Dielectric composition, multilayer ceramic electronic component, and method for manufacturing a multilayer ceramic electronic component.

Abstract

To provide a dielectric composition which enables achievement of both of a long life and superior capacity temperature characteristic; a laminate ceramic electronic part; and a manufacturing method of the laminate ceramic electronic part.SOLUTION: A dielectric composition comprises: a base material containing barium titanate zirconate as a primary component, which includes zirconium of 4 at% or more and 30 at% or less to a total quantity of titanium and zirconium, and of which the atomic concentration ratio of barium is 1 up to 1.1 to a total atomic concentration of titanium and zirconium; and a subcomponent containing europium of 2 at% or more and 4 at% or less to a quantity of titanium of the barium titanate zirconate.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a dielectric composition, a multilayer ceramic electronic component, and a method for manufacturing a multilayer ceramic electronic component.

Background Art

[0002] In high-frequency communication systems typified by mobile phones, multilayer ceramic capacitors are used to remove noise. Also, multilayer ceramic capacitors are used in electronic circuits related to human life such as in-vehicle electronic control devices (high reliability applications). Since high reliability is required for multilayer ceramic capacitors, techniques for improving reliability have been disclosed (see, for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is conceivable to use barium zirconate titanate (BaTi (1-x) Zr x O3) in the dielectric of a multilayer ceramic capacitor. Barium zirconate titanate is obtained by replacing Ti in BaTiO3 with Zr 4+ with Zr 4+This material, substituted with barium titanate, possesses high reduction resistance, suppresses the formation of oxygen vacancies, and prevents deterioration of insulation resistance. However, barium zirconate titanate has a tendency to grow grains. Excessive grain growth worsens the capacitance-temperature characteristics and reduces the high-temperature load life, making it difficult to use barium zirconate titanate in high-reliability applications.

[0005] The present invention has been made in view of the above problems, and aims to provide a dielectric composition, a multilayer ceramic electronic component, and a method for manufacturing a multilayer ceramic electronic component that can achieve both a long lifespan and excellent capacitance-temperature characteristics. [Means for solving the problem]

[0006] The dielectric composition according to the present invention comprises a base material having barium zirconate titanate as the main component, containing zirconium in an amount of 4 at% to 30 at% relative to titanium and zirconium, with an atomic concentration ratio of barium to titanium and zirconium of 1 to 1.1, and a secondary component containing europium in an amount of 2 at% to 4 at% relative to the titanium of the barium zirconate titanate.

[0007] In the dielectric composition described above, the base material may contain 14 at% or more zirconium relative to the titanium and zirconium in the barium zirconate titanate.

[0008] In the dielectric composition described above, the base material may contain 20 at% or less of zirconium relative to the titanium and zirconium in the barium zirconate titanate.

[0009] In the dielectric composition described above, the dielectric crystal comprising the base material and the auxiliary components has a core-shell structure, and the average grain size of the dielectric crystal may be 200 nm or more and 400 nm or less.

[0010] In the dielectric composition described above, the auxiliary component includes divalent europium and trivalent europium, and the ratio of divalent europium to the total of the divalent europium and trivalent europium may be 21% or more.

[0011] In the dielectric composition described above, the auxiliary component includes divalent europium and trivalent europium, and the ratio of divalent europium to the total of the divalent europium and trivalent europium may be 80% or less.

[0012] The multilayer ceramic electronic component according to the present invention comprises a base material having barium zirconate titanate as the main component and containing zirconium in an amount of 4 at% to 30 at% relative to titanium and zirconium, with an atomic concentration ratio of barium to titanium and zirconium of 1 to 1.1; a plurality of dielectric layers having a secondary component containing europium in an amount of 2 at% to 4 at% relative to titanium of the barium zirconate titanate; a plurality of internal electrode layers stacked via the plurality of dielectric layers and facing each other alternately; and external electrodes provided on the sides of the stacked plurality of dielectric layers and the plurality of internal electrode layers and electrically connected to the plurality of internal electrode layers.

[0013] In the above-described multilayer ceramic electronic component, the base material may contain 14 at% or more zirconium relative to the titanium and zirconium in the barium zirconate titanate.

[0014] In the above-described multilayer ceramic electronic component, the base material may contain 20 at% or less of zirconium relative to the titanium and zirconium in the barium zirconate titanate.

[0015] In the above-described multilayer ceramic electronic component, the plurality of dielectric layers include dielectric crystals having a core-shell structure, and the average particle size of the dielectric crystals may be 200 nm or more and 400 nm or less.

[0016] In the above-described multilayer ceramic electronic component, the auxiliary component includes divalent europium and trivalent europium, and the ratio of divalent europium to the total of the divalent europium and trivalent europium may be 21% or more.

[0017] In the above-described multilayer ceramic electronic component, the auxiliary component includes divalent europium and trivalent europium, and the ratio of divalent europium to the total of the divalent europium and trivalent europium may be 80% or less.

[0018] The above multilayer ceramic electronic component may satisfy the X7T characteristics.

[0019] The present invention relates to a method for manufacturing a multilayer ceramic electronic component, comprising the steps of: forming a ceramic green sheet by mixing a base material mainly composed of barium zirconate titanate, containing zirconium in an amount of 4 at% to 30 at% relative to titanium and zirconium, with an atomic concentration ratio of barium to titanium and zirconium of 1 to 1.1; and a secondary component containing europium in an amount of 2 at% to 4 at% relative to titanium of the barium zirconate titanate; forming an internal electrode pattern on the ceramic green sheet; stacking the ceramic green sheets on which the internal electrode pattern is formed to obtain a laminate; and firing the laminate to form a plurality of dielectric layers and a plurality of internal electrodes.

[0020] In the above method for manufacturing multilayer ceramic electronic components, the laminate may be fired at a heating rate of 6000°C / h or higher. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a dielectric composition, a multilayer ceramic electronic component, and a method for manufacturing a multilayer ceramic electronic component that can achieve both a long lifespan and excellent capacitance-temperature characteristics. [Brief explanation of the drawing]

[0022] [Figure 1] This is a partial cross-sectional perspective view of a multilayer ceramic capacitor. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This is a cross-sectional view along line BB in Figure 1. [Figure 4] (a) is a diagram illustrating core-shell particles, and (b) is a schematic cross-sectional view of the dielectric layer. [Figure 5] This diagram illustrates a flow chart of the manufacturing process for multilayer ceramic capacitors. [Figure 6] This is a schematic diagram of the SEM image of the stacked dielectric layer and internal electrode layer in the capacitance region for Example 1. [Figure 7] This is a schematic diagram of a TEM image of a dielectric layer in the capacitance region. [Modes for carrying out the invention]

[0023] The embodiments will be described below with reference to the drawings.

[0024] (Embodiment) Figure 1 is a partial cross-sectional perspective view of a multilayer ceramic capacitor 100 according to an embodiment. Figure 2 is a cross-sectional view taken along line AA in Figure 1. Figure 3 is a cross-sectional view taken along line BB in Figure 1. As illustrated in Figures 1 to 3, the multilayer ceramic capacitor 100 comprises a multilayer chip 10 having a substantially rectangular parallelepiped shape and external electrodes 20a and 20b provided on two opposing end faces of either of the multilayer chips 10. Of the four faces of the multilayer chip 10 other than the two end faces, the two faces other than the top and bottom faces in the stacking direction are referred to as side faces. The external electrodes 20a and 20b extend to the top, bottom, and two side faces of the multilayer chip 10 in the stacking direction. However, the external electrodes 20a and 20b are spaced apart from each other.

[0025] The multilayer chip 10 has a structure in which dielectric layers 11 containing a ceramic material that functions as a dielectric and internal electrode layers 12 containing a base metal material are alternately stacked. The edges of each internal electrode layer 12 are alternately exposed to the end face of the multilayer chip 10 where the external electrode 20a is provided and the end face where the external electrode 20b is provided. As a result, each internal electrode layer 12 is alternately electrically connected to the external electrode 20a and the external electrode 20b. Consequently, the multilayer ceramic capacitor 100 has a structure in which multiple dielectric layers 11 are stacked via internal electrode layers 12. Furthermore, in the laminate of dielectric layers 11 and internal electrode layers 12, the outermost layer in the stacking direction is an internal electrode layer 12, and the top and bottom surfaces of the laminate are covered by a cover layer 13. The cover layer 13 mainly consists of a ceramic material. For example, the cover layer 13 may have the same composition as the dielectric layer 11 or a different composition. Furthermore, the configuration is not limited to that shown in Figures 1 to 3, as long as the internal electrode layer 12 is exposed on two different surfaces and is electrically connected to different external electrodes.

[0026] The dimensions of the multilayer ceramic capacitor 100 are, for example, 0.25 mm in length, 0.125 mm in width, and 0.125 mm in height, or 0.4 mm in length, 0.2 mm in width, and 0.2 mm in height, or 0.6 mm in length, 0.3 mm in width, and 0.3 mm in height, or 1.0 mm in length, 0.5 mm in width, and 0.5 mm in height, or 3.2 mm in length, 1.6 mm in width, and 1.6 mm in height, or 4.5 mm in length, 3.2 mm in width, and 2.5 mm in height, but are not limited to these dimensions.

[0027] The internal electrode layer 12 mainly consists of base metals such as nickel (Ni), copper (Cu), and tin (Sn). Precious metals such as platinum (Pt), palladium (Pd), silver (Ag), and gold (Au), or alloys containing these, may also be used as the internal electrode layer 12. The thickness of the internal electrode layer 12 is, for example, 0.1 μm to 3 μm, 0.1 μm to 1 μm, or 0.1 μm to 0.5 μm.

[0028] The dielectric layer 11 is a dielectric composition that includes a base material mainly composed of a ceramic material having a perovskite structure represented by the general formula ABO3. The perovskite structure is an ABO3 structure that deviates from the stoichiometric composition. 3-α This includes. In this embodiment, the ceramic material is barium zirconate titanate (BaTi (1-x) Zr x O3) is used. For example, the dielectric layer 11 contains 90 at% or more barium zirconate titanate. The dielectric layer 11 also contains a minor component including europium. Details of the minor component will be described later. The thickness of the dielectric layer 11 is, for example, 0.2 μm to 10 μm, 0.2 μm to 5 μm, or 0.2 μm to 2 μm.

[0029] As illustrated in Figure 2, the region where the internal electrode layer 12 connected to the external electrode 20a and the internal electrode layer 12 connected to the external electrode 20b face each other is a region in the multilayer ceramic capacitor 100 where capacitance is generated. Therefore, this region where capacitance is generated is referred to as the capacitance region 14. In other words, the capacitance region 14 is the region where adjacent internal electrode layers 12 connected to different external electrodes face each other.

[0030] The region where internal electrode layers 12 connected to external electrode 20a face each other without being connected to an internal electrode layer 12 connected to external electrode 20b is called the end margin 15. Similarly, the region where internal electrode layers 12 connected to external electrode 20b face each other without being connected to an internal electrode layer 12 connected to external electrode 20a is also called the end margin 15. In other words, the end margin 15 is the region where internal electrode layers 12 connected to the same external electrode face each other without being connected to an internal electrode layer 12 connected to a different external electrode. The end margin 15 is a region where no capacitance is generated.

[0031] As illustrated in FIG. 3, in the multilayer chip 10, the region from both side surfaces of the multilayer chip 10 to the internal electrode layer 12 is referred to as a side margin 16. That is, the side margin 16 is a region provided so as to cover the end portions where the plurality of internal electrode layers 12 laminated in the above-described laminated structure extend to both side surfaces. The side margin 16 is also a region where no capacitance is generated.

[0032] Here, barium zirconate titanate (BaTi (1-x) Zr x O3) has high reduction resistance, suppresses the generation of oxygen defects, and has a function of suppressing the deterioration of insulation resistance. However, barium zirconate titanate has a property of being prone to grain growth. When excessive grain growth occurs, the capacitance temperature characteristics deteriorate and the high-temperature load life also deteriorates, so it is difficult to use barium zirconate titanate for high-reliability applications. Therefore, the multilayer ceramic capacitor 100 according to the present embodiment has a configuration capable of achieving both a long life and excellent capacitance temperature characteristics.

[0033] Since barium zirconate titanate has a form in which zirconium is doped into barium titanate, the lattice constant of the crystal of barium titanate having a perovskite structure represented by the general formula ABO3 is enlarged, and rare earth elements such as holmium (Ho), dysprosium (Dy), and yttrium (Y), which are important for life, are more likely to be doped into the Ti site (B site) than the Ba site (A site). As a result, an acceptor excess occurs, and the life improvement effect is limited.

[0034] Therefore, the inventors investigated rare earth elements with large ionic radii that readily substitute and solid-solve in the Ba site of barium zirconate titanate. As a result, they found that adding europium (Eu) improved the lifetime by about an order of magnitude compared to rare earth elements such as holmium, dysprosium, and yttrium. The reason why europium improves lifetime is not fully understood, but it is thought that europium is stable in both divalent and trivalent states, and among rare earth element ions that fluctuate between divalent and trivalent states and are stable in divalent states, it has the largest ionic radius, thus selectively substitutes and solid-solves in the Ba site. Other rare earth elements are stable in trivalent states and unstable in divalent states.

[0035] Table 1 shows the ionic radii of each rare earth element in six coordination states. The source of Table 1 is "RDShannon, Acta Crystallogr., A32, 751 (1976)". [Table 1]

[0036] In the dielectric layer 11 of the capacitance region 14, if the amount of europium relative to titanium in barium zirconate titanate, the main component of the dielectric layer 11 (the amount of europium (at%) when titanium is set to 100 at%, there is a risk that a sufficiently long lifespan cannot be obtained. Therefore, in this embodiment, a lower limit is set for the amount of europium relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of europium relative to titanium is set to 2 at% or more. The amount of europium relative to titanium is preferably 2 at% or more, and more preferably 3 at% or more.

[0037] On the other hand, in the dielectric layer 11 of the capacitance region 14, if the amount of europium relative to titanium in barium zirconate titanate, which is the main component of the dielectric layer 11, is high, the dielectric layer 11 may become semiconductor-like, and a long lifespan may not be obtained. Therefore, in this embodiment, an upper limit is set on the amount of europium relative to titanium. Specifically, in the dielectric layer 11 of the capacitance region 14, the amount of europium relative to titanium is set to 4 at% or less. The amount of europium relative to titanium is preferably 4 at% or less, and more preferably 3 at% or less.

[0038] Next, (BaTi (1-x) Zr x If x in O3 is small, sufficient reduction resistance cannot be obtained, and there is a risk of many oxygen vacancies being generated. Therefore, in this embodiment, a lower limit is set for x. Specifically, x is set to 0.04 or more. In other words, in barium zirconate titanate, the amount of zirconium is 4 at% or more relative to titanium and zirconium. In barium zirconate titanate, it is preferable that the amount of zirconium is 9 at% or more relative to titanium and zirconium, and more preferably 14 at% or more.

[0039] On the other hand, if x is large, the diffusion of barium zirconate titanate will progress, which may make it difficult to control grain growth. Therefore, in this embodiment, an upper limit is set for x. Specifically, x is set to 0.30 or less. In other words, in barium zirconate titanate, the amount of zirconium is 30 at% or less relative to titanium and zirconium. In barium zirconate titanate, it is preferable to have 30 at% or less of zirconium relative to titanium and zirconium, and more preferably 20 at% or less.

[0040] Next, in barium zirconate titanate, if the Ba / (Ti+Zr) (the atomic concentration ratio of barium to titanium and zirconium) is large, the diffusion of barium zirconate titanate may be suppressed, making sintering difficult. Therefore, in this embodiment, an upper limit is set on the atomic concentration ratio of barium to titanium and zirconium. Specifically, the atomic concentration ratio of barium to titanium and zirconium is set to 1.1 or less. The atomic concentration ratio of barium to titanium and zirconium is preferably 1.1 or less, and more preferably 1.08 or less.

[0041] On the other hand, in barium zirconate titanate, if the atomic concentration ratio of barium to titanium and zirconium is small, diffusion of barium zirconate titanate may progress, making grain growth control difficult. Therefore, in this embodiment, a lower limit is set for the atomic concentration ratio of barium to titanium and zirconium. Specifically, the atomic concentration ratio of barium to titanium and zirconium is set to 1.0 or higher. Preferably, the atomic concentration ratio of barium to titanium and zirconium is 1.0 or higher, and more preferably 1.03 or higher.

[0042] In the dielectric layer 11 of the capacitance region 14 of such a multilayer ceramic capacitor 100, if at least a portion of the dielectric crystal, including the base material and minor components, has a core-shell structure, the dielectric layer 11 in the capacitance region 14 will have a high dielectric constant, excellent temperature characteristics, and a stable microstructure will coexist.

[0043] Magnesium is a typical additive that makes up the shell. However, magnesium is a simple acceptor whose valency does not change, and it forms a solid solution in the barium zirconate titanate of the dielectric layer 11, creating oxygen vacancies, which limits its reliability.

[0044] Therefore, in this embodiment, it is preferable that in the dielectric layer 11 of the capacitance region 14, at least a portion of the dielectric crystal including the base material and minor components has a core portion mainly composed of barium zirconate titanate and a zirconium diffusion layer as the shell portion, thus having a core-shell structure. The shell portion is mainly composed of barium zirconate titanate.

[0045] As illustrated in Figure 4(a), the core-shell particle 30 comprises a roughly spherical core portion 31 and a shell portion 32 that surrounds and covers the core portion 31. The core portion 31 is a crystalline portion in which the added compound is not solid-dissolved or the amount of added compound solid-dissolved is small. The shell portion 32 is a crystalline portion in which the added compound is solid-dissolved and has a higher concentration of the added compound than the concentration of the added compound in the core portion 31. In this embodiment, it is preferable that the zirconium concentration in the shell portion 32 is higher than the zirconium concentration in the core portion 31.

[0046] Figure 4(b) is a schematic cross-sectional view of the dielectric layer 11. As illustrated in Figure 4(b), the dielectric layer 11 comprises multiple dielectric crystals 17 of the main component ceramic. At least a portion of these dielectric crystals 17 are the core-shell particles 30 described in Figure 4(a). By covering the core portion 31 with a shell portion 32 that has a high zirconium concentration and high reduction resistance, a material with a stable structure and high reliability can be obtained while maintaining a high dielectric constant.

[0047] The europium concentration in the shell portion 32 tends to be higher than the europium concentration in the core portion 31.

[0048] In the dielectric layer 11, if the average particle size of the dielectric crystal 17 is too small or too large, the capacitance change rate will be large, and there is a risk that the multilayer ceramic capacitor 100 will not have X7T characteristics. Therefore, in this embodiment, a lower limit and an upper limit are set for the average particle size of the dielectric crystal 17 in the dielectric layer 11 of the capacitance region 14. Specifically, it is preferable that the average particle size of the dielectric crystal 17 in the dielectric layer 11 of the capacitance region 14 be 200 nm or more and 400 nm or less. The average particle size of the dielectric crystal 17 in the dielectric layer 11 of the capacitance region 14 is preferably 250 nm or more, and preferably 300 nm or more. On the other hand, the average particle size of the dielectric crystal 17 in the dielectric layer 11 of the capacitance region 14 is preferably 375 nm or less, and more preferably 350 nm or less. The average particle size can be measured by using an SEM image of the dielectric layer 11 with a field of view of 40,000x, measuring the constant directional diameter (Ferret diameter) of 100 particles constituting the dielectric layer 11, and taking the average value.

[0049] If the amount of divalent europium added to the dielectric layer 11 in the capacitance region 14 is small, a sufficiently long lifespan may not be obtained. Therefore, it is preferable to set a lower limit on the amount of divalent europium in the dielectric layer 11 in the capacitance region 14. For example, in the dielectric layer 11 in the capacitance region 14, the ratio of divalent europium is preferably 21% or more, and more preferably 26% or more, relative to the total europium (sum of divalent and trivalent europium).

[0050] In order to increase the proportion of divalent europium, it is necessary to reduce a large amount of trivalent europium. However, during the annealing process to reduce europium to divalent europium, grain growth may occur in the dielectric layer 11 during the period in which a large amount of trivalent europium is reduced. If grain growth occurs, the lifespan of the dielectric layer 11 may decrease. Therefore, if grain growth occurs in the dielectric layer 11, the effect of grain growth on reducing the lifespan may offset the effect of improving the lifespan of the valence of europium, and the internal electrode layer 12 may not be able to maintain its structure due to grain growth, potentially causing a short circuit. For this reason, it is preferable to set an upper limit on the amount of divalent europium in the dielectric layer 11 of the capacitance region 14. For example, in the dielectric layer 11 of the capacitance region 14, it is preferable that divalent europium accounts for 80% or less of the total europium, more preferably 70% or less, and even more preferably 59% or less.

[0051] Next, in the dielectric layer 11 of the capacitance region 14, if the amount of rare earth elements other than europium added is too large, the lifetime improvement effect of europium will be weakened, and a sufficient lifetime may not be obtained. Therefore, it is preferable to set an upper limit on the amount of rare earth elements other than europium added. Specifically, in the dielectric layer 11 of the capacitance region 14, it is preferable to make the atomic concentration of rare earth elements other than europium less than the atomic concentration of europium. If there are multiple types of rare earth elements other than europium, it is preferable to make the total atomic concentration of these multiple types of rare earth elements less than the atomic concentration of europium.

[0052] Silicon has the effect of lowering the sintering temperature of barium zirconate titanate, and if the amount added is small, sintering may become difficult. Therefore, in barium zirconate titanate, it is preferable to have a silicon content of 1 at% or more relative to titanium and zirconium.

[0053] If the amount of silicon added is too large, grain growth of barium zirconate titanate will progress, which may prevent a sufficient lifespan from being achieved. Therefore, it is preferable that the amount of silicon in barium zirconate titanate be 1.5 at% or less relative to titanium and zirconium.

[0054] In addition to its acceptor function described above, magnesium also inhibits grain growth of barium zirconate titanate. However, if the amount added is too small, it may cause grain growth in barium zirconate titanate. Therefore, it is preferable to use a magnesium content of 0.5 at% or more relative to titanium and zirconium in barium zirconate titanate.

[0055] If the amount of magnesium added is too large, grain growth will progress, and there is a risk that a sufficient lifespan will not be achieved. Therefore, in barium zirconate titanate, it is preferable to limit the amount of magnesium to 1.5 at% or less relative to titanium and zirconium.

[0056] As described above, according to this embodiment, the dielectric layer 11 in the capacitance region includes a base material mainly composed of barium zirconate titanate, containing zirconium in an amount of 4 at% to 30 at% relative to titanium and zirconium, with an atomic concentration ratio of barium to titanium and zirconium of 1 to 1.1, and a secondary component containing europium in an amount of 2 at% to 4 at% relative to titanium of the barium zirconate titanate, thereby achieving both a long lifespan and excellent capacitance-temperature characteristics.

[0057] Next, the manufacturing method of the multilayer ceramic capacitor 100 will be described. Figure 5 is a diagram illustrating the flow of the manufacturing method of the multilayer ceramic capacitor 100.

[0058] (Process for producing raw material powder) First, a dielectric material is prepared to form the dielectric layer 11. The A-site and B-site elements contained in the dielectric layer 11 are usually present in the form of a sintered body of ABO3 particles. Barium zirconate titanate can be obtained by synthesizing various materials through reaction. Various methods for synthesizing barium zirconate titanate are conventionally known, such as the solid-phase method, the sol-gel method, and the hydrothermal method. In this embodiment, any of these methods can be employed.

[0059] A predetermined additive compound is added to the obtained ceramic powder according to the purpose. Examples of additive compounds include oxides of magnesium, manganese, vanadium (V), chromium (Cr), europium, and oxides or glasses of cobalt (Co), nickel, lithium (Li), boron (B), sodium (Na), potassium (K), and silicon (Si). If necessary, oxides of rare earth elements other than europium (scandium (Sc), yttrium, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), gadolinium (Gd), terbium (Tb), dysprosium, holmium, erbium (Er), thulium (Tm), Yb, and lutetium (Lu)) may also be added.

[0060] For example, a ceramic material is prepared by wet mixing a compound containing an additive compound with ceramic raw material powder, drying, and grinding. For example, the ceramic material obtained as described above may be ground to adjust the particle size as needed, or the particle size may be adjusted by combining it with a classification process. A dielectric material is obtained through the above steps. In this dielectric material, a base material is mixed in which barium zirconate titanate is the main component, zirconium is contained in an amount of 4 at% to 30 at% relative to titanium and zirconium, and the atomic concentration ratio of barium to titanium and zirconium is 1 to 1.1, and a secondary component is mixed in which europium is contained in an amount of 2 at% to 4 at% relative to titanium of the barium zirconate titanate.

[0061] (Coating process) Next, a binder such as polyvinyl butyral (PVB) resin, an organic solvent such as ethanol or toluene, and a plasticizer are added to the obtained dielectric material and wet-mixed. Using the resulting slurry, a strip-shaped ceramic green sheet, for example, with a thickness of 0.5 μm or more, is coated onto a substrate using a die coater or doctor blade method and then dried.

[0062] (Internal electrode formation process) Next, a metal conductive paste containing an organic binder for forming internal electrodes is printed onto the surface of the ceramic green sheet by screen printing, gravure printing, or the like, to arrange an internal electrode pattern that alternately leads to a pair of external electrodes with different polarities. Ceramic particles are added to the metal conductive paste as a co-material. The main component of the ceramic particles is not particularly limited, but it is preferable that it is the same as the main component ceramic of the dielectric layer 11. For example, barium titanate with an average particle diameter of 50 nm or less may be uniformly dispersed.

[0063] (Crimping process) Subsequently, the ceramic green sheet with the internal electrode pattern printed on it is punched out to a predetermined size, and with the substrate peeled off, the punched ceramic green sheet is stacked for a predetermined number of layers (e.g., 100 to 1000 layers) such that the internal electrode layer 12 and the dielectric layer 11 are staggered, and the edges of the internal electrode layer 12 are alternately exposed on both ends of the dielectric layer 11 in the longitudinal direction, alternately leading out to a pair of external electrodes 20a and 20b with different polarities. Cover sheets for forming the cover layer 13 are pressed onto the top and bottom of the stacked ceramic green sheet and cut to a predetermined chip size (e.g., 1.0 mm x 0.5 mm).

[0064] (Firing process) The ceramic laminate thus obtained is subjected to binder removal treatment in an N2 atmosphere, and then a metal paste that will serve as the base layer for the external electrodes 20a and 20b is applied by the dip method, and the oxygen partial pressure is 10 -12 MPa~10 -9The product is fired in a reducing atmosphere at MPa and 1160°C to 1280°C for 5 to 10 minutes.

[0065] Furthermore, if the heating rate is set to a slow rate of about 10°C / h, the diffusion of rare earth elements and zirconium is promoted in the dielectric material barium titanate, and totally solid-solution particles are formed. In this case, a long lifespan can be obtained, but the dielectric constant tends to decrease, and the sintering stability and capacitance temperature characteristics tend to deteriorate. Therefore, in this embodiment, it is preferable to suppress the diffusion of zirconium by setting the heating rate to 6000°C / h or higher and 10000°C / h or lower, thereby forming a core-shell structure with a large zirconium concentration gradient.

[0066] Furthermore, by adjusting the firing conditions such as the particle size of the barium titanate powder in the dielectric material, the firing temperature, and the firing time, the average particle size of the dielectric crystals 17 in the dielectric layer 11 of the capacitance region 14 obtained after firing can be adjusted.

[0067] (Re-oxidation process) In order to return oxygen to the partially reduced main phase, barium titanate, of the dielectric layer 11 fired in a reducing atmosphere, heat treatment may be performed at approximately 1000°C in a mixed gas of N2 and water vapor, or at 500°C to 700°C in air, without oxidizing the internal electrode layer 12. This process is called the re-oxidation process.

[0068] (Plating process) Subsequently, a metal coating of copper, nickel, tin, etc. is applied to the underlayer of the external electrodes 20a and 20b by plating. Through these steps, the multilayer ceramic capacitor 100 is completed.

[0069] According to the manufacturing method of this embodiment, a multilayer ceramic capacitor 100 that achieves both a long lifespan and excellent capacitance-temperature characteristics can be manufactured by mixing a base material having barium zirconate titanate as the main component, containing zirconium in an amount of 4 at% to 30 at% relative to titanium and zirconium, with an atomic concentration ratio of barium to titanium and zirconium of 1 to 1.1, and a secondary component containing europium in an amount of 2 at% to 4 at% relative to the titanium of the barium zirconate titanate, and firing the mixture to form a ceramic green sheet.

[0070] Although the above embodiments describe multilayer ceramic capacitors as an example of ceramic electronic components, they are not limited to this. For example, the configurations of the above embodiments can also be applied to other multilayer ceramic electronic components such as varistors and thermistors. [Examples]

[0071] Below, a multilayer ceramic capacitor according to the embodiment was fabricated and its characteristics were investigated.

[0072] (Example 1) Barium zirconate titanate with a particle size of 200 nm, rare earth oxides, various additives, and organic solvents were weighed in predetermined ratios and mixed and ground using 1 mm diameter zirconia beads.

[0073] Barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.30. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1 at%; the amount of manganese added was set to 0.65 at%; and the amount of magnesium added was set to 1.5 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.100.

[0074] (Example 2) In Example 2, barium zirconate titanate (BaTi(1-x) Zr x The value of x in O3 was set to 0.30. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1 at%; the amount of manganese added was set to 0.65 at%; and the amount of magnesium added was set to 1.5 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.090.

[0075] (Example 3) In Example 3, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.20. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.080.

[0076] (Example 4) In Example 4, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.20. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1 at%; the amount of manganese added was set to 0.65 at%; and the amount of magnesium added was set to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.060.

[0077] (Example 5) In Example 5, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.20. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1 at%; the amount of manganese added was set to 0.65 at%; and the amount of magnesium added was set to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.060.

[0078] (Example 6) In Example 6, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.006.

[0079] (Example 7) In Example 7, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.10. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.003.

[0080] (Example 8) In Example 8, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.10. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1 at%; the amount of manganese added was set to 0.65 at%; and the amount of magnesium added was set to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.003.

[0081] (Example 9) In Example 9, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.09. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.004.

[0082] (Example 10) In Example 10, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.09. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2.5 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.005.

[0083] (Example 11) In Example 11, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.09. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.006.

[0084] (Example 12) In Example 12, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.04. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.004.

[0085] (Example 13) In Example 13, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.04. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2.5 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.002.

[0086] (Example 14) In Example 14, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.04. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2.5 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.005.

[0087] (Example 15) In Example 15, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.04. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 0.75 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.006.

[0088] (Example 16) In Example 16, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 4 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.003.

[0089] (Example 17) In Example 17, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 0.75 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.004.

[0090] (Example 18) In Example 18, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.003.

[0091] (Example 19) In Example 19, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2.5 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.25 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.003.

[0092] (Example 20) In Example 20, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2.5 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.005.

[0093] (Example 21) In Example 21, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1 at%; the amount of manganese added was set to 0.65 at%; and the amount of magnesium added was set to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.002.

[0094] (Example 22) In Example 22, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.006.

[0095] (Comparative Example 1) In Comparative Example 1, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.35. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 3 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1 at%; the amount of manganese added was set to 0.65 at%; and the amount of magnesium added was set to 1.5 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.100.

[0096] (Comparative Example 2) In Comparative Example 2, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.02. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.000.

[0097] (Comparative Example 3) In Comparative Example 3, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Dysprosium (Dy) oxide was used as the rare earth oxide, and the amount of dysprosium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 0.999.

[0098] (Comparative Example 4) In Comparative Example 4, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.14. Dysprosium oxide was used as the rare earth oxide, and the amount of dysprosium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 0 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.000.

[0099] (Comparative Example 5) In Comparative Example 5, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Gadolinium (Gd) oxide was used as the rare earth oxide, and the amount of gadolinium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.001.

[0100] (Comparative Example 6) In Comparative Example 6, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Gadolinium oxide was used as the rare earth oxide, and the amount of gadolinium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 0 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.001.

[0101] (Comparative Example 7) In Comparative Example 7, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.14. Lanthanum (La) oxide was used as the rare earth oxide, and the amount of lanthanum added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 0.993.

[0102] (Comparative Example 8) In Comparative Example 8, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Lanthanum oxide was used as the rare earth oxide, and the amount of lanthanum added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 0 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 0.993.

[0103] (Comparative Example 9) In Comparative Example 9, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Holmium (Ho) oxide was used as the rare earth oxide, and the amount of holmium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.000.

[0104] (Comparative Example 10) In Comparative Example 10, barium zirconate titanate (BaTi (1-x) Zr xThe value of x in O3 was set to 0.14. Holmium oxide was used as the rare earth oxide, and the amount of holmium added to the titanium in barium zirconate titanate was set to 2 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1.5 at%, the amount of manganese added to 0.65 at%, and the amount of magnesium added to 0 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.000.

[0105] (Comparative Example 11) In Comparative Example 11, barium zirconate titanate (BaTi (1-x) Zr x The value of x in O3 was set to 0.14. Europium oxide was used as the rare earth oxide, and the amount of europium added to the titanium in barium zirconate titanate was set to 1 at%. The amount of silicon added to the titanium in barium zirconate titanate was set to 1 at%; the amount of manganese added was set to 0.65 at%; and the amount of magnesium added was set to 1 at%. The atomic concentration ratio (A / B ratio) of barium to titanium and zirconium was set to 1.000.

[0106] For each of Examples 1-22 and Comparative Examples 1-11, a ceramic green sheet was coated with a slurry obtained by adding a binder, an internal electrode pattern was printed with nickel paste, the layers were laminated, and cut into a 1005 shape to produce a 1005-shaped ceramic laminate. The ceramic laminate was heated to 1230°C at a heating rate of 6000°C / h and subjected to high-speed firing. The thickness of the dielectric layer after firing was 2.0 μm. The average particle size was adjusted by the amount of titanium (x), the amount of silicon and magnesium added, and the A / B ratio in each example and comparative example. When the amount of titanium and silicon added was large, the average particle size tended to be large, and when the amount of magnesium added and the A / B ratio were large, the average particle size tended to be small.

[0107] (Average particle size) For each of Examples 1-22 and Comparative Examples 1-11, the average grain size of the dielectric crystal in the dielectric layer in the capacitance region was measured. The average grain size of the dielectric crystal was measured from SEM images of the cross-section along the stacking direction. The average grain size of Example 1 was 390 nm. The average grain size of Example 2 was 400 nm. The average grain size of Example 3 was 360 nm. The average grain size of Example 4 was 340 nm. The average grain size of Example 5 was 350 nm. The average grain size of Example 6 was 290 nm. The average grain size of Example 7 was 330 nm. The average grain size of Example 8 was 320 nm. The average grain size of Example 9 was 320 nm. The average grain size of Example 10 was 340 nm. The average grain size of Example 11 was 350 nm. The average grain size of Example 12 was 240 nm. The average grain size of Example 13 was 280 nm. The average grain size of Example 14 was 260 nm. The average particle size of Example 15 was 260 nm. The average particle size of Example 16 was 280 nm. The average particle size of Example 17 was 350 nm. The average particle size of Example 18 was 320 nm. The average particle size of Example 19 was 320 nm. The average particle size of Example 20 was 340 nm. The average particle size of Example 21 was 330 nm. The average particle size of Example 22 was 380 nm. The average particle size of Comparative Example 1 was 450 nm. The average particle size of Comparative Example 2 was 300 nm. The average particle size of Comparative Example 3 was 270 nm. The average particle size of Comparative Example 4 was 480 nm. The average particle size of Comparative Example 5 was 320 nm. The average particle size of Comparative Example 6 was 500 nm. The average particle size of Comparative Example 7 was 320 nm. The average particle size of Comparative Example 8 was 450 nm. The average particle size of Comparative Example 9 was 320 nm. The average particle size of Comparative Example 10 was 460 nm. The average particle size of Comparative Example 11 was 350 nm.

[0108] (Characteristic testing) The relative permittivity was measured under conditions of 1 Vrms and 1 kHz. The temperature characteristic coefficient (TCC) of the permittivity was measured under conditions of 0.2 Vrms and 1 kHz in the range of -55°C to 125°C. For accelerated lifetime testing, 10 samples were tested at a high temperature and high electric field of 140°C and 50 V / μm until all samples failed, and the average time was defined as the lifetime value.

[0109] If the X7T characteristics (capacity change rate based on 25°C from -55°C to 125°C, +22% to -33%) were met, the X7T characteristics were judged as passing ("〇"), and if they were not met, the X7T characteristics were judged as failing ("×"). A lifespan of 4000 min or more was judged as sufficiently long, and a lifespan of 10000 min or more was judged as particularly sufficiently long. If the X7T characteristics were passed and the lifespan was 4000 min or more, the overall judgment was good ("〇"). If the X7T characteristics were not passed or the lifespan was less than 4000 min, the overall judgment was poor ("×"). If the X7T characteristics were passed and the lifespan was 10000 min or more, the overall judgment was very good ("◎"). The results are shown in Table 2.

[0110] Examples 1 to 15 were judged as good ("〇") or very good ("◎") overall. This is thought to be because the dielectric layer in the capacitance region consists of a base material mainly composed of barium zirconate titanate, containing zirconium in amounts of 4 at% to 30 at% relative to titanium and zirconium, with an atomic concentration ratio of barium to titanium and zirconium of 1 to 1.1, and a secondary component containing europium in amounts of 2 at% to 4 at% relative to titanium in the barium zirconate titanate.

[0111] In contrast, Comparative Example 1 did not satisfy the X7T characteristics. This is thought to be because the high zirconium content led to increased diffusion of barium zirconate titanate, making grain growth control difficult. Comparative Example 2 satisfied the X7T characteristics, but its lifetime was shortened. This is thought to be because the low zirconium content resulted in the formation of many oxygen vacancies.

[0112] Furthermore, when x was 0.14 or greater, the lifetime value was 10,000 min or greater. Therefore, it can be seen that it is preferable for x to be 0.14 or greater. From the relative permittivity results of Examples 3 to 15 and Comparative Example 1, it can be seen that in order to maintain a high relative permittivity, it is preferable for x to be 0.20 or less.

[0113] The results from Examples 16-22 show that if the average grain size of the dielectric crystal is in the range of 200 nm to 400 nm, the X7T characteristics are satisfied and a lifetime value of 10,000 min or more is obtained.

[0114] The results from Comparative Examples 3-10 showed that sufficient lifetime values ​​could not be obtained under conditions where other rare earth elements were added instead of europium. In contrast, the results from Examples 21 and 22 show that sufficient lifetime values ​​can be obtained when the same amount of europium is used.

[0115] In Comparative Example 11, a sufficient lifetime value was not obtained. This is thought to be because the amount of europium relative to titanium was insufficient.

[0116] Figure 6 is a schematic diagram of a cross-sectional SEM image of the dielectric layer 11 in the capacitance region 14 of Example 18. As shown in Figure 6, the average grain size of the dielectric crystals is between 200 nm and 400 nm, indicating that abnormal grain growth was suppressed. Figure 7 is a schematic diagram of a TEM (Transmission Electron Microscope) image of the dielectric layer in the capacitance region of Example 18. As shown in Figure 7, a core portion 31 and a shell portion 32 covering the core portion 31 were confirmed in the dielectric layer in the capacitance region after firing. [Table 2]

[0117] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0118] 10 stacked chips 11 Dielectric layer 12 Internal electrode layer 13. Cover layer 14 capacity area 15 End margin 16 Side margins 17 Dielectric Crystals 20a,20b external electrode 100 Multilayer Ceramic Capacitors

Claims

1. A base material having barium zirconate titanate as the main component, containing zirconium in an amount of 4 at% to 30 at% relative to titanium and zirconium, and having an atomic concentration ratio of barium to titanium and zirconium of 1.06 to 1.1, A dielectric composition having a minor component containing 2 at% to 4 at% europium relative to the titanium of the barium zirconate titanate.

2. The dielectric composition according to claim 1, wherein the base material contains 14 at% or more zirconium relative to the titanium and zirconium of the barium zirconate titanate.

3. The dielectric composition according to claim 1 or 2, wherein the base material contains 20 at% or less zirconium relative to the titanium and zirconium of the barium zirconate titanate.

4. The dielectric crystal comprising the base material and the auxiliary components has a core-shell structure. The dielectric composition according to any one of claims 1 to 3, wherein the average grain size of the dielectric crystal is 200 nm or more and 400 nm or less.

5. A plurality of dielectric layers comprising: a base material having barium zirconate titanate as the main component, containing zirconium in an amount of 4 at% to 30 at% relative to titanium and zirconium, with an atomic concentration ratio of barium to titanium and zirconium of 1.06 to 1.1; and a secondary component containing europium in an amount of 2 at% to 4 at% relative to the titanium of the barium zirconate titanate; Multiple internal electrode layers are stacked via the aforementioned multiple dielectric layers and alternately face each other, A multilayer ceramic electronic component having a plurality of stacked dielectric layers and a plurality of internal electrode layers, and external electrodes provided on the sides of the plurality of internal electrode layers and electrically connected to the plurality of internal electrode layers.

6. The multilayer ceramic electronic component according to claim 5, wherein the base material contains 14 at% or more zirconium relative to the titanium and zirconium of the barium zirconate titanate.

7. The multilayer ceramic electronic component according to claim 5 or 6, wherein the base material contains 20 at% or less of zirconium relative to the titanium and zirconium of the barium zirconate titanate.

8. The plurality of dielectric layers include dielectric crystals having a core-shell structure. The multilayer ceramic electronic component according to any one of claims 5 to 7, wherein the average grain size of the dielectric crystal is 200 nm or more and 400 nm or less.

9. A multilayer ceramic electronic component according to any one of claims 5 to 8, which satisfies the X7T characteristics.

10. A process of forming a ceramic green sheet by mixing a base material having barium zirconate titanate as the main component, containing zirconium in an amount of 4 at% to 30 at% relative to titanium and zirconium, with an atomic concentration ratio of barium to titanium and zirconium of 1.06 to 1.1, and a secondary component containing europium in an amount of 2 at% to 4 at% relative to the titanium of the barium zirconate titanate, The process of forming an internal electrode pattern on the ceramic green sheet, A step of obtaining a laminate by stacking the ceramic green sheets on which the internal electrode pattern is formed, A method for manufacturing a multilayer ceramic electronic component, comprising the step of firing the laminate to form a plurality of dielectric layers and a plurality of internal electrodes.

11. The method for manufacturing a multilayer ceramic electronic component according to claim 10, wherein the laminate is fired at a heating rate of 6000°C / h or higher.

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