JP2007022820A - Dielectric porcelain composition and electronic parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric porcelain composition, where capacitive temperature characteristic satisfies the X8R characteristic of the EIA standards, firing can be performed in a reduction atmosphere, a specific dielectric constant is high and capacity variation is improved. <P>SOLUTION: The dielectric porcelain composition comprises barium titanate as a main component, a first auxiliary component containing one or more kinds among MgO, CaO, BaO and SrO, a second auxiliary component whose main component is silicon oxide, a third auxiliary component containing one or more kinds among V<SB>2</SB>O<SB>5</SB>, MoO<SB>3</SB>and WO<SB>3</SB>, a fourth-a auxiliary component containing the oxide of R1 (wherein, R1 is one or more kinds among Sc, Er, Tm, Yb and Lu) and a fifth auxiliary component containing CaZrO<SB>3</SB>or CaO+ZrO<SB>2</SB>. The ratio of each auxiliary component relative to 100 mole of the main component is 0.1-3 mole for the first auxiliary component, 2-10 mole for the second auxiliary component, 0.01-0.5 mole for the third auxiliary component, 0.5-7 mole in terms of R1 for the fourth-a auxiliary component and more than 0 and 5 mole or less for the fifth auxiliary component. In addition, the dielectric porcelain composition optionally further comprises a sixth auxiliary component containing a P oxide and/or S and the ratio of the sixth auxiliary component relative to 100 mole of the main component is more than 0 and 1 mole or less in terms of P and/or S. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dielectric ceramic composition having resistance to reduction and an electronic component such as a multilayer ceramic capacitor using the dielectric ceramic composition.

  Multilayer ceramic capacitors as electronic components have high dielectric constant, long life of insulation resistance IR, good DC bias characteristics (low relative dielectric constant change over time), and good temperature characteristics In particular, depending on the application, the temperature characteristics are required to be flat under severe conditions. In recent years, multilayer ceramic capacitors have been used in various electronic devices such as an engine electronic control unit (ECU), a crank angle sensor, and an antilock brake system (ABS) module mounted in an engine room of an automobile. Since these electronic devices are for performing engine control, drive control, and brake control stably, it is required that the circuit has good temperature stability.

  The environment in which these electronic devices are used is expected to drop to about −20 ° C. or lower in winter in cold regions, and to increase to about + 130 ° C. or higher in summer after engine startup. Recently, there is a tendency to reduce the number of wire harnesses that connect an electronic device and its control target equipment, and the electronic device is sometimes installed outside the vehicle, so the environment for the electronic device has become increasingly severe. Therefore, capacitors used in these electronic devices need to have flat temperature characteristics over a wide temperature range. Specifically, it is not sufficient for the capacity-temperature characteristics to satisfy the EIA standard X7R characteristics (−55 to 125 ° C., ΔC / C = within ± 15%), but the EIA standard X8R characteristics (−55 to 150 ° C.). , ΔC / C = within ± 15%) is required.

  There are several proposals for dielectric ceramic compositions that satisfy the X8R characteristics.

In Patent Documents 1 and 2, in order to satisfy the X8R characteristic in a dielectric ceramic composition containing BaTiO ₃ as a main component, the Curie temperature is increased to a high temperature side by replacing Ba in BaTiO ₃ with Bi, Pb or the like. It has been proposed to shift. It has also been proposed to satisfy X8R characteristics by selecting a BaTiO ₃ + CaZrO ₃ + ZnO + Nb ₂ O ₅ composition (Patent Documents 3 to 7).

  However, in any of these composition systems, Pb, Bi, and Zn, which are likely to be evaporated and scattered, are used, and thus firing in an oxidizing atmosphere such as in air is a prerequisite. For this reason, there is a problem that an inexpensive base metal such as Ni cannot be used for the internal electrode of the capacitor, and an expensive noble metal such as Pd, Au, or Ag must be used.

On the other hand, the present applicant has already proposed the dielectric ceramic composition shown below for the purpose of having a high dielectric constant, satisfying X8R characteristics, and enabling firing in a reducing atmosphere. (Patent Document 8). The dielectric ceramic composition described in Patent Document 8 includes BaTiO _{3 as} a main component, a first subcomponent including at least one selected from MgO, CaO, BaO, SrO, and Cr ₂ O ₃ ; _{Ba, Ca) x SiO 2 +} x ( where, first comprises a second subcomponent expressed by x = 0.8 to _1.2), at least one selected from V ₂ O 5, MoO ₃ and WO ₃ 3 subcomponents and at least a fourth subcomponent including an oxide of R1 (where R1 is at least one selected from Sc, Er, Tm, Yb and Lu), and each subcomponent with respect to 100 moles of the main component The ratio of the first subcomponent: 0.1-3 mol, the second subcomponent: 2-10 mol, the third subcomponent: 0.01-0.5 mol, the fourth subcomponent: 0.5-7 Moles (provided that the number of moles of the fourth subcomponent is the ratio of R1 alone).

Further, the present applicant has already proposed the following dielectric ceramic composition (Patent Document 9). The dielectric ceramic composition described in Patent Document 9 includes a main component including barium titanate, a first subcomponent including at least one selected from MgO, CaO, BaO, SrO, and Cr ₂ O ₃ ; A second subcomponent containing silicon oxide as a main component; a third subcomponent containing at least one selected from V ₂ O ₅ , MoO ₃ and WO _3; and an oxide of R1 (wherein R1 is Sc, A fourth subcomponent containing at least one selected from Er, Tm, Yb and Lu) and a fifth subcomponent containing CaZrO ₃ or CaO + ZrO ₂ , and the ratio of each component to 100 mol of the main component is , 1st subcomponent: 0.1-3 mol, 2nd subcomponent: 2-10 mol, 3rd subcomponent: 0.01-0.5 mol, 4th subcomponent: 0.5-7 mol (however, The number of moles of the fourth subcomponent is R1 alone Ratio), the fifth subcomponent: 0 <fifth subcomponent ≦ 5 mol.

  In any of the above-mentioned applications by the present applicant, the ratio of the first subcomponent such as MgO to 100 mol of the main component is 0.1 mol or more.

  The present applicant has already proposed the following dielectric ceramic composition (Patent Document 10). The dielectric ceramic composition described in Patent Document 10 includes a main component containing barium titanate and an AE oxide (where AE is at least one selected from Mg, Ca, Ba and Sr). 1 subcomponent and a second subcomponent containing an oxide of R (where R is at least one selected from Y, Dy, Ho and Er), and each subcomponent with respect to 100 moles of the main component. The ratio of the first subcomponent: 0 mol <first subcomponent <0.1 mol, and the second subcomponent: 1 mol <second subcomponent <7 mol.

  According to the techniques of the above-mentioned Patent Documents 8 to 10 by the present applicant, the dielectric constant is certainly high, the X8R characteristics are satisfied, and firing in a reducing atmosphere is possible.

However, while satisfying the X8R characteristics, the relative permittivity tends to decrease, and when the annealing temperature after firing is increased to improve the high temperature accelerated life (for example, about 1200 ° C.), the capacity defect in the product It has been confirmed that the rate (the ratio of products whose capacity has become less than the standard value) becomes high, which causes a new problem that capacity variation is likely to occur.
Japanese Patent Laid-Open No. 10-25157 Japanese Patent Laid-Open No. 9-40465 JP-A-4-295048 JP-A-4-292458 Japanese Unexamined Patent Publication No. Hei 4-29259 JP-A-5-109319 JP-A-6-243721 JP 2000-154057 A JP 2001-192264 A (Patent No. 3348081) JP 2002-255639 A (Patent No. 334003)

  The object of the present invention is that the capacity-temperature characteristic satisfies the X8R characteristic (-55 to 150 ° C., ΔC = ± 15% or less) of the EIA standard, can be fired in a reducing atmosphere, and has a relative dielectric constant of It is intended to provide a dielectric ceramic composition that has a high capacity variation and an electronic component such as a multilayer ceramic capacitor using such a dielectric ceramic composition.

In order to achieve the above object, according to a first aspect of the present invention,
A main component comprising barium titanate;
A first subcomponent comprising at least one selected from MgO, CaO, BaO and SrO;
A second subcomponent containing silicon oxide as a main component;
A third subcomponent comprising at least one selected from V ₂ O ₅ , MoO ₃ and WO ₃ ;
A subcomponent 4a containing an oxide of R1, wherein R1 is at least one selected from Sc, Er, Tm, Yb and Lu;
A fifth subcomponent comprising CaZrO ₃ or CaO + ZrO ₂ ,
The ratio of each subcomponent to 100 moles of the main component is
1st subcomponent: 0.1-3 mol,
Second subcomponent: 2 to 10 mol,
Third subcomponent: 0.01 to 0.5 mol,
4a subcomponent: 0.5-7 mol in terms of R1,
Fifth subcomponent: 0 to 5 mol (excluding 0 mol),
A dielectric ceramic composition comprising:
A sixth subcomponent containing P oxide and / or S;
A dielectric ceramic composition is provided wherein the ratio of the sixth subcomponent to 100 mol of the main component is 0 to 1 mol (excluding 0 mol) in terms of P and / or S.

  In the first aspect, it preferably further comprises a 4b subcomponent containing an oxide of R2 (wherein R2 is at least one selected from Y, Dy, Ho, Tb, Gd and Eu), and the main component The ratio of the 4b subcomponent to 100 mol is 0 to 9 mol (excluding 0 mol) in terms of R2.

In the first aspect, preferably, the second subcomponent contains SiO ₂ as a main component, and MO (where M is at least one element selected from Ba, Ca, Sr and Mg), Li ₂ It is a complex oxide comprising at least one selected from O and B ₂ O ₃ .

In the first aspect, preferably, the composite oxide is represented by (Ba, Ca) _x SiO _{2 + x} (where x = 0.7 to 1.2).

According to a second aspect of the invention,
A main component comprising barium titanate;
A first subcomponent comprising at least one selected from MgO, CaO, BaO and SrO;
A fourth c subcomponent containing an oxide of R3 (wherein R3 is at least one selected from Y, Dy, Ho and Er),
The ratio of each subcomponent to 100 moles of the main component is
First subcomponent: 0 to 0.1 mol (excluding 0 mol and 0.1 mol),
4c subcomponent: 1 to 7 mol (excluding 1 mol and 7 mol),
A dielectric ceramic composition comprising:
A sixth subcomponent containing P oxide and / or S;
A dielectric ceramic composition is provided wherein the ratio of the sixth subcomponent to 100 mol of the main component is 0 to 1 mol (excluding 0 mol) in terms of P and / or S.

In the second aspect, it preferably further includes a fifth subcomponent containing CaZrO ₃ or CaO + ZrO _2, and the ratio of the fifth subcomponent to 100 mol of the main component is 0 to 5 mol (0 mol and 5 mol). Is excluded).

In the second aspect, preferably, MxSiO ₃ (where M is at least one selected from Ba, Ca, Sr, Li, and B, and when M = Ba, x = 1, M = Ca In the case of x = 1, x = 1 in the case of M = Sr, x = 2 in the case of M = Li, and x = 2/3 in the case of M = B). The composition further comprises a component, and the ratio of the second subcomponent to 100 mol of the main component is 2 to 10 mol.

In a second aspect, _preferably, V ₂ O 5, MoO ₃ and WO further comprising a third subcomponent including at least one ₃ is selected from the ratio of the third subcomponent to 100 moles of the main component Is 0.01 to 0.5 mol.

In any of the first and second aspects, it preferably further includes a seventh subcomponent containing MnO and / or Cr ₂ O _3, and the ratio of the seventh subcomponent to 100 mol of the main component is 0. -0.5 mol (excluding 0 mol).

In any of the first and second aspects, preferably, it further has an eighth subcomponent containing Al ₂ O _3, and the ratio of the eighth subcomponent to 100 mol of the main component is 0 to 4 mol ( 0 moles are excluded).

  The electronic component according to the present invention is not particularly limited as long as it is an electronic component having a dielectric layer. For example, the electronic component is a multilayer ceramic capacitor element having a capacitor element body in which internal electrodes are alternately laminated together with dielectric layers. is there. In the present invention, the dielectric layer is composed of any one of the above dielectric ceramic compositions. The conductive material contained in the internal electrode layer is not particularly limited, but is Ni or Ni alloy, for example. In the present invention, the effect is great particularly when the thickness of the dielectric layer is less than about 10 μm.

  As a result of advancing research on a specific element group that can increase the relative permittivity without affecting the target temperature characteristics (X8R characteristics) and improve the capacitance variation, P) and / or sulfur (S) was found to be effective, and the present invention was reached based on this finding.

  In the present invention, a predetermined amount of the eighth subcomponent containing P and / or S is added to the dielectric composition satisfying the X8R characteristic. For this reason, the dielectric ceramic composition according to the present invention satisfies the X8R characteristic, has an increased relative dielectric constant, and has a small capacitance variation. Therefore, an electronic component such as a multilayer ceramic chip capacitor using the dielectric ceramic composition of the present invention can be suitably used even in an environment where it is exposed to high temperatures such as an automobile engine room.

  In addition, since the dielectric ceramic composition according to the present invention does not contain elements such as Pb, Bi, and Zn that are evaporated and scattered, it can be fired in a reducing atmosphere. For this reason, when manufacturing electronic parts such as a multilayer ceramic chip capacitor using the dielectric ceramic composition of the present invention, it becomes possible to use base metals such as Ni and Ni alloys as internal electrodes, thereby reducing the cost of the electronic parts. Is realized.

  That is, according to the present invention, the dielectric ceramic composition whose capacitance-temperature characteristic satisfies the X8R characteristic of the EIA standard, can be fired in a reducing atmosphere, has a high relative dielectric constant, and has improved capacitance variation. And an electronic component such as a multilayer ceramic capacitor using the dielectric ceramic composition can be provided.

  The electronic component according to the present invention is not particularly limited, and examples thereof include a multilayer ceramic capacitor, a piezoelectric element, a chip inductor, a chip varistor, a chip thermistor, a chip resistor, and other surface mount (SMD) chip type electronic components.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings. FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.

  In this embodiment, the multilayer ceramic capacitor 1 shown in FIG. 1 is illustrated as an electronic component, and the structure and manufacturing method thereof will be described.

  As shown in FIG. 1, a multilayer ceramic capacitor 1 as an electronic component according to an embodiment of the present invention includes a capacitor element body 10 in which dielectric layers 2 and internal electrode layers 3 are alternately stacked. At both ends of the capacitor element body 10, a pair of external electrodes 4 are formed which are electrically connected to the internal electrode layers 3 arranged alternately in the element body 10. The internal electrode layers 3 are laminated so that the end faces are alternately exposed on the surfaces of the two opposite ends of the capacitor element body 10. The pair of external electrodes 4 are formed at both ends of the capacitor element body 10 and are connected to the exposed end surfaces of the alternately arranged internal electrode layers 3 to constitute a capacitor circuit.

  The outer shape and dimensions of the capacitor element body 10 are not particularly limited and can be appropriately set according to the application. Usually, the outer shape is substantially a rectangular parallelepiped shape, and the dimensions are usually vertical (0.4 to 5.6 mm) × It can be about horizontal (0.2-5.0 mm) × height (0.2-1.9 mm).

  The dielectric layer 2 contains each dielectric ceramic composition according to the first and second aspects of the present invention.

The dielectric ceramic composition according to the first aspect is:
A main component comprising barium titanate (preferably represented by the composition formula Ba _m TiO _{2 + m} , where m is the ratio of Ba and Ti is 0.995 ≦ m ≦ 1.010);
A first subcomponent comprising at least one selected from MgO, CaO, BaO and SrO;
A second subcomponent containing silicon oxide as a main component;
A third subcomponent comprising at least one selected from V ₂ O ₅ , MoO ₃ and WO ₃ ;
A subcomponent 4a containing an oxide of R1, wherein R1 is at least one selected from Sc, Er, Tm, Yb and Lu;
A fifth subcomponent comprising CaZrO ₃ or CaO + ZrO ₂ ,
The ratio of each subcomponent to 100 moles of the main component is
1st subcomponent: 0.1-3 mol,
Second subcomponent: 2 to 10 mol,
Third subcomponent: 0.01 to 0.5 mol,
4a subcomponent: 0.5-7 mol in terms of R1,
Fifth subcomponent: 0 to 5 mol (excluding 0 mol).

  In the first aspect, the X8R characteristic can be satisfied by including the first to third, fourth, and fifth subcomponents. The preferred contents and reasons for the first to third, fourth, and fifth subcomponents are as follows.

The ratio of the first subcomponent to 100 mol of the main component is 0.1 to 3 mol, preferably 0.5 to 2.5 mol.
The first subcomponent exhibits the effect of flattening the capacity-temperature characteristics. However, if the content of the first subcomponent is too small, this effect becomes insufficient, and the capacity-temperature characteristics are generally deteriorated. On the other hand, when there is too much content of a 1st subcomponent, sinterability will deteriorate. The composition ratio of each oxide in the first subcomponent is arbitrary.

The ratio of the second subcomponent to 100 mol of the main component is 2 to 10 mol, preferably 2 to 6 mol.
The second subcomponent mainly acts as a sintering aid, but has the effect of improving the defective rate of the initial insulation resistance IR when thinned, but if the content of the second subcomponent is too small, There is a tendency that the capacity-temperature characteristic cannot be satisfied, and there is a tendency that the insulation resistance is deteriorated. On the other hand, when the content is too large, the life characteristics of the insulation resistance become insufficient, and the dielectric constant tends to decrease rapidly. The constituent ratio of each oxide in the second subcomponent is arbitrary.

Preferably, the second subcomponent is composed mainly of SiO ₂ , and MO (where M is at least one element selected from Ba, Ca, Sr and Mg), Li ₂ O and B ₂ O _3. A composite oxide comprising at least one selected from the group consisting of More preferably, the composite oxide is represented by (Ba, Ca) _x SiO _{2 + x} (where x = 0.7 to 1.2). BaO and CaO in [(Ba, Ca) _x SiO _{2 + x} ] as a more preferred embodiment of the _second subcomponent are also included in the first subcomponent, but (Ba, Ca) _x SiO _{2 + x} which is a composite oxide is Since the melting point is low and the reactivity with respect to the main component is good, in the present invention, it is preferable to add BaO and / or CaO as the composite oxide. _{X in} (Ba, Ca) _x SiO _{2 + x} as a more preferred embodiment of the _second subcomponent is preferably 0.7 to 1.2, more preferably 0.8 to 1.1. If x is too small, that is, if SiO ₂ is too much, it reacts with the main component BaTiO ₃ to deteriorate the dielectric properties. On the other hand, if x is too large, the melting point becomes high and the sinterability deteriorates, which is not preferable. In addition, the ratio of Ba and Ca is arbitrary and may contain only one side.

The ratio of the third subcomponent to 100 mol of the main component is 0.01 to 0.5 mol, preferably 0.01 to 0.4 mol, more preferably 0.1 to 0.4.
The third subcomponent exhibits the effect of flattening the capacity-temperature characteristics above the Curie temperature and the effect of improving the IR life. However, if the content of the third subcomponent is too small, the above-described effect is insufficient. Tend to be. On the other hand, when there is too much content, IR will fall remarkably. The constituent ratio of each oxide in the third subcomponent is arbitrary.

The ratio of the 4a subcomponent to 100 mol of the main component is 0.5 to 7 mol, preferably 0.5 to 5 mol.
The 4a subcomponent exhibits the effect of shifting the Curie temperature to the high temperature side and the effect of flattening the capacity-temperature characteristics. However, if the content of the 4a subcomponent is too small, such an effect becomes insufficient. As a result, the capacity-temperature characteristic deteriorates. On the other hand, when there is too much content, it exists in the tendency for sinterability to deteriorate rapidly. Among the 4a subcomponents, Yb oxide is preferable because it has a high effect of improving characteristics and is inexpensive.

The ratio of the 4a subcomponent is not the molar ratio of the R1 oxide, but the molar ratio of R1 alone. That is, for example, when an oxide of Yb is used as the 4a subcomponent, the ratio of the 4a subcomponent is 1 mol because the ratio of Yb ₂ O ₃ is not 1 mol but the ratio of Yb is 1 mol. It means that.

The ratio of the fifth subcomponent to 100 mol of the main component is 0-5 mol (excluding 0 mol and 5 mol), preferably 0-3 mol (excluding 0 mol), more preferably 0.5-3. Is a mole.
The fifth subcomponent has effects such as shifting the Curie temperature to the high temperature side, flattening the capacitance-temperature characteristics, improving the insulation resistance (IR), improving the breakdown voltage, and lowering the firing temperature. When the addition amount of the 5 subcomponent is too large, the IR life is remarkably reduced, and the capacity-temperature characteristic (X8R characteristic) tends to deteriorate.

The addition form of CaZrO ₃ is not particularly limited, and examples thereof include oxides composed of Ca such as CaO, carbonates such as CaCO ₃ , organic compounds, and CaZrO ₃ . The ratio of Ca and Zr is not particularly limited, and may be determined so as not to be dissolved in barium titanate contained in the main component. The molar ratio of Ca to Zr (Ca / Zr) is preferably 0.5 to 1.5, more preferably 0.8 to 1.5, particularly preferably 0.9 to 1.1.

  The first aspect is characterized in that the following sixth subcomponent is contained in a predetermined amount with respect to the dielectric composition satisfying the X8R characteristic described above.

The sixth subcomponent contains P oxide and / or S. The ratio of the sixth subcomponent to 100 mol of the main component is 0 to 1 mol (excluding 0 mol), preferably 0.1 to 0.7 mol, more preferably 0.3 in terms of P and / or S. -0.5 mol.
The sixth subcomponent does not significantly affect the capacity-temperature characteristics and shows the effect of improving the relative dielectric constant and the capacity variation. However, if the ratio of the sixth subcomponent is too small, the relative dielectric constant is improved. Not very effective. If the amount is too large, the capacity change rate deteriorates.

The above ratio of the sixth subcomponent is not a molar ratio of a compound such as an oxide of P and / or S but a molar ratio in terms of P and / or S. That is, for example, when P ₂ O ₅ is used as the sixth subcomponent, the ratio of the sixth subcomponent is 1 mol because the ratio of P ₂ O ₅ is not 1 mol but the ratio of P is 1 mol. It means that.

  In addition, when using P oxide and S as a 6th subcomponent, what is necessary is just to make it a total content be the said range with respect to 100 mol of said main components. That is, the component ratio of each component in the sixth subcomponent is arbitrary. However, preferably when the ratio of P and S is between 0.9: 1.1 and 1.1: 0.9, that is, when the ratio of the two is substantially equal, the effect of improving the variation in capacity is further improved. It is preferable.

  The dielectric ceramic composition according to the first aspect further includes a 4b subcomponent containing an oxide of R2 (where R2 is at least one selected from Y, Dy, Ho, Tb, Gd, and Eu). Is preferred.

The ratio of the 4b subcomponent to 100 mol of the main component is preferably 0 to 9 mol (excluding 0 mol), more preferably 0.5 to 9 mol in terms of R2.
The 4b subcomponent exhibits an effect of improving IR and IR lifetime, and has little adverse effect on the capacity-temperature characteristics. However, if the content of the 4b subcomponent is too large, the sinterability tends to deteriorate. Among the 4b subcomponents, Y oxide is preferable because it has a high effect of improving characteristics and is inexpensive.

The total content of the 4a subcomponent and the 4b subcomponent is preferably 13 mol or less, more preferably 10 mol or less with respect to 100 mol of BaTiO _{3 as} the main component (however, the 4a subcomponent and the 4b subcomponent) The number of moles of the component is the ratio of R1 and R2 alone). This is for maintaining good sinterability.

The dielectric ceramic composition according to the second aspect is
A main component comprising barium titanate;
A first subcomponent;
A fourth c subcomponent containing an oxide of R3 (wherein R3 is at least one selected from Y, Dy, Tm, Ho and Er),
The ratio of each subcomponent to 100 moles of the main component is
First subcomponent: 0 to 0.1 mol (excluding 0 mol and 0.1 mol),
4c subcomponent: 1 to 7 mol (excluding 1 mol and 7 mol).

  The details of barium titanate and the first subcomponent are the same as in the first aspect.

  In the second aspect, the X8R characteristic can be satisfied by including the first and fourth subcomponents. The preferred contents and reasons for the first and fourth subcomponents are as follows.

In the second aspect, the ratio of the first subcomponent to 100 moles of the main component is less than that of the first aspect described above, and is 0 to 0.1 mole (excluding 0 mole and 0.1 mole), preferably 0. 0.01 to 0.1 mol (excluding 0.1 mol), more preferably 0.04 to 0.08 mol.
In the case where the ratio of the first subcomponent is 0.1 mol or more as in the first aspect, when applied to the dielectric layer 2 having a normal thickness (for example, about 4.5 μm), the X8R characteristic can be satisfied. When the thickness of the dielectric layer per layer (for example, 2.0 μm or less) is advanced, regarding the capacity-temperature characteristics, the capacity change rate particularly on the high temperature side tends to increase. That is, the capacity change rate curve on the high temperature side tends to be clockwise. In the second aspect, by reducing the ratio of the first subcomponent (specifically, less than 0.1 mol) than in the first aspect, the dielectric layers per layer (for example, 1.. Even when 0 μm or less is advanced, the capacity change rate curve on the high temperature side can be directed in the counterclockwise direction, and the X8R characteristic can be satisfied. As a result, it is possible to reduce the size and increase the capacity, and in particular, it is possible to obtain a multilayer ceramic capacitor 1 that is compatible with thin layer size reduction.

The ratio of the 4c subcomponent to 100 mol of the main component is 1 to 7 mol (excluding 1 mol and 7 mol), preferably 1 to 6 mol (excluding 1 mol), more preferably 3 to 5 mol. .
The 4c subcomponent exhibits the effect of shifting the Curie temperature to the high temperature side and the effect of flattening the capacity-temperature characteristics. However, if the content of the 4c subcomponent is too small, such an effect becomes insufficient. As a result, the capacity-temperature characteristic deteriorates. On the other hand, when there is too much content, it exists in the tendency for sinterability to deteriorate rapidly. In particular, there is an advantage that the capacity-temperature characteristic can be further flattened by increasing the content of the 4c subcomponent while reducing the content of the first subcomponent as much as possible.

The ratio of the 4c subcomponent is not the molar ratio of R alone, but the molar ratio of the oxide of R. That is, for example, when an oxide of Y is used as the 4c subcomponent, the ratio of the 4c subcomponent is 1 mol. The ratio of Y is not 1 mol but the ratio of Y ₂ O ₃ is 1 mol. It means that.

  The second aspect is characterized in that the sixth subcomponent is contained in a predetermined amount with respect to the dielectric composition satisfying the X8R characteristic described above. The details of the sixth subcomponent are the same as in the first aspect.

The dielectric ceramic composition according to the second aspect is MxSiO ₃ (where M is at least one selected from Ba, Ca, Sr, Li, and B, and x = 1 when M = Ba) , When M = Ca, x = 1, when M = Sr, x = 1, when M = Li, x = 2, when M = B, x = 2/3. It is preferable to further include a second subcomponent. The ratio, role, and reason for limiting the ratio of the second subcomponent are the same as in the first aspect.

  The dielectric ceramic composition according to the second aspect preferably further has a third subcomponent. Details of the third subcomponent are the same as those in the first aspect.

  The dielectric ceramic composition according to the second aspect preferably further includes a fifth subcomponent. The details of the fifth subcomponent are the same as those in the first aspect.

In addition, it is preferable that each dielectric ceramic composition according to the first aspect and the second aspect further includes a seventh subcomponent containing MnO and / or Cr ₂ O ₃ .
The ratio of the seventh subcomponent to 100 mol of the main component is preferably 0 to 0.5 mol (excluding 0 mol), more preferably 0.1 to 0.5 mol.
The seventh subcomponent exhibits an effect of promoting sintering, an effect of increasing IR, and an effect of improving the IR life. However, if the content of the seventh subcomponent is too large, the capacity-temperature characteristic is adversely affected. And may deteriorate the IR life.

Moreover, it is preferable that each dielectric ceramic composition according to the first aspect and the second aspect further has an eighth subcomponent containing Al ₂ O ₃ .
The ratio of the eighth subcomponent to 100 mol of the main component is preferably 0 to 4 mol (excluding 0 mol), more preferably 0 to 3.5 mol (excluding 0 mol).

  The eighth subcomponent shows the effect of improving IR temperature dependency and Tc-bias characteristics, but if the content of the eighth subcomponent is too small, the effect of improving IR temperature dependency and Tc-bias characteristics is insufficient. On the other hand, if the amount is too large, the capacity-temperature characteristic tends to deteriorate.

  In this specification, each oxide constituting the main component and each subcomponent is represented by a stoichiometric composition, but the oxidation state of each oxide may be out of the stoichiometric composition. However, the said ratio of each subcomponent is calculated | required by converting into the oxide of the said stoichiometric composition from the metal amount contained in the oxide which comprises each subcomponent.

In addition, when at least one of Sr, Zr, and Sn substitutes Ba or Ti in the main component constituting the perovskite structure, the Curie temperature shifts to a low temperature side, so that the capacity-temperature characteristics at 125 ° C. or higher Becomes worse. For this reason, it is preferable not to use BaTiO ₃ [for example, (Ba, Sr) TiO ₃ ] containing these elements as a main component. However, there is no particular problem as long as the level is contained as an impurity (about 0.1 mol% or less of the entire dielectric ceramic composition).

  The average crystal grain size of the dielectric ceramic composition of the present invention is not particularly limited, and may be appropriately determined from a range of, for example, 0.1 to 3 μm according to the thickness of the dielectric layer. Capacitance-temperature characteristics tend to deteriorate as the dielectric layer is thinner, and worsen as the average crystal grain size is reduced. Therefore, the dielectric ceramic composition of the present invention is particularly effective when the average crystal grain size needs to be reduced, specifically when the average crystal grain size is 0.1 to 0.5 μm. is there. In addition, if the average crystal grain size is reduced, the IR lifetime becomes longer, and the change with time of the capacity under a direct current electric field is reduced. From this point, the average crystal grain size is preferably small as described above. .

  The Curie temperature (phase transition temperature from ferroelectric to paraelectric) of the dielectric ceramic composition of the present invention can be changed by selecting the composition, but is preferable for satisfying the X8R characteristics. Is 120 ° C. or higher, more preferably 123 ° C. or higher. The Curie temperature can be measured by DSC (differential scanning calorimetry) or the like.

The multilayer ceramic capacitor using the dielectric ceramic composition of the present invention is suitable for use as an electronic device for equipment used in an environment of 80 ° C. or higher, particularly 125 to 150 ° C. In such a temperature range, the temperature characteristic of the capacitance satisfies the R characteristic of the EIA standard, and further satisfies the X8R characteristic. In addition, the X7R characteristic (-55 to 125 ° C., ΔC / C = within ± 15%) of the EIA standard can be satisfied simultaneously.
In a multilayer ceramic capacitor, an AC electric field of 0.02 V / μm or more, particularly 0.2 V / μm or more, more preferably 0.5 V / μm or more, and generally about 5 V / μm or less is superimposed on the dielectric layer. Then, a DC electric field of 5 V / μm or less is applied, but even if such an electric field is applied, the temperature characteristics of the capacitance are stable.

  Various conditions such as the number of laminated layers and the thickness of the dielectric layer 2 may be appropriately determined according to the purpose and application. In the present embodiment, the thickness of the dielectric layer 2 is preferably 4.5 μm or less, more preferably It is thinned to 3.0 μm or less. In the present embodiment, even when the thickness of the dielectric layer 2 is reduced as described above, various electrical characteristics of the capacitor 1, in particular, a predetermined capacitance-temperature characteristic is satisfied while having a high dielectric constant, and a capacitance. Variability has been improved.

  The conductive material contained in the internal electrode layer 3 is not particularly limited, but a base metal can be used because the constituent material of the dielectric layer 2 has reduction resistance. As the base metal used as the conductive material, Ni or Ni alloy is preferable. The Ni alloy is preferably an alloy of Ni and one or more elements selected from Mn, Cr, Co, and Al, and the Ni content in the alloy is preferably 95% by weight or more. In addition, in Ni or Ni alloy, various trace components, such as P, may be contained about 0.1 wt% or less. The thickness of the internal electrode layer may be appropriately determined according to the application, etc., but it is usually preferably about 0.5 to 5 μm, particularly preferably about 0.5 to 2.5 μm.

  The conductive material contained in the external electrode 4 is not particularly limited, but in the present invention, inexpensive Ni, Cu, and alloys thereof can be used. The thickness of the external electrode may be appropriately determined according to the use, etc., but is usually preferably about 10 to 50 μm.

  In the multilayer ceramic capacitor using the dielectric ceramic composition of the present invention, as in the conventional multilayer ceramic capacitor, a green chip is produced by a normal printing method or sheet method using a paste, and this is fired, and then externally It is manufactured by printing or transferring an electrode and firing. Hereinafter, the manufacturing method will be specifically described.

  First, the dielectric ceramic composition powder contained in the dielectric layer paste is prepared, and this is made into a paint to prepare the dielectric layer paste.

  The dielectric layer paste may be an organic paint obtained by kneading a dielectric ceramic composition powder and an organic vehicle, or may be a water-based paint.

As the dielectric ceramic composition powder, the above-described oxides, mixtures thereof, and composite oxides can be used. In addition, various compounds that become the above-described oxides and composite oxides by firing, such as carbonates and An acid salt, a nitrate, a hydroxide, an organometallic compound, or the like can be appropriately selected and mixed for use. What is necessary is just to determine content of each compound in a dielectric ceramic composition powder so that it may become a composition of the above-mentioned dielectric ceramic composition after baking.
The particle size of the dielectric ceramic composition powder is usually about 0.1 to 3 [mu] m in average before the coating.

  An organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used for the organic vehicle is not particularly limited, and may be appropriately selected from usual various binders such as ethyl cellulose and polyvinyl butyral. Further, the organic solvent to be used is not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, acetone, toluene, and the like, depending on a method to be used such as a printing method or a sheet method.

  Further, when the dielectric layer paste is used as a water-based paint, a water-based vehicle in which a water-soluble binder or a dispersant is dissolved in water and a dielectric material may be kneaded. The water-soluble binder used for the water-based vehicle is not particularly limited, and for example, polyvinyl alcohol, cellulose, water-soluble acrylic resin, or the like may be used.

The internal electrode layer paste is prepared by kneading the above-mentioned organic vehicle with various conductive metals made of various dielectric metals and alloys, or various oxides, organometallic compounds, resinates, etc. that become the above-mentioned conductive materials after firing. Prepare.
The external electrode paste may be prepared in the same manner as the internal electrode layer paste described above.

  There is no restriction | limiting in particular in content of the organic vehicle in each above-mentioned paste, For example, what is necessary is just about 1-5 weight% of binders, for example, about 10-50 weight% of binders. Each paste may contain additives selected from various dispersants, plasticizers, dielectrics, insulators, and the like as necessary. The total content of these is preferably 10% by weight or less.

  When the printing method is used, the dielectric layer paste and the internal electrode layer paste are laminated and printed on a substrate such as PET, cut into a predetermined shape, and then peeled from the substrate to obtain a green chip.

  When the sheet method is used, a dielectric layer paste is used to form a green sheet, the internal electrode layer paste is printed thereon, and these are stacked to form a green chip.

Before firing, the green chip is subjected to binder removal processing. The binder removal treatment may be appropriately determined according to the type of the conductive material in the internal electrode layer paste. However, when a base metal such as Ni or Ni alloy is used as the conductive material, the oxygen partial pressure in the binder removal atmosphere is 10 It is preferable to be ⁻⁴⁵ to 10 ⁵ Pa. When the oxygen partial pressure is less than the above range, the binder removal effect is lowered. If the oxygen partial pressure exceeds the above range, the internal electrode layer tends to oxidize.

As other binder removal conditions, the temperature rising rate is preferably 5 to 300 ° C./hour, more preferably 10 to 100 ° C./hour, and the holding temperature is preferably 180 to 400 ° C., more preferably 200 to 350. The temperature holding time is preferably 0.5 to 24 hours, more preferably 2 to 20 hours. The firing atmosphere is preferably air or a reducing atmosphere, and as an atmosphere gas in the reducing atmosphere, for example, a mixed gas of N ₂ and H ₂ is preferably used after being humidified.

The atmosphere at the time of green chip firing may be appropriately determined according to the type of conductive material in the internal electrode layer paste, but when a base metal such as Ni or Ni alloy is used as the conductive material, the oxygen content in the firing atmosphere The pressure is preferably 10 ⁻⁷ to 10 ⁻³ Pa. When the oxygen partial pressure is less than the above range, the conductive material of the internal electrode layer may be abnormally sintered and may be interrupted. Further, when the oxygen partial pressure exceeds the above range, the internal electrode layer tends to be oxidized.

  Moreover, the holding temperature at the time of baking becomes like this. Preferably it is 1100-1400 degreeC, More preferably, it is 1200-1380 degreeC, More preferably, it is 1260-1360 degreeC. If the holding temperature is lower than the above range, the densification becomes insufficient. If the holding temperature is higher than the above range, the electrode temperature is interrupted due to abnormal sintering of the internal electrode layer, the capacity temperature characteristic deteriorates due to diffusion of the constituent material of the internal electrode layer, and the dielectric Reduction of the body porcelain composition is likely to occur.

As other firing conditions, the rate of temperature rise is preferably 50 to 500 ° C./hour, more preferably 200 to 300 ° C./hour, and the temperature holding time is preferably 0.5 to 8 hours, more preferably 1 to 3 hours. The time and cooling rate are preferably 50 to 500 ° C./hour, more preferably 200 to 300 ° C./hour. Further, the firing atmosphere is preferably a reducing atmosphere, and as the atmosphere gas, for example, a mixed gas of N ₂ and H ₂ is preferably used by humidification.

  When firing in a reducing atmosphere, it is preferable to anneal the capacitor element body. Annealing is a process for re-oxidizing the dielectric layer, and this can significantly increase the IR lifetime, thereby improving the reliability.

  The oxygen partial pressure in the annealing atmosphere is preferably 0.1 Pa or more, particularly 0.1 to 10 Pa. When the oxygen partial pressure is less than the above range, it is difficult to reoxidize the dielectric layer, and when it exceeds the above range, the internal electrode layer tends to be oxidized.

  The holding temperature at the time of annealing is preferably 1100 ° C. or less, particularly 500 to 1100 ° C. When the holding temperature is lower than the above range, the dielectric layer is not sufficiently oxidized, so that the IR is low and the IR life tends to be short. On the other hand, if the holding temperature exceeds the above range, not only the internal electrode layer is oxidized and the capacity is lowered, but the internal electrode layer reacts with the dielectric substrate, the capacity temperature characteristic is deteriorated, the IR is lowered, the IR Life is likely to decrease. In addition, you may comprise annealing only from a temperature rising process and a temperature falling process. That is, the temperature holding time may be zero. In this case, the holding temperature is synonymous with the maximum temperature.

As other annealing conditions, the temperature holding time is preferably 0 to 20 hours, more preferably 2 to 10 hours, and the cooling rate is preferably 50 to 500 ° C./hour, more preferably 100 to 300 ° C./hour. . Further, as the annealing atmosphere gas, for example, humidified N ₂ gas or the like is preferably used.

In the above-described binder removal processing, firing and annealing, for example, a wetter or the like may be used to wet the N ₂ gas, mixed gas, or the like. In this case, the water temperature is preferably about 5 to 75 ° C.

The binder removal treatment, firing and annealing may be performed continuously or independently. When these are performed continuously, after removing the binder, the atmosphere is changed without cooling, and then the temperature is raised to the holding temperature at the time of baking to perform baking, and then cooled to reach the annealing holding temperature. Sometimes it is preferable to perform annealing by changing the atmosphere. On the other hand, when performing these independently, at the time of firing, after raising the temperature under N ₂ gas atmosphere with N ₂ gas or wet to the holding temperature of the binder removal processing, further continuing the heating to change the atmosphere Preferably, after cooling to the holding temperature at the time of annealing, it is preferable to change to the N ₂ gas or humidified N ₂ gas atmosphere again and continue cooling. In annealing, the temperature may be changed to a holding temperature in an N ₂ gas atmosphere, and then the atmosphere may be changed, or the entire annealing process may be a humidified N ₂ gas atmosphere.

The capacitor element body obtained as described above is subjected to end surface polishing, for example, by barrel polishing or sand blasting, and the external electrode paste is printed or transferred and baked to form the external electrode 4. The firing conditions of the external electrode paste are preferably, for example, about 10 minutes to 1 hour at 600 to 800 ° C. in a humidified mixed gas of N ₂ and H ₂ . Then, if necessary, a coating layer is formed on the surface of the external electrode 4 by plating or the like.
The multilayer ceramic capacitor of the present invention thus manufactured is mounted on a printed circuit board by soldering or the like and used for various electronic devices.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement in various aspects. .

  For example, in the above-described embodiment, the multilayer ceramic capacitor is exemplified as the electronic component according to the present invention. However, the electronic component according to the present invention is not limited to the multilayer ceramic capacitor, and is composed of a dielectric ceramic composition having the above composition. Any material having a dielectric layer can be used.

  Next, the present invention will be described in more detail with reference to examples that further embody the embodiment of the present invention. However, the present invention is not limited to only these examples.

Example 1
First, as a starting material for producing a dielectric material, a main component material (BaTiO ₃ ) and first to _third , fourth, fourth, and fifth to seventh subcomponent materials having an average particle diameter of 0.1 to 1 μm were prepared. . Carbonates (first subcomponent: MgCO ₃ , seventh subcomponent: MnCO ₃ ) are used as raw materials for MgO and MnO, and oxides (second subcomponent: (Ba _0.6 Ca _{0. 4} ) SiO ₃ , third subcomponent: V ₂ O ₅ , 4a subcomponent: Yb ₂ O ₃ , 4b subcomponent: Y ₂ O ₃ , fifth subcomponent: CaZrO ₃ , sixth subcomponent: P ₂ O _5, 8 subcomponent: _Al 2 _{O 3)} was used.

The second subcomponent (Ba _0.6 Ca _0.4 ) SiO ₃ is obtained by wet-mixing BaCO ₃ , CaCO ₃ and SiO ₂ with a ball mill for 16 hours, drying, and firing in air at 1150 ° C., It was manufactured by wet grinding with a ball mill for 100 hours. CaZrO _{3 as} the fifth subcomponent was produced by wet mixing CaCO ₃ and ZrO ₂ with a ball mill for 16 hours, drying, firing in air at 1150 ° C., and further wet pulverizing with a ball mill for 24 hours.

In addition, BaTiO _{3 as} a main component is obtained by weighing BaCO ₃ and TiO ₂ respectively, wet-mixing them for about 16 hours using a ball mill, drying them, and then firing them in air at a temperature of 1100 ° C. Similar characteristics were obtained even when a ball mill was used for approximately 16 hours of wet pulverization. Further, the same characteristics were obtained even when BaTiO ₃ as the main component was produced by hydrothermal synthesis powder, oxalate method or the like.

With respect to 100 mol of BaTiO _{3 as} a main component, these raw materials have a first subcomponent: 1 mol, a second subcomponent: 3 mol, a third subcomponent: 0.1 mol, 4a subcomponent: (1.75 moles _Yb 2 _{O 3} equivalent) Yb converted at 3.5 moles, the 4b subcomponent: Y ₍₂ mol in terms _of Y 2 _{O 3)} 4 moles in terms of the fifth subcomponent: 1.5 mol, sixth subcomponent: see Table 1 (however, the number of moles in terms of P), seventh subcomponent: 0.374 mol, eighth subcomponent: 1 mol, Wet mixed for 16 hours by a ball mill and dried to obtain a dielectric material.
Next, 100 parts by weight of the obtained dielectric material after drying, 4.8 parts by weight of acrylic resin, 100 parts by weight of ethyl acetate, 6 parts by weight of mineral spirit, and 4 parts by weight of toluene were mixed with a ball mill. A dielectric layer paste was obtained by pasting.

  Next, 100 parts by weight of Ni particles having an average particle size of 0.2 to 0.8 μm, 40 parts by weight of an organic vehicle (8 parts by weight of ethyl cellulose dissolved in 92 parts by weight of butyl carbitol), and 10 parts by weight of butyl carbitol Were kneaded with three rolls to obtain a paste, and an internal electrode layer paste was obtained.

  Next, 100 parts by weight of Cu particles having an average particle size of 0.5 μm, 35 parts by weight of an organic vehicle (8 parts by weight of ethyl cellulose resin dissolved in 92 parts by weight of butyl carbitol) and 7 parts by weight of butyl carbitol were kneaded. To obtain a paste for an external electrode.

  Next, a 4.5 μm-thick green sheet was formed on the PET film using the dielectric layer paste, and the internal electrode layer paste was printed thereon, and then the green sheet was peeled from the PET film. Next, these green sheets and protective green sheets (not printed with internal electrode layer paste) were laminated and pressure-bonded to obtain green chips. The number of sheets having internal electrodes was four.

  Next, the green chip was cut into a predetermined size and subjected to binder removal processing, firing and annealing to obtain a multilayer ceramic fired body.

  The binder removal treatment was performed under conditions of a temperature rising time of 15 ° C./hour, a holding temperature of 280 ° C., a holding time of 2 hours, and an air atmosphere.

Firing is performed in a temperature rising rate of 200 ° C./hour, a holding temperature of 1260 to 1340 ° C., a holding time of 2 hours, a cooling rate of 300 ° C./hour, and a humidified N ₂ + H ₂ mixed gas atmosphere (oxygen partial pressure is 10 ⁻⁶ Pa). Performed under conditions.

  The annealing was performed under the conditions of a holding temperature of 1200 ° C., a temperature holding time of 2 hours, a cooling rate of 300 ° C./hour, and a nitrogen atmosphere. Note that a wetter with a water temperature of 35 ° C. was used for humidifying the atmospheric gas during the debinding process and firing.

Next, after polishing the end face of the multilayer ceramic fired body by sand blasting, the external electrode paste is transferred to the end face and fired at 800 ° C. for 10 minutes in a humidified N ₂ + H ₂ atmosphere to form the external electrode. A sample of the multilayer ceramic capacitor having the configuration shown in FIG. 1 was obtained.

  The size of each sample thus obtained is 3.2 mm × 1.6 mm × 0.6 mm, the number of dielectric layers sandwiched between internal electrode layers is 4, and the thickness is 3.5 μm. The thickness of the internal electrode layer was 1.0 μm.

  The obtained capacitor sample was evaluated for relative dielectric constant (ε), capacitance-temperature characteristic (Tc), and capacitance variation (capacity defect rate). The results are shown in Table 1.

  The relative dielectric constant ε was measured for a capacitor sample at a reference temperature of 25 ° C. using a digital LCR meter (4274A manufactured by YHP) under the conditions of a frequency of 1 kHz and an input signal level (measurement voltage) of 1.0 Vrms. Calculated from the electric capacity (no unit). When the value of ε was 1000 or more, it was judged to be good.

  For the capacity-temperature characteristic (Tc), the capacitance was measured in the temperature range of −55 ° C. to 150 ° C. for the obtained sample. The capacitance was measured using a digital LCR meter (YHP 4274A) under the conditions of a frequency of 1 kHz and an input signal level of 1 Vrms. Then, the rate of change in capacitance (ΔC / C. The unit is%) under a temperature environment of 150 ° C. at which the capacity-temperature characteristic becomes the worst in these temperature ranges is calculated, and the X8R characteristic (−55 to 150 ° C. is calculated). , ΔC / C = within ± 15%).

  Regarding the capacitance variation (capacity defect rate), first, the capacitance of 100 capacitor samples was measured with a digital LCR meter at a reference temperature of 25 ° C. under a frequency of 1 kHz and an input signal level of 1.0 Vrms. . And the average capacity | capacitance was calculated | required by averaging the measurement result of 100 samples. Next, when the average capacity was set to 100%, the ratio of the samples whose electrostatic capacity was less than 80% was obtained, and this was regarded as capacity variation. In this example, a sample having a capacity variation of 30% or less (that is, 30 samples or less having a capacitance of less than 80% out of 100 samples) was judged to be good.

  For the obtained capacitor sample, dielectric loss (tan δ), IR lifetime under DC electric field, DC dielectric breakdown strength, DC bias characteristics (dependence of DC permittivity on dielectric constant), and TC bias are also evaluated. did.

  The dielectric loss (tan δ) was measured with a digital LCR meter (YHP 4274A) at a reference temperature of 25 ° C. and a frequency of 1 kHz and an input signal level (measurement voltage) of 1.0 Vrms with respect to a capacitor sample. . As a result, good results were obtained for all samples of 10% or less.

  The IR life under a direct current electric field was calculated by performing an acceleration test on a capacitor sample at 200 ° C. under an electric field of 10 V / μm, and calculating the time until the insulation resistance was 1 MΩ or less as the life time. As a result, good results were obtained for all samples of 10 hours or more.

  The DC breakdown strength is 100 V / sec. The voltage (DC breakdown voltage VB, unit is V / μm) when a leakage current of 100 mA was detected was measured and the average value was calculated. As a result, good results were obtained for all samples of 100 V / μm or more.

  The DC bias characteristics were plotted by measuring the change in capacitance (ΔC / C) when a DC voltage was gradually applied to each sample at a constant temperature (25 ° C.) with respect to the capacitor sample. As a result, it was confirmed that any sample had a stable DC bias characteristic because the capacitance was difficult to decrease even when a high voltage was applied.

The TC bias is obtained by changing the temperature of the obtained sample from −55 ° C. to 150 ° C. with a bias voltage (DC voltage) of 1 kHz, 1 Vrms, 7.0 V / μm using a digital LCR meter (YHP 4274A). Measurement was performed, and the rate of change in capacitance was calculated and evaluated from a measured value during application of no bias voltage at 25 ° C. The capacitance was measured using an LCR meter under conditions of a frequency of 1 kHz and an input signal level of 1 Vrms. As a result, all the samples had good results of -40% or more.

  As shown in Table 1, when the content of the sixth subcomponent is too small (Sample 1), the X8R characteristic is satisfied and ε is good, but the capacity variation becomes remarkable. If the content of the sixth subcomponent is too large (Sample 5), the capacity variation is improved, but the X8R characteristic cannot be satisfied. On the other hand, when the content of the sixth subcomponent is in the appropriate range (samples 2 to 4), the X8R characteristics are satisfied, ε is good, and the capacity variation is 30 or less, which improves the capacity variation. It was confirmed that

Example 2
A capacitor sample was produced in the same manner as in Example 1 except that the type and content of the sixth subcomponent were changed as shown in Tables 2 and 3, and the same evaluation was performed.

As shown in Table 2, it can be confirmed that even if the sixth subcomponent is changed to S, the same effect as P ₂ O _{5 of} Example 1 can be obtained.

As shown in Table 3, even if the sixth subcomponent is changed to a composite form of P ₂ O ₅ and S, the same effect as that obtained when P ₂ O ₅ is added alone can be obtained if the total addition amount is appropriate. Can be confirmed. In particular, as in sample 22, when the ratio of P and S was 1: 1, the capacity variation was 0, and it was confirmed that it was even more preferable.

FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Multilayer ceramic capacitor 10 ... Capacitor element main body 2 ... Dielectric layer 3 ... Internal electrode layer 4 ... External electrode

Claims (12)

A main component comprising barium titanate;
A first subcomponent comprising at least one selected from MgO, CaO, BaO and SrO;
A second subcomponent containing silicon oxide as a main component;
A third subcomponent comprising at least one selected from V ₂ O ₅ , MoO ₃ and WO ₃ ;
A subcomponent 4a containing an oxide of R1, wherein R1 is at least one selected from Sc, Er, Tm, Yb and Lu;
A fifth subcomponent comprising CaZrO ₃ or CaO + ZrO ₂ ,
The ratio of each subcomponent to 100 moles of the main component is
1st subcomponent: 0.1-3 mol,
Second subcomponent: 2 to 10 mol,
Third subcomponent: 0.01 to 0.5 mol,
4a subcomponent: 0.5-7 mol in terms of R1,
Fifth subcomponent: 0 to 5 mol (excluding 0 mol),
A dielectric ceramic composition comprising:
A sixth subcomponent containing P oxide and / or S;
The dielectric ceramic composition wherein a ratio of the sixth subcomponent to 100 mol of the main component is 0 to 1 mol (excluding 0 mol) in terms of P and / or S. And further comprising a 4b subcomponent containing an oxide of R2 (wherein R2 is at least one selected from Y, Dy, Ho, Tb, Gd and Eu), and the fourth b subcomponent with respect to 100 moles of the main component. The dielectric ceramic composition according to claim 1, wherein the ratio is 0 to 9 mol (excluding 0 mol) in terms of R2. The second subcomponent is mainly composed of SiO ₂ , and is further selected from MO (where M is at least one element selected from Ba, Ca, Sr and Mg), Li ₂ O and B ₂ O _3. The dielectric ceramic composition according to claim 1 or 2, which is a composite oxide containing at least one kind. The dielectric ceramic composition according to claim 3, wherein the composite oxide is represented by (Ba, Ca) _x SiO _{2 + x} (where x = 0.7 to 1.2). A main component comprising barium titanate;
A first subcomponent comprising at least one selected from MgO, CaO, BaO and SrO;
A fourth c subcomponent containing an oxide of R3 (wherein R3 is at least one selected from Y, Dy, Ho and Er),
The ratio of each subcomponent to 100 moles of the main component is
First subcomponent: 0 to 0.1 mol (excluding 0 mol and 0.1 mol),
4c subcomponent: 1 to 7 mol (excluding 1 mol and 7 mol),
A dielectric ceramic composition comprising:
A sixth subcomponent containing P oxide and / or S;
The dielectric ceramic composition wherein a ratio of the sixth subcomponent to 100 mol of the main component is 0 to 1 mol (excluding 0 mol) in terms of P and / or S. Further comprising a fifth subcomponent including CaZrO ₃ or CaO + ZrO _2,
The dielectric ceramic composition according to claim 5, wherein a ratio of the fifth subcomponent to 100 mol of the main component is 0 to 5 mol (excluding 0 mol and 5 mol). MxSiO ₃ (where M is at least one selected from Ba, Ca, Sr, Li, and B. When M = Ba, x = 1, when M = Ca, x = 1, M A second subcomponent including: x = 1 when = Sr, x = 2 when M = Li, and x = 2/3 when M = B.
The dielectric ceramic composition according to claim 5, wherein a ratio of the second subcomponent with respect to 100 mol of the main component is 2 to 10 mol. A third subcomponent comprising at least one selected from V ₂ O ₅ , MoO ₃ and WO ₃ ;
The dielectric ceramic composition according to claim 5, wherein a ratio of the third subcomponent to 0.01 mol of the main component is 0.01 to 0.5 mol. A seventh subcomponent comprising MnO and / or Cr ₂ O ₃ ;
The dielectric ceramic composition according to claim 1 or 5, wherein a ratio of the seventh subcomponent to 100 mol of the main component is 0 to 0.5 mol (excluding 0 mol). An eighth subcomponent comprising Al ₂ O ₃ ;
The dielectric ceramic composition according to claim 1 or 5, wherein a ratio of the eighth subcomponent to 100 mol of the main component is 0 to 4 mol (excluding 0 mol). The electronic component which has a dielectric material layer comprised with the dielectric material ceramic composition in any one of Claims 1-10. A multilayer ceramic capacitor having a capacitor element body in which dielectric layers composed of the dielectric ceramic composition according to claim 1 and internal electrode layers are alternately stacked.

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