Multilayer ceramic electronic component

Abstract

To provide a multilayer ceramic electronic component with reduced residual stress and improved DC bias characteristics.SOLUTION: A battery has a laminated structure in which dielectric layers and internal electrode layers are alternately stacked, and the internal electrode layers contain a silicate structural material consisting of an oxide of silicon and aluminum and an oxide of at least one element selected from the group consisting of lithium, boron, magnesium, zinc, barium, titanium, zirconium, phosphorus, sodium, potassium, and boron.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a multilayer ceramic electronic component. [Background technology]

[0002] For multilayer ceramic electronic components, it is always desirable to reduce residual stress during manufacturing to improve product yield and to improve bias characteristics. Patent Document 1 proposes that amorphous silica, which functions as a steric hindrance between metal particles, be present in the internal electrode layer in order to improve AC voltage characteristics. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-151231 Summary of the Invention [Problem to be solved by the invention]

[0004] When an internal electrode paste containing amorphous silica is fired, some of the amorphous silica is incorporated into the internal electrode and some is expelled from the internal electrode layer. However, during firing, high-thermal expansion crystals such as cristobalite may be produced from the amorphous silica, which may result in a high thermal expansion coefficient. Furthermore, a high thermal expansion coefficient increases residual stress in the dielectric layer, degrading bias characteristics and possibly causing cracks. The present disclosure provides a multilayer ceramic electronic component with reduced residual stress and improved DC bias characteristics. [Means for solving the problem]

[0005] The multilayer ceramic electronic component according to the present disclosure has a laminated structure in which dielectric layers and internal electrode layers are alternately laminated, The internal electrode layers contain a silicate structural material consisting of oxides of silicon and aluminum and an oxide of at least one element selected from the group consisting of lithium, boron, magnesium, zinc, barium, titanium, zirconium, phosphorus, sodium, potassium and boron. [Effects of the Invention]

[0006] According to the present disclosure, the silicate structural material present in the internal electrode layer suppresses shrinkage of the internal electrode layer during cooling after firing and reduces residual stress in the dielectric layer, thereby reducing the residual stress generated in the dielectric layer, facilitating polarization reversal when DC is applied, and improving DC bias characteristics. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view showing a multilayer ceramic capacitor 1 according to an embodiment of the present disclosure. [Figure 2] 2 is a perspective view showing an element part 2 of the multilayer ceramic capacitor 1 of FIG. [Figure 3] FIG. 2 is a perspective view showing the laminate 13 after firing. [Figure 4] FIG. 2 is a schematic diagram showing a silicate structure material present in voids generated in an internal electrode layer. [Figure 5A] FIG. 10 is a diagram schematically showing a state in which the dielectric layer and the internal electrode layer are not bonded to each other. [Figure 5B] FIG. 2 is a diagram schematically showing a state in which a dielectric layer and an internal electrode layer are bonded together. [Figure 5C] FIG. 2 is a diagram schematically showing an element component including a silicate structural material in an internal electrode layer. [Figure 6] 10 is a graph showing the relationship between the electrode continuity ratio and residual stress in an internal electrode layer. [Figure 7] 1 is a graph showing the relationship between ceramic particle size and effective relative dielectric constant. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the laminate component of the present disclosure will be described with reference to the drawings. Note that, although a multilayer ceramic capacitor will be described as an example of the laminate component, the laminate component of the present disclosure is not limited to the multilayer ceramic capacitor and can be applied to various laminate components having ferromagnetic layers, such as multilayer piezoelectric elements, multilayer thermistor elements, multilayer chip coils, and ceramic multilayer substrates.

[0009] <Multilayer ceramic electronic components> In this embodiment, FIG. 1 is a perspective view showing a multilayer ceramic capacitor 1 according to an embodiment of the present disclosure, FIG. 2 is a perspective view showing an element component 2 of the multilayer ceramic capacitor 1 of FIG. 1, and FIG. 3 is a perspective view showing a precursor of the element component 2 of FIG. 2. FIG. 2 is a diagram showing the element component 2 after firing, but it is also a diagram showing the element component before firing. The element component 2 after firing has shrunk due to firing, but it has the same structure as the element component 2 before firing. FIG. 3 is a diagram showing a laminate 13 after firing, but it is also a diagram showing the laminate before firing.

[0010] A multilayer ceramic capacitor 1, which is an embodiment of a multilayer ceramic electronic component, includes a laminate 13 and dielectric protection layers 6A and 6B. As shown in FIG. 1, the multilayer ceramic capacitor 1 may also include a first external electrode 3A and a second external electrode 3B for electrical connection to the outside. As shown in FIG. 2, the laminate 13 and the dielectric protection layers 6A and 6B constitute an element component 2. The laminate 13 is a precursor of the element component 2 and is also referred to as an element precursor 13. The dielectric protection layers 6A and 6B are also referred to as protection layers 6.

[0011] As shown in Fig. 3, the laminate 13 is configured by alternately stacking dielectric layers 4 and internal electrode layers 5 in a third direction (Z-axis direction). The laminate 13 has a substantially rectangular parallelepiped shape. The laminate 13 has a first surface 7A and a second surface 7B that face each other in the third direction. The laminate 13 has a first end surface 8A and a second end surface 8B that face each other in the first direction (X-axis direction), and a first cut side surface 9A and a second cut side surface 9B that face each other in a second direction (Y-axis direction).

[0012] The first external electrode 3A and the second external electrode 3B may be collectively referred to as the external electrode 3. Furthermore, the first surface 7A and the second surface 7B may be collectively referred to as the main surface 7, the first end surface 8A and the second end surface 8B may be collectively referred to as the end surface 8, and the first cut side surface 9A and the second cut side surface 9B may be collectively referred to as the cut side surface 9. Each component will be described below.

[0013] <Dielectric layer> The dielectric layer 4 is made of an insulating material. The dielectric layer 4 may be made of a ceramic material such as BaTiO3 (barium titanate), CaTiO3 (calcium titanate), SrTiO3 (strontium titanate), or BaZrO3 (barium zirconate). The dielectric layer 4 may also contain trace amounts of rare earth elements such as Y (yttrium), Dy (dysprosium), Ho (holmium), and Yb (ytterbium), as well as V (vanadium), manganese, etc.

[0014] In this embodiment, the insulating material constituting the dielectric layer 4 preferably has a particle size of 0.2 μm or less. This increases the number of particles of the insulating material in the dielectric layer and the number of grain boundaries, thereby increasing the volume of the paraelectric shell that does not have DC bias characteristics and improving the DC bias characteristics. The thinner the thickness of the dielectric layer 4, the greater the capacitance of the multilayer ceramic capacitor 1. The thickness of the dielectric layer 4 may be, for example, 0.5 μm to 10 μm.

[0015] <Internal electrode layer> 3, the internal electrode layers 5 are exposed on a first cut side surface 9A and a second cut side surface 9B. The internal electrode layers 5 have end portions 19 exposed on the cut side surfaces 9, and the end portions 19 extend in a first direction. The internal electrode layers 5 are exposed on a first end surface 8A or a second end surface 8B depending on the polarity.

[0016] The internal electrode layers 5 are made of a conductive material. The conductive material may be, for example, a metal material such as Ni (nickel), Cu (copper), Ag (silver), Sn (tin), Pt (platinum), Pd (palladium), Au (gold), or an alloy material containing these metal materials. In this embodiment, the internal electrode layers 5 contain a silicate structural material 10, and the silicate structural material 10 exists in voids that are generated in the internal electrode layers 5 as metal grains that constitute the internal electrode layers 5 grow during firing. The silicate structural material 10 in this embodiment preferably has a particle size of 0.2 μm to 8 μm.

[0017] 4 is a diagram schematically showing the internal electrode layers 5 in the laminate 13 after firing, and the silicate structural material 10 present in the voids generated in the internal electrode layers 5 by firing. The silicate structural material 10 may be any material that contains silicic acid and can suppress the shrinkage of the internal electrode layers 5 during cooling after firing, thereby reducing the residual stress generated in the dielectric layers 4 around the voids in the internal electrode layers 5. Examples of such silicate structural material 10 include silicate structural materials containing oxides of silicon and aluminum and at least one oxide selected from the group consisting of lithium, boron, magnesium, zinc, barium, titanium, zirconium, phosphorus, sodium, potassium, and vanadium.

[0018] Specifically, the silicate structural material 10 may include SiO2 and Al2O3 and at least one selected from Li2O, B2O3, MgO, ZnO, BaO, TiO2, ZrO2, P2O5, Na2O, K2O, and V2O5. More specifically, the silicate structural material 10 may be SiO2-TiO2-Al2O3-B2O3-based glass, Li2O-Al2O3-SiO2-based glass, MgO-Al2O3-SiO2-based glass, or ZnO-Al2O3-SiO2-based glass.

[0019] Furthermore, the silicate structural material 10 of this embodiment has a thermal expansion coefficient of 0.1×10 -6 / K~1.0×10 -6 / K. It is presumed that the reason why the silicate structure material 10 of this embodiment has a small thermal expansion coefficient is that a silicate structure material 10 with a β-quartz structure is formed in the internal electrode layer 5 when the element component 2 is fired to manufacture the multilayer ceramic capacitor 1. The β-quartz structure is a quartz structure in which Li + The structure is one in which ions such as Li ions are dissolved, and Al is dissolved in the four-coordination site of Si, and the ions are in the gaps of the crystal lattice. + The movement of the SiO2 causes the crystal to contract, lowering the thermal expansion coefficient. By suppressing the contraction of the internal electrode (Ni) layer 5, the pressure load on the dielectric barium titanate (BaTiO3) can be reduced.

[0020] 5A to 5C are diagrams schematically showing the stress absorption mechanism due to the difference in shrinkage rate between the dielectric layers 4 and the internal electrode layers 5 when the element component 2 is cooled after being fired. Fig. 5A schematically shows a state in which the dielectric layers 4 and the internal electrode layers 5 are not bonded together, and the dielectric layers 4 and the internal electrode layers 5 have the same length before firing, but after cooling after firing, they shrink to lengths according to their respective shrinkage rates.

[0021] 5B is a schematic diagram showing the state in which the dielectric layer 4 and the internal electrode layer 5 are bonded together, and when cooled after firing, they each shrink according to their respective shrinkage rates, but because the dielectric layer 4 and the internal electrode layer 5 are bonded together, the dielectric layer 4, which has a smaller shrinkage rate, suppresses the shrinkage of the internal electrode layer 5, which has a larger shrinkage rate. As a result, the dielectric layer 4 is subjected to a force (residual stress) that pulls it in the shrinkage direction of the internal electrode layer 5, and if the strength of the element part 2 is smaller than the residual stress, cracks will occur.

[0022] 5C is a schematic diagram of an element component 2 containing a silicate structural material 10 in the internal electrode layer 5. The silicate structural material 10 present in the internal electrode layer 5 does not shrink because it has an extremely small shrinkage rate, and even after cooling, together with the dielectric layer 4, it absorbs the force (residual stress) that is pulled in the shrinkage direction, thereby reducing the residual stress of the dielectric layer 4. This reduces the residual stress generated in the dielectric layer 4, making it easier to reverse the polarization when DC is applied, and as a result, the DC bias characteristics can be improved.

[0023] Examples of silicate structural materials 10 with a β-quartz structure include β-petalite (Li2O-Al2O3-8SiO2), β-spodumene (Li2O-Al2O3-4SiO2), and β-eucryptite (Li2O-Al2O3-2SiO2), and any of these may be used in this embodiment.

[0024] The silicate structural material 10 contained in the internal electrode layers 5 is composed of the above-mentioned SiO2 and Al2O3 and at least one selected from Li2O, B2O3, MgO, ZnO, BaO, TiO2, ZrO2, P2O5, Na2O, K2O and V2O5, and among these, SiO2 and Al2O3 and at least Li2O and B2O 3と A silicate structural material 10 containing as a major component is preferred.

[0025] Taking the silicate structure material 10 containing SiO2 and Al2O3, and at least Li2O and B2O3 as main components, as an example of a composition ratio, it is preferable to use a material containing 0.05 to 0.40 mol of Al2O3, 0.05 to 0.30 mol of Li2O, and 0.05 to 0.15 mol of B2O3 per mol of SiO2. Furthermore, it is preferable to adjust the glass powder of the silicate structure material 10 so that its glass softening point is in the range of 400 to 600°C. For example, a mixture of oxides is used as the glass powder. The glass softening point is adjusted by adjusting the composition ratio.

[0026] When the multilayer ceramic capacitor 1 is a capacitor with a large number of layers, the thickness T of the internal electrode layers 5 may be, for example, 0.4 μm to 1.0 μm. As long as the characteristics as a capacitor can be ensured, the thinner the thickness T of the internal electrode layers 5, the fewer internal defects caused by internal stress will be, and the more reliable the multilayer ceramic capacitor 1 will be.

[0027] In this embodiment, the internal electrode layers 5 preferably have an electrode continuity ratio of 75% to 90%, and if the electrode continuity ratio is less than 75%, the effective area of ​​the internal electrode layers 5 may be reduced, resulting in a small effective capacitance, although the residual stress is sufficiently alleviated. Also, if the electrode continuity ratio exceeds 90%, the occurrence of residual stress may not be fully alleviated, resulting in a small effective capacitance.

[0028] The electrode continuity ratio can be adjusted by adjusting the composition ratio and particle size of the conductive material used to form the internal electrode layers 5 and the silicate structural material 10. An example of a preferable composition ratio is, for example, 0.74 to 6.74 parts by mass of SiO2, 0.10 to 0.87 parts by mass of Al2O3, 0.05 to 0.46 parts by mass of B2O3, and 0.15 to 1.39 parts by mass of Li2O relative to 100 parts by mass of Ni.

[0029] <Protective layer> The laminate 13 is provided with a protective layer 6. The protective layer 6 is made of an insulating material. The protective layer 6 may be made of a ceramic material such as BaTiO3, CaTiO3, SrTiO3, or BaZrO3. The protective layer 6 may be made of the same ceramic material as the ceramic material that forms the dielectric layer 4. The first protective layer 6A is located on the first cut side surface 9A and covers the internal electrode layers 5 exposed at the first cut side surface 9A. The second protective layer 6B is located on the second cut side surface 9B and covers the internal electrode layers 5 exposed at the second cut side surface 9B.

[0030] <External electrodes, etc.> 1, the external electrodes 3 include a first external electrode 3A and a second external electrode 3B. The first external electrode 3A is located on the first end surface 8A and is electrically connected to the internal electrode layers 5 exposed at the first end surface 8A. The second external electrode 3B is located on the second end surface 8B and is electrically connected to the internal electrode layers 5 exposed at the second end surface 8B. The external electrodes 3 wrap around to the first surface 7A and the second surface 7B.

[0031] The first external electrode 3A wraps around onto the first cut side surface 9A and the second cut side surface 9B, covering a portion of the first protective layer 6A closer to the first end surface 8A. The second external electrode 3B wraps around onto the first cut side surface 9A and the second cut side surface 9B, covering a portion of the second protective layer 6B closer to the second end surface 8B. The first external electrode 3A and the second external electrode 3B are electrically insulated from each other.

[0032] The external electrodes 3 may be composed of an underlayer that connects to the element component 2 and a plated outer layer that facilitates solder mounting. The underlayer may be applied and baked onto the element component 2 after firing, or may be applied to the element component 2 before firing and fired simultaneously with the element component 2.

[0033] The base layer may be formed by plating directly onto the base part 2. The base layer and the plated outer layer may each consist of a single layer or multiple layers. The base layer and the plated outer layer may be made of a metal material such as Ni, Cu, Ag, Pd, or Au, or an alloy material containing these metal materials. The base layer and the plated outer layer may have a conductive resin layer as an intermediate layer or outer layer.

[0034] On the cut side surface 9 of the laminate 13, the positive internal electrode layers 5 and the negative internal electrode layers 5 are alternately adjacent to each other with the dielectric layer 4 interposed therebetween.

[0035] In this embodiment, a protective layer 6 for electrical insulation between the internal electrode layers 5 of opposite polarity and for physical protection of the end portions 19 is located on the first cut side surface 9A and the second cut side surface 9B. The protective layer 6 may be made of a ceramic material, in which case the protective layer 6 can have insulating properties and relatively high mechanical strength. Furthermore, when the protective layer 6 is made of a ceramic material, the laminate 13 and the protective layer 6 can be fired simultaneously. In FIG. 2, the boundary between the laminate 13 and the protective layer 6 is indicated by a two-dot chain line, but the actual boundary is not clearly visible. The thinner the protective layer 6, the smaller the size and larger the capacitance of the multilayer ceramic capacitor 1 can be. The thickness of the protective layer 6 may be, for example, 5 μm to 40 μm.

[0036] <Manufacturing method> The laminate device of the present disclosure can be manufactured by the following method. First, a ceramic powder mixture consisting of a ceramic dielectric material and an additive is wet-pulverized and mixed in a bead mill. The ceramic dielectric material is not particularly limited as long as it is used in electronic components, but a preferred specific example is a mixture of barium titanate, one of the rare earth oxides selected from divanadium pentoxide (VO), magnesium oxide (MgO), yttrium oxide (YO), dysprosium oxide (DyO), holmium oxide (HoO), and ytterbium oxide (YbO), and manganese carbonate.

[0037] In this case, the barium titanate (BaTiO3) should have a Ba / Ti molar ratio of 1.001 to 1.01, a purity of 99.9% or higher, and an average particle size of 0.1 to 0.2 μm. For 100 moles of barium titanate (BaTiO3), the amount of vanadium pentoxide (VO5) is preferably 0.03 to 0.1 moles, magnesium oxide (MgO) is preferably 0.5 to 1 mole, yttrium oxide (YO3), dysprosium oxide (Dy2O3), holmium oxide (Ho2O3), or ytterbium oxide (Yb2O3) is preferably 0.5 to 2 moles, and manganese carbonate is preferably 0.2 to 0.3 moles.

[0038] Next, a polyvinyl butyral binder, a plasticizer, and an organic solvent are added to the pulverized and mixed slurry and mixed to prepare a ceramic slurry.

[0039] Next, a die coater is used to form a ceramic green sheet on a carrier film. The thickness of the ceramic green sheet may be, for example, about 1 to 10 μm. The thinner the ceramic green sheet, the higher the capacitance of the multilayer ceramic capacitor. The method for forming the ceramic green sheet is not limited to a die coater, and may also be performed using, for example, a doctor blade coater or a gravure coater. Next, a conductive paste containing nickel (Ni), a ferromagnetic metal material that will become the internal electrode layers 5, is printed in a predetermined pattern on the ceramic green sheet prepared above using a screen printing method. The method for printing the conductive paste is not limited to a screen printing method, and may also be a gravure printing method, for example.

[0040] The conductive paste contains a silicate structural material raw material, in addition to metals such as Ni, Pd, Cu, and Ag, or alloys thereof. Examples of silicate structural material raw materials include oxides of silicon and aluminum, and at least one oxide selected from lithium, boron, magnesium, zinc, barium, titanium, zirconium, phosphorus, sodium, potassium, and vanadium. Of these, oxides of lithium and boron are preferred. Specifically, it is preferable to use 0.05 to 0.3 moles of lithium oxide, 0.05 to 0.4 moles of aluminum oxide, and 0.05 to 0.15 moles of boron oxide per mole of silicon oxide.

[0041] After printing, the conductive paste is dried. The drying process primarily volatilizes the solvent, leaving the internal electrode layer with nickel particles and silicate structural material raw materials dispersed in the organic binder. The thinner the internal electrode layer 5, the more likely it is to reduce internal defects caused by internal stress, as long as the capacitor's characteristics are maintained. For a capacitor with a high number of layers, the thickness of the internal electrode layer 5 may be, for example, 2.0 μm or less.

[0042] Next, a predetermined number of ceramic green sheets on which internal electrode layers 5 are printed are stacked on top of the predetermined number of stacked ceramic green sheets, and then a predetermined number of ceramic green sheets are stacked on top of that. A predetermined number of ceramic green sheets on which internal electrode layers 5 are printed are stacked while shifting the patterns of the internal electrode layers 5. Next, a laminate formed by stacking multiple ceramic green sheets is pressed in the stacking direction to obtain a base laminate. The pressing of the laminate can be performed using, for example, an isostatic press. Inside the base laminate, the internal electrode layers 5 are embedded in a layered manner, sandwiching the ceramic green sheets between them. When the base laminate is cut lengthwise and crosswise, it becomes an element precursor 13 shown in Figure 3.

[0043] Next, the element precursors 13 or element components 2 are aligned by the alignment method described above, and the necessary processing is performed on the side surfaces 9 of each element component 2. The processing may be a process of forming a protective layer 6 on the element precursors 13, or a process of polishing the element components 2. The element components 2 obtained in this manner are fired, and then external electrodes 3 are formed, thereby producing the multilayer ceramic capacitor 1.

[0044] The firing temperature can be set appropriately depending on the metal materials contained in the conductive paste that will become the dielectric layers 4 and the internal electrode layers 5, and the temperature at which the silicate structure material 10 is formed from the silicate structure material raw material. The firing temperature may be, for example, 1100 to 1250°C. When removing the element precursor 13 after it has been aligned in the magnetic field, it can be removed while maintaining its aligned orientation by moving it to a region in the perpendicular magnetic field where the element component does not reverse. If the magnet is an electromagnet, it may be removed after being switched off.

[0045] Example 1 The following specific multilayer capacitors were fabricated to verify the effects of the present invention. First, the following dielectric powders were prepared as materials for the ceramic layers. Barium titanate powder, MgO powder, Dy2O3 powder, and MnCO3 powder, each with a different average particle size, were prepared as raw dielectric powders. These powders were mixed with 100 moles of barium titanate powder, adding 0.5 moles of MgO powder, 1 mole of Dy2O3 powder, and 0.3 moles of MnCO3 powder. Furthermore, 1.3 parts by mass of glass powder (SiO2 = 55, BaO = 20, CaO = 15, Li2O = 10 (mol %)) per 100 parts by mass of barium titanate powder to prepare a dielectric powder. Next, this dielectric powder was wet-mixed with a 0.1 mm diameter zirconia ball and a mixed solvent consisting of toluene and alcohol.

[0046] A Ni electrode paste was prepared by adding 3.74 parts by mass of SiO2, 0.48 parts by mass of LiO2, 0.26 parts by mass of Al2O3, and 0.77 parts by mass of B2O3 as silicate structural material raw materials to 100 parts by mass of Ni. This paste was used to laminate 260 sheets with printed internal electrodes, which were then sandwiched between dielectric green sheets without printed internal electrodes and compressed. After compression, the sheets were cut into small pieces and heat-treated (binder removal) in a nitrogen gas atmosphere. They were then fired at 1200°C in a hydrogen-nitrogen gas atmosphere. The fired chips were then reoxidized to produce multilayer ceramic capacitors for DC characteristic measurements. The dielectric layer thickness after firing was 1.32 μm.

[0047] The DC bias characteristics of the obtained multilayer ceramic capacitor for DC characteristic measurement were measured by changing the average particle size of BaTiO3 and rare earth elements and by combining the presence or absence of silicate structural material raw materials, and the effects of these combinations were investigated.

[0048] <Measurement method> Residual stress was measured as follows. The samples were embedded in resin, cross-sectioned, and used as measurement samples. Wide-angle X-ray diffraction patterns were measured at the center of each sample using a detector capable of obtaining two-dimensional diffraction patterns. A measuring device manufactured by Bruker Japan was used. Residual stress at each location was determined by X-ray residual stress measurement (2D method) using the 323 peak of BaTiO3 (2θ ≒ 128.7°C). The Young's modulus and Poisson's ratio of BaTiO3 were set to 100 GPa and 0.30, respectively.

[0049] The dielectric constant and effective dielectric constant were measured as follows. The capacitance at room temperature (25°C) was measured using an LCR meter (Keysight E4980A) at a temperature of 25°C, a frequency of 1.0 kHz, and an AC voltage of 1.0 V / μm. Twenty samples were used, and the average value was calculated. The DC bias characteristics were measured in the same way by applying DC 10 V / μm.

[0050] <Results and Discussion> The results are shown in Figure 7. Figure 7 shows that multilayer ceramic capacitors containing silicate structural materials in the internal electrode layers have higher effective dielectric constants than multilayer ceramic capacitors that do not contain silicate structural materials in the internal electrode layers, even if the average grain size of the ceramic in the dielectric layers is the same, because residual stress is suppressed, and the effective dielectric constant difference is 50 (10 V / μm) when the ceramic grain size is 0.25 μm or more, 100 (10 V / μm) when the ceramic grain size is 0.20 μm, and 200 (10 V / μm) when the ceramic grain size is 0.15 μm.

[0051] Furthermore, for multilayer ceramic capacitors with ceramics having the same average particle size, the difference in effective relative dielectric constant was large when the average particle size was 0.2 μm or less, regardless of whether the multilayer ceramic capacitor contained a silicate structural material in the internal electrode layer or did not contain a silicate structural material in the internal electrode layer.

[0052] This indicates that the residual stress of the multilayer ceramic capacitor is suppressed by including a silicate structure material in the internal electrode layer and setting the ceramic grain size to 0.2 μm, and the increased number of grain boundaries increases the shell volume of the paraelectric material, resulting in improved DC bypass characteristics of the multilayer ceramic capacitor.

[0053] Example 2 Simulations were performed to investigate the relationship between the electrode continuity ratio and residual stress in the internal electrode layer 5. ANSYS, a software program based on the finite element method, was used for the simulation. A 2D model was created by extracting a portion of the laminated portion of a multilayer ceramic capacitor manufactured in the same manner as in Example 1. The structure of this 2D model was as follows: dielectric layer thickness td = 1 μm, electrode layer thickness te = 0.5 μm, number of layers N = 5, effective portion W length = 200 μm, side margin width SM = 50 μm, and cover thickness CM = 1 μm. Using this model, we also investigated the change in residual stress due to the material and electrode continuity ratio of the electrode discontinuity. When changing the electrode continuity ratio, the location of the discontinuity was randomly selected from candidate electrode discontinuity locations with lengths of 1-4 μm, depending on the electrode continuity ratio. The residual stress was calculated by taking the average residual stress of the effective portion, and the average of 100 random calculations was compared with the electrode continuity ratio.

[0054] <Results and Discussion> The results are shown in Figure 6. Compared to when the electrode continuity ratio is 100%, it is clear that as the electrode continuity ratio increases, the residual stress decreases, and that an electrode continuity ratio of 75% to 90% reduces the residual stress σ and suppresses the decrease in effective capacitance.

[0055] According to the present disclosure, the silicate structural material 10 present in the internal electrode layer 5 suppresses the shrinkage of the internal electrode layer 5 during cooling after firing and reduces the residual stress σ of the dielectric layer 4, thereby reducing the residual stress σ generated in the dielectric layer 4, facilitating polarization reversal when DC is applied, and improving the DC bias characteristics.

[0056] The present disclosure can be implemented in the following configurations (1) to (4).

[0057] (1) A laminated structure in which dielectric layers and internal electrode layers are alternately laminated, The internal electrode layers are a multilayer ceramic electronic component containing a silicate structure material made of an oxide of silicon and aluminum and an oxide of at least one element selected from the group consisting of lithium, boron, magnesium, zinc, barium, titanium, zirconium, phosphorus, sodium, potassium, and boron.

[0058] (2) The silicate structural material has a thermal expansion coefficient of 0.1 × 10 -6 / K~1.0×10 -6 The multilayer ceramic electronic component according to the above configuration (1), wherein:

[0059] (3) The multilayer ceramic electronic component according to the above configuration (1) or (2), wherein the dielectric layers are made of ceramic, and the ceramic constituting the dielectric layers has a grain size of 0.2 μm or less.

[0060] (4) A multilayer ceramic electronic component according to the above configuration (1) or (2), wherein the electrode continuity ratio of the internal electrode layers is 75% or more and 90% or less.

[0061] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the gist of the present disclosure. It goes without saying that all or part of the components constituting each of the above-described embodiments can be combined as appropriate within the scope of not contradicting each other. [Explanation of symbols]

[0062] 1. Multilayer ceramic capacitors 2 Body parts 3 External electrode 3A 1st external electrode 3B 2nd external electrode 4 Dielectric Layer 5 Internal electrode layer 6 Protective layer 6A,6B Protective layer 7 Main Surface 7A 1st page 7B 2nd side 8 End face 8A 1st end face 8B 2nd end face 9 Cut side 9A 1st cutting side 9B 2nd cutting side 10 Silicate structural materials 13 Laminate (element precursor)

Claims

1. The laminated structure has dielectric layers and internal electrode layers stacked alternately, The internal electrode layers are a multilayer ceramic electronic component containing a silicate structure material made of an oxide of silicon and aluminum and an oxide of at least one element selected from the group consisting of lithium, boron, magnesium, zinc, barium, titanium, zirconium, phosphorus, sodium, potassium, and boron.

2. The silicate structural material has a thermal expansion coefficient of 0.1×10 －６ / K ~ 1.0 x 10 －６ 2. The multilayer ceramic electronic component according to claim 1, wherein the tensile strength is 1.0 / K.

3. 3. The multilayer ceramic electronic component according to claim 1, wherein the dielectric layers are made of ceramic, and the ceramic has a grain size of 0.2 [mu]m or less.

4. 3. The multilayer ceramic electronic component according to claim 1, wherein the electrode continuity ratio of the internal electrode layers is 75% or more and 90% or less.

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