Dielectric ceramic, process for producing the same, and laminated ceramic capacitor

Abstract

The invention provides a dielectric ceramic and its manufacturing method as well as multilayer ceramic capacitor. Wherein, the dielectric ceramic of the invention comprises (Ba, Ca) (Ti, X) O3 as the main component (wherein X is an element of valence greater than that of Ti) and per 100 mol of the main component, 0.1 to 4.0 mol of each of 1st to 3rd addition components. The 1st addition component is a given rare earth element, the 2nd addition component has a given element whose valence is smaller than that of Ti, and the 3rd addition component has a sintering auxiliary containing Si. In >=90% of the main component particles (1), the sum of the solid-solution ratios exhibiting the states of solid solution of individual addition components (2) in the main component particles (1) is <= 10% in terms of sectional area ratio. The molar ratio of Ca loaded is in the range of 0 to 0.20 (preferably 0.02 to 0.20), and the molar ratio (y) of element X loaded in B-site is in the range of 0.0001 to 0.005. As a result, even when the thickness of the dielectric layer is reduced to about 1 to 3 micrometers, a high specific inductive capacity can be exhibited, and excellent insulation and high-temperature load life can be attained without detriment to the temperature characteristic of electrostatic capacity.

Description

technical field [0001] The present invention relates to a dielectric ceramic, a method for preparing a dielectric ceramic, and a laminated ceramic capacitor, and in particular, to a dielectric ceramic suitable for a dielectric material of a small-sized, large-capacity laminated ceramic capacitor, a method for preparing a dielectric ceramic, and a method for preparing a dielectric ceramic using the dielectric ceramic. into multilayer ceramic capacitors. Background technique [0002] With the development of electronic technology in recent years, the miniaturization and increase in capacity of multilayer ceramic capacitors have been promoted. In this multilayer ceramic capacitor, the dielectric layer is thinned by embedding internal electrodes inside the ceramic sintered body. , Multi-layer, realize miniaturization and increase in capacity of multilayer ceramic capacitors. [0003] Furthermore, there has been proposed a dielectric ceramic composition which is composed of (Ba ...

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Problems solved by technology

[0012] However, the problems in the above-mentioned Patent Documents 1 and 2 are that when the thickness of the dielectric layer is more than 20 μm, good insulation and durability under high-temperature load can be ensured, but if the thickness of the dielectric layer is reduced to about 1 to 3 μm, These insulation properties and durability under high-temperature loads deteriorate, resulting in reduced reliability.

[0013] In addition, the problem in Patent Document 2 is that the dielectric ceramic composition has a core-shell structure in which a low-permittivity dielectric phase partly exists, so when the thickness of the dielectric layer is reduced to about 1 to 3 μm, the dielectric constant decreases.

[0014] In addition, since Patent Document 3, like Patent Document 2, has a core-shell structure in which a low-permittivity dielectric phase partly exists, once the thickness of the dielectric layer is reduced to about 1 to 3 μm, the dielectric constant will decrease.

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