JP2008069056A - Dielectric porcelain composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric porcelain composition which enhances a dielectric constant and a Q value, downsizes a dielectric filter and a resonator, and reduces a dielectric loss, and can be sintered at a temperature lower than a melting point of silver, copper or the like. <P>SOLUTION: 25-35 pts.wt. of a Li glass is added to 100 pts.wt. of a composition represented by a general formula: xMgTiO<SB>3</SB>*yMg<SB>2</SB>TiO<SB>4</SB>*zCaTiO<SB>3</SB>, where x, y, and z are respectively in the range of 69.3≤x≤84.0, 14.1≤y≤30.0, and 0.8≤z≤6.1 by mol%. Thus, the dielectric constant and the Q value are improved while a sintering temperature can be lowered to a temperature lower than a melting point of a metal composed of a conductor pattern. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dielectric ceramic composition suitable for materials such as a dielectric filter and a resonator used in a high frequency region such as a microwave and a millimeter wave.

In recent years, while the mobile communication field centering on mobile phones has been rapidly developing, the demand for miniaturization, thinning, and high functionality has become stronger for electronic components used in these terminal devices. Yes. There are no exceptions in the field of dielectric filters and resonators, and not only structural improvements but also material improvements are needed to meet these requirements.
Dielectric ceramic compositions used for dielectric filters and resonators are desired to have a high dielectric constant and a low dielectric loss, that is, a high Q value. In addition, when the dielectric filter or resonator is a multilayer electronic component, it is necessary to laminate a dielectric ceramic composition and a conductor pattern such as silver or copper, and to fire these laminates. A dielectric ceramic composition that can be sintered at a temperature lower than the melting point is desired.
Japanese Patent Laid-Open No. 9-181549 Japanese Patent Application No. 2005-206542

In a conventional dielectric ceramic composition, MgTiO ₃ —CaTiO ₃ or the like is known as one having a relatively high dielectric constant and a high Q value. However, these conventional dielectric porcelain compositions have a problem that the sintering temperature is high, and cannot be used for multilayer electronic components that can be reduced in size and thickness. Could not contribute.

  The present invention enables a dielectric filter and a resonator to be reduced in size and loss by increasing the dielectric constant and Q value, and can be sintered at a temperature lower than the melting point of silver, copper, or the like. An object of the present invention is to provide a dielectric ceramic composition.

The dielectric ceramic composition of the present invention is represented by the general formula xMgTiO ₃ · yMg ₂ TiO ₄ · zCaTiO _3, and x, y, and z are mol%, and 69.3 ≦ x ≦ 84.0 and 14.1 respectively. 25 to 35 parts by weight of Li-based glass is added to 100 parts by weight of the composition in the range of ≦ y ≦ 30.0 and 0.8 ≦ z ≦ 6.1.

The dielectric ceramic composition of the present invention is represented by the general formula xMgTiO ₃ · yMg ₂ TiO ₄ · zCaTiO _3, and x, y, and z are mol%, and 69.3 ≦ x ≦ 84.0 and 14.1 respectively. Since Li-type glass is added in an amount of 25 to 35 parts by weight with respect to 100 parts by weight of the composition in the range of ≦ y ≦ 30.0 and 0.8 ≦ z ≦ 6.1, the dielectric constant and the Q value are The sintering temperature can be made lower than the melting point of silver or copper.

The dielectric ceramic composition of the present invention is represented by the general formula xMgTiO ₃ · yMg ₂ TiO ₄ · zCaTiO _3, and x, y, and z are mol%, and 69.3 ≦ x ≦ 84.0 and 14.1 respectively. Glass containing Li (so-called Li-based glass) is added to the ceramic main component in the range of ≦ y ≦ 30.0 and 0.8 ≦ z ≦ 6.1. At this time, the Li-containing glass is a silver constituting the conductor pattern between the dielectric layers of the multilayer electronic component by adjusting in the range of 25 to 35 parts by weight with respect to 100 parts by weight of the ceramic main component. Sintering is possible at a temperature of 950 ° C. or lower, which is lower than the melting point of copper or copper. Further, the dielectric constant and the Q value can be improved by adjusting x, y, and z within the aforementioned ranges.

Examples of the dielectric ceramic composition of the present invention will be described below.
First, a method for producing a dielectric ceramic composition according to the present invention will be described. MgTiO ₃ , Mg ₂ TiO ₄ , CaTiO _3, and Li-based glass raw material powder were weighed so as to have a predetermined composition, and this was wet-mixed for 16 hours using a ball mill or the like, and dried. These mixed powders were calcined at 750 to 800 ° C., and this calcined powder was wet-ground for 20 hours using a ball mill or the like. The pulverized product was dried, mixed with a binder, and granulated using a sieve. The granulated powder was formed into a cylindrical shape by applying a pressure of 3 t / cm ² and fired at 850 to 1050 ° C. in the air to obtain a material according to the present invention.

  The characteristics of the dielectric ceramic composition of the present invention were measured by molding and baking the above-mentioned dielectric ceramic composition to obtain an evaluation sample. This characteristic was measured by measuring the relative dielectric constant (εr) and the Q value (Qf) at 7 to 8 GHz by the Hakki & Coleman method.

FIG. 1 shows the sintering temperature and relative dielectric constant of xMgTiO ₃ .yMg ₂ TiO ₄ .zCaTiO _{3 when} the molar ratio x, y, z of each composition is changed and the addition amount of Li-based glass is changed. (Εr) and Q value (Qf) are summarized in a table. The Li-based glass has 17 parts by weight of SiO ₂ , 19.7 parts by weight of CaO, 12.6 parts by weight of Li ₂ O, 21.5 parts by weight of BaO, and 29.2 parts by weight of B ₂ O _3. Sample No. * indicates that it is outside the scope of the present invention.
In the dielectric ceramic composition of the present invention, the ratio x of MgTiO ₃ is 69.3 ≦ x ≦ 84.0, the ratio y of Mg ₂ TiO ₄ is 14.1 ≦ y ≦ 30.0, and the ratio z of CaTiO ₃ is 0.8 ≦ z ≦ 6.1, the amount of Li-based glass added is in the range of 25 parts by weight to 35 parts by weight, the sintering temperature is 950 ° C. or less, the relative dielectric constant is about 20, and the Q value is 10,000 or more. We were able to.

  Thus, in the dielectric ceramic composition of the present invention, the value of x is 69.3 ≦ x ≦ 84.0, the value of y is 14.1 ≦ y ≦ 30.0, and the value of z is 0.8 ≦ z. ≦ 6.1, Li-based glass added in the range of 25 parts by weight to 35 parts by weight, dielectric constant of 17.5 to 20.5 desired in laminated type dielectric filters, etc., Q value is 10,000 or more In addition, the sintering temperature can be 950 ° C. or lower, which is lower than the melting point of silver or copper.

It is a table | surface for demonstrating the characteristic of the dielectric material ceramic composition of this invention.

Claims (2)

General formula xMgTiO ₃ · yMg ₂ TiO ₄ · zCaTiO ₃
And
In 100 parts by weight of the composition in which x, y and z are in mol% and are in the ranges of 69.3 ≦ x ≦ 84.0, 14.1 ≦ y ≦ 30.0 and 0.8 ≦ z ≦ 6.1, respectively. On the other hand, a dielectric ceramic composition comprising 25 to 35 parts by weight of Li-based glass added. The components of the Li-based glass are 17 parts by weight of SiO ₂ , 19.7 parts by weight of CaO, 12.6 parts by weight of Li ₂ O, 21.5 parts by weight of BaO, and 29.2 parts by weight of B ₂ O _3. The dielectric ceramic composition according to claim 1, which is a part.

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