JP2017108032A - Multilayer ceramic capacitor and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer ceramic capacitor having a sufficient high temperature load life, while thinning a ceramic layer.SOLUTION: A multilayer ceramic capacitor 10 includes a laminate 20 formed by laminating a plurality of ceramic layers 30 containing crystal grains having a perovskite structure and a plurality of first and second internal electrode layers 40a, 40b, and first and second external electrode 50a, 50b formed on the first and second end faces 26a, 26b of the laminate 20. Assuming the content of Ti is 100 parts by mol, 0.10-15.00 parts by mol of Ca, 0.0010-0.0097 parts by mol of Mg, 0.50-4.00 parts by mol of R, 0.10-2.00 parts by mol of M, and 0.50-2.00 parts by mol of Si are contained, and Ca is contained in the crystal grains.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a multilayer ceramic capacitor and a method for manufacturing the same.

  In recent years, there has been an increasing demand for miniaturization and higher capacity for multilayer ceramic capacitors. In order to meet such requirements, it is necessary to make the ceramic layer thinner. As a multilayer ceramic capacitor in which the ceramic layer is thinned, for example, there is a multilayer ceramic capacitor using a dielectric ceramic composition for low-temperature firing disclosed in Patent Document 1.

The multilayer ceramic capacitor of Patent Document 1 includes a capacitor body in which a dielectric layer (corresponding to the “ceramic layer” of the present invention) and an internal electrode layer are alternately stacked, and a dielectric ceramic composition contained in the dielectric layer is provided. , (Ba _1-x Ca _x ) _m TiO ₃ as a main component and MgCO ₃ , RE ₂ O ₃ (RE ₂ O ₃ is Y ₂ O ₃ , Dy ₂ O ₃ and Ho ₂ O ₃ as subcomponents) Rare earth oxides selected from one or more), MO (M is one element of Ba and Ca), MnO, V ₂ O ₅ , Cr ₂ O ₃ and SiO ₂ which is a sintering aid. Composition formula of the dielectric ceramic composition, expressed as _{a (Ba 1-x Ca x} ) m TiO 3 -bMgCO 3 -cRE 2 O 3 -dMO-eMnO-fSiO 2 -gV 2 O 5 -hCr 2 O 3 In this case, the molar ratios are a = 100, 0.1 ≦ b ≦ 3.0, 0.1 ≦ c ≦ 3.0, 0.1 ≦ d ≦ 3.0, 0.05 ≦ e ≦ 1.0, 0.2 ≦ f ≦ 3.0, 0.01 ≦ g ≦ 1.0, 0.01 ≦ h ≦ 1.0, 0.005 ≦ x ≦ 0.15, 0.995 ≦ m ≦ 1. 03 is satisfied.

JP 2007-31273 A

  In the multilayer ceramic capacitor as in Patent Document 1, a Ni—Mg segregation phase is generated in the ceramic layer, and there is a concern that the multilayer ceramic capacitor is locally thinned. As a result, there is a problem that the high temperature load life of the multilayer ceramic capacitor may be reduced.

Therefore, a main object of the present invention is to provide a multilayer ceramic capacitor having a sufficient high-temperature load life while reducing the thickness of the ceramic layer.
Another object of the present invention is to provide a method of manufacturing a multilayer ceramic capacitor having a sufficient high temperature load life while reducing the thickness of the ceramic layer.

A multilayer ceramic capacitor according to the present invention includes a multilayer body formed by laminating a plurality of ceramic layers containing crystal particles having a perovskite structure and a plurality of internal electrode layers, and an internal electrode layer and an electric electrode on the surface of the multilayer body. A multilayer ceramic capacitor having a pair of external electrodes formed so as to be connected to each other, wherein the ceramic layer includes a perovskite type compound containing Ba, Ca and Ti, Mg, and R (R is a rare earth element) La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) and M (M is Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo and W) and Si, and when the Ti content is 100 mol parts, Ca is 0.10 mol parts or more. 15.00 mol parts or less, Mg is 0.0010 mol parts or more and 0.0097 mol parts or less, R is 0.50 mol parts or more and 4.00 mol parts or less, and M is 0.10 mol parts or more and 2. 00 mol part or less, Si is contained in an amount of 0.50 mol part or more and 2.00 mol part or less, and Ca is contained in the core part of the crystal grain.
A multilayer ceramic capacitor according to the present invention includes a multilayer body formed by laminating a plurality of ceramic layers containing crystal particles having a perovskite structure and a plurality of internal electrode layers, and an internal electrode layer and an electric electrode on the surface of the multilayer body. A multilayer ceramic capacitor having a pair of external electrodes formed so as to be connected to each other, wherein the laminate includes a perovskite type compound containing Ba, Ca and Ti, Mg, and R (R is a rare earth element) La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) and M (M is Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo, and W) and Si, and when the Ti content is 100 mol parts, Ca is 0.10 mol parts or more and 15 00 mol part or less, Mg is 0.0010 mol part or more and 0.0097 mol part or less, R is 0.50 mol part or more and 4.00 mol part or less, and M is 0.10 mol part or more and 2.00 mol part or less. Part or less, Si is contained in an amount of 0.50 mol part or more and 2.00 mol part or less, and Ca is contained in the core part of the crystal grain.
A multilayer ceramic capacitor according to the present invention includes a multilayer body formed by laminating a plurality of ceramic layers containing crystal particles having a perovskite structure and a plurality of internal electrode layers, and an internal electrode layer and an electric electrode on the surface of the multilayer body. A multilayer ceramic capacitor having a pair of external electrodes formed so as to be connected to each other, wherein the laminate includes a perovskite type compound containing Ba, Ca and Ti, Mg, and R (R is a rare earth element) La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) and M (M is Zr, Mn, Co, Fe, When containing at least one of Cr, Cu, Al, V, Mo and W) and Si, and the content of Ti when the laminate is dissolved with a solvent is 100 mol parts Ca is 0.10 mol part or more and 15.00 mol part or less, Mg is 0.0010 mol part or more and 0.0097 mol part or less, R is 0.50 mol part or more and 4.00 mol part or less, M is 0.10 mol part or more and 2.00 mol part or less, Si is contained by 0.50 mol part or more and 2.00 mol part or less, and Ca is contained in the core part of the crystal grain.
Preferably, R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb).
Preferably, R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb) and R2 (R2 is a rare earth element Ce, Pr, Nd, Eu, At least one of Tm, Lu and Tb), and the value of the molar part of R1 / the molar part of R2 is 4.0 or more.
The method for manufacturing a multilayer ceramic capacitor according to the present invention includes a powder mainly composed of a perovskite compound containing Ba, Ca and Ti, an Mg compound, and an R compound (where R is a rare earth element La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) and a compound of M (M is Zr, Mn, Co, Fe, Cr, Cu, Al, A step of obtaining a ceramic slurry by mixing at least one of V, Mo and W) and a Si compound, a step of obtaining a ceramic green sheet by sheet-forming the ceramic slurry, a ceramic green sheet, By laminating ceramic green sheets with internal electrode patterns on ceramic green sheets, Forming a raw laminate by cutting the laminate block, and firing the raw laminate to obtain a laminate in which an internal electrode layer containing Ni is formed. When the Ti content in the ceramic slurry is 100 mol parts, Ca is 0.10 mol parts or more and 15.00 mol parts or less, Mg is 0.0010 mol parts or more and 0.0097 mol parts or less, and R is 0.50 mol part or more and 4.00 mol part or less, M is contained by 0.10 mol part or more and 2.00 mol part or less, and Si is contained by 0.50 mol part or more and 2.00 mol part or less. And
Preferably, in the step of obtaining a ceramic slurry, a Ca compound is further mixed with powder containing a perovskite type compound containing Ba, Ca, and Ti as a main component.
Preferably, R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb).
Preferably, R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb) and R2 (R2 is a rare earth element Ce, Pr, Nd, Eu, At least one of Tm, Lu, and Tb), and the value of the molar part of R1 / the molar part of R2 is 4.0 or more.

  In the multilayer ceramic capacitor according to the present invention, the Mg content of the ceramic layer is 0.0010 mol part or more and 0.0097 mol part or less when Ti is 100 mol parts, which is extremely small compared to the prior art. . Thereby, it can suppress that the segregation phase of Ni-Mg is produced | generated. In addition, adverse effects such as abnormal grain growth that can be caused by reducing the Mg content are suppressed by elements other than Mg contained in the ceramic layer. As a result, the multilayer ceramic capacitor according to the present invention has a sufficient high temperature load life.

According to the present invention, it is possible to provide a multilayer ceramic capacitor having a sufficient high-temperature load life while reducing the thickness of the ceramic layer.
In addition, according to the present invention, it is possible to manufacture a multilayer ceramic capacitor having a sufficient high temperature load life while reducing the thickness of the ceramic layer.

  The above-described object, other objects, features, and advantages of the present invention will become more apparent from the following description of embodiments for carrying out the invention with reference to the drawings.

1 is an external perspective view showing a multilayer ceramic capacitor according to an embodiment of the present invention. It is II-II sectional drawing of FIG. 1 which shows the laminated ceramic capacitor which concerns on one embodiment of this invention. It is the schematic for demonstrating the measuring method of the thickness of the ceramic layer with which the multilayer ceramic capacitor which concerns on one embodiment of this invention is provided.

1. Multilayer Ceramic Capacitor Hereinafter, a multilayer ceramic capacitor according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view showing a multilayer ceramic capacitor according to an embodiment of the present invention. 2 is a cross-sectional view taken along the line II-II of FIG. 1 showing a multilayer ceramic capacitor according to an embodiment of the present invention.

  The multilayer ceramic capacitor 10 according to this embodiment includes a multilayer body 20, and a first external electrode 50a and a second external electrode 50b (a pair of external electrodes) formed on the surface of the multilayer body 20.

(Laminated body 20)
The multilayer body 20 is formed in a rectangular parallelepiped shape by laminating a plurality of ceramic layers 30, a plurality of first internal electrode layers 40a, and a plurality of second internal electrode layers 40b. That is, the stacked body 20 includes a first main surface 22a and a second main surface 22b that face each other in the stacking direction (T direction), and a first side surface 24a that faces in the width direction (W direction) orthogonal to the T direction. And a second side surface 24b, and a first end surface 26a and a second end surface 26b that face each other in the length direction (L direction) orthogonal to the T direction and the W direction. The laminate 20 is preferably rounded at the corners and ridges. Further, the rectangular parallelepiped shape of the stacked body 20 is a shape including the first and second main surfaces 22a and 22b, the first and second side surfaces 24a and 24b, and the first and second end surfaces 26a and 26b. There is no particular limitation.

(First and second internal electrode layers 40a and 40b)
The first internal electrode layer 40 a extends in a flat plate shape at the interface of the ceramic layer 30, and an end portion thereof is exposed at the first end surface 26 a of the multilayer body 20. On the other hand, the second internal electrode layer 40b extends in a flat plate shape at the interface of the ceramic layer 30 so as to face the first internal electrode layer 40a with the ceramic layer 30 interposed therebetween, and the end thereof is the second of the laminate 20. It is exposed at the end face 26b. Therefore, the first and second internal electrode layers 40a and 40b have opposing portions that face each other with the ceramic layer 30 interposed therebetween, and lead portions that are drawn to the first and second end surfaces 26a and 26b. The first and second internal electrode layers 40a and 40b are opposed to each other with the ceramic layer 30 therebetween, thereby generating a capacitance.

(First and second external electrodes 50a and 50b)
The first external electrode 50a is formed on the first end surface 26a of the multilayer body 20, and from there, a part of each of the first and second main surfaces 22a, 22b, and the first and second side surfaces 24a, 24b. It is formed to reach each part. Note that the first external electrode 50 a may be formed only on the first end face 26 a of the stacked body 20. The first external electrode 50a is electrically connected to the first internal electrode layer 40a at the first end face 26a of the multilayer body 20. On the other hand, the second external electrode 50b is formed on the second end face 26b of the multilayer body 20, and from there, a part of each of the first and second main faces 22a, 22b, and the first and second side faces 24a. , 24b is formed so as to reach a part of each. The second external electrode 50b may be formed only on the second end face 26b of the stacked body 20. The second external electrode 50b is electrically connected to the second internal electrode layer 40b at the second end face 26b of the multilayer body 20.

(Ceramic layer 30)
The ceramic layer 30 is sandwiched between the first internal electrode layer 40a and the second internal electrode layer 40b and laminated in the T direction.

  The ceramic layer 30 (or the laminate 20) includes a perovskite type compound containing Ba, Ca, and Ti, Mg, and R (R is a rare earth element La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) and M (M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo and W). And Si. The content (molar part) of each element described above in the ceramic layer 30 (or the laminate 20) is as follows.

  The content of each element when the Ti content is 100 mol parts is as follows. Ca is 0.10 mol part or more and 15.00 mol part or less. In addition, it is preferable that Ca is 0.40 mol part or more and 10.00 mol part or less, and it is more preferable that it is 0.75 mol part or more and 7.50 mol part or less. Mg is 0.0010 mol part or more and 0.0097 mol part or less. In addition, it is preferable that Mg is 0.0010 mol part or more and 0.0090 mol part or less, and it is more preferable that it is 0.0010 mol part or more and 0.0075 mol part or less. R is 0.50 mol part or more and 4.00 mol part or less. In addition, it is preferable that R is 0.50 mol part or more and 3.00 mol part or less, and it is more preferable that it is 0.50 mol part or more and 2.50 mol part or less. M is 0.10 mol part or more and 2.00 mol part or less. M is preferably from 0.10 mol part to 1.50 mol part, more preferably from 0.10 mol part to 1.00 mol part. Si is 0.50 mol part or more and 2.00 mol part or less. Si is preferably 0.60 mol part or more and 1.90 mol part, and more preferably 0.80 mol part or more and 1.60 mol part or less.

  In addition, content (mol part) of said each element is the numerical value measured when producing the ceramic raw material (dielectric raw material compound) for forming the ceramic layer 30, or melt | dissolves the laminated body 20 with a solvent. It is a numerical value obtained by carrying out ICP analysis of the solution obtained in this way.

  Moreover, Ca is contained in the core part of the crystal grains of the ceramic layer 30 (or the laminate 20).

  R described above is preferably R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb).

  Alternatively, R described above is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb) and R2 (R2 is a rare earth element Ce, Pr, Nd, Eu). , At least one of Tm, Lu, and Tb), and the value of the molar part of R1 / the molar part of R2 is preferably 4.0 or more.

(effect)
In the multilayer ceramic capacitor 10 according to this embodiment, the Mg content of the ceramic layer 30 (or the multilayer body 20) is 0.0010 mol part or more and 0.0097 mol part or less when Ti is 100 mol parts. , Extremely less compared to the prior art. Thereby, it can suppress that the segregation phase of Ni-Mg is produced | generated. In addition, adverse effects such as abnormal grain growth that can be caused by reducing the Mg content are suppressed by elements (Ca, R, M, and Si) other than Mg contained in the ceramic layer 30 (or the laminate 20). . As a result, the multilayer ceramic capacitor 10 according to this embodiment has a sufficient high temperature load life.

  Further, R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb) (that is, only R1 is used as R). The load life is further improved, and the reliability of the multilayer ceramic capacitor 10 is improved. This is because, among the rare earth elements shown as R, R1 has a great effect of suppressing the movement of oxygen vacancies.

  Further, R has the rare earth element specified for R1 and R2 described above (that is, R1 and R2 are used together as R), and the value of the molar part of R1 / the molar part of R2 is 4.0 or more. As a result, the high-temperature load life is further improved, and the reliability of the multilayer ceramic capacitor 10 is improved. This is because R1 has a greater inhibitory effect on enzyme vacancy migration than R2.

2. Manufacturing Method for Multilayer Ceramic Capacitor A manufacturing method for a multilayer ceramic capacitor according to the present invention will be described by taking the multilayer ceramic capacitor 10 according to the above-described embodiment as an example. First, a process for producing a ceramic raw material (dielectric material composition) will be described, and then a process for producing a multilayer ceramic capacitor will be described.

(Production of ceramic raw materials)
First, powders of BaCO ₃ , CaCO ₃ and TiO ₂ are prepared as starting materials, and a predetermined amount is weighed so that the content (mole part) is (Ba + Ca): Ti = 1: 1.

  Next, the starting materials weighed as described above are mixed by a ball mill.

Then, by performing heat treatment at 1150 ° C., BaTiO ₃ (barium titanate) which is a perovskite type compound containing Ba and Ti and (Ba, Ca) TiO ₃ (titanic acid) which is a perovskite type compound containing Ba, Ca and Ti. Barium calcium). The main component of barium calcium titanate may be produced by a solid phase synthesis method, a hydrothermal synthesis method or a hydrolysis method.

To the BaTiO ₃ and (Ba, Ca) TiO ₃ obtained as described above, MgO, R ₂ O ₃ , M oxide and SiO ₂ (Mg compound, R compound, M compound and Si compound) were added as additional components. ) And optionally, CaCO ₃ is weighed appropriately and mixed by a ball mill. Here, R is at least one of rare earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo, and W. At this time, when Ti content is 100 mol parts, Ca is 0.10 mol parts or more and 15.00 mol parts or less, Mg is 0.0010 mol parts or more and 0.0097 mol parts or less, and R is 0.50 mol parts. Parts and 4.00 mole parts, M is 0.10 mole parts and 2.00 mole parts, and Si is weighed and mixed so that 0.50 mole parts and 2.00 mole parts is contained. Thereafter, the ceramic raw material is obtained by drying.

The additive component may be an oxide and a carbonate as described above, but is not limited thereto, and may be a chloride or a metal organic compound. Further, as described above, mixing of CaCO ₃ (post-added Ca) performed at the timing of adding other additives after the production of barium calcium titanate is arbitrary. That is, the mixing of CaCO ₃ may be performed so as not to be performed by the post-added Ca but to be included in the starting material for producing barium calcium titanate (that is, only by the pre-added Ca). With the pre-added Ca, Ca can be contained in the core part of the crystal grains of the ceramic layer (or laminate) after completion. In addition, when post-addition Ca is performed in addition to pre-addition Ca, the total amount of pre-addition Ca and post-addition Ca is weighed so that the Ca content is 0.10 mol part or more and 15.00 mol part or less. And mix. Further, the ratio A / B of the content (mole part) of the A site and B site of (Ba, Ca) TiO _{3 as} the main component is preferably in the range of 0.980 to 1.020. However, the content (mole part) ratio A / B is not limited to the stoichiometric composition as long as it is within the range where the effects of the present invention are achieved.

(Production of multilayer ceramic capacitor)
A polyvinyl butyral binder, a plasticizer and ethanol as an organic solvent are added to the ceramic raw material obtained as described above, and these are wet mixed by a ball mill to obtain a ceramic slurry.

  Next, a ceramic green sheet having a rectangular shape (thickness: 4.5 μm) is obtained by sheet-forming the ceramic slurry obtained as described above by a lip method.

  Then, a conductive paste is screen-printed on the surface of the ceramic green sheet obtained as described above to form a conductive paste film (internal electrode pattern) to be an internal electrode mainly composed of Ni. The main component of the conductive paste film is not limited to Ni, but may be Ni alloy or the like.

  Further, the ceramic green sheets on which the conductive paste film is formed are stacked so as to sandwich the ceramic green sheets on which the conductive paste film is not formed. At this time, the conductive paste films are laminated so that the drawn ends are staggered. Thus, a laminated body block is formed, and a raw laminated body is obtained by cutting this laminated body block.

Subsequently, the raw laminate obtained as described above was heated in an N ₂ atmosphere at 350 ° C. for 3 hours to burn the binder, and then the oxygen partial pressure was 10 ⁻⁹ MPa to 10 ⁻¹² MPa. By firing at 1200 ° C. for 2 hours in a reducing atmosphere composed of H ₂ —N ₂ —H ₂ O gas, a sintered laminate (a laminate in which an internal electrode layer containing Ni is formed) is obtained.

Finally, a Cu paste containing glass frit is applied to both end faces of the laminate obtained as described above, and baked at a temperature of 800 ° C. in an N ₂ atmosphere, and Ni plating and Sn plating are applied to the surface. As a result, an external electrode electrically connected to the internal electrode layer is formed to obtain a multilayer ceramic capacitor.

3. Experimental Examples Hereinafter, Experimental Examples 1 and 2 conducted by the inventors in order to confirm the effects of the present invention will be described. In Experimental Examples 1 and 2, samples of Examples 1 to 27 and Comparative Examples 1 to 13 were prepared according to the method for manufacturing a multilayer ceramic capacitor described above, and the respective high temperature load lifetimes were evaluated.

(Examples and Comparative Examples)
The specifications of Examples 1-27 and Comparative Examples 1-13 are as follows. Each numerical value is an actual measurement value.
T-direction dimension: 1.25 mm (including a pair of external electrodes)
Dimensions in the W direction: 1.25mm (same as above)
L direction dimension: 2.0mm (same as above)
Thickness per layer of ceramic layer: average 3.0μm
Thickness per internal electrode layer: 0.6 μm on average
Number of laminated effective ceramic layers: 300 layers Area of opposing portions per layer of effective ceramic layers: 1.6 mm ^{2 on} average

(Method of measuring the thickness of the ceramic layer)
The thickness per ceramic layer was measured as follows. FIG. 3 is a schematic diagram for explaining a method of measuring the thickness of the ceramic layer provided in the multilayer ceramic capacitor according to one embodiment of the present invention. In FIG. 3, the description of the first and second external electrodes 50a and 50b is omitted. First, five each of Examples 1 to 27 and Comparative Examples 1 to 13 (multilayer ceramic capacitor 10) were prepared. Next, the surface composed of the L direction and the T direction (hereinafter referred to as “LT surface”) of the multilayer ceramic capacitor 10 was polished using a polishing machine until the dimension in the W direction became about ½. Further, in order to eliminate sagging of the first and second internal electrode layers 40a and 40b, the polished LT surface was processed by ion milling. Then, on the polished LT surface, a reference line B extending substantially orthogonally to the first and second internal electrode layers 40a and 40b at a position about ½ of the L direction (that is, approximately the center of the L direction is the T direction). The center line indicated by the alternate long and short dash line in FIG. Next, in the reference line B and the vicinity thereof, the region where the first and second internal electrode layers 40a and 40b are stacked is divided into three equal parts in the T direction to form an upper region 62, an intermediate region 64, and a lower region 66. . Further, in each of the upper region 62, the intermediate region 64, and the lower region 66, five ceramic layers 30 were randomly selected, and the thickness of each of the five layers on the reference line B was measured with a scanning electron microscope (SEM). That is, the total number of measurement locations is 5 multilayer ceramic capacitors × 3 regions × 5 ceramic layers = 75 locations. Finally, the average value of the measured values at 75 locations was determined and used as the thickness per ceramic layer. The thickness per internal electrode layer was also measured by the same method.

  The preparation compositions of Examples 1 to 16 and Comparative Examples 1 to 13 are as shown in Table 1 (Table for Experimental Example 1), respectively. Each of these samples contains one kind of rare earth element R. The preparation compositions of Examples 17 to 27 are as shown in Table 2 (Table for Experimental Example 2), respectively. Each of these samples contains two types of rare earth elements R1 and R2. In addition, content (mol part) of each element shown in Table 1 and 2 is a numerical value when content of Ti is 100 mol part.

  As described in the method for manufacturing the multilayer ceramic capacitor, R is a rare earth element La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. At least one of them. R1 is at least one of Y, Dy, Gd, La, Ho, Er, Sm, and Yb. R2 is at least one of Ce, Pr, Nd, Eu, Tm, Lu, and Tb. M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo, and W.

Moreover, the total Ca content (mole parts) of Examples 1 to 27 and Comparative Examples 1 to 13 shown in Tables 1 and 2 is the content of pre-added Ca (that is, Ca contained in CaCO _{3 as} a starting material). It is a value obtained by adding (mol part) and the content (mol part) of post-added Ca (that is, Ca contained in the additive component CaCO ₃ ). That is, the content of pre-added Ca is a value obtained by subtracting the content of post-added Ca from the total Ca content shown in Tables 1 and 2. Here, Examples 1 to 14 and 17 to 27 and Comparative Examples 1 to 11 (that is, all samples except Examples 15 and 16 and Comparative Examples 12 and 13) have a content of post-added Ca of 0.00. The mole part. That is, these samples were prepared by mixing CaCO ₃ with only pre-added Ca. On the other hand, in Examples 15 and 16, the content of post-added Ca is 5.00 mol parts and 0.05 mol parts, respectively. That is, these samples were prepared by adding CaCO ₃ to the pre-added Ca and performing the post-added Ca. In Comparative Examples 12 and 13, the total Ca content and the post-added Ca content are the same. In other words, Comparative Examples 12 and 13 were prepared by mixing CaCO ₃ not with pre-added Ca but only with post-added Ca. Since Comparative Examples 12 and 13 were produced in this manner, Ca was not contained in the core portion of the crystal particles.

In the preparation of each sample (Examples 1 to 27 and Comparative Examples 1 to 13), the average particle diameters of barium titanate and barium calcium titanate obtained by mixing the starting materials and heat-treating were 0.00. It was 15 μm. Moreover, the barium titanate and the barium calcium titanate which are the main components of each sample were produced from the above starting materials by a solid phase synthesis method. In the production of the laminate of each sample, the oxygen partial pressure in the reducing atmosphere made of H ₂ —N ₂ —H ₂ O gas when firing the raw laminate was 10 ⁻¹⁰ MPa. Further, structural analysis of the laminate of each sample by XRD (X-ray diffraction) revealed that the main component had a barium titanate-based perovskite structure.

  Further, the external electrodes of each sample (Examples 1 to 27 and Comparative Examples 1 to 13) were removed by polishing, and the obtained laminate was dissolved to form a solution. When this solution was analyzed by ICP, an internal electrode layer was obtained. It was confirmed that the composition was almost the same as the preparation composition shown in Tables 1 and 2 except for Ni which is a component of. That is, it can be said that the content (mole part) of each element shown in Tables 1 and 2 is the content in a solution obtained by dissolving the laminate with a solvent.

In addition, the ceramic layers of Examples 1 to 27 and Comparative Examples 1 to 11 were randomly thinned at 10 locations, and the core portion of the crystal particles using STEM-EDS (transmission electron microscope-energy dispersive X-ray analysis). When (center part) (10 measurement places) was observed, Ca was detected from the core part of the crystal grain in any measurement place. On the other hand, in the ceramic layers of Comparative Examples 12 and 13, Ca was not detected from the core portion of the crystal particles. Note that “JEM-2200FS” manufactured by JEOL Ltd. was used as the STEM, and the acceleration voltage was 200 kV. As the detector EDS, “JED-2300T” manufactured by JEOL Ltd. is used, and an SDD detector having a diameter of 60 mm ² is used. As the EDS system, “Noran System 7” manufactured by Thermo Fisher Scientific Co., Ltd. was used.

  In addition, Comparative Examples 1 and 2 do not satisfy the condition of the present invention that the total Ca content is 0.10 mol part or more and 15.00 mol part or less. Moreover, Comparative Examples 3-5 do not satisfy | fill the conditions of this invention that Mg content is 0.0010 mol part or more and 0.0097 mol part or less. Further, Comparative Examples 6 and 7 do not satisfy the condition of the present invention that the R content is 0.50 mol part or more and 4.00 mol part or less. Further, Comparative Examples 8 and 9 do not satisfy the condition of the present invention that the M content is 0.10 mol part or more and 2.00 mol part or less. Further, Comparative Examples 10 and 11 do not satisfy the condition of the present invention that the Si content is 0.50 mol part or more and 2.00 mol part or less. Further, Comparative Examples 12 and 13 do not satisfy the condition of the present invention that Ca is contained in the core part of the crystal grains because the pre-added Ca is 0.00 mol part.

(Evaluation method)
100 pieces of each sample (Examples 1 to 27 and Comparative Examples 1 to 13) were prepared, a voltage of 16 V was applied to each of them at a temperature of 125 ° C., and the change in insulation resistance with time was observed. A sample having an insulation resistance of 0.1 MΩ or less was regarded as defective.

  In Experimental Example 1, for each sample (Examples 1 to 16 and Comparative Examples 1 to 13) in which the rare earth element contained is one type (R), by checking the number of defects 1000 hours after the start of the test, It was used as an index for evaluating the high temperature load life.

  In Experimental Example 2, for each sample (Examples 17 to 27) containing two types of rare earth elements (R1 and R2), by checking the number of defects 1000 hours and 2000 hours after the start of the test, It was used as an index of high temperature load life.

(Evaluation results)
Table 1 shows the evaluation results and preparation compositions of Experimental Example 1.

As shown in Table 1, in all of Examples 1 to 16, the number of defects after 1000 hours (after h) was zero. On the other hand, in Comparative Examples 1 to 13, there were 5 to 70 failures after 1000 hours. From this evaluation result, it was confirmed that the high temperature load life was improved by setting the ceramic layer to the above-described preparation composition of the present invention. The reason why the high temperature load life is improved in this manner is that the Mg content (mole part) is extremely small compared to the prior art, so that no Ni-Mg segregation phase is generated and the Mg content is low. This is probably because elements other than Mg (Ca, R, M, and Si) suppress adverse effects such as abnormal grain growth. The number of defects in Comparative Examples 12 and 13 was particularly large, 51 and 70, respectively. This is presumably because, in Comparative Examples 12 and 13, Ca was not contained in the core of the crystal particles because CaCO ₃ was not included in the starting material when the ceramic material was produced. Thereby, in Comparative Examples 12 and 13, since the solid solution of the additive component is not promoted, the effect of suppressing the movement of oxygen vacancies is not sufficiently exhibited, and it is presumed that the high temperature load life is reduced.

  Table 2 shows the evaluation results and preparation compositions of Experimental Example 2.

  As shown in Table 2, in Examples 17 to 25, all of the defects after 1000 hours (after h) and 2000 hours were zero. From this evaluation result, it was confirmed that when two kinds of rare earth elements R1 and R2 are contained and the value of the molar part of R1 / the molar part of R2 is 4.0 or more, the high temperature load life is further improved. . In Examples 26 and 27, the number of defects after 1000 hours (after h) was zero, and the number of defects after 2000 hours was five. That is, since Example 26 does not contain an element designated as R1, since Example 27 has a value of the molar part of R1 / the molar part of R2 is not 4.0 or more, it is compared with Examples 1-16. The high temperature load life was not improved. However, also in Examples 26 and 27, the high temperature load life was improved as compared with Comparative Examples 1 to 13 and the prior art.

  The effect of the present invention increases as the size of the multilayer ceramic capacitor decreases. In particular, it has been confirmed that the effect is remarkable in a size of 0.6 mm in the L direction × 0.3 mm in the W direction × 0.3 mm in the T direction.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is carried out within the range of the summary.

DESCRIPTION OF SYMBOLS 10 Multilayer ceramic capacitor 20 Laminated body 22a 1st main surface 22b 2nd main surface 24a 1st side surface 24b 2nd side surface 26a 1st end surface 26b 2nd end surface 30 Ceramic layer 40a 1st internal electrode layer 40b Second internal electrode layer 50a First external electrode 50b Second external electrode 62 Upper region 64 Intermediate region 66 Lower region B Reference line

Claims (9)

A laminate formed by laminating a plurality of ceramic layers containing crystal grains having a perovskite structure and a plurality of internal electrode layers, and electrically connected to the internal electrode layer on the surface of the laminate A multilayer ceramic capacitor comprising a pair of formed external electrodes,
The ceramic layer is
A perovskite compound containing Ba, Ca and Ti;
Mg,
R (R is at least one of rare earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y);
M (M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo and W);
Containing Si,
When the Ti content is 100 mole parts,
Ca is 0.10 mol part or more and 15.00 mol part or less,
Mg is 0.0010 mol part or more and 0.0097 mol part or less,
R is 0.50 mol part or more and 4.00 mol part or less,
M is 0.10 mol part or more and 2.00 mol part or less,
Si is contained in an amount of 0.50 mol part or more and 2.00 mol part or less,
A multilayer ceramic capacitor characterized in that Ca is contained in the core of the crystal grains. A laminate formed by laminating a plurality of ceramic layers containing crystal grains having a perovskite structure and a plurality of internal electrode layers, and electrically connected to the internal electrode layer on the surface of the laminate A multilayer ceramic capacitor comprising a pair of formed external electrodes,
The laminate is
A perovskite compound containing Ba, Ca and Ti;
Mg,
R (R is at least one of rare earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y);
M (M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo and W);
Containing Si,
When the Ti content is 100 mole parts,
Ca is 0.10 mol part or more and 15.00 mol part or less,
Mg is 0.0010 mol part or more and 0.0097 mol part or less,
R is 0.50 mol part or more and 4.00 mol part or less,
M is 0.10 mol part or more and 2.00 mol part or less,
Si is contained in an amount of 0.50 mol part or more and 2.00 mol part or less,
A multilayer ceramic capacitor characterized in that Ca is contained in the core part of the crystal grains. A laminate formed by laminating a plurality of ceramic layers containing crystal grains having a perovskite structure and a plurality of internal electrode layers, and electrically connected to the internal electrode layer on the surface of the laminate A multilayer ceramic capacitor comprising a pair of formed external electrodes,
The laminate is
A perovskite compound containing Ba, Ca and Ti;
Mg,
R (R is at least one of rare earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y);
M (M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo and W);
Containing Si,
When the content of Ti when the laminate was dissolved with a solvent was 100 mol parts,
Ca is 0.10 mol part or more and 15.00 mol part or less,
Mg is 0.0010 mol part or more and 0.0097 mol part or less,
R is 0.50 mol part or more and 4.00 mol part or less,
M is 0.10 mol part or more and 2.00 mol part or less,
Si is contained in an amount of 0.50 mol part or more and 2.00 mol part or less,
A multilayer ceramic capacitor characterized in that Ca is contained in the core of the crystal grains.   The multilayer ceramic capacitor according to claim 1, wherein R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm, and Yb). R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb) and R2 (R2 is a rare earth element Ce, Pr, Nd, Eu, Tm, And at least one of Lu and Tb),
The multilayer ceramic capacitor according to any one of claims 1 to 3, wherein a value of a molar part of R1 / a molar part of R2 is 4.0 or more. A powder composed mainly of a perovskite type compound containing Ba, Ca and Ti, a Mg compound, and a compound of R (R is a rare earth element La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) and a compound of M (M is at least one of Zr, Mn, Co, Fe, Cr, Cu, Al, V, Mo and W) And a step of obtaining a ceramic slurry by mixing the Si compound,
Obtaining a ceramic green sheet by sheet-forming the ceramic slurry;
A step of forming a laminated body block by laminating the ceramic green sheet and a ceramic green sheet having an internal electrode pattern formed on the ceramic green sheet, and obtaining a raw laminated body by cutting the laminated body block When,
By firing the raw laminate to obtain a laminate in which an internal electrode layer containing Ni is formed,
When the content of Ti in the ceramic slurry is 100 mole parts,
Ca is 0.10 mol part or more and 15.00 mol part or less,
Mg is 0.0010 mol part or more and 0.0097 mol part or less,
R is 0.50 mol part or more and 4.00 mol part or less,
M is 0.10 mol part or more and 2.00 mol part or less,
Si is contained 0.50 mol part or more and 2.00 mol part or less, The manufacturing method of the multilayer ceramic capacitor characterized by the above-mentioned.   The method for producing a multilayer ceramic capacitor according to claim 6, wherein in the step of obtaining the ceramic slurry, a Ca compound is further mixed with a powder containing a perovskite compound containing Ba, Ca, and Ti as a main component.   The method for producing a multilayer ceramic capacitor according to claim 6 or 7, wherein R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm, and Yb). R is R1 (R1 is at least one of rare earth elements Y, Dy, Gd, La, Ho, Er, Sm and Yb) and R2 (R2 is a rare earth element Ce, Pr, Nd, Eu, Tm, And at least one of Lu and Tb),
8. The method for manufacturing a multilayer ceramic capacitor according to claim 6, wherein a value of a mole part of R1 / a mole part of R2 is 4.0 or more.