Electronic Components

Abstract

To provide an electronic component in which the temperature dependence of a resistance value is improved.SOLUTION: An electronic component includes an element assembly including at least two internal electrode layers and a dielectric layer stacked between the internal electrode layers. A Ni oxide particle exists at a border between the internal electrode layer and the dielectric layer. The dielectric layer is in contact with the adjacent internal electrode layers at a first border and a second border. The dielectric layer includes a first dielectric large particle in contact with the Ni oxide particle existing at the first border and in contact with the internal electrode layer at the second border, and a second dielectric large particle in contact with the internal electrode layer at the first border and in contact with the Ni oxide particle existing at the second border.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an electronic component having a dielectric layer and an internal electrode layer. [Background technology]

[0002] Ceramic capacitors having dielectric layers and internal electrode layers are widely used in various electronic circuits, power supply circuits, etc. These ceramic capacitors are required to have stable characteristics such as capacitance that do not fluctuate with temperature changes. For example, Patent Document 1 discloses a multilayer ceramic capacitor in which dielectric layers containing dielectric particles with a core-shell structure are laminated, and discloses that this multilayer ceramic capacitor can suppress fluctuations in capacitance due to temperature.

[0003] Not only capacitance but also resistance tends to decrease as the temperature increases, so there is a need to suppress temperature-related fluctuations in resistance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-305844 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the exemplary embodiments of the present disclosure is to provide an electronic component with improved temperature dependency of resistance. [Means for solving the problem]

[0006] In order to achieve the above object, an electronic component according to a first aspect of the present disclosure comprises: An element body including at least two internal electrode layers and a dielectric layer laminated between the internal electrode layers, Ni oxide particles are present at the boundary between the internal electrode layer and the dielectric layer, The dielectric layer is the internal electrode layer is in contact with the adjacent internal electrode layer at a first boundary and a second boundary, The dielectric layer includes a first dielectric large particle that contacts the Ni oxide particle at the first boundary and contacts the internal electrode layer at the second boundary, and a second dielectric large particle that contacts the internal electrode layer at the first boundary and contacts the Ni oxide particle at the second boundary.

[0007] The electronic component according to the first aspect has the above-described characteristics, and thus it is possible to suppress fluctuations in resistance value due to temperature. For example, when the resistance value of the electronic component at 20°C is R 20 The resistance of the electronic component at 85°C is R 85 As, R 20 / R 85 can be suppressed to 2.0 or less.

[0008] Preferably, the Ni oxide particles include first Ni oxide particles that are in contact with both of the two adjacent dielectric layers via the internal electrode layers.

[0009] the element body includes a plurality of internal electrode layers and a plurality of dielectric layers, Preferably, each of the internal electrode layers is in contact with an average of two or more of the Ni oxide particles in one cross section of the element body.

[0010] the element body includes a plurality of internal electrode layers and a plurality of dielectric layers, Preferably, the average number of the Ni oxide particles in contact with the internal electrode layers per unit length is 0.002 particles / μm or more.

[0011] the element body includes a plurality of internal electrode layers and a plurality of dielectric layers, The dielectric layer may include a third dielectric large particle in contact with both the Ni oxide particle at the first boundary and the Ni oxide particle at the second boundary, Preferably, the average number of the third dielectric large particles contained in the dielectric layer per unit length is 0 or more and 0.0003 particles / μm or less.

[0012] An electronic component according to a second aspect of the present disclosure has an element body including at least two internal electrode layers and a dielectric layer laminated between the internal electrode layers, p-type semiconductor particles are present at the boundary between the internal electrode layer and the dielectric layer, The dielectric layer is the internal electrode layer is in contact with the adjacent internal electrode layer at a first boundary and a second boundary, The dielectric layer includes a first dielectric large particle that contacts the p-type semiconductor particle at the first boundary and contacts the internal electrode layer at the second boundary, and a second dielectric large particle that contacts the internal electrode layer at the first boundary and contacts the p-type semiconductor particle at the second boundary.

[0013] The electronic component according to the second aspect has the above-mentioned characteristics, and thus it is possible to suppress fluctuations in resistance value due to temperature. For example, when the resistance value of the electronic component at 20°C is R 20 The resistance of the electronic component at 85°C is R 85 As, R 20 / R 85 can be suppressed to 2.0 or less. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing a cross section of an electronic component according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is an enlarged schematic diagram of a cross section of the element body shown in FIG. [Figure 3A] FIG. 3A is a schematic diagram showing an enlarged portion of the boundary between the dielectric layer and the internal electrode layer. [Figure 3B] FIG. 3B is a conceptual diagram showing the circuitry associated with the structure shown in FIG. 3A. [Figure 3C] FIG. 3C is a conceptual diagram showing a circuit related to the structure shown in FIG. 3A. [Figure 4A]FIG. 4A is a schematic diagram showing an enlarged portion of the boundary between the dielectric layer and the internal electrode layer. [Figure 4B] FIG. 4B is a conceptual diagram showing an equivalent circuit related to the structure shown in FIG. 4A. [Figure 5] FIG. 5 is a schematic diagram showing an enlarged portion of the boundary between the dielectric layer and the internal electrode layer. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0016] As shown in FIG. 1, the multilayer ceramic electronic component 2 of this preferred embodiment includes an element body 4 and a pair of external electrodes 6 formed on the outer surface of the element body 4.

[0017] The element body 4 shown in FIG. 1 is typically shaped like a rectangular parallelepiped, with two end faces 4a, 4b along the YZ plane and four side faces 4c connecting the two end faces 4a, 4b. However, the shape of the element body 4 is not particularly limited and may be an elliptical cylinder, a circular cylinder, a rectangular column, or the like. The outer dimensions of the element body 4 are also not particularly limited. For example, the length L0 in the X-axis direction may be 0.2 mm to 5.7 mm, the width W0 in the Y-axis direction may be 0.1 mm to 5.0 mm, and the height T0 in the Z-axis direction may be 0.1 mm to 3.0 mm. In this embodiment, the X-axis, Y-axis, and Z-axis are perpendicular to each other.

[0018] The multilayer ceramic electronic component 2 has a pair of external electrodes 6: a first external electrode 6a in contact with one end face 4a and a second external electrode 6b in contact with the other end face 4b. The first external electrode 6a and the second external electrode 6b are electrically insulated so as not to contact each other in the X-axis direction. Each external electrode 6 need only be conductive, and the specifications (material, structure, thickness, etc.) of each external electrode 6 are not particularly limited. Each external electrode 6 may include a baked electrode layer, a resin electrode layer, a plated electrode layer, etc., and may have a single-layer structure or a multilayer structure including multiple electrode layers. For example, each external electrode 6 may have a three-layer structure (layered in the order listed) of a baked electrode layer containing Cu, a Ni-plated layer, and a Sn-plated layer.

[0019] The element body 4 has a capacitance region 40 and an exterior region 41 located outside the capacitance region 40. The capacitance region 40 has dielectric layers 10 and internal electrode layers 20 that are substantially parallel to a plane including the X-axis and Y-axis, and inside the capacitance region 40, the dielectric layers 10 and internal electrode layers 20 are alternately stacked along the Z-axis. Here, "substantially parallel" means that most of the portions are parallel, but there may be some portions that are not parallel, and both the dielectric layers 10 and the internal electrode layers 20 may have some irregularities or be tilted.

[0020] The internal electrode layers 20 in the capacitive region 40 can be classified into first internal electrode layers 21 and second internal electrode layers 22. A portion of the edge of each first internal electrode layer 21 is exposed at one end face 4a, and each first internal electrode layer 21 is electrically connected to a first external electrode 6a. A portion of the edge of each second internal electrode layer 22 is exposed at the other end face 4b, and each second internal electrode layer 22 is electrically connected to a second external electrode 6b.

[0021] Each dielectric layer 10 in the capacitance region 40 is laminated between the first internal electrode layer 21 and the second internal electrode layer 22. In other words, the first internal electrode layer 21 and the second internal electrode layer 22 are insulated from each other via the dielectric layer 10. In this way, the capacitance region 40 has a structure in which the first internal electrode layer 21, the dielectric layer 10, and the second internal electrode layer 22 are repeatedly laminated in the order described above. When a voltage is applied to the multilayer ceramic electronic component 2, the first external electrode 6a and the second external electrode 6b have polarities opposite to each other, and a voltage can be applied to each dielectric layer 10 in the capacitance region 40.

[0022] In this embodiment, the bonding interface between the dielectric layer 10 and the first internal electrode layer 21 will be referred to as a first boundary 31, and the bonding boundary between the dielectric layer 10 and the second internal electrode layer 22 will be referred to as a second boundary 32. In other words, each dielectric layer 10 contacts the first internal electrode layer 21 at the first boundary 31, and contacts the second internal electrode layer 22 at the second boundary 32. In the description of this embodiment, when the term "internal electrode layer 20" is used as a general term without distinguishing between the first internal electrode layer 21 and the second internal electrode layer 22, the description using the term "internal electrode layer 20" means that it relates commonly to the first internal electrode layer 21 and the second internal electrode layer 22.

[0023] The exterior region 41 is laminated outside the capacitive region 40 in the Z-axis direction and covers the top and bottom surfaces of the capacitive region 40. The exterior region 41 may also be present outside the capacitive region 40 in the Y-axis direction. That is, the side surface of the capacitive region 40 intersecting the Y-axis may be covered with the exterior region 41 that does not include the internal electrode layer 20. The material and thickness of the exterior region 41 are not particularly limited. For example, the exterior region 41 may contain a dielectric compound having the same composition as the dielectric layer 10, or may contain a glass component together with the dielectric compound. In principle, the exterior region 41 is a region that does not include the internal electrode layer 20, but may include a dummy electrode that does not contribute to capacitance.

[0024] The dielectric layer 10 contains a dielectric compound as a main component. The main component of the dielectric layer 10 means a component that occupies 80 mol % or more of the dielectric layer 10, and the material of the dielectric compound as the main component is not particularly limited. For example, the main component of the dielectric layer 10 may be a dielectric compound with a perovskite structure such as BaTiO3, Ba(Ti,Zr)O3, (Ba,Ca)TiO3, (Ba,Ca)(Ti,Zr)O3, (Ca,Sr)TiO3, (Ca,Sr)ZrO3, (Ca,Sr)(Zr,Ti)O3, or (K,Na)NbO3, or Ba3ZrNb4O 15 , Ba3TiNb4O 15 , (K,Na)Sr2Nb5O 15 The dielectric compound may be selected from tungsten bronze structure compounds such as:

[0025] Furthermore, the dielectric layer 10 may contain one or more subcomponents in addition to the main component. The type and content of the subcomponents contained in the dielectric layer 10 are not particularly limited. For example, the dielectric layer 10 may contain, as the subcomponent, a Si compound, an Al compound, a Mn compound, an Mg compound, a Cr compound, a Ni compound, a compound containing a rare earth element, a Li compound, a B compound, or a V compound. The main component and subcomponents of the dielectric layer 10 can be identified by component analysis using a wavelength dispersive X-ray spectrometer (WDS), an energy dispersive X-ray spectrometer (EDS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), or the like.

[0026] The average thickness T of each dielectric layer 10 DL is preferably 1.7 μm or less, and more preferably 0.17 μm or more and 0.86 μm or less. The capacitance region 40 only needs to include at least one dielectric layer 10, and the number of dielectric layers 10 stacked in the capacitance region 40 is not particularly limited. For example, the capacitance region 40 preferably includes 20 or more dielectric layers 10, and more preferably includes 50 or more dielectric layers 10. The average thickness T DLcan be calculated by observing the cross section of the element body 4 using a metallurgical microscope or an electron microscope. For example, it is preferable to analyze five or more dielectric layers 10, and the thickness of each of the analyzed dielectric layers 10 is measured at at least 30 points to calculate the average thickness T DL It is preferable to calculate

[0027] Each dielectric layer 10 includes a plurality of dielectric particles 11 and grain boundaries 17 that are interfaces between adjacent dielectric particles 11. The dielectric particles 11 are crystal grains that include the main component of the dielectric layer 10, and the dielectric particles 11 in the dielectric layer 10 can be analyzed by observing a cross section of the element body 4 using an electron microscope such as a scanning transmission electron microscope (STEM) or a scanning electron microscope (SEM). The dielectric particles 11 may contain a solid solution of a minor component of the dielectric layer 10, or the dielectric particles 11 may have a core-shell structure due to the solid solution of the minor component. The dielectric layer 10 may also include a segregation phase in which the concentration of a predetermined element is higher than that of the dielectric particles 11.

[0028] Average particle size d of the dielectric particles 11 DP is preferably 0.05 μm or more, and more preferably 0.1 μm or more and 1 μm or less. DP Average thickness T of the dielectric layer 10 DL The ratio (T DL / d DP ) is preferably 1.5 or less, and more preferably 1 or less. The average particle size d DP is the arithmetic mean value of the equivalent circle diameters of the dielectric particles 11. For example, it is preferable to observe the cross section of the element body 4 and analyze five or more dielectric layers 10, and measure the equivalent circle diameters of at least 50 dielectric particles 11 to determine the average particle size d DP It is preferable to calculate

[0029] When a cross section along the thickness direction (Z-axis direction) of the dielectric layer 10 is analyzed, the dielectric particles 11 can be classified into large particles 13 and small particles 15. In other words, in the description of this embodiment, the term "dielectric particles 11" is a general term for the large particles 13 and the small particles 12, and the dielectric particles 11 include the large particles 13 and the small particles 12.

[0030] The large particles 13 are dielectric particles 11 that contact both the first boundary 31 (the junction boundary between the dielectric layer 10 and the first internal electrode layer 21) and the second boundary 32 (the junction boundary between the dielectric layer 10 and the second internal electrode layer 22). In other words, the large particles 13 are dielectric particles 11 that appear on both the upper and lower surfaces of the dielectric layer 10 that contains the large particles 13. The length of the large particles 13 in the Z-axis direction is approximately equal to the thickness of the dielectric layer 10 at the location where the large particles 13 are present. On the other hand, the small particles 15 are dielectric particles 11 other than the large particles 13. In other words, the small particles 15 include dielectric particles 11 that contact only either the first boundary 31 or the second boundary 32, and dielectric particles 11 that contact neither the first boundary 31 nor the second boundary 32.

[0031] The average number of large particles 13 contained in dielectric layer 10 per unit length is preferably 0.05 particles / μm or more, and more preferably 0.1 particles / μm or more. The upper limit of the average number of large particles 13 is not particularly limited and may be, for example, 3 particles / μm or less.

[0032] The average number of the large particles 13 described above is expressed as ND / LD, where LD is the total length of the dielectric layer 10 observed in the cross section of the capacitance region 40, and ND is the number of large particles 13 contained in the dielectric layer 10 of the total length LD. When calculating ND / LD, it is preferable to analyze five or more dielectric layers 10, and it is preferable that the total length LD of the dielectric layers 10 is 30 μm or more. It is also preferable to set the analysis field so that the edge of the analysis field is approximately parallel to the dielectric layer 10. In this case, the length of the edge of the analysis field that is approximately parallel to the dielectric layer 10 can be considered as the length of the dielectric layer 10 in the analysis field. For example, the length of each dielectric layer 10 in FIG. 2 is expressed as the length L in the X-axis direction of the analysis field. XIt can be considered as such.

[0033] Each internal electrode layer 20 is conductive and contains a metal component. The composition of the internal electrode layer 20 is not particularly limited, and for example, the internal electrode layer 20 may contain at least one metal component selected from Ni, Cu, Ag, Pd, Au, and Pt. When the main component of the dielectric layer 10 is resistant to reduction, the metal component of the internal electrode layer 20 is preferably pure Ni or a Ni alloy containing 85 wt% or more of Ni. In this case, the Ni alloy may contain subcomponents such as Cu, Cr, and Mn. The metal component of the internal electrode layer 20 can be identified by component analysis using WDS, EDS, LA-ICP-MS, etc.

[0034] The internal electrode layer 20 may contain, as a common material, particles of a dielectric compound having the same composition as the main component of the dielectric layer 10. The internal electrode layer 20 may also contain a small amount (for example, about 0.1 mass % or less) of a non-metallic element such as S or P, and may also contain voids. When the internal electrode layer 20 is observed in a cross section as shown in Figure 1 or Figure 2, there may be some portions where the internal electrode layer 20 appears to be partially discontinued.

[0035] The internal electrode layers 20 are stacked between the dielectric layers 10 in the Z-axis direction, and the number of stacked internal electrode layers 20 in the capacitance region 40 is determined according to the number of stacked dielectric layers 10. In addition, the average thickness T EL is not particularly limited, and is preferably 3 μm or less, and more preferably 0.2 μm or more and 1 μm or less. EL can be calculated by observing the cross section of the element body 4 using a metallurgical microscope or an electron microscope. For example, it is preferable to analyze five or more internal electrode layers 20, and the thickness of each internal electrode layer 20 to be analyzed is measured at at least 30 points, and the average thickness T EL It is preferable to calculate

[0036] When a cross section of the internal electrode layer 20 is analyzed by a combination of STEM or SEM and EDS or WDS, it can be confirmed that the internal electrode layer 20 contains crystal grains of a metal component (hereinafter referred to as metal crystals). The average grain size d of the metal crystals contained in each internal electrode layer 20 is M is not particularly limited, and is preferably 1 μm or less, and more preferably 0.03 μm or more and 0.8 μm or less. M is the arithmetic mean value of the circle-equivalent diameter of the metal crystals. For example, it is preferable to observe the cross section of the element body 4 and analyze five or more internal electrode layers 20, and measure the circle-equivalent diameters of at least 50 metal crystals contained in each of the analyzed internal electrode layers 20 to determine the average particle size d M It is preferable to calculate

[0037] In cross-sectional analysis using a combination of STEM or SEM and EDS or WDS, the internal electrode layers 20 included in the analysis field of view may be classified into first internal electrode layers 21 and second internal electrode layers 22 in the following procedure. First, the internal electrode layers 20 observed in the analysis field of view are assigned serial integer numbers in order from the lower or upper side of the analysis field of view. Then, the odd-numbered internal electrode layers 20 may be defined as the first internal electrode layers 21, and the even-numbered internal electrode layers 20 may be defined as the second internal electrode layers 22.

[0038] As shown in FIG. 2, the capacitance region 40 contains Ni oxide particles 30. The Ni oxide particles 30 mainly contain NiO and may contain trace amounts of elements contained in the dielectric layer 10 and the internal electrode layer 20. The content of components other than NiO in the Ni oxide particles 30 is not particularly limited, but the total content of Ni and O in the Ni oxide particles 30 is preferably 80 mol % or more. The Ni oxide particles 30 in the capacitance region 40 can be identified by performing a mapping analysis on a cross section of the element body 4 as shown in FIG. 2. For example, a mapping image of Ni and a mapping image of O (oxygen) are taken, and a region having a higher Ni concentration than the dielectric layer 10 and a higher O concentration than the internal electrode layer 20 can be identified as the Ni oxide particle 30.

[0039] The Ni oxide particles 30 in the capacitance region 40 are present at the boundaries (31, 32) between the dielectric layer 10 and the internal electrode layer 20. More specifically, the capacitance region 40 includes Ni oxide particles 30 present at a first boundary 31 between the dielectric layer 10 and the first internal electrode layer 21, and Ni oxide particles 30 present at a second boundary 32 between the dielectric layer 10 and the second internal electrode layer 22.

[0040] Here, "being present at the boundaries (31, 32) between the dielectric layer 10 and the internal electrode layer 20" more specifically means that the Ni oxide particles 30 are in contact with both the dielectric particles 11 of the dielectric layer 10 and the metal components of the internal electrode layer 20. The Ni oxide particles 30 may be present so as to penetrate into the internal electrode layer 20 from the boundaries (31, 32), or may be present so as to penetrate into the dielectric layer 10 from the boundaries (31, 32).

[0041] The capacitance region 40 may contain Ni oxide particles 30 present in locations other than the boundaries (31, 32) between the dielectric layer 10 and the internal electrode layer 20. For example, the capacitance region 40 may contain Ni oxide particles 30 that are contained in the internal electrode layer 20 and are not in contact with the dielectric layer 10, and Ni oxide particles 30 that are contained in the dielectric layer 10 and are not in contact with the internal electrode layer 20.

[0042] To describe the Ni oxide particles 30 in more detail, at the first boundary 31, there are at least Ni oxide particles 30 in contact with the large particles 13 of the dielectric layer 10, and there may also be Ni oxide particles 30 that are not in contact with the large particles 13 but are in contact with the small particles 15. Similarly, at the second boundary 32, there are at least Ni oxide particles 30 in contact with the large particles 13 of the dielectric layer 10, and there may also be Ni oxide particles 30 that are not in contact with the large particles 13 but are in contact with the small particles 15.

[0043] The large particles 13 observed in the cross section of the dielectric layer 10 can be classified into four types, first large particles 13a to fourth large particles 13d, as shown in Fig. 2. The first large particles 13a are large particles 13 that are in contact with Ni oxide particles 30 at the first boundary 31 and are in contact with the metal component of the second internal electrode layer 22 at the second boundary 32. The second large particles 13b are large particles 13 that are in contact with the metal component of the first internal electrode layer 21 at the first boundary 31 and are in contact with Ni oxide particles 30 at the second boundary 32. The third large particles 13c are large particles 13 that are in contact with both the Ni oxide particles 30 at the first boundary 31 and the Ni oxide particles 30 at the second boundary 32. The fourth large particles 13d are large particles 13 that are not in contact with the Ni oxide particles 30, and are in contact with the metal component of the first internal electrode layer 21 at a first boundary 31, and are in contact with the metal component of the second internal electrode layer 22 at a second boundary 32. The dielectric layer 10 includes at least the first large particles 13a and the second large particles 13b, and may also include the third large particles 13c and the fourth large particles 13d.

[0044] 4A is a schematic diagram showing an enlarged cross section of a portion where the first large particles 13a and the second large particles 13b are present. Where the first large particles 13a are present, a structure is formed in which the metal components of the first internal electrode layers 21, Ni oxide particles 30, the first large particles 13a, and the metal components of the second internal electrode layers 22 are connected in the order shown. Where the second large particles 13b are present, a structure is formed in which the metal components of the first internal electrode layers 21, the second large particles 13b, Ni oxide particles 30, and the metal components of the second internal electrode layers 22 are connected in the order shown. Having the capacitance region 40 of the multilayer ceramic electronic component 2 with the structure shown in FIG. 4A can reduce the temperature dependence of the resistance value. That is, even in a high temperature range (e.g., 85°C or higher), a decrease in the resistance value can be suppressed, and the insulation resistance can be maintained.

[0045] The reason why the temperature dependency of the resistance value can be improved is not entirely clear, but it is thought to be related to the Schottky barrier. Below, a hypothesis regarding the insulation resistance between the internal electrode layers will be explained based on Figures 3A to 4B.

[0046] First, the insulation resistance between the internal electrode layers when the Ni oxide particles 30 are not present will be described. FIG. 3A is a schematic diagram showing an enlarged cross section of a portion where the Ni oxide particles 30 are not present. That is, the cross section of the dielectric layer 10 shown in FIG. 3A shows the presence of fourth large particles 13d and small particles 15. In particular, in the portion where the small particles 15 are present, a structure is formed in which two or more small particles 15 are connected in the thickness direction via grain boundaries 17. In addition, a bonding interface B between the metal component of the internal electrode layer 20 and the dielectric particles 11 exists between the internal electrode layer 20 and the dielectric layer 10. Of the bonding interface B, the portion between the metal component of the first internal electrode layer 21 and the dielectric particles 11 (13, 15) will be referred to as bonding interface B1, and the portion between the metal component of the second internal electrode layer 22 and the dielectric particles 11 (13, 15) will be referred to as bonding interface B2.

[0047] Here, the dielectric compound, which is the main component of the dielectric layer 10, is considered to be an n-type semiconductor that uses free electrons as carriers that carry electric charges. In other words, the dielectric particles 11 are considered to have the properties of n-type semiconductor particles. In this case, it is considered that a Schottky junction between the metal and the n-type semiconductor occurs at all of the junction interfaces B, and it is considered that current flows easily in the direction from the internal electrode layer 20 side toward the dielectric particles 11, but does not flow easily in the direction from the dielectric particles 11 side toward the internal electrode layer 20. Specifically, it is considered that a circuit C1 as shown in FIG. 3B is formed at the location where the fourth large particles 13d are present by a Schottky junction between the metal and the n-type semiconductor.

[0048] In the circuit C1, the Schottky diode SD-n1 corresponds to the junction interface B1, the resistor R1 corresponds to the fourth large particle 13d, and the Schottky diode SD-n2 corresponds to the junction interface B2. In the circuit C1, when a current flows clockwise (i.e., the first internal electrode layer 21 is positive and the second internal electrode layer 22 is negative), the Schottky diode SD-n2 at the junction interface B2 acts as a barrier (Schottky barrier) and prevents the current from flowing. On the other hand, when a current flows counterclockwise (i.e., the first internal electrode layer 21 is negative and the second internal electrode layer 22 is positive), the Schottky diode SD-n1 at the junction interface B1 acts as a barrier (Schottky barrier) and prevents the current from flowing. In other words, in the location where the fourth large particle 13d exists, the insulation resistance between the internal electrode layers is considered to mainly depend on the Schottky barrier at the junction interface B.

[0049] Furthermore, where small particles 15 exist, a double Schottky barrier is thought to be formed at the grain boundary 17 between adjacent small particles, forming a circuit C2 as shown in Figure 3C. Similar to circuit C1, Schottky diodes SD-n1 and SD-n2 in circuit C2 correspond to junction interfaces B1 and B2, respectively. Resistor R1 in circuit C2 corresponds to small particle 15, and the double Schottky barrier DSB corresponds to grain boundary 17. In circuit C2, the double Schottky barrier DSB prevents current flow both clockwise and counterclockwise. In other words, where small particles 15 exist, the insulation resistance between the wall-internal electrode layers is thought to depend primarily on the double Schottky barrier at grain boundary 17.

[0050] As described above, when Ni oxide particles 30 are not present, the Schottky barrier at the bonding interface B and the double Schottky barrier at the grain boundary 17 are thought to contribute to the insulation resistance, but both the Schottky barrier and the double Schottky barrier are highly temperature-dependent. In other words, in conventional multilayer ceramic electronic components that do not contain Ni oxide particles 30, the resistance action of the Schottky barrier and the resistance action of the double Schottky barrier are thought to be reduced in high temperature ranges, resulting in a decrease in insulation resistance.

[0051] On the other hand, where the Ni oxide particles 30 exist, it is considered that a Schottky junction having a polarity direction different from that of the Schottky junction at the junction interface B is formed. As shown in Fig. 4A, when the Ni oxide particles 30 exist between the internal electrode layer 20 and the dielectric layer 10, a junction interface A is formed between the metal component of the internal electrode layer 20 and the Ni oxide particles 30. Of the matching interfaces A, the interface between the metal component of the first internal electrode layer 21 and the Ni oxide particles 30 is referred to as junction interface A1, and the interface between the metal component of the second internal electrode layer 22 and the Ni oxide particles 30 is referred to as junction interface A2.

[0052] Here, NiO is considered to be a p-type semiconductor that uses holes as carriers, which is unusual for an oxide. In other words, the Ni oxide particles 30 are considered to have the properties of p-type semiconductor particles. In this case, a Schottky junction between a metal and a p-type semiconductor is considered to occur at the junction interface A, and current is considered to flow more easily in the direction from the Ni oxide particles 30 toward the internal electrode layer 20, and less easily in the direction from the internal electrode layer 20 toward the Ni oxide particles 30. Specifically, it is considered that an equivalent circuit EC1 shown on the left side of FIG. 4B is formed where the first large particles 13a exist, and an equivalent circuit EC2 shown on the right side of FIG. 4B is formed where the second large particles 13b exist.

[0053] In the equivalent circuit EC1, the Schottky diode SD-p1 corresponds to the junction interface A1, the resistor R1 corresponds to the first large particle 13a, the resistor R2 corresponds to the Ni oxide particle 30, and the Schottky diode SD-n2 corresponds to the junction interface B2. In the equivalent circuit EC2, the Schottky diode SD-n1 corresponds to the junction interface B1, the resistor R1 corresponds to the second large particle 13b, the resistor R2 corresponds to the Ni oxide particle 30, and the Schottky diode SD-p2 corresponds to the junction interface A2. If the direction in which current flows relatively easily is defined as the "forward direction," then in the equivalent circuit EC1, the forward direction is counterclockwise, while in the equivalent circuit EC2, the forward direction is clockwise, opposite to that in the equivalent circuit EC1.

[0054] When a voltage is applied with the first internal electrode layer 21 as the negative electrode and the second internal electrode layer 22 as the positive electrode, the insulation resistance between the internal electrode layers is considered to depend mainly on the resistance of the first large particles 13a in the equivalent circuit EC1. Also, when a voltage is applied with the first internal electrode layer 21 as the positive electrode and the second internal electrode layer 22 as the negative electrode, the insulation resistance between the internal electrode layers is considered to depend mainly on the resistance of the second large particles 13b in the equivalent circuit EC2. In other words, the formation of the two equivalent circuits EC1 and EC2 is considered to suppress the occurrence of Schottky barriers and double Schottky barriers, and as a result, the temperature dependence of the resistance value is considered to be improved.

[0055] The capacitance region 40 of the multilayer ceramic electronic component 2 has a plurality of dielectric layers 10 and internal electrode layers 20, and when a cross section of the capacitance region 40 taken along the Z-axis direction is observed, there may be internal electrode layers 20 that are not in contact with Ni oxide particles 30, and dielectric layers 10 that do not contain the first large particles 13a and the second large particles 13b. However, it is preferable that the Ni oxide particles 30, the first large particles 13a, and the second large particles 13b are present in the following proportions, respectively.

[0056] Each internal electrode layer 20 is preferably in contact with an average of two or more Ni oxide particles 30, and more preferably in contact with an average of two to ten Ni oxide particles 30, in a cross section along the Z-axis direction of the capacitance region 40. That is, in a cross section of the element body 4 as shown in FIG. 1 , the average number ANP of Ni oxide particles 30 in contact with each internal electrode layer 20 per layer is preferably two or more, and more preferably two to ten. By satisfying 2≦ANP, the temperature dependence of the resistance value can be further reduced, and by satisfying 2≦ANP≦10, the temperature dependence of the resistance value can be further reduced while ensuring sufficient capacitance.

[0057] The above-mentioned average number ANP is preferably analyzed in a cross section where both ends in the X-axis direction of the internal electrode layer 20 can be observed, as shown in Fig. 1. In such a cross section, it is preferable to analyze five or more internal electrode layers 20 having a length L1, and the average number ANP can be calculated by counting the number of Ni oxide particles 30 in contact with each internal electrode layer 20 of the length L1.

[0058] Each dielectric layer 10 preferably includes, in a cross section along the Z-axis direction of the capacitance region 40, one or more first large particles 13a and one or more second large particles 13b on average. That is, in a cross section of the element body 4 as shown in FIG. 1 , if the average number of first large particles 13a included in each dielectric layer 10 is AND1 and the average number of second large particles 13b included in each dielectric layer 10 is AND2, then both AND1 and AND2 are preferably one or more. Furthermore, the average total number AND0 of the first large particles 13a and the second large particles 13b included in each dielectric layer 10 is preferably two or more. Having both AND1 and AND2 at one or more can further reduce the temperature dependence of the resistance value, and having AND0 at four or more can further reduce the temperature dependence of the resistance value while ensuring sufficient capacitance.

[0059] AND0, AND1, and AND2 can be calculated in the same way as ANP. It is preferable to analyze five or more dielectric layers 10 of length L0 in a cross section such as that shown in Figure 1, and calculate AND0, AND1, and AND2 by measuring the number of first large particles 13a and the number of second large particles 13b contained in each dielectric layer 10 of length L0.

[0060] The total length of the internal electrode layers 20 observed in the cross section of the capacitance region 40 as shown in FIG. 2 is defined as LE. The number of Ni oxide particles 30 in contact with the internal electrode layers 20 within the range of the total length LE is defined as NP0. The average number of Ni oxide particles 30 in contact with the internal electrode layers 20 per unit length can be expressed as the ratio of NP0 to LE, where NP0 / LE is preferably 0.002 particles / μm or more, and more preferably 0.002 particles / μm or more and 0.02 particles / μm or less. When NP0 / LE is 0.002 particles / μm or more, the temperature dependence of the resistance value can be further reduced. When NP0 / LE is 0.002 particles / μm or more and 0.02 particles / μm or less, the temperature dependence of the resistance value can be further reduced while ensuring sufficient capacitance.

[0061] When calculating NP0 / LE, the cross section of the capacitance region 40 is set to 500 μm 2 It is preferable to analyze the above, and the total length LE is preferably set to 500 μm or more. Also, it is preferable to set the analysis field so that some edges of the analysis field are approximately parallel to the internal electrode layer 20, and in this case, the length of the edge of the analysis field that is approximately parallel to the internal electrode layer 20 can be considered as the length of the internal electrode layer 20 in the analysis field. For example, in the cross section shown in FIG. 2, the total length LE of the internal electrode layer 20 is 4L X (Edge length L X Since there are 14 Ni oxide particles 30 in the cross section of FIG. 2, the NP0 / LE calculated for the cross section of FIG. 2 is 14 / 4L X (pieces / μm).

[0062] The total length of the dielectric layer 10 observed in the cross section of the capacitance region 40 as shown in FIG. 2 is defined as LD. Within the range of the total length LD, the number of first large particles 13a contained in the dielectric layer 10 is defined as ND1, and the number of second large particles 13b contained in the dielectric layer 10 is defined as ND2. The average number of first large particles 13a contained in the dielectric layer 10 per unit length can be expressed as ND1 / LD, and the average number of second large particles 13b contained in the dielectric layer 10 per unit length can be expressed as ND2 / LD. Both ND1 / LD and ND2 / LD are preferably 0.001 particles / μm or more. By satisfying this requirement, the temperature dependence of the resistance value can be further reduced.

[0063] The total average number of the first large particles 13a and the second large particles 13b contained in the dielectric layer 10 per unit length can be expressed as (ND1+ND2) / LD. (ND1+ND2) / LD is preferably 0.002 particles / μm or more, and by satisfying this requirement, the temperature dependence of the resistance value can be further reduced while ensuring sufficient capacitance.

[0064] When measuring ND1 and ND2, the cross section of the capacitance region 40 is measured at a distance of 500 μm. 2 It is preferable to analyze the above, and the total length LD is preferably set to 500 μm or more.

[0065] As shown in Fig. 5, the capacitance region 40 preferably includes a first Ni oxide particle 30α. The first Ni oxide particle 30α is in contact with both of the two adjacent dielectric layers 10 via the internal electrode layer 20. That is, the first Ni oxide particle 30α is present so as to penetrate through the front and back surfaces of one internal electrode layer 20 in the cross section of the capacitance region 40. On the other hand, the Ni oxide particle 30 in contact with only one of the two adjacent dielectric layers 10 via the internal electrode layer 20 is referred to as a "second Ni oxide particle 30β."

[0066] As shown in FIG. 5, since the first Ni oxide particles 30α are in contact with the two dielectric layers 10, they can contact more large particles 13 than the second Ni oxide particles 30β. That is, it is considered that the first Ni oxide particles 30α can form more equivalent circuits EC than the second Ni oxide particles 30β, and it is considered that they greatly contribute to reducing the temperature dependence of the resistance value.

[0067] When the number of the first Ni oxide particles 30α included in the cross-section as shown in FIG. 2 is defined as NPα, and the number of the second Ni oxide particles 30β is defined as NPβ, it is preferable to satisfy NPβ < NPα. That is, when the Ni oxide particles 30 are classified based on the state of the Ni oxide particles 30 observed in the body cross-section, the Ni oxide particles 30 preferably mainly include the first Ni oxide particles 30α. By including the first Ni oxide particles 30α to such an extent that the capacitance region 40 satisfies NPβ < NPα, the temperature dependence of the resistance value can be further reduced. When measuring NPα and NPβ, it is preferable to analyze a cross-section of the capacitance region 40 that is 200 μm 2 or more.

[0068] The dielectric layer 10 may include third large particles 13c that are in contact with the Ni oxide particles 30 at both the first boundary 31 and the second boundary 32. However, when the large particles 13 are in contact with the Ni oxide particles 30 at both the first boundary 31 and the second boundary 32, it is considered that Schottky junctions (Schottky junctions formed by a metal and a p-type semiconductor) of the internal electrode layer 20 and the Ni oxide particles 30 are formed at both the first boundary 31 and the second boundary 32. Therefore, it is considered that equivalent circuits EC (EC1, EC2) as shown in FIG. 4B are not formed at the locations where the third large particles 13c are present, and it is considered that the third large particles 13c do not contribute to reducing the temperature dependence of the resistance value.

[0069] <The average number ND3 / LD of the third large particles 13c contained in the dielectric layer 10 per unit length is preferably 0 or more and 0.0003 particles / μm or less. ND3 is the number of the third large particles 13c contained in the dielectric layer 10 in the cross section of the capacitance region 40 as shown in FIG. 2. When calculating the above ND3 / LD, similarly to ND1 / LD and ND2 / LD, the cross section of the capacitance region 40 is cut into 500 μm 2 It is preferable to analyze the above, and the total length LD is preferably set to 500 μm or more.

[0070] Average particle size d of Ni oxide particles 30 P is not particularly limited, and is preferably 0.03 μm or more and 1.5 μm or less, and more preferably 0.05 μm or more and 1 μm or less. P is the average grain size d of the metal crystals contained in the internal electrode layer 20 M It is preferable that the value is larger than d M d against P The ratio (d P / d M ) is preferably 3 or more. P / d M The upper limit of is not particularly limited, and for example, d P / d M The average particle diameter d of the Ni oxide particles 30 can be set to 10 or less. P is preferably calculated by observing the cross section of the capacitance region 40 and measuring the circle-equivalent diameters of at least five Ni oxide particles 30.

[0071] Next, an example of a method for manufacturing the multilayer ceramic electronic component 2 shown in FIG. 1 will be described.

[0072] First, a dielectric paste and an internal electrode paste are prepared. The dielectric paste can be produced by adding a dielectric raw material powder (main component powder) and a sub-component powder to a known organic vehicle or a known aqueous vehicle and kneading them. In addition to the above, a dispersant, a plasticizer, a glass frit, etc. may be added to the dielectric paste. On the other hand, the internal electrode paste can be produced by adding a metal powder such as Ni powder and NiO powder to a known organic vehicle or a known aqueous vehicle and kneading them. The internal electrode paste may contain a dielectric raw material powder as a co-material, and may also contain a dispersant, a plasticizer, etc.

[0073] Next, the dielectric paste is formed into a sheet by a method such as a doctor blade to obtain a green sheet, and then the internal electrode paste is applied in a predetermined pattern onto this green sheet by various printing methods such as screen printing or a transfer method.

[0074] Here, the NiO powder added to the internal electrode paste is the raw material of the Ni oxide particles 30. The above-mentioned ANP, NP0 / LE, NPα, and NPβ can be controlled based on the compounding ratio of the NiO powder in the internal electrode paste, the particle size of the NiO powder, the thickness of the internal electrode layer 20, and the like.

[0075] For example, in the internal electrode paste, the average particle size of the NiO powder is preferably 0.03 μm or more, more preferably 0.05 μm or more and 0.8 μm or less. The average particle size of the metal powder is preferably 0.8 μm or less, more preferably 0.03 μm or more and 0.5 μm or less. The compounding ratio of the NiO powder in the internal electrode paste is preferably 10 parts by weight or more and 25 parts by weight or less, more preferably 15 parts by weight or more and 20 parts by weight or less, relative to 100 parts by weight of the metal powder. The average thickness T of the internal electrode layer 20 is EL This can be controlled by the thickness of the internal electrode paste applied onto the green sheet, and the thickness of the internal electrode paste is preferably 2 μm or less, and more preferably 0.2 μm or more and 1 μm or less.

[0076] The ratio ND / LD, which indicates the proportion of large particles 13 in the dielectric layer 10, can be controlled based on the particle size of the dielectric raw material powder and the thickness of the dielectric layer 10. For example, the average particle size of the dielectric raw material powder is preferably 0.05 μm or more, and more preferably 0.06 μm or more and 0.2 μm or less. The average thickness T of the dielectric layer 10 DL can be controlled by the thickness of the green sheet, and the average thickness of the green sheet is preferably 2 μm or less, and more preferably 0.2 μm or more and 1 μm or less. The ratios (AND0, AND1, AND2, ND1 / LD, ND2 / LD, (ND1+ND2) / LD, etc.) of the large particles 13 (first large particles 13a, second large particles 13b) in contact with the Ni oxide particles 30 can be controlled based on the ratio of the particle size of the dielectric raw material powder to the thickness of the green sheet, the compounding ratio of the NiO powder in the internal electrode paste, etc.

[0077] Next, multiple layers of green sheets coated with the internal electrode paste are stacked and then pressed in the stacking direction to obtain a mother laminate. At the top and bottom of the mother laminate in the stacking direction, one or more green sheets not coated with the internal electrode paste are stacked. By stacking the green sheets not coated with the internal electrode paste in this way, exterior regions 41 can be formed above and below the capacitance region 40.

[0078] The mother laminate obtained by the above steps is cut into a predetermined size by dicing or cutting to obtain a plurality of green chips. If necessary, the green chips may be dried to remove plasticizers and the like, and after drying, may be barrel polished using a horizontal centrifugal barrel machine or the like.

[0079] Next, the green chip obtained above is subjected to a binder removal process and a firing process to obtain an element body 4.

[0080] The conditions for the binder removal treatment are not particularly limited and may be determined appropriately depending on the types of binders contained in the dielectric paste and the internal electrode paste. For example, the temperature rise rate is preferably 5 to 300°C / hour, the holding temperature is preferably 180 to 400°C, and the temperature holding time is preferably 0.5 to 24 hours. The atmosphere for the binder removal treatment can be an atmospheric atmosphere (i.e., air) or a reducing atmosphere, and an atmospheric atmosphere is preferred.

[0081] The firing conditions are not particularly limited and may be appropriately set depending on the main component composition of the dielectric layer 10 and the metal components of the internal electrode layer 20. For example, the holding temperature during firing is preferably 1200 to 1350°C, more preferably 1220 to 1300°C, and the holding time is preferably 0.05 to 8 hours, more preferably 0.5 to 3 hours. The firing atmosphere is preferably a reducing atmosphere, and the atmospheric gas may be, for example, a humidified mixed gas of N2 and H2. Furthermore, when the internal electrode layer 20 is made of a base metal such as Ni or a Ni alloy, the oxygen partial pressure in the firing atmosphere should be set to 1.0 x 10 -14 MPa~1.0×10 -10 It is preferable to set it to MPa.

[0082] The fired element 4 may be subjected to an annealing treatment. For example, the annealing treatment is preferably performed to reoxidize the dielectric layer 10 or to remove distortion caused by firing. The conditions for the annealing treatment are not particularly limited and may be determined appropriately depending on the main component composition of the dielectric layer 10. For example, the holding temperature is preferably 650 to 1150°C, the temperature holding time is preferably 0 to 20 hours, and the temperature rise rate and temperature fall rate are preferably 50 to 500°C / hour. Furthermore, it is preferable to use dry N2 gas or humidified N2 gas as the atmospheric gas.

[0083] In the above-mentioned binder removal treatment, firing treatment, and annealing treatment, a wetter or the like may be used to humidify the N2 gas or mixed gas, and in this case, the water temperature is preferably about 5 to 75° C. Furthermore, the binder removal treatment, firing treatment, and annealing treatment may be performed consecutively or independently.

[0084] The end faces 4a and 4b of the element body 4 may be polished before forming the external electrodes 6. Examples of polishing methods include barrel polishing, sandblasting, and laser. Polishing the end faces 4a and 4b of the element body 4 makes it easier to electrically connect the internal electrode layers 20 and the external electrodes 6.

[0085] Next, a pair of external electrodes 6 are formed on the outer surface of the element body 4. There are no particular restrictions on the method for forming the external electrodes 6, and any known method may be used. Through the above steps, the multilayer ceramic electronic component 2 shown in FIG. 1 is obtained.

[0086] (Summary of the embodiment) The multilayer ceramic electronic component 2 of this embodiment has internal electrode layers 20 and dielectric layers 10 stacked between the internal electrode layers 20. The capacitive region 40 of the element body 4 has Ni oxide particles 30 present at the boundaries (first boundaries 31 and second boundaries 32) between the internal electrode layers 20 and the dielectric layers 10. The dielectric layers 10 include first large particles 13a that are in contact with the Ni oxide particles 30 present at the first boundaries 31 and are in contact with the internal electrode layers 20 at the second boundaries 32, and second large particles 13b that are in contact with the internal electrode layers 20 at the first boundaries 31 and are in contact with the Ni oxide particles 30 present at the second boundaries 32.

[0087] The multilayer ceramic electronic component 2 having the above characteristics can suppress fluctuations in resistance value due to temperature. For example, when the resistance value of the multilayer ceramic electronic component 2 at 20°C is R 20 The resistance value of the multilayer ceramic electronic component 2 at 85°C is R 85 Then, R 20 / R 85 can be suppressed to 2.0 or less.

[0088] Although the reason for the improved temperature dependence of resistance is not entirely clear, it is thought that this is because the formation of Schottky barriers and double Schottky barriers is suppressed. Specifically, it is thought that two equivalent circuits EC1 and EC2, as shown in FIG. 4B, are formed at the contact points between the Ni oxide particles 30 and the first large particles 13a and between the Ni oxide particles 30 and the second large particles 13b. When such equivalent circuits EC1 and EC2 are formed, the insulation resistance between the internal electrode layers depends on the resistance of the dielectric particles 11, and it is thought that the formation of Schottky barriers and double Schottky barriers, which are highly temperature-dependent, is suppressed.

[0089] 4B, it is sufficient that the p-type semiconductor particles are present at the first boundary 31 and the second boundary 32 and are in contact with the large particles 13 of the dielectric layer 10. In other words, in FIGS. 2 and 4A, the particles indicated by the reference numeral "30" are not necessarily limited to Ni oxide particles (NiO), and may be p-type semiconductor particles.

[0090] The Ni oxide particles 30 preferably include first Ni oxide particles 30α that contact two adjacent dielectric layers 10 via the internal electrode layers 20. The first Ni oxide particles 30α may be able to contact more large particles 13 than the second Ni oxide particles 30β. In other words, when the capacitance region 40 includes the first Ni oxide particles 30α, the temperature dependence of the resistance value can be more effectively reduced.

[0091] Each internal electrode layer 20 is preferably in contact with an average of two or more Ni oxide particles 30 in one cross section of the element body 4. In other words, the average number ANP of Ni oxide particles 30 in contact with an internal electrode layer 20 per layer is preferably two or more. When the multilayer ceramic electronic component 2 satisfies this requirement, the temperature dependency of the resistance value can be further reduced.

[0092] It is preferable that the average number NP0 / LE of Ni oxide particles 30 in contact with the internal electrode layers 20 per unit length is 0.002 particles / μm or more. When the multilayer ceramic electronic component 2 satisfies this requirement, the temperature dependency of the resistance value can be further reduced.

[0093] The dielectric layer 10 may include third large particles 13c that contact both the Ni oxide particles 30 at the first boundary 31 and the Ni oxide particles 30 at the second boundary 32. The average number ND3 / LD of the third large particles 13c contained in the dielectric layer 10 per unit length is preferably 0 or more and 0.0003 particles / μm or less. When the multilayer ceramic electronic component 2 satisfies this requirement, the temperature dependence of the resistance value can be further reduced.

[0094] The above describes embodiments of the present disclosure, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways within the scope of the gist of the present disclosure.

[0095] For example, the external electrode 6 may be a pad-shaped electrode present on one side surface 4c of the element body 4. In this case, the pad-shaped external electrode 6 may be electrically connected to the internal electrode layer 20 via a through-hole electrode or a via-hole electrode.

[0096] Furthermore, the electronic component of the present disclosure is not limited to the multilayer ceramic electronic component 2 shown in FIG. 1 as long as it has at least one first internal electrode layer 21, one second internal electrode layer 22, and one dielectric layer 10. [Example]

[0097] The present disclosure will be described below in more detail based on examples, but the present disclosure is not limited to these examples.

[0098] (Experiment 1) In Experiment 1, the multilayer ceramic electronic components according to Example A1 and Comparative Examples 1 to 3 were manufactured according to the following procedure.

[0099] Example A1 First, a dielectric paste, which is the raw material for the dielectric layers, was prepared using (Ba,Ca)(Ti,Zr)O3 powder (main component powder) with an average particle size of 0.09 μm and secondary component powders (MgCO3 powder, YO3 powder, MnCO3 powder, VO5 powder, and SiO2 powder). Furthermore, an internal electrode paste was prepared using Ni powder with an average particle size of 0.18 μm and NiO powder with an average particle size of 0.15 μm. The compounding ratio of NiO powder in the internal electrode paste was 17 parts by weight per 100 parts by weight of Ni powder.

[0100] Next, the dielectric paste was applied to a PET film and formed into a sheet to obtain a green sheet with a thickness of 0.65 μm, and then the internal electrode paste was applied to the green sheet in a predetermined pattern. The amount of the applied internal electrode paste was determined based on the average thickness T of the internal electrode layer after firing. EL The thickness was controlled to be 0.55 μm.

[0101] Next, a plurality of green sheets coated with the internal electrode paste were stacked and pressed to obtain a mother laminate. At this time, green sheets not coated with the internal electrode paste were stacked at the top and bottom in the stacking direction of the mother laminate. The number of stacked green sheets coated with the internal electrode paste was controlled so that the number of dielectric layers in the capacitance region was 350. The thickness of the exterior region 41 after firing was controlled so that it was 20 μm or more.

[0102] The mother laminate was cut to a specified size to obtain green chips, which were then subjected to binder removal, firing, and annealing. External electrodes containing sintered bodies primarily composed of Cu were then formed on each end face of the element. These steps resulted in a multilayer ceramic electronic component with a cross-sectional structure similar to that shown in Figure 1. The average dimensions of the element in this multilayer ceramic electronic component were L0 × W0 = 0.7 mm × 0.45 mm.

[0103] Comparative Example 1 In Comparative Example 1, both the first internal electrode layer and the second internal electrode layer were formed using an internal electrode paste that did not contain NiO powder. Specifically, in Comparative Example 1, an internal electrode paste was prepared using Ni powder with an average particle size of 0.18 μm, and no NiO powder was added to the internal electrode paste. Then, the internal electrode paste was applied in a predetermined pattern onto a green sheet with a thickness of 0.65 μm. In Comparative Example 1, a dielectric paste with the same specifications as in Example A1 was used, and the thickness of the green sheet was also controlled to be approximately the same as in Example A1. The manufacturing conditions other than those described above were the same as in Example A1, and a multilayer ceramic electronic component according to Comparative Example 1 was manufactured.

[0104] Comparative Example 2 In Comparative Example 2, a first internal electrode paste containing NiO powder and a second internal electrode paste to which NiO powder was not added were prepared as raw materials for the internal electrode layers. Ni powder having an average particle size of 0.18 μm and NiO powder having an average particle size of 0.15 μm were added to the first internal electrode paste, and the compounding ratio of the NiO powder in the first internal electrode paste was 17 parts by weight per 100 parts by weight of the Ni powder. On the other hand, Ni powder having an average particle size of 0.18 μm was added to the second internal electrode paste, and no NiO powder was added. In Comparative Example 2, a dielectric paste with the same specifications as in Example A1 was used, and the thickness of the green sheet was also controlled to the same extent as in Example A1.

[0105] In Comparative Example 2, a first green sheet coated with a paste for a first internal electrode and a second green sheet coated with a paste for a second internal electrode were prepared, and the first green sheet and the second green sheet were alternately laminated to obtain a mother laminate. The manufacturing conditions other than those described above were the same as those of Example A1, and a multilayer ceramic electronic component according to Comparative Example 2 was manufactured.

[0106] Comparative Example 3 In Comparative Example 3, internal electrode layers were formed using an internal electrode paste with the same specifications as in Example A1. However, in Comparative Example 3, dielectric layers were formed under conditions different from those in Example A1. Specifically, in Comparative Example 3, a dielectric paste containing (Ba,Ca)(Ti,Zr)O powder (main component powder) with an average particle size of 0.04 μm was prepared, and a green sheet with a thickness of 0.65 μm was produced using this dielectric paste. As described above, the (Ba,Ca)(Ti,Zr)O powder used in Comparative Example 3 had an average particle size different from that of Example A1, but the accessory component powders added to the dielectric paste and the compounding ratio of the accessory component powders were the same as those in Example A1. A multilayer ceramic electronic component according to Comparative Example 3 was produced under the same manufacturing conditions as in Example A1, except for the above.

[0107] Cross-sectional analysis of the element The cross section of the element in the lamination direction (the cross section of the capacitance region as shown in Figures 1 and 2) was observed with STEM, and the average thickness T EL (μm), the average thickness of the dielectric layer T DL (μm), and the average particle size d of the dielectric particles contained in the dielectric layer DP (μm) was measured.

[0108] In the cross-sectional observation, the internal electrode layers in the analysis field were numbered from the bottom side of the analysis field. The odd-numbered internal electrode layers were identified as the first internal electrode layers, and the even-numbered internal electrode layers were identified as the second internal electrode layers. In addition, elemental mapping analysis by EDS was performed on five analysis fields (each with an area of ​​54 μm 2 ) to investigate whether or not Ni oxide particles exist at the first boundary between the first internal electrode layer and the dielectric layer, and at the second boundary between the second internal electrode layer and the dielectric layer. In Table 1, the column for "Presence or Absence of Ni Oxide Particles" contains the entries "Y" and "N." "Y" means that Ni oxide particles existed at the first boundary or the second boundary, and "N" means that Ni oxide particles were not observed at the specified location.

[0109] In the above cross-sectional analysis, the dielectric particles that contacted the Ni oxide particles at the first boundary and the metal component of the internal electrode layer at the second boundary were identified as first large particles (13a). Furthermore, the dielectric particles that contacted the metal component of the internal electrode layer at the first boundary and the Ni oxide particles at the second boundary were identified as second large particles (13b). In the "First Large Particles" column of Table 1, "Y" means that the dielectric layer contained the first large particles, and "N" means that the dielectric layer did not contain the first large particles. Similarly, in the "Second Large Particles" column of Table 1, "Y" means that the dielectric layer contained the second large particles, and "N" means that the dielectric layer did not contain the second large particles.

[0110] Evaluation of temperature dependence of resistance value A DC voltage of 4V was applied to the multilayer ceramic electronic component from any direction for 30 seconds, and the insulation resistance of the multilayer ceramic electronic component was measured and this value was taken as the resistance value. The environmental temperatures for measuring the resistance value were set to 20°C and 85°C, and the resistance value R at 85°C was 85 Resistance R at 20°C 20 The ratio (R 20 / R 85 ) was calculated. 85 The direction of the DC voltage when measuring is the resistance value R 20 The direction of the DC voltage was adjusted to match the direction when the measurement was performed.

[0111] In this experiment, the temperature dependence of the resistance value was 20 / R 85 Samples with an R of 2.0 or less were judged as "good" and 20 / R 85 Samples with a value of 1.5 or less were judged to be “particularly good.” The evaluation results of Example A1 and Comparative Examples 1 to 3 are shown in Table 1.

[0112] [Table 1]

[0113] In Comparative Example 1, an internal electrode paste containing no NiO powder was used, so no Ni oxide particles were present at the boundary between the dielectric layer and the internal electrode layer, and the first large particles and second large particles in contact with the Ni oxide particles were not contained in the dielectric layer. In Comparative Example 2, a first internal electrode paste containing NiO and a second internal electrode paste containing no NiO were used, so Ni oxide particles were observed at one first boundary, and the dielectric layer contained the first large particles. However, in Comparative Example 2, no Ni oxide particles were observed at the other second boundary, and the dielectric layer did not contain the second large particles.

[0114] In Comparative Example 3, Ni oxide particles were observed at both the first and second boundaries. However, the dielectric layer of Comparative Example 3 contained almost no large particles (reference numeral 13), and cross-sectional analysis of Comparative Example 3 failed to detect the first and second large particles in contact with the Ni oxide particles. In other words, in Comparative Example 3, the Ni oxide particles in the capacitance region were in contact with the small particles (reference numeral 15) of the dielectric layer, but not with the large particles.

[0115] On the other hand, in the cross-sectional analysis of Example A1, Ni oxide particles were observed at both the first and second boundaries, and it was confirmed that the first and second large particles in contact with the Ni oxide particles existed in the dielectric layer. In other words, it was confirmed that the cross-sectional structure shown in FIG. 4A existed in the capacitance region in Example A1.

[0116] In Comparative Examples 1 to 3, the insulation resistance decreased at 85°C, and R 20 / R 85 In contrast, the multilayer ceramic electronic component of Example A1 having the cross-sectional structure shown in FIG. 4A exhibited high insulation resistance even at 85°C, and R 20 / R 85 The results of Experiment 1 showed that the temperature dependence of the resistance value can be reduced by having Ni oxide particles at both the first and second boundaries and by having the dielectric layer contain first and second large particles that are in contact with the Ni oxide particles.

[0117] (Experiment 2) In Experiment 2, the compounding ratio of NiO in the internal electrode paste was changed to manufacture four multilayer ceramic electronic components according to Examples B1 to B4 shown in Table 2. The manufacturing conditions other than the compounding ratio of NiO were the same as those of Example A1 in Experiment 1.

[0118] In the cross-sectional observation of Experiment 2, the number of Ni oxide particles in contact with each internal electrode layer was counted in the cross section of the element body in the lamination direction as shown in Figure 1. Then, the average number of Ni oxide particles in contact with the internal electrode layer per layer, ANP, was calculated. 2 The internal electrode layers with a total length of 920 μm or more included in the cross section were analyzed, and the average number of Ni oxide particles NP0 / LE (particles / μm) in contact with the internal electrode layer per unit length was calculated.

[0119] Also, 1134 μm 2 The dielectric layers with a total length of 920 μm or more in the cross section were analyzed, and the dielectric particles that contacted Ni oxide particles at the first boundary and Ni oxide particles at the second boundary were identified as the third large particles (13c). The average number of the third large particles per unit length in the dielectric layer 10, ND3 / LD, was then calculated.

[0120] In Examples B1 to B4 of Experiment 2, Ni oxide particles were observed at both the first boundary and the second boundary, confirming that the dielectric layer contained first large particles and second large particles in contact with the Ni oxide particles.

[0121] In Experiment 2, the insulation resistance of the multilayer ceramic electronic components was measured in the same manner as in Experiment 1, and the temperature dependence of the resistance value in each example was evaluated. In addition, in Experiment 2, the capacitance (μF) of the multilayer ceramic electronic components was measured using an LCR meter. At this time, the measurement temperature was set to room temperature (25°C), and a signal with a frequency of 1 kHz and an input signal level (measurement voltage) of 1 Vrms was input to the multilayer ceramic electronic components. With regard to capacitance, samples with a capacitance of 3.0 μF or more were judged to be "good," and samples with a capacitance of 3.5 μF or more were judged to be "particularly good." The evaluation results of Experiment 2 are shown in Table 2.

[0122] [Table 2]

[0123] As shown in Table 2, it was found that the average number ANP of Ni oxide particles in contact with the internal electrode layer per layer is preferably 2 or more, and more preferably 2 to 10. It was also found that the average number NP0 / LE of Ni oxide particles in contact with the internal electrode layer per unit length is preferably 0.002 particles / μm or more, and more preferably 0.002 particles / μm to 0.02 particles / μm.

[0124] Furthermore, from the viewpoint of reducing the temperature dependence of the resistance value while ensuring sufficient capacitance, it was found that it is preferable that the average number of third large particles contained in the dielectric layer per unit length, ND3 / LD, be 0.0003 particles / μm or less.

[0125] (Experiment 3) In Experiment 3, an internal electrode paste was prepared using NiO powder with a finer particle size than that of Example A1. Specifically, the average particle size of the NiO powder used in Experiment 3 was 0.06 μm. The manufacturing conditions other than the specifications of the NiO powder were the same as those of Example A1, and a multilayer ceramic electronic component according to Example C1 was manufactured.

[0126] In the cross-sectional analysis of Experiment 3, elemental mapping analysis by EDS was performed on five analysis fields (each analysis field area was 54 μm 2 ) and identified the Ni oxide particles present within the analysis range. These Ni oxide particles were then classified into "first Ni oxide particles (30α)" and "second Ni oxide particles (30β)." The number of first Ni oxide particles NPα and the number of second Ni oxide particles NPβ were then measured. Note that the first Ni oxide particles are Ni oxide particles that are in contact with both of the two adjacent dielectric layers via the internal electrode layers, while the second Ni oxide particles are Ni oxide particles that are in contact with only one of the two dielectric layers (see Figure 5).

[0127] In addition, in the cross-sectional analysis of Experiment 3, the average grain size d of the metal crystals contained in the internal electrode layer was M , and the average particle size of Ni oxide particles d P Measure and d M d against P The ratio (unitless) was calculated.

[0128] In Example C1, as in Example A1, Ni oxide particles were observed at the first and second boundaries, and it was confirmed that the first large particles and the second large particles were present in contact with the Ni oxide particles in the dielectric layer. The evaluation results of Experiment 3 are shown in Table 3.

[0129] [Table 3]

[0130] As shown in Table 3, Example A1, which has a higher ratio of the first Ni oxide particles, has a higher R than Example C1, which has a lower ratio of the first Ni oxide particles. 20 / R 85 This result shows that the temperature dependence of the resistance value can be further improved by having the first Ni oxide particles in contact with the two dielectric layers in the capacitance region. [Explanation of symbols]

[0131] 2... Multilayer ceramic electronic components 4... Base body 4a,4b … End face 4c…side 40 … Capacity area 41 … Exterior area 6 … External electrode 6a … 1st external electrode 6b…Second external electrode 10...Dielectric layer 11...Dielectric particles 13...Large particles 13a … First large particle 13b … Second large particle 13c … Third large particle 13d… The 4th largest particle 15… small particles 17 … Particle boundary 20 … Internal electrode layer 21 … First inner electrode layer 22 … Second inner electrode layer 31 … First Realm 32 … Second Realm 30…Ni acid compound particles 30α…1st Ni acid compound particle 30β … Second Ni oxide particle

Claims

1. An element body including at least two internal electrode layers and a dielectric layer laminated between the internal electrode layers, Ni oxide particles are present at the boundary between the internal electrode layer and the dielectric layer, The dielectric layer is the internal electrode layer is in contact with the adjacent internal electrode layer at a first boundary and a second boundary, An electronic component comprising: a first dielectric large particle that contacts the Ni oxide particle present at the first boundary and contacts the internal electrode layer at the second boundary; and a second dielectric large particle that contacts the internal electrode layer at the first boundary and contacts the Ni oxide particle present at the second boundary.

2. The electronic component according to claim 1 , wherein the Ni oxide particles include first Ni oxide particles that are in contact with both of the two adjacent dielectric layers via the internal electrode layers.

3. the element body includes a plurality of internal electrode layers and a plurality of dielectric layers, 3. The electronic component according to claim 1, wherein each of the internal electrode layers is in contact with an average of two or more of the Ni oxide particles in one cross section of the element body.

4. the element body includes a plurality of internal electrode layers and a plurality of dielectric layers, 3. The electronic component according to claim 1, wherein the average number of said Ni oxide particles in contact with said internal electrode layers per unit length is 0.002 particles / [mu]m or more.

5. the element body includes a plurality of internal electrode layers and a plurality of dielectric layers, The dielectric layer may include a third dielectric large particle in contact with both the Ni oxide particle at the first boundary and the Ni oxide particle at the second boundary, 3. The electronic component according to claim 1, wherein the average number of the third dielectric large particles contained in the dielectric layer per unit length is 0 or more and 0.0003 particles / [mu]m or less.

6. An element body including at least two internal electrode layers and a dielectric layer laminated between the internal electrode layers, p-type semiconductor particles are present at the boundary between the internal electrode layer and the dielectric layer, The dielectric layer is the internal electrode layer is in contact with the adjacent internal electrode layer at a first boundary and a second boundary, An electronic component comprising: a first dielectric large particle that contacts the p-type semiconductor particle at the first boundary and contacts the internal electrode layer at the second boundary; and a second dielectric large particle that contacts the internal electrode layer at the first boundary and contacts the p-type semiconductor particle at the second boundary.

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