Dielectric ceramics, multilayer ceramic capacitor and method for manufacturing the same

A technology of ceramic capacitors and dielectric layers, which is applied in the direction of laminated capacitors, fixed capacitor dielectrics, and parts of fixed capacitors, etc. It can solve the problems of reduced insulation, reduced reliability, and increased temperature characteristics.

Active Publication Date: 2006-05-10
KYOCERA CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In multilayer ceramic capacitors having such crystal grains, the temperature characteristic of the dielectric constant increases, the insulation performance decreases, and the reliability in high-temperature load tests in particular decreases.

Method used

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  • Dielectric ceramics, multilayer ceramic capacitor and method for manufacturing the same
  • Dielectric ceramics, multilayer ceramic capacitor and method for manufacturing the same
  • Dielectric ceramics, multilayer ceramic capacitor and method for manufacturing the same

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Experimental program
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Effect test

Embodiment 1

[0085] The effect of the volume per unit cell represented by the product of the lattice constants (a, b, c) obtained by X-ray diffraction was confirmed for the dielectric ceramic of the present invention. First, dielectric material powders obtained by the sol-gel method, the hydrothermal synthesis method, the oxalate method, and the solid-phase method shown in Table 1 were prepared. These powders were mixed so that the Ba / Ti ratio became 1.005.

[0086] Then, without using a zeolite-based desiccant for drying the powder, the powder was preliminarily dried under atmospheric pressure and an atmosphere at a temperature of 200°C.

[0087] On the other hand, when a zeolite-based desiccant is used, the prepared dielectric material powder is prepared at atmospheric pressure and 400°C, using alumina silicate as the main component and having a specific surface area of ​​600m 2 / g of zeolite-based desiccant was subjected to drying heat treatment to obtain dielectric powder. The amount...

Embodiment 2

[0097] First, in order to confirm the effect of the softening point of the glass and the thermal expansion coefficient, the dielectric powder was made into a tablet shape with a diameter of 12 mm and a thickness of 1 mm, and the evaluation was performed by firing the tablet. The results are shown in Tables 2 and 3 as dielectric ceramics. Tables 2 and 3 show the average particle size, A / B ratio, c / a ratio, addition amount, firing temperature, and glass composition of the barium titanate used. The barium titanate powder used was a material containing 0.1, 1, and 0.2 parts by mass of Mg, Y, and Mn in terms of oxides relative to 100 parts by mass of the barium titanate powder. As the glass powder, a glass component containing 1 part by mass based on 100 parts by mass of barium titanate powder was used. The A / B site ratios of the BT powder used here were 1.003 and 1.001.

[0098] The softening point of the glass powder was measured using TG-DTA by making the glass powder into a t...

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Abstract

The present invention provides a multilayer ceramic capacitor and a manufacturing method thereof. The average particle size of the crystal grains mainly composed of barium titanate is 0.2 μm or less, and the product of the lattice constants (a, b, c) obtained from the X-ray diffraction pattern of the crystal grains is expressed. If the volume V of each unit cell is set below 0.0643nm3, a dielectric ceramic with a high dielectric constant can be obtained. A multilayer ceramic capacitor includes a capacitor body formed by alternately laminating dielectric layers made of the dielectric ceramic and internal electrode layers, and external electrodes formed at both ends of the capacitor body.

Description

technical field [0001] The present invention relates to dielectric ceramics, multilayer ceramic capacitors using the same, and their manufacturing methods. Background technique [0002] In recent years, with the popularization of mobile phones and mobile devices, and the high-speed and high-frequency semiconductor devices that are the main components of personal computers, etc., there is a demand for smaller and higher-capacity multilayer ceramic capacitors mounted in such electronic devices. Gradually increase. [0003] In response to such demands, in multilayer ceramic capacitors (MLCs), the capacitance is increased by thinning the dielectric layer, and the number of stacked layers is increased to realize miniaturization and high capacity. Therefore, in order to respond to the above-mentioned thinning and high lamination requirements of the dielectric layer constituting the multilayer ceramic capacitor, the dielectric powder constituting the dielectric ceramics has been m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01G4/12C04B35/468H01B3/12H01G4/30
Inventor 山崎洋一伊东裕见子神垣耕世松原圣
Owner KYOCERA CORP
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