JP2012051750A - Method for manufacturing dielectric ceramic composition and laminated ceramic electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a dielectric ceramic composition capable of stably having excellent dielectric characteristics without causing any fluctuation in its composition, and a laminated ceramic electronic component.SOLUTION: The method for manufacturing a dielectric ceramic composition includes: a raw material mixture powder preparing process for mixing a principal ingredient raw material and accessory ingredient raw materials with water to obtain a raw material mixture powder; a heat treatment process for treating the raw material mixture powder with heat under an oxygen atmosphere; and a glass ingredient adding and crushing process for adding glass including LiO to the raw material mixture powder after the heat treatment and crushing the glass by using an organic solvent.

Description

  The present invention relates to a method for producing a dielectric ceramic composition formed by simultaneously firing a dielectric ceramic composition at a low temperature, and a multilayer ceramic electronic component.

  When manufacturing a multilayer ceramic electronic component such as a chip filter or a capacitor, it is necessary to simultaneously fire a dielectric ceramic composition and a conductor such as an electrode or a wiring (hereinafter referred to as a “conductor material”). For multilayer ceramic electronic parts and the like used in a high frequency region such as microwaves, it is desirable to use a low-resistance metal as a conductor material because conductor loss also greatly contributes to product characteristics.

As a dielectric material used for manufacturing a dielectric ceramic composition, for example, a dielectric ceramic composition containing forsterite (Mg ₂ SiO ₄ ) as a main component (hereinafter referred to as “forsterite composition”) is used. is there. Since the sintering temperature of the forsterite-based composition is about 1000 ° C. or lower and is lower than the sintering temperature of the conventional dielectric ceramic composition, the metal Ag is substituted for the conventionally used conductor materials such as Pd and Pt. Alternatively, an Ag-based alloy (hereinafter referred to as Ag-based metal) can be used as the conductor material. Ag-based metals have a lower melting point, lower resistance, and lower cost than conventional conductor materials such as Pd and Pt. Since the forsterite composition can be co-fired at a temperature (low temperature) below the melting point (eg, 900 ° C.) of the Ag-based metal, the forsterite-based composition is simultaneously formed with a conductor material such as an Ag-based metal. It is used as a low-temperature firing material (LTCC) that can be fired, and is suitable for a dielectric material that forms an LC filter, a capacitor, and the like.

  In general, a ceramic material for microwaves is blended with a main component material (base material) that plays a role of a desired value of high-frequency characteristics, and then heat-treated (calcined) at a temperature of about 1100 ° C. to 1400 ° C., pulverized, and fired In order to lower the temperature, the auxiliary component raw material (sintering aid) is added and mixed, and then heat treatment (calcination) is performed again and pulverized to obtain a dielectric ceramic composition.

In order to perform low-temperature firing, low melting point oxides (for example, Li ₂ O, B ₂ O ₃ , MoO ₃ , Bi ₂ O _3, etc.) and glasses (SiO ₂ —B ₂ O ₃ -alkali metal) are used as auxiliary component materials. An oxide-alkaline earth oxide, zinc borosilicate glass, or the like) is used (for example, see Patent Documents 1 and 2). In particular, a substance containing Li ₂ O (for example, Li ₂ O as an oxide or glass containing Li ₂ O) has a low softening point, and thus is used as an effective auxiliary component material for low-temperature firing.

Japanese Patent Laid-Open No. 10-242604 JP 2008-37739 A

However, the following problems occur depending on the addition timing of the substance containing Li ₂ O.

That is, in the stage of mixing the main component raw material and the subcomponent raw material, it is common to use water rather than an organic solvent from the viewpoint of reducing manufacturing cost, but a substance containing Li ₂ O is dissolved in water. Therefore, when a substance containing Li ₂ O is added at the stage of mixing the main component raw material and the subcomponent raw material, the substance containing Li ₂ O is dissolved in the slurry, so that the composition of the obtained dielectric ceramic composition There was a problem that there was a risk of fluctuation.

Further, when a substance containing Li ₂ O is added when forming a paint for forming a sheet, the dispersibility of the Li component in the dielectric ceramic composition is lowered, and the properties of the obtained dielectric ceramic composition are lowered. There was a problem.

As described above, Li ₂ O is effectively used as a secondary component raw material for low-temperature firing. However, depending on the timing of adding a substance containing Li ₂ O, the composition of the obtained dielectric ceramic composition may change or In some cases, the characteristics of the dielectric ceramic composition obtained by lowering the dispersibility of Li in the interior are lowered, and a dielectric ceramic composition having excellent dielectric characteristics cannot be obtained.

  Therefore, the dielectric ceramic composition can be stably provided with excellent dielectric characteristics without causing composition fluctuation of the dielectric ceramic composition obtained in order to obtain a dielectric ceramic composition having more stable and excellent dielectric characteristics. There is a need for a method for producing a body porcelain composition.

  The present invention has been made in view of the above, and provides a method for manufacturing a dielectric ceramic composition and a multilayer ceramic electronic component that can stably have excellent dielectric characteristics without causing composition fluctuations. The purpose is to do.

In order to solve the above-described problems and achieve the object, the present inventors have intensively studied a method for producing a dielectric ceramic composition and a multilayer ceramic electronic component. As a result, when producing a dielectric ceramic composition, by optimizing the addition time of the glass containing Li ₂ O, the resulting dielectric ceramic composition does not change in composition and does not cause deterioration of characteristics. The present inventors have found that stable and high characteristics can be obtained and excellent dielectric characteristics can be obtained. The present invention has been completed based on such findings.

A method for producing a dielectric ceramic composition according to the present invention includes a raw material mixed powder production step of mixing a main component raw material and a subcomponent raw material with water to obtain a raw material mixed powder, and the raw material mixed powder in an oxygen atmosphere. And a glass component addition / crushing step of adding glass containing Li ₂ O to the raw material mixed powder after the heat treatment and crushing using an organic solvent.

According to the above configuration, by optimizing the addition timing of the substance containing Li ₂ O, the resulting dielectric ceramic composition does not change in composition, and does not deteriorate in characteristics, and stably has high characteristics. Can be obtained and have excellent dielectric properties.

  The dielectric ceramic composition is a raw material composition for dielectric ceramic, and the dielectric ceramic is a sintered body obtained by sintering the dielectric ceramic composition. Sintering is a phenomenon in which a dielectric ceramic composition becomes a sintered body (dielectric ceramic) and becomes a dense object by heating the dielectric ceramic composition. In general, the density, mechanical strength, etc. of the sintered body (dielectric ceramic) are increased as compared with the dielectric ceramic composition before heating. The sintering temperature is the temperature of the dielectric ceramic composition when the dielectric ceramic composition is sintered. Further, firing means a heat treatment for the purpose of sintering, and the firing temperature is the temperature of the atmosphere to which the dielectric ceramic composition is exposed during the heat treatment.

As a preferred embodiment of the present invention, it is preferable that at least Mg ₂ SiO ₄ is contained as the main component. Since Mg ₂ SiO ₄ can be co-fired as a forsterite-based composition at a low temperature (a temperature below the melting point of the Ag-based metal), the forsterite-based composition can be used simultaneously with a conductor material such as an Ag-based metal. It is used as a LTCC that can be fired, and can be suitably used as a dielectric material for forming a multilayer ceramic electronic component or the like.

As a preferred embodiment of the present invention, it is preferable that at least one glass containing Li ₂ O is contained as the subcomponent. When the glass component contains Li ₂ O, the reaction between the unreacted secondary component raw material (sintering aid) and Mg ₂ SiO ₄ is further promoted. After firing the dielectric ceramic composition, Since the subcomponent raw material remaining unreacted can be further reduced and the subcomponent raw material can be completely reacted, the sinterability of the dielectric ceramic can be secured more stably. For this reason, the Q value of the obtained sintered body (dielectric ceramic) can be further increased, and the dielectric loss can be further reduced.

  As a preferred embodiment of the present invention, it is preferable that at least zinc oxide is contained as the subcomponent. Zinc oxide (particularly ZnO) contributes to firing at a low temperature (a temperature lower than the melting point of the Ag-based metal) when the dielectric ceramic composition is fired simultaneously with the Ag-based metal. By including, the dielectric ceramic composition can be stably co-fired with the Ag-based metal at a low temperature (a temperature lower than the melting point of the Ag-based metal).

  The multilayer ceramic electronic component according to the present invention includes a dielectric layer containing a dielectric ceramic composition obtained by using any one of the above methods for producing a dielectric ceramic composition. Since the dielectric ceramic composition according to the present invention is included in the dielectric layer, high dielectric properties can be stably obtained without causing a composition variation of the components contained in the dielectric layer, and excellent dielectric properties can be obtained. Therefore, for example, characteristics suitable for use in a high frequency band can be obtained, and a highly reliable multilayer ceramic electronic component can be provided.

  According to the present invention, it is possible to stably have excellent dielectric characteristics without causing composition fluctuations.

FIG. 1 is a conceptual cross-sectional view schematically showing an embodiment of an LC filter to which the dielectric ceramic composition according to this embodiment is applied as a dielectric layer. FIG. 2 is a flowchart showing an example of a method for manufacturing a multilayer ceramic electronic component according to the present embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, modes for suitably carrying out the present invention (hereinafter referred to as embodiments) will be described in detail. In addition, this invention is not limited by the content described in the following embodiment. In addition, constituent elements in the embodiments described below include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the components disclosed in the embodiments described below can be appropriately combined.

<Multilayer ceramic electronic parts>
An embodiment of a multilayer ceramic electronic component to which a dielectric layer containing a dielectric ceramic composition according to this embodiment is applied will be described with reference to the drawings. In this embodiment, a case where an LC filter is used as the multilayer ceramic electronic component will be described. FIG. 1 is a conceptual cross-sectional view schematically showing an embodiment of an LC filter to which the dielectric ceramic composition according to this embodiment is applied as a dielectric layer. As shown in FIG. 1, the LC filter 10 includes a plurality of dielectric layers 11, a coil portion 12, capacitor pattern portions 13-1 to 13-3, and vias (via conductors) 14. The dielectric layer 11 is formed using the dielectric ceramic composition according to the present embodiment. The coil part 12 and the capacitor pattern parts 13-1 to 13-3 are formed of an Ag conductor. The via portion 14 is a via hole portion filled with an Ag conductor that makes the coil portion 12 and the capacitor pattern portion 13-1 conductive, and an LC resonance circuit is formed. The capacitor pattern portion 13-1 is connected to the coil portion 12 by the via portion 14. The LC filter 10 is provided with capacitor pattern portions 13-1 to 13-3, and the capacitor portion of the LC filter 10 has a three-layer structure. However, the LC filter 10 is not limited to a three-layer structure, and may have an arbitrary multilayer structure. Can do.

[Dielectric layer]
The dielectric layer 11 is a dielectric layer formed including the dielectric ceramic composition according to the present embodiment. The dielectric ceramic composition according to the present embodiment includes a main component and a subcomponent.

As will be described later, the dielectric ceramic composition according to the present embodiment includes a raw material mixed powder production step in which a raw material mixed powder is obtained by mixing a main component raw material and a subcomponent raw material with water, and the raw material mixed powder is oxygenated. It is obtained by a manufacturing method including a heat treatment step in which heat treatment is performed in an atmosphere, and a glass component addition and pulverization step in which glass containing Li ₂ O is added to the raw material mixed powder after heat treatment and pulverized using an organic solvent.

  In the present embodiment, the dielectric ceramic composition is a raw material composition for dielectric ceramic, and the dielectric ceramic is a sintered body obtained by sintering the dielectric ceramic composition. Sintering is a phenomenon in which a dielectric ceramic composition becomes a sintered body (dielectric ceramic) and becomes a dense object by heating the dielectric ceramic composition. In general, the density, mechanical strength, etc. of the sintered body (dielectric ceramic) are increased as compared with the dielectric ceramic composition before heating. The sintering temperature is the temperature of the dielectric ceramic composition when the dielectric ceramic composition is sintered. Further, firing means a heat treatment for the purpose of sintering, and the firing temperature is the temperature of the atmosphere to which the dielectric ceramic composition is exposed during the heat treatment.

  Whether the dielectric ceramic composition can be fired at a low temperature (low temperature sinterability) is evaluated by gradually lowering the firing temperature of the dielectric ceramic composition and firing the dielectric ceramic composition according to the present embodiment. The determination can be made based on whether the dielectric ceramic composition is sintered to such an extent that the desired ceramic high-frequency characteristics can be obtained. In addition, the dielectric characteristics of the dielectric ceramic composition according to the present embodiment can be evaluated by the Q · f value, the change of the resonance frequency due to the temperature change (temperature coefficient τf of the resonance frequency), and the relative dielectric constant εr. . The Q · f value and the relative dielectric constant εr can be measured in accordance with Japanese Industrial Standard “Test Method for Dielectric Properties of Fine Ceramics for Microwaves” (JIS R1627 1996). In the present embodiment, the Q value is used for evaluating the dielectric loss.

(Main component)
The main component of the dielectric layer 11 is not particularly limited, and a known material can be used. The main component contained in the dielectric layer 11 is, for example, forsterite (also referred to as forestlite. The chemical formula is generally represented by 2MgO.SiO ₂ or Mg ₂ SiO ₄ ), enstatite (MgO.SiO ₂ ). ₂ ), diopside (CaO · MgO · 2SiO ₂ ), BaNdTiO-based oxides containing BaO, Nd ₂ O ₃ and TiO ₂ . Among these main components, Mg ₂ SiO ₄ is particularly preferable. Mg ₂ SiO ₄ is preferably contained in the dielectric layer 11 in the form of forsterite crystal from the viewpoint of reducing dielectric loss. Whether the dielectric layer 11 contains a forsterite crystal can be confirmed by an X-ray diffraction spectroscopy (XRD).

Mg ₂ SiO ₄ has a Q · f value of 200,000 GHz or more alone and a small dielectric loss, and thus has a function of reducing the dielectric loss of the dielectric ceramic. Mg ₂ SiO ₄ also has a function of lowering the relative dielectric constant εr of the dielectric ceramic because its relative dielectric constant εr is as low as about 6 to 7.

  Here, dielectric loss is a phenomenon in which part of high-frequency energy is dissipated as heat. Normally, when an alternating current is applied to an ideal dielectric ceramic, the current and voltage have a phase difference of 90 degrees. However, when the AC frequency is increased and the frequency is increased, the electric polarization of the dielectric ceramic or the orientation of the polar molecules cannot follow the change of the electric field of the high frequency, or the electric flux density is phase-shifted with respect to the electric field due to conduction of electrons or ions. Therefore, the actual current and voltage have a phase other than 90 degrees. A phenomenon in which a part of high-frequency energy is dissipated as heat due to such a phase difference is called dielectric loss. The magnitude of the dielectric loss is expressed by the reciprocal Q (Q = 1 / tan δ) of the tangent tan δ of the loss angle δ, which is the difference between the actual current and voltage phase difference and the ideal current and voltage phase difference of 90 degrees. It is. Evaluation of the dielectric loss of the dielectric ceramic composition is expressed using a Q · f value which is a product of the Q and the resonance frequency f. The Q · f value increases as the dielectric loss decreases, and the Q · f value decreases as the dielectric loss increases. Since the dielectric loss means the power loss of the high frequency device, it is preferable that the Q · f value of the dielectric ceramic composition is large.

From the viewpoint that Mg ₂ SiO ₄ has a low relative dielectric constant εr and a large Q · f value, the dielectric layer 11 is made of a dielectric layer mainly composed of Mg ₂ SiO ₄ , so that the relative dielectric constant can be obtained. It is possible to decrease εr and increase the Q · f value.

From the viewpoint of reducing the dielectric loss of the dielectric ceramic composition, the ratio of Mg ₂ SiO ₄ to the main component is preferably 100% by mass, but in order to adjust the relative dielectric constant εr, other than Mg ₂ SiO ₄ The main component can be used in combination with Mg ₂ SiO ₄ . As main components other than Mg ₂ SiO ₄ , for example, BaNdTiO-based oxide, magnesium titanate (MgTiO ₃ ) having a relative dielectric constant εr of around 17, and calcium titanate (CaTiO ₃ ) having a relative dielectric constant εr of around 200 ₃ ).

The molar ratio of MgO and SiO ₂ which constitutes the mg ₂ SiO _4, the stoichiometrically MgO pair SiO ₂ is 2 to 1, this embodiment is not limited thereto, the present embodiment You may remove | deviate from stoichiometry within the range which does not impair the effect of the dielectric ceramic which concerns on a form. For example, MgO to SiO ₂ can be in the range of 1.9 to 1.1 to 2.1 to 0.9.

The content of the main component in the dielectric ceramic composition of the present embodiment is preferably the remainder obtained by removing each subcomponent described later from the entire dielectric ceramic composition. When the dielectric ceramic composition contains Mg ₂ SiO ₄ as a main component under such conditions, the effect of reducing the dielectric loss and the relative dielectric constant εr can be obtained with certainty. In addition, when a component other than Mg ₂ SiO ₄ as described above is included as the main component, the total of the main components is the remainder obtained by removing each subcomponent described later from the entire dielectric ceramic composition.

When the dielectric layer 11 includes a BaNdTiO-based oxide as a main component, examples of the main component of the dielectric layer 11 include a BaO—Nd ₂ O ₃ —TiO ₂ system, Bi ₂ O ₃ —BaO—Nd ₂ O, for example. Examples include dielectric ceramics such as _3- TiO ₂ . The contents of BaO, Nd ₂ O ₃ and TiO ₂ are not particularly limited and may be adjusted as appropriate.

When the BaNdTiO-based oxide is a BaO—Nd ₂ O ₃ —TiO ₂ -based compound, the relationship represented by the following formulas (2) to (5) in the composition formula represented by the following formula (1) is preferable. Those satisfying these conditions are preferred. In the following formulas (1) to (5), x, y, and z are mol%.
xBaO · yNd ₂ O ₃ · zTiO ₂ (1)
6.0 ≦ x ≦ 23.0 (2)
13.0 ≦ y ≦ 30.0 (3)
64.0 ≦ z ≦ 68.0 (4)
x + y + z = 100 (5)

The BaO—Nd ₂ O ₃ —TiO ₂ based compound has a high relative dielectric constant εr, and the relative dielectric constant εr is about 55 to 105. Mg ₂ SiO ₄ alone has a low relative permittivity εr, and the value of the relative permittivity εr is about 6.8. The dielectric layer 11 contains a BaO—Nd ₂ O ₃ —TiO ₂ compound having a high relative dielectric constant εr as a main component and Mg ₂ SiO ₄ having a low relative dielectric constant εr, whereby the ratio of the dielectric layer 11 is increased. Lower the dielectric constant εr.

The Q · f value of the BaO—Nd ₂ O ₃ —TiO ₂ compound is 2000 GHz or more and 8000 GHz or less. On the other hand, Q · f value of Mg ₂ SiO ₄ is about 200,000 GHz, the dielectric loss of Mg ₂ SiO ₄ is smaller than the dielectric loss of BaO-Nd ₂ O ₃ -TiO ₂ based compound. In the present embodiment, the main component of the dielectric layer 11 includes a BaO—Nd ₂ O ₃ —TiO ₂ compound and Mg ₂ SiO ₄ , whereby a dielectric layer having a low dielectric loss can be obtained.

(Subcomponent)
The dielectric layer 11 further includes a subcomponent with respect to the main component. The subcomponent is obtained from a subcomponent raw material (sintering aid) that forms a liquid phase when the dielectric ceramic composition is fired. When the dielectric ceramic composition contains the subcomponent raw material as a subcomponent, the sintering temperature of the dielectric ceramic composition can be lowered. The dielectric ceramic composition is included in the dielectric ceramic composition by using the dielectric ceramic composition according to the present embodiment by including the subcomponent raw material in the dielectric ceramic composition and lowering the sintering temperature of the dielectric ceramic composition below the melting point of the conductor material. During production, the dielectric ceramic composition can be fired at the same time as the Ag-based metal at a low temperature (a temperature lower than the melting point of the Ag-based metal), and low-temperature firing can be achieved. Thereby, a conductor material made of an Ag-based metal can be used as the inner conductor of the LC filter 10. In addition, since the dielectric ceramic composition of the present embodiment can be obtained by firing at a low temperature while ensuring sinterability, the dielectric ceramic composition according to the present embodiment can be obtained. The resulting dielectric layer 11 can have excellent dielectric properties.

  Examples of subcomponents contained in the dielectric layer 11 include zinc oxide, boron oxide, bismuth oxide, cobalt oxide, manganese oxide, copper oxide, lithium oxide, aluminum oxide, titanium oxide, Examples include alkaline earth metal oxides and glass components, but are not particularly limited thereto.

  The content of subcomponents is not particularly limited, but the content of all subcomponents other than glass components is 1.0% by mass or more and 20.0% by mass or less with respect to the sum of all main components. It is preferable. In addition, when the main component contained in the dielectric layer 11 is only forsterite, the content of subcomponents increases when only forsterite is sintered at low temperature. For this reason, the content of the subcomponents contained in the dielectric layer 11 is 16.1% by mass or more and 48.0% by mass or less of all the subcomponents other than the glass component with respect to the sum of all main components. It is preferable.

  The sintering aid preferably contains zinc oxide. Examples of zinc oxide include ZnO. Zinc oxide (particularly ZnO) contributes to firing at a low temperature (a temperature lower than the melting point of the Ag-based metal) when the dielectric ceramic composition is fired simultaneously with the Ag-based metal. By including, the dielectric ceramic composition can be stably co-fired with the Ag-based metal at a low temperature (a temperature lower than the melting point of the Ag-based metal).

As the glass component, glass containing lithium oxide (Li ₂ O) is used. The glass component preferably contains at least one glass containing lithium oxide (Li ₂ O). The glass component contained as an auxiliary component raw material plays a role as a liquid phase. When Mg ₂ SiO ₄ is contained as the main component material because the glass component contains Li ₂ O, the reaction between the unreacted auxiliary component material (sintering aid) and Mg ₂ SiO ₄ as the main component material Promote sex. Thereby, after baking of a dielectric ceramic composition, the subcomponent raw material which remains unreacted in a sintered compact (dielectric ceramic) can be reduced. Further, since the subcomponent raw material can be completely reacted, the sinterability of the dielectric ceramic composition can be secured more stably. Thereby, the Q value of the obtained sintered body (dielectric ceramic) can be further increased, and the dielectric loss can be further reduced.

As such a glass component, for example, SiO ₂ —RO—Li ₂ O (RO contains at least one alkaline earth metal oxide) glass and B ₂ O ₃ —RO—Li ₂ O glass. What comprises any one or both is preferable. As glass component, _{specifically,} the SiO ₂ -RO-Li 2 O-based _glass, SiO ₂ -CaO-Li 2 O-based glass, SiO ₂ -SrO-Li ₂ O-based glass, SiO ₂ -BaO-Li ₂ O-based _{glass, SiO 2 -CaO-SrO-Li} 2 O -based _{glass, SiO 2 -BaO-CaO-Li} 2 O -based _{glass, SiO 2 -SrO-BaO-Li} 2 O -based glass, SiO ₂ -CaO-SrO such -BaO-Li ₂ O system glass. B ₂ O ₃ as the -RO-Li ₂ O-based _{glass, B 2 O 3 -CaO-Li} 2 O -based _{glass, B 2 O 3 -SrO-Li} 2 O -based _{glass, B 2 O 3 -BaO-Li} 2 O glass, B ₂ O ₃ —CaO—SrO—Li ₂ O glass, B ₂ O ₃ —BaO—CaO—Li ₂ O glass, B ₂ O ₃ —SrO—BaO—Li ₂ O glass, B Examples include ₂ O ₃ —CaO—SrO—BaO—Li ₂ O-based glass. Among these, SiO ₂ —BaO—CaO—Li ₂ O-based glass is preferable.

  When zinc oxide is contained as a subcomponent, the content of zinc oxide is such that when the mass of zinc oxide is converted to ZnO, the mass ratio of ZnO is 0.1 mass% or more with respect to 100 mass% of the main component. It is preferably 7.0% by mass or less, more preferably 1.5% by mass or more and 7.0% by mass or less, and further preferably 4.5% by mass or more and 7.0% by mass or less. Zinc oxide (particularly ZnO) contributes to firing at a low temperature (a temperature lower than the melting point of the Ag-based metal) when the dielectric ceramic composition is fired simultaneously with the Ag-based metal. Therefore, by setting the content of zinc oxide within the above range, the dielectric ceramic composition can be stably co-fired with the Ag-based metal at a low temperature (a temperature lower than the melting point of the Ag-based metal). Become.

  If the zinc oxide content is less than 0.1% by mass, the low-temperature sintering effect (that is, the effect that enables the dielectric ceramic composition to be sintered at a lower temperature) tends to be insufficient. The sintered density of the dielectric ceramic according to the present embodiment is decreased, the quality factor Q is decreased, and the dielectric loss tends to be increased. On the other hand, if the zinc oxide content exceeds 7.0% by mass, the quality factor Q tends to decrease and the dielectric loss tends to increase. Therefore, these tendencies can be suppressed by setting the content of zinc oxide within the above range.

  When the main component included in the dielectric layer 11 is only forsterite, as described above, when only forsterite is sintered at a low temperature, the content of subcomponents increases, so that the subcomponent included in the dielectric layer 11 is increased. The content of the components will vary. In this case, the content of zinc oxide, when the mass of zinc oxide is converted to ZnO, the mass ratio of ZnO is 8.0% by mass or more and 20.0% by mass or less with respect to 100% by mass of the main component. It is preferably 10.0% by mass or more and 16.0% by mass or less, more preferably 12.0% by mass or more and 16.0% by mass or less.

  When the main component contained in the dielectric layer 11 is only forsterite, when the zinc oxide content is less than 8.0% by mass, the low-temperature sintering effect (that is, the dielectric ceramic composition at a lower temperature) The effect of enabling the sintering of the dielectric ceramic according to the present embodiment tends to be insufficient, the sintered density of the dielectric ceramic according to the present embodiment decreases, the quality factor Q decreases, and the dielectric loss tends to increase. . Moreover, when content of zinc oxide exceeds 20.0 mass%, the quality factor Q will fall and there exists a tendency for a dielectric loss to become large. Therefore, these tendencies can be suppressed by setting the content of zinc oxide within the above range.

Examples of the boron oxide include B ₂ O ₃ . If boron oxide is contained as a sub-component, the content of boron oxide, when the mass of boron oxide is converted as B ₂ O _3, the mass ratio of B ₂ O ₃ is with respect to the main component of 100 wt% 0 It is preferably 1% by mass or more and 3.0% by mass or less, and more preferably 1.0% by mass or more and 2.5% by mass or less.

  If the boron oxide content is less than 0.1% by mass, the low-temperature sintering effect tends to be insufficient, the quality factor Q tends to decrease, and the dielectric loss tends to increase. On the other hand, if the boron oxide content exceeds 3.0 mass%, the sintered density of the dielectric ceramic composition according to the present embodiment tends to be low, the quality factor Q decreases, and the dielectric loss increases. Therefore, these tendencies can be suppressed by setting the content of boron oxide within the above range.

When the main component included in the dielectric layer 11 is only forsterite, as described above, when only forsterite is sintered at a low temperature, the content of subcomponents increases, so that the subcomponent included in the dielectric layer 11 is increased. The content of the components will vary. In this case, the content of boron oxide, when converted to mass of boron oxide as _{B 2 O 3, B 2 O} 3 mass ratio is more than 3.0 mass% with respect to the main component of 100 wt% 10. It is preferably 0% by mass or less, more preferably 4.0% by mass or more and 8.0% by mass or less, and further preferably 5.0% by mass or more and 7.0% by mass or less.

  When the main component contained in the dielectric layer 11 is only forsterite, if the boron oxide content is less than 3.0% by mass, the low-temperature sintering effect tends to be insufficient, and the quality factor Q is It tends to decrease and increase the dielectric loss. On the other hand, if the content of boron oxide exceeds 10.0% by mass, the sintered density of the dielectric ceramic composition according to the present embodiment tends to be low, the quality factor Q is lowered, and the dielectric loss is increased. Therefore, these tendencies can be suppressed by setting the content of boron oxide within the above range.

If the bismuth oxide is contained as a sub-component, the content of bismuth oxide, when converted to the weight of bismuth oxide as Bi ₂ O _3, the mass ratio of Bi ₂ O ₃ with respect to the main component of 100% by mass 1.0 It is preferable that it is mass% or more and 4.0 mass% or less, and it is more preferable that they are 1.5 mass% or more and 3.5 mass% or less.

  When cobalt oxide is contained as an accessory component, the content of cobalt oxide is such that when the mass of cobalt oxide is converted as CoO, the mass ratio of CoO is 0.5% by mass or more and 20.0% with respect to 100% by mass of the main component. It is preferable that it is mass% or less, and it is more preferable that it is 1.0 mass% or more and 1.5 mass% or less.

  When manganese oxide is contained as an accessory component, the content of manganese oxide is such that when the mass of manganese oxide is converted to MnO, the mass ratio of MnO is 0.3 mass% or more to 1.5 mass% with respect to 100 mass% of the main component. It is preferable that it is mass% or less, and it is more preferable that it is 0.5 mass% or more and 1.0 mass% or less.

  When copper oxide is contained as a subcomponent, the content of copper oxide is such that when the mass of copper oxide is converted as CuO, the mass ratio of CuO is 0.1 mass% or more and 2.0 mass% with respect to 100 mass% of the main component. It is preferable that it is mass% or less, and it is more preferable that it is 0.7 mass% or more and 1.3 mass% or less.

  When alkaline earth metal oxide is included as a subcomponent, the content of alkaline earth metal oxide is when the mass of alkaline earth metal oxide is converted to RO (R represents an alkaline earth metal element). The content is preferably 1.0% by mass or more and 4.0% by mass or less, and more preferably 2.0% by mass or more and 3.0% by mass or less with respect to 100% by mass of the main component. By including the alkaline earth metal oxide in the dielectric ceramic composition, the low-temperature sintering effect of the dielectric ceramic becomes remarkable.

  When the content of the alkaline earth metal oxide is less than 1.0% by mass, the low-temperature sintering effect tends to be insufficient, and the sintered density of the dielectric ceramic according to the present embodiment tends to be low. The quality factor Q tends to decrease and the dielectric loss tends to increase. On the other hand, when the content of the alkaline earth metal oxide exceeds 4.0% by mass, the low temperature sintering effect becomes remarkable, but the quality factor Q tends to decrease and the dielectric loss tends to increase. Therefore, these tendencies can be suppressed by setting the content of the alkaline earth metal oxide within the above range.

As R, which is an alkaline earth metal, any of Ba, Sr, Ca, and Mg is preferable, and a mixture of two or more of these may be used. Specific examples of the alkaline earth metal oxide RO include BaO, SrO, CaO, and MgO. When an alkaline earth metal oxide is used as a subcomponent, the alkaline earth metal oxide is more preferably calcium oxide (CaCO ₃ ).

If it contains calcium oxide as an alkaline earth metal oxide, the content of calcium oxide, when converted to the weight of calcium oxide as CaCO _3, the mass ratio of CaCO ₃ with respect to the main component of 100% by mass 0.1 The mass is preferably from 1.5% by mass to 1.5% by mass, and more preferably from 0.5% by mass to 1.5% by mass.

The content of the glass component which is a kind of subcomponent is 100% by mass of the dielectric composition excluding the glass component from the subcomponent when the mass of the glass component is converted to SiO ₂ —BaO—CaO—Li ₂ O-based glass. On the other hand, it is preferably 2.0% by mass or more and 10.0% by mass or less, more preferably 2.0% by mass or more and 7.0% by mass or less, and 4.0% by mass or more and 6.0% by mass. % Or less is more preferable.

  When the content of the glass component is less than 2.0% by mass, the low-temperature sintering effect is insufficient, the sintering is insufficient, the sintered density of the dielectric ceramic according to the present embodiment is reduced, and the quality factor Q is It tends to decrease and the dielectric loss increases. Moreover, when content of a glass component exceeds 10.0 mass%, the quality factor Q will fall and there exists a tendency for a dielectric loss to become large. Therefore, these tendencies can be suppressed by setting the content of the glass component within the above range.

<Manufacturing method of multilayer ceramic electronic component>
An example of a method for manufacturing a multilayer ceramic electronic component according to this embodiment will be described with reference to the drawings. FIG. 2 is a flowchart showing an example of a method for manufacturing a multilayer ceramic electronic component according to the present embodiment. As shown in FIG. 2, the manufacturing method of the multilayer ceramic electronic component according to this embodiment includes the following steps.
(A) Dielectric porcelain composition manufacturing step for obtaining a dielectric porcelain composition by mixing a main component material and a subcomponent material (step S11)
(B) Sheet body production process for producing a sheet body (green sheet) for forming a slurry (paste) containing the dielectric ceramic composition into a sheet by forming the dielectric ceramic composition into a paint (step S12)
(C) Sheet laminated body forming step (step S13) in which a plurality of sheet bodies (green sheets) are alternately laminated to form a sheet laminated body.
(D) A firing step of obtaining a laminated sintered body by firing the sheet laminated body at a temperature of 800 ° C. or higher and 1000 ° C. or lower in an oxygen atmosphere (step S14).

<Production Process of Dielectric Porcelain Composition: Step S11>
As the raw material of the main component of the dielectric ceramic composition, the main component material used in the dielectric ceramic composition according to the above-described embodiment is used, and examples thereof include Mg ₂ SiO ₄ and BaNdTiO-based oxides. . Mg ₂ SiO ₄ is obtained, for example, by mixing a raw material powder of magnesium oxide (MgO) and a raw material powder of silicon oxide (SiO ₂ ) and heat-treating (calcining). Further, for example, a BaNdTiO-based oxide is prepared by mixing a raw material powder of barium carbonate (BaCO ₃ ), a raw material powder of neodymium hydroxide (Nd (OH) ₃ ), and a raw material powder of titanium oxide (TiO ₂ ). It is obtained by calcining.

  As each raw material of the subcomponent of the dielectric ceramic composition, subcomponent raw materials used in the dielectric ceramic composition according to the above-described embodiment are used. For example, zinc oxide, boron oxide, bismuth oxide, Cobalt oxide, manganese oxide, copper oxide, alkaline earth metal oxide, lithium oxide, aluminum oxide, titanium oxide, and glass component, or these by firing (heat treatment such as calcination described later) A compound that becomes an oxide or a complex oxide can be used. Examples of the compound that becomes the oxide upon firing include carbonates, nitrates, oxalates, hydroxides, sulfides, organometallic compounds, and the like.

As the glass component, glass containing Li ₂ O is used as described above. Examples of the glass containing Li ₂ O include SiO ₂ —RO—Li ₂ O-based glass and B ₂ O ₃ —RO—Li ₂ O-based glass. As a raw material of the glass component, it is possible to use the oxide of Li constituting the glass component described above, a mixture thereof, a composite oxide, or various compounds that form the oxide or composite oxide constituting the glass component by firing. it can. The glass component can be obtained by mixing raw materials such as oxides constituting the glass component, firing, then quenching, and vitrifying. Since the glass component contains Li ₂ O, the reaction between the sintering aid that remains unreacted and Mg ₂ SiO ₄ can be promoted, so that the sinterability of the dielectric ceramic composition is stabilized. In addition, the dielectric ceramic composition can be co-fired with the Ag-based metal at a low temperature such that the Ag-based metal does not melt.

The production process (step S11) of the dielectric ceramic composition includes the following processes in producing the dielectric ceramic composition.
(A-1) Raw material mixed powder production process for obtaining raw material mixed powder by mixing main component raw material and subcomponent raw material with water (step S11-1)
(A-2) Heat treatment step (step S11-2) for heat-treating (calcining) the raw material mixed powder at a temperature of 800 ° C. or higher and 950 ° C. or lower in an oxygen atmosphere.
(A-3) Glass component addition and crushing step of adding glass containing Li ₂ O to the raw material mixed powder after heat treatment and crushing using an organic solvent (step S11-3)

  Subcomponent materials other than the main component materials and glass components are added and mixed with water to obtain a raw material mixed powder (step S11-1). The weighing of each subcomponent raw material is performed so that the content of the subcomponent raw material becomes a desired mass ratio (mass%) with respect to the main component in the completed dielectric ceramic composition.

  The mixing of the main component raw material and the subcomponent raw material is performed by a wet mixing method. For example, the main component raw material and the sub component raw material can be mixed using pure water as a solvent by a mixing and dispersing machine such as a ball mill. The mixing time may be about 4 to 24 hours.

  The raw material mixed powder is preferably dried at a drying temperature of 100 ° C. to 200 ° C., more preferably 120 ° C. to 140 ° C. for about 12 to 36 hours.

  The dried raw material mixed powder is heat-treated (calcined) at, for example, 800 ° C. or higher and 950 ° C. or lower in an oxygen atmosphere to prepare a raw material mixed powder of calcined powder (step S11-2). The firing temperature at the time of heat treatment is preferably 800 ° C. or higher and 950 ° C. or lower, more preferably 800 ° C. or higher and 900 ° C. or lower, and most preferably 830 ° C. or higher and 870 ° C. or lower. The firing time is not particularly limited, but is preferably about 1 to 10 hours. By performing the calcining at a temperature equal to or lower than the firing temperature in this way, it is possible to suppress melting of the main component material in the raw material mixed powder, and the dielectric ceramic composition contains the main component material in the form of crystals. be able to. Moreover, unreacted subcomponent raw materials can be reduced.

  After the calcined powder is pulverized, the glass component that is the remainder of the subcomponent raw material powder is added to the calcined powder and mixed, and an organic solvent, a dispersant, and the like are added. Although it does not specifically limit as a method of adding an organic solvent to the calcining powder which mixed the glass component, It carries out by wet mixing using a ball mill etc. As the organic solvent, for example, alcohols such as ethanol and methanol are used. The calcined powder mixed with the glass component is pulverized to a desired particle size and then dried. Thereby, a dielectric ceramic composition is obtained (step S11-3).

  The pulverization can be performed by a pulverization method such as dry pulverization or wet pulverization. The pulverization time may be about 4 to 24 hours. Drying of the raw material mixed powder after pulverization is preferably performed at a treatment temperature of 100 ° C. or higher and 200 ° C. or lower, more preferably 120 ° C. or higher and 140 ° C. or lower for about 12 to 36 hours.

  In the production process of the dielectric ceramic composition (step S11), the glass component is added after the main component material and the subcomponent material other than the glass component are mixed and after the heat treatment (calcination). As a result, the resulting dielectric ceramic composition does not fluctuate, the dielectric constant ε, the dielectric loss Q value, etc. do not decrease, stable high dielectric characteristics can be obtained, and excellent dielectric characteristics can be obtained. Can have.

That is, in the step of mixing the main ingredient raw material and the sub ingredient raw material other than the glass component to obtain the raw material mixed powder (step S11-1), when the glass component as the remaining sub ingredient raw material is added to the main ingredient raw material, In order to spray-dry and dry the liquid mixture containing the component raw material and the subcomponent raw material other than the glass component, water is generally used as a solvent in the mixing and dispersing machine such as a ball mill. Used. However, Li ₂ O is liable to dissolve in water, to dissolve the Li ₂ O in water containing a main component material and subcomponent material, resulting in compositional variation of the dielectric ceramic composition obtained. In addition, when mixing the main component raw material and the subcomponent raw material other than the glass component, when using an organic solvent such as alcohol instead of water as the solvent, when the raw material mixed powder is heat-treated (calcined) and then finely pulverized, Again, since solvent pulverization is performed using an organic solvent such as alcohol, the manufacturing cost increases, which is not preferable. Furthermore, as will be described later, when the sheet body containing the dielectric ceramic composition is produced in the step S12, the dielectric ceramic composition is made into a paint and the slurry (paste) containing the dielectric ceramic composition is glass. When the component is added, since the dispersibility of the Li component with respect to the dielectric ceramic composition is lowered, the characteristics of the obtained dielectric ceramic composition are lowered.

Therefore, in the dielectric ceramic composition manufacturing step (step S11), the glass component is added after the heat treatment (calcination) by mixing the main component material and the subcomponent material other than the glass component. Thereby, the main component and subcomponent of a dielectric ceramic composition are mixed uniformly, and the dielectric ceramic composition with a uniform material can be obtained. Considering the solubility of Li ₂ O in water and the dispersibility of the Li component in the dielectric ceramic composition, the composition variation of the resulting dielectric ceramic composition is optimized by optimizing the addition time of the glass containing Li ₂ O. Without causing a decrease in dielectric constant ε, dielectric loss (Q value), etc., stable high dielectric characteristics can be obtained, and excellent dielectric characteristics can be obtained.

<Sheet body production process: Step S12>
After producing the dielectric ceramic composition, the dielectric ceramic composition is made into a paint to prepare a slurry (paste) containing the dielectric ceramic composition, and the resulting slurry is formed into a sheet shape. ) Is prepared (step S12).

  A predetermined amount of the dielectric ceramic composition is blended with an organic binder such as acrylic or ethyl cellulose, to prepare a slurry containing the dielectric ceramic composition. The slurry is used for forming a sheet, and a green sheet is obtained by applying the slurry in a sheet form on a substrate by a doctor blade method or the like and drying the slurry applied in a sheet form on the substrate. The green sheet molding method is not particularly limited as long as it can be applied in a sheet form, and may be a wet molding method such as a sheet method or a printing method, or a dry molding method such as press molding.

<Sheet Laminate Forming Step: Step S13>
After producing the green sheet, a conductive paste containing Ag is applied on the green sheet so that an internal electrode having a predetermined shape is formed, thereby producing a green sheet on which the conductive paste is applied. A plurality of green sheets to which conductive paste is applied and green sheets to which conductive paste is not applied are alternately stacked. A sheet laminate is formed by alternately laminating and pressing a plurality of Ag-based metal conductors that serve as internal electrodes between the green sheets (step S13).

<Baking process: Step S14>
After producing the sheet laminate, the sheet laminate is removed from the substrate, the sheet laminate is cut into a predetermined shape and chamfered to form a chip-type sheet laminate, and the binder contained in the green sheet is removed. Thereafter, the sheet laminate is fired to obtain a laminated sintered body (step S14). Firing is preferably performed in an oxygen atmosphere such as in air. For example, the firing temperature is preferably 800 ° C. or higher and 1000 ° C. or lower, more preferably 880 ° C. or higher and 920 ° C. or lower, and most preferably 900 ° C. or higher and 920 ° C. or lower.

  The green sheet becomes the dielectric layer 11 by firing. Since the green sheet is obtained by forming the main component material into a sheet shape, the main component material is directly included in the dielectric layer 11 as the main component.

  After cooling the laminated sintered body, the obtained laminated sintered body was subjected to end face polishing, for example, by barrel polishing or sand blasting, and the external electrode paste was applied and dried on both sides of the laminated sintered body. Then, external electrodes and the like are formed by baking. The baking temperature is baking and baking at a temperature lower than the temperature for baking the chip. For example, baking is performed at a temperature of 650 ° C. to 700 ° C. The external electrode paste can be prepared by kneading, for example, a conductive material such as silver and the above-described organic vehicle. Further, it is preferable to perform electroplating with Cu—Ni—Sn, Ni—Sn, Ni—Au, Ni—Ag or the like on the external electrode.

  After an external electrode or the like is formed on the laminated sintered body, the laminated ceramic electronic component having an internal electrode made of an Ag-based metal is obtained by plating the laminated sintered body until a predetermined film thickness is obtained.

As described above, the LC filter 10 according to the present embodiment is obtained by the method for manufacturing a multilayer ceramic electronic component according to the present embodiment. When the dielectric ceramic composition is manufactured, the dielectric ceramic composition described above is obtained. By optimizing the addition time of the glass containing Li ₂ O in consideration of the solubility of Li ₂ O in water and the dispersibility of the Li component in the dielectric ceramic composition in the manufacturing process of the product (step S11) , A glass containing Li ₂ O can be stably included in the dielectric ceramic composition. According to the method for manufacturing a multilayer ceramic electronic component according to the present embodiment, the dielectric constant ε, dielectric loss (Q value), and the like are reduced without causing a composition variation of the obtained sintered body (dielectric ceramic). However, it is possible to manufacture a monolithic ceramic electronic component having stable and high dielectric characteristics and excellent dielectric characteristics.

  In addition, as described above, the glass component contained as an auxiliary component serves as a liquid phase when firing the dielectric ceramic composition, and promotes the reactivity between the unreacted auxiliary component material and the main component material. Can be made. For this reason, even if the dielectric ceramic composition is fired at a low temperature, the unreacted subcomponent raw material can be eliminated, the subcomponent raw material can be completely reacted, and the sinterability of the dielectric ceramic composition can be ensured. As a result, the Q value of the dielectric ceramic (sintered body) obtained can be increased, and the dielectric loss can be reduced.

  The characteristic deterioration of the Q value means that the loss of the electronic component becomes large. The larger the Q value, the smaller the loss of the electronic component. By optimizing the addition timing of the glass component contained as a subcomponent, the Q value of the LC filter 10 according to the present embodiment is maintained at a predetermined value (for example, 1000) or more while maintaining the low temperature of the dielectric ceramic composition. Sintering can be achieved. In addition, by firing the dielectric ceramic composition at a low temperature, the dielectric ceramic composition can be simultaneously fired with the Ag-based metal at a low temperature at which the Ag-based metal does not melt.

  Therefore, the LC filter 10 according to the present embodiment can achieve low-temperature firing, can ensure the sinterability of the dielectric layer 11, can stably keep the dielectric loss small, and has excellent dielectric characteristics. Since the dielectric layer 11 is included, a highly reliable multilayer ceramic electronic component can be obtained.

  The LC filter 10 is mounted on a printed board by soldering or the like and used for various electronic devices. The LC filter 10 can be suitably used as a multilayer SMD (Surface Mount Device).

  The multilayer ceramic electronic component according to the present embodiment is limited to a multilayer ceramic electronic component in which the dielectric layers 11 and the capacitor pattern portions 13-1 to 13-3 are alternately stacked, like the LC filter 10. Any multilayer ceramic electronic component including a dielectric layer can be preferably used. Moreover, the multilayer ceramic electronic component according to the present embodiment can be suitably used even if it is a multilayer ceramic electronic component in which elements are individually mounted on the outside.

  In the present embodiment, the case where the dielectric ceramic composition according to the present invention is used as the dielectric layer of the LC filter 10 has been described, but the present embodiment is not limited to this. Other multilayer ceramic electronic components including the dielectric ceramic composition according to the present embodiment include, for example, a capacitor, a resonator, a circuit board, a low-pass filter (LPF), a band-pass filter, Dielectric that forms part of multilayer ceramic electronic parts such as filters (BPF), diplexers (DPX), couplers (directional couplers), baluns (or baluns; balanced and unbalanced impedance converters) It can be suitably used as a layer.

  The preferred embodiment of the multilayer ceramic electronic component according to the present invention has been described above, but the present invention is not necessarily limited to the above-described embodiment. For example, in the multilayer ceramic electronic component according to the present invention, the heat shrinkage behavior of the dielectric layers composed of materials different from each other in the main component and subcomponent are combined and within the range that does not hinder the effect of being able to be fired simultaneously, Other compounds may be included.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to a following example.

<Preparation of dielectric layer>
[Example 1]
It contains Mg ₂ SiO ₄ and BaNdTiO-based oxides as main components, and ZnO, B ₂ O ₃ , Bi ₂ O ₃ , CoO, MnCO ₃ and Li-based glasses as subcomponents, with respect to 100% by mass of the main components A dielectric ceramic composition in which the content of SiO ₂ —BaO—CaO—Li ₂ O glass is 5% by mass with respect to 100% by mass of the dielectric composition excluding the glass component from the subcomponents is shown below. Produced by the procedure.

First, as a main component constituting the dielectric ceramic composition according to the present invention, a component containing only Mg ₂ SiO ₄ as the main component 1 and further containing a BaNdTiO-based oxide as the main component 2 was used. As the main component material was prepared _{MgO, SiO2, BaCO 3, Nd} (OH) 3, TiO 2. Further, as subcomponent materials were prepared _{SiO 2 -BaO-CaO-Li 2} O -based glass. A commercially available glass was used as the SiO ₂ —BaO—CaO—Li ₂ O-based glass.

The main ingredients MgO and SiO ₂ were weighed so that the number of moles of magnesium atoms was twice the number of moles of silicon atoms. Pure water was added to the weighed raw materials to prepare a slurry having a slurry concentration of 25% by mass. This slurry was wet mixed in a ball mill for 16 hours and then dried at about 120 ° C. for 24 hours to obtain a main component raw material mixed powder. This main component raw material mixed powder was calcined at about 1200 ° C. in air for 3 hours to obtain Mg ₂ SiO ₄ crystals. Pure water was added to the Mg ₂ SiO ₄ crystal to prepare a slurry having a slurry concentration of 25%. This slurry was pulverized with a ball mill for 16 hours and then dried at 120 ° C. for 24 hours to produce Mg ₂ SiO ₄ crystal powder, which is the main component of the dielectric ceramic composition.

In addition, BaCO ₃ , Nd (OH) ₃ and TiO ₂ which are other main component raw materials were weighed so that the number of moles of neodymium atoms was twice the number of moles of barium atoms and the number of moles of titanium atoms. . The sum of BaCO ₃ , Nd (OH) ₃ and TiO ₂ is 100% by mass, the weighed powder is placed in a ball mill, and pure water and a commercially available dispersant are added to prepare a slurry having a slurry concentration of 25%. For 16 hours. The obtained slurry was dried with a dryer, and the dried mixed powder was calcined at about 1000 ° C. in a heating furnace to obtain a BaNdTiO-based calcined powder. A mixed powder of Mg ₂ SiO ₄ crystal powder and BaNdTiO-based oxide calcined powder was used as the main component raw material mixed powder.

The raw material powder of ZnO, B ₂ O ₃ , Bi ₂ O ₃ , CoO, MnCO ₃ which are subcomponent raw materials other than the glass component is added to the main component raw material mixed powder as the main components (Mg ₂ SiO ₄ crystal powder and BaNdTiO series oxide) A predetermined amount was added to 100% by mass, and pure water was further added to prepare a slurry having a slurry concentration of 25% by mass. This slurry was placed in a ball mill and wet mixed for 16 hours (mixing step). Then, the obtained slurry was dried at 120 ° C. for about 24 hours with a dryer to obtain a raw material mixed powder of a main component raw material mixed powder and a raw material powder of subcomponent raw materials other than glass components.

The obtained raw material mixed powder was calcined in an oxygen atmosphere in an oxygen atmosphere at 850 ° C. for 2 hours to obtain a calcined powder. Dielectric composition obtained by removing SiO ₂ —BaO—CaO—Li ₂ O-based glass, which is a subcomponent raw material, from this calcined powder, excluding subcomponent raw materials other than SiO ₂ —BaO—CaO—Li ₂ O based glass ( A predetermined amount was added to 100% by mass of the main component and SiO ₂ —BaO—CaO—Li ₂ O-based glass), and alcohol was added to prepare a slurry having a slurry concentration of 25% by mass. After this slurry was put into a ball mill and wet mixed for 16 hours, the resulting slurry was dried at about 120 ° C. for 24 hours with a dryer, and then the dried mass obtained by drying the slurry with a pulverizer was pulverized. A raw material for the dielectric ceramic composition was obtained.

  The dielectric ceramic composition obtained by the above method is placed in a ball mill, an organic binder is added to make the dielectric ceramic composition a paint, a slurry (paste) containing the dielectric ceramic composition is prepared, and a sheet body is formed. A slurry for was obtained. This was applied onto a substrate by a doctor blade method to produce a plurality of sheet bodies. A plurality of sheet bodies were stacked and then pressed to produce a sheet stack. After cutting this sheet laminate to a desired size, the chip was chamfered and fired at a firing temperature (900 ° C.) at which Ag does not melt for 2.5 hours to produce a laminated sintered body.

[Example 2]
A laminated sintered body was produced in the same manner as in Example 1 except that the laminated sintered body was produced by changing the firing temperature of the sheet laminated body from 900 ° C. to 880 ° C.

[Example 3]
A laminated sintered body was produced in the same manner as in Example 1 except that the laminated sintered body was produced by changing the firing temperature of the sheet laminated body from 900 ° C. to 860 ° C.

[Example 4]
A laminated sintered body was produced in the same manner as in Example 1 except that only the Mg ₂ SiO ₄ crystal powder was used as the main component contained in the dielectric ceramic composition.

[Example 5]
Examples except that only the Mg ₂ SiO ₄ crystal powder was used as the main component contained in the dielectric ceramic composition, and the firing temperature of the sheet laminate was changed from 900 ° C. to 880 ° C. to produce a laminated sintered body. 1 was used to produce a laminated sintered body.

[Example 6]
Example except that only the Mg ₂ SiO ₄ crystal powder was used as the main component contained in the dielectric ceramic composition, and the firing temperature of the sheet laminate was changed from 900 ° C. to 860 ° C. to produce a laminated sintered body. 1 was used to produce a laminated sintered body.

[Comparative Examples 1 and 2]
The addition of the SiO ₂ —BaO—CaO—Li ₂ O-based glass is performed after the heat treatment (preliminary firing) of the raw material mixed powder of the main component raw material and the subcomponent raw material and before pulverization. A laminated sintered body was produced in the same manner as in Example 1 except that the raw material was mixed with water (mixing step).

[Comparative Example 3]
In the same manner as in Example 1, except that the solvent used for pulverizing the calcined powder of the raw material mixed powder of the main component raw material and the subcomponent raw material was changed from alcohol to pure water, Produced.

[Comparative Example 4]
As a main component contained in the dielectric ceramic composition, only Mg ₂ SiO ₄ crystal powder is used, and SiO ₂ —BaO—CaO—Li ₂ O system is used as a calcined powder of a raw material mixed powder composed of a main component raw material and a subcomponent raw material. A laminated sintered body was produced in the same manner as in Example 1 except that the solvent used for adding and mixing the glass was changed from alcohol to pure water.

[Comparative Example 5]
Dielectric porcelain composition is made into a paint from the time of addition of glass component after heat treatment (calcination) of raw material mixed powder of main component raw material and subcomponent raw material and before fine pulverization to include dielectric porcelain composition A laminated sintered body was produced in the same manner as in Example 1 except that the slurry (paste) was changed to the addition when the slurry (paste) was being adjusted.

[Comparative Example 6]
The main component contained in the dielectric ceramic composition is Mg ₂ SiO ₄ crystal powder only, and the glass component is added after the heat treatment (calcination) of the raw material mixed powder of the main component material and the subcomponent material. In the same manner as in Example 1, except that the dielectric ceramic composition was made into a coating material before being finely pulverized and the slurry (paste) containing the dielectric ceramic composition was added during preparation. A laminated sintered body was produced.

Examples 1 to 6 and types of main components used in Comparative Examples 1 to 6, glass component (SiO ₂ —BaO—CaO—Li ₂ O-based glass) addition time, after heat treatment (calcination) of raw material mixed powder Table 1 shows the types of solvents used when pulverizing and the firing temperature when firing the sheet laminate.

<Evaluation>
Li ion elution amount in the stage of mixing the main component raw material and subcomponent raw material with water (mixing step), the dispersion state of the Li component in the sheet body, dielectric constant ε and Q value, sintering density ρs, The shape retention after sintering was confirmed. These evaluation results are shown in Table 1.

[Dielectric constant ε]
The dielectric constant ε was measured by the cavity resonator perturbation method. A test piece having a size of 0.8 mm square was inserted into the cavity resonator, the change in capacitance in the cavity resonator was measured, and converted into a dielectric constant ε. The measurement frequency was 1.9 GHz, and the dielectric constant ε was the average value of the dielectric constant ε obtained three times. The evaluation criteria are 32.0 or more when the main component is composed of Mg ₂ SiO ₄ crystal powder and BaNdTiO-based oxide, and 7) when the main component is composed only of Mg ₂ SiO ₄ crystal powder. A value of 0 or more was considered good. The measurement results are shown in Table 1.

[Q value]
The Q value was measured by the cavity resonator perturbation method. A test piece having a size of 0.8 mm square was inserted into the cavity resonator, and the change in the Q value in the cavity resonator was measured. The measurement frequency was 1.9 GHz, and the Q value was the average value of the Q values obtained three times. The evaluation criteria were good if the Q value was 1000 or more. The measurement results are shown in Table 1.

[Sintering density ρs]
The test piece after firing is cut and processed so as to be around 4.5 × 3.2 × 0.8 mm in the LWT direction, the dimensions in each direction are measured with a micrometer, the mass is measured with an electronic balance, and from there The bulk density was defined as the sintered density ρs (unit: g / cm ³ ). When the main component is composed of Mg ₂ SiO ₄ crystal powder and a BaNdTiO-based oxide, the evaluation criteria is about 4.5, and when the main component is composed only of Mg ₂ SiO ₄ crystal powder, About 3 was considered good. The measurement results are shown in Table 1.

[Shape retention after sintering]
The appearance of the laminated sintered body obtained after sintering was visually observed to confirm the shape retention of the laminated sintered body after sintering. Table 1 shows the results of visual observation.

From Table 1, in Examples 1-6, the addition time of the glass component is after calcining the raw material mixed powder of the main component material and the subcomponent material and before pulverization, and the main component material and the subcomponent material By using alcohol as the solvent used when pulverizing the calcined powder of the raw material mixed powder, the dispersion state of the Li component in the sheet body is good, the dielectric constant ε is good, and the Q value is 1000 or more The sintering density ρs was also stable, and the shape retention after sintering was also stable. In addition, even when the main component is composed of Mg ₂ SiO ₄ crystal powder and BaNdTiO-based oxide or only Mg ₂ SiO ₄ crystal powder, the Q value tended to decrease as the firing temperature decreased. Even in this case, it was confirmed that the Q value was maintained at 1400 or more. Further, the main component is better when consisting of only Mg ₂ SiO ₄ crystal powder than when made of Mg ₂ SiO ₄ crystal powder and BaNdTiO based oxide, it was confirmed Q value is high.

  On the other hand, in Comparative Examples 1 and 2, elution of Li ions was observed in the mixing process by adding the glass component at the time of mixing the main component material and the subcomponent material. From this, the dielectric constant ε and Q value of the laminated sintered body, the sintered density, and the shape retention after sintering were not confirmed, but the dielectric constant ε and Q of the laminated sintered bodies of Comparative Examples 1 and 2 were confirmed. It is considered that the value, sintered density, and shape retention after sintering are lowered.

  Further, in Comparative Examples 3 and 4, as in Examples 1 to 6, the glass component was added after the heat treatment (calcination) of the raw material mixed powder of the main component raw material and the subcomponent raw material and before pulverization. However, after the heat treatment (calcination) of the raw material mixed powder, pure water was used as a solvent to be used for fine pulverization, so that it was gelled at the time of slurrying and could not be measured. This is considered to be due to the dispersibility of the Li component at the stage where the dielectric ceramic composition is made into a paint to prepare a slurry (paste) containing the dielectric ceramic composition. Table 2 shows the dispersibility of Li in Example 3 and Comparative Example 3.

  From Table 2, since the CV value of Example 3 was lower than that of Comparative Example 3, it was confirmed that Example 3 had better dispersibility than Comparative Example 3. Therefore, the dispersibility of the Li component is improved by using alcohol rather than pure water as a solvent to be used when finely pulverizing after the heat treatment (calcination) of the raw material mixed powder of the main component material and the subcomponent material. It can be said that gelation can be prevented at the time when the dielectric ceramic composition is made into a paint to prepare a slurry (paste) containing the dielectric ceramic composition.

  In Comparative Examples 5 and 6, the laminated sintered body is obtained by setting the addition time of the glass component to the time when the dielectric ceramic composition is made into a paint and the slurry (paste) containing the dielectric ceramic composition is adjusted. The sinterability of (dielectric ceramic) was lowered, and the dispersibility of the Li component contained in the laminated sintered body was poor. Therefore, the dielectric constant ε of the laminated sintered body (dielectric ceramic) is also reduced, the Q value is 1000 or less, the electrical characteristics are lowered, and the shape retention after sintering cannot be maintained.

Therefore, when manufacturing the dielectric ceramic composition, the addition timing of the glass component containing Li in consideration of the solubility of Li ₂ O in water and the dispersibility of the Li component in the dielectric ceramic composition, Alcohol is used as a solvent for calcination of the calcined powder of the raw material mixed powder of the main component raw material and subcomponent raw material after the calcining of the raw material mixed powder with the auxiliary component raw material and before pulverizing. By using it, the dispersion state of the Li component after producing the sheet body can be made favorable, so that the dielectric characteristics of the laminated sintered body can be kept stable without causing a composition fluctuation of the dielectric ceramic composition. It was found that a dielectric ceramic composition can be easily produced.

  As described above, the method for manufacturing a dielectric ceramic composition and the multilayer ceramic electronic component according to the present invention stably increase the dielectric characteristics of the multilayer sintered body without causing composition fluctuation of the dielectric ceramic composition. Since it can be easily manufactured while maintaining, it can be used as LTCC and can be suitably used as a multilayer ceramic electronic component.

DESCRIPTION OF SYMBOLS 10 LC filter 11 Dielectric layer 12 Coil part 13-1 to 13-3 Capacitor pattern part 14 Via part (via conductor)

Claims (5)

A raw material mixed powder production step of mixing a main component raw material and subcomponent raw material with water to obtain a raw material mixed powder;
A heat treatment step of heat-treating the raw material mixed powder in an oxygen atmosphere;
After heat treatment, adding glass containing Li ₂ O to the raw material mixed powder, and adding and crushing glass components to crush using an organic solvent,
A method for producing a dielectric ceramic composition comprising: The method for producing a dielectric ceramic composition according to claim 1, wherein the main component contains at least Mg ₂ SiO ₄ . 3. The method for producing a dielectric ceramic composition according to claim 1, comprising at least one glass containing Li ₂ O as the subcomponent. 4.   The method for producing a dielectric ceramic composition according to any one of claims 1 to 3, wherein the subcomponent includes at least zinc oxide.   A multilayer ceramic electronic component comprising a dielectric layer comprising a dielectric ceramic composition obtained by using the method for producing a dielectric ceramic composition according to any one of claims 1 to 4.

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