaTiO3 and the following auxiliary additives, in relative to 100 g of BaTiO3: 0.1-1.0 g of MnCO3, 0.1-2.0 g of MgO, 0.1-2.0 g of BaCO3, 0.1-2.0 g of CaCO3, 0.1-2.0 g of Al2O3, 0.5-2.0 g of SiO2, 0.1-3.0 g of at least one or more compounds selected from Y2O3, Er2O3, Ho2O3, Dy203 and Gd2O3 and 0.5-2.0 g of at least one or more compounds selected from MoO3, SrO, WO3 and V2O5. The multilayer ceramic capacitor is manufactured by using the dielectric ceramic material comprises medium layers and inner electrodes alternated with the medium layers; and the inner electrodes are composed of nickel (Ni) or a nickel alloy. The multilayer ceramic capacitor has good high temperature insulation performance and meets X8R characteristic of an American EIA standard. At a temperature of 125 DEG C, a product of resistance * capacity is higher than 100 ohm-farad.

Description

technical field [0001] The invention relates to a composition of a dielectric ceramic material and a manufacturing method thereof, and a multilayer ceramic capacitor made of the dielectric ceramic material, in particular to a dielectric ceramic material for a multilayer ceramic capacitor with high temperature and high insulation performance. Background technique [0002] The development of science and technology and the continuous progress of electronic information technology have promoted the continuous development of chip multilayer ceramic capacitors (MLCC) to large capacity and miniaturization, and the miniaturization of MLCC has put forward higher requirements for reliability. At the same time, in the high temperature environment, MLCC is required to have good dielectric properties. For example, according to EIA standards, X7R, X8R, and X9R specification MLCCs require capacitors to have more stable capacitance at -55°C to +125°C, 150°C, and 200°C. It will deteriorate, ...

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Problems solved by technology

[0003] Usually BaTiO 3 When the material system is sintered in a reducing atmosphere, BaTiO 3 Part of the B-site titanium ions in the perovskite crystal structure changes from 4 to 3 valence, that is, Ti 4+ → Ti 3+ , oxygen vacancies are formed in the crystal structure, due to the Ti on the lattice 3+ It is not stable, it loses an electron after absorbing a small amount of energy and returns to Ti 4+ , while Ti 3+ The lost electrons are captured by oxygen vacancies to form F - Center, at F - The electrons in the center are weakly bound electrons. Under the action of an electric field, the weakly bound electrons participate in conduction, so the material is semiconducting and the resistivity is very low (less than 10 5 Ωcm), totally unsuitable as a capacitor dielectric material

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