Multilayer ceramic electronic component and manufacturing method for the same

Abstract

To provide a multilayer ceramic electronic component which can be miniaturized.SOLUTION: A multilayer ceramic electronic component comprises: an element body in which an internal electrode and a dielectric layer are alternately stacked in a first direction, the internal electrode has a pair of side surfaces in which a first internal electrode and a second internal electrode are alternately provided in a first direction, a pair of end surfaces facing each other in a second direction, and an upper surface and a lower surface facing each other in a third direction, and the first internal electrode is exposed at a first end part of the lower surface in the second direction and the second internal electrode is not exposed, the second internal electrode is exposed at the second end part of the lower surface in the second direction and the first internal electrode is not exposed, and the first internal electrode and the second internal electrode in a capacitance region are exposed from the pair of end surfaces and the upper surface; a first insulation layer provided on the pair of side surfaces; a second insulation layer provided on the pair of end surfaces and the upper surface; and a pair of external electrodes in contact with each of the first internal electrode and the second internal electrode that are exposed from the first and second end parts.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a multilayer ceramic electronic component and a method for manufacturing the same.

Background Art

[0002] In multilayer ceramic electronic components such as multilayer ceramic capacitors in which internal electrodes and dielectric layers are laminated, it is known to form a side margin region by attaching a dielectric sheet (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the surfaces to which the dielectric sheets are attached are two surfaces, making it difficult to miniaturize.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a multilayer ceramic electronic component capable of miniaturization and a method for manufacturing the same.

Means for Solving the Problems

[0006] The present invention relates to a multilayer ceramic electronic component in which a plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic are alternately laminated in a first direction. In the first direction, the plurality of internal electrodes are alternately provided with a first internal electrode and a second internal electrode. The multilayer ceramic electronic component has a pair of side faces facing each other in the first direction, a pair of end faces facing each other in a second direction, and an upper surface and a lower surface facing each other in a third direction. At a first end of the lower surface in the second direction, the first internal electrode is exposed and the second internal electrode is not exposed. At a second end of the lower surface in the second direction, the second internal electrode is exposed and the first internal electrode is not exposed. In a capacitance region where the first internal electrode and the second internal electrode face each other in the first direction, the first internal electrode and the second internal electrode are exposed from the pair of end faces and the upper surface, forming a body. A first insulator layer provided on the pair of side faces and mainly composed of a material different from the ceramic, a second insulator layer provided on the pair of end faces and the upper surface and mainly composed of a material different from the ceramic, and a pair of external electrodes respectively contacting the first internal electrode and the second internal electrode exposed from the first end and the second end.

[0007] In the above configuration, the dielectric constant of the first insulator layer and the second insulator layer can be set to be 1 / 2 times or less of that of the plurality of dielectric layers.

[0008] In the above configuration, the thickness of the first insulator layer and the second insulator layer can be set to be 2 times or less of the thickness of at least one of the plurality of dielectric layers.

[0009] In the above configuration, when the maximum thickness and the minimum thickness of the first insulator layer and the second insulator layer are Tmax and Tmin respectively, (Tmax - Tmin) / (Tmax + Tmin) < 0.5.

[0010] The main component of the first insulator layer and the main component of the second insulator layer can be different.

[0011] In the above configuration, the toughness of the first insulator layer can be made higher than that of the second insulator layer.

[0012] In the above configuration, the thermal conductivity of the second insulator layer can be made higher than that of the first insulator layer.

[0013] In the above configuration, the resistivity of the second insulator layer can be made higher than that of the first insulator layer.

[0014] In the above configuration, the thickness of the first insulator layer can be made larger than that of the second insulator layer.

[0015] In the above configuration, the first insulator layer and the second insulator layer can be made of a composition mainly composed of aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, zirconium oxide, yttrium oxide, forsterite or diamond-like carbon.

[0016] The present invention provides a method for manufacturing a multilayer ceramic electronic component, which includes the steps of: alternately laminating a plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic in a first direction, wherein in the first direction, the plurality of internal electrodes are alternately provided with a first internal electrode and a second internal electrode; preparing a body having a pair of side surfaces facing each other in the first direction, a pair of end surfaces facing each other in a second direction, and an upper surface and a lower surface facing each other in a third direction, wherein at a first end of the lower surface in the second direction, the first internal electrode is exposed and the second internal electrode is not exposed, and at a second end of the lower surface in the second direction, the second internal electrode is exposed and the first internal electrode is not exposed, and the first internal electrode and the second internal electrode are exposed from the pair of end surfaces and the upper surface in a capacitance region facing each other in the first direction; forming a first insulator layer provided on the pair of side surfaces and mainly composed of a material different from the ceramic, a second insulator layer provided on the pair of end surfaces and the upper surface and mainly composed of a material different from the ceramic, by using a sputtering method, a CVD method or a vacuum evaporation method; and forming a pair of external electrodes respectively contacting the first internal electrode and the second internal electrode exposed from the first end and the second end. It is a method for manufacturing a multilayer ceramic electronic component including the above steps.

Effects of the Invention

[0017] According to the present invention, it is possible to provide a multilayer ceramic electronic component capable of miniaturization and a method for manufacturing the same.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments will be described by taking a multilayer ceramic capacitor as an example of a multilayer ceramic electronic component with reference to the drawings.

[0020] (Embodiment 1) FIG. 1 is a partial cross-sectional perspective view of the multilayer ceramic capacitor according to Embodiment 1. FIGS. 2 to 6 are cross-sectional views of the multilayer ceramic capacitor according to Embodiment 1. FIG. 7 is a top view of the body of the multilayer ceramic capacitor according to Embodiment 1. FIG. 8 is a bottom view of the body of the multilayer ceramic capacitor according to Embodiment 1. FIG. 9 is an end view of the body of the multilayer ceramic capacitor according to Embodiment 1. FIG. 2 is a cross-sectional view taken along line A-A of FIGS. 4 to 6. FIG. 3 is a cross-sectional view taken along line B-B of FIGS. 4 to 6. FIG. 4 is a cross-sectional view taken along line C-C of FIGS. 2 and 3. FIG. 5 is a cross-sectional view taken along line D-D of FIGS. 2 and 3. FIG. 6 is a cross-sectional view taken along line E-E of FIGS. 2 and 3.

[0021] In FIGS. 1 to 9, the Y direction (first direction) is the stacking direction in which the dielectric layers 14, the internal electrodes 12a and 12b are stacked, and is the direction in which the side surfaces 53 and 54 of the multilayer ceramic capacitor 100 face each other. The X direction (second direction) is the length direction of the multilayer ceramic capacitor 100, and is the direction in which the pair of end surfaces 51 and 52 face each other. The Z direction (third direction) is the direction in which the pair of lower surfaces 55 and upper surfaces 56 of the multilayer ceramic capacitor 100 face each other. The X direction, the Y direction, and the Z direction intersect or are orthogonal to each other.

[0022] The multilayer ceramic capacitor 100 includes a body 10 having a substantially rectangular parallelepiped shape, insulator layers 16a to 16e, and external electrodes 20a and 20b. The body 10 has a plurality of dielectric layers 14 and a plurality of internal electrodes 12a and 12b. In the body 10, the plurality of internal electrodes 12a (first internal electrodes) and the plurality of internal electrodes 12b (second internal electrodes) are alternately stacked. One of the plurality of dielectric layers 14 is provided between one of the plurality of internal electrodes 12a and one of the plurality of internal electrodes 12b.

[0023] The element body 10 has a pair of side surfaces 53a and 54a facing each other in the Y direction, a pair of end surfaces 51a and 52a facing each other in the X direction, and an upper surface 56a and a lower surface 55 facing each other in the Z direction. In the element body 10, the region where the internal electrodes 12a and 12b face each other alternately is the capacitance region 42. Among the element body 10, the region between the capacitance region 42 and the lower surface 55 is the margin region 44. As shown in FIG. 7, the internal electrodes 12a and 12b in the capacitance region 42 are exposed from the upper surface of the element body 10. As shown in FIG. 9, the internal electrodes 12a and 12b in the capacitance region 42 are exposed from the end surface 51a (and 52a) of the element body 10. As shown in FIG. 8, the internal electrode 12a is exposed from the end portion 40a (first end portion) in the -X direction on the lower surface 55 of the element body 10, and the internal electrode 12b is not exposed. The internal electrode 12b is exposed from the end portion 40b (second end portion) in the +X direction on the lower surface 55 of the element body 10, and the internal electrode 12a is not exposed.

[0024] The external electrode 20a is in contact with the internal electrode 12a exposed from the element body 10 at the end portion 40a of the lower surface 55. The external electrode 20b is in contact with the internal electrode 12b exposed from the element body 10 at the end portion 40b of the lower surface 55.

[0025] Insulator layers 16a and 16b are respectively provided on the end surfaces 51a and 52a of the element body 10. Insulator layers 16c and 16d are respectively provided on the side surfaces 53a and 54a of the element body 10. An insulator layer 16e is provided on the upper surface 56a of the element body 10. The outer surfaces of the insulator layers 16a, 16b, 16c, 16d, and 16e constitute the end surfaces 51, 52, side surfaces 53, 54, and upper surface 56 respectively.

[0026] The size of the multilayer ceramic capacitor 100 is, for example, a length (length in the X direction) of 0.25 mm, a width (width in the Y direction) of 0.125 mm, a height (height in the Z direction) of 0.125 mm, or a length of 0.4 mm, a width of 0.2 mm, a height of 0.2 mm, or a length of 0.6 mm, a width of 0.3 mm, a height of 0.3 mm, or a length of 1.0 mm, a width of 0.5 mm, a height of 0.5 mm, or a length of 3.2 mm, a width of 1.6 mm, a height of 1.6 mm, or a length of 4.5 mm, a width of 3.2 mm, a height of 2.5 mm, but is not limited to these sizes.

[0027] The internal electrodes 12a and 12b are mainly composed of base metals such as nickel (Ni), copper (Cu), and tin (Sn), for example. As the internal electrodes 12a and 12b, noble metals such as platinum (Pt), palladium (Pd), silver (Ag), or gold (Au), or alloys containing these may be used. The thickness of the internal electrodes 12a and 12b is, for example, 0.1 μm or more and 1 μm or less.

[0028] The dielectric layer 14 mainly consists of a ceramic material having a perovskite structure represented by the general formula ABO3, for example. Note that the perovskite structure contains ABO 3-α deviating from the stoichiometric composition. For example, as the ceramic material, at least one selected from barium titanate (BaTiO3), calcium zirconate (CaZrO3), calcium titanate (CaTiO3), strontium titanate (SrTiO3), magnesium titanate (MgTiO3), and Ba 1-x-y Ca x Sr y Ti 1-z Zr z O3 (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1), etc. can be selected and used. Ba 1-x-y Ca x Sr y Ti 1-z Zr zO3 includes barium strontium titanate, barium calcium titanate, barium zirconate, barium titanate zirconate, calcium titanate zirconate, and barium calcium titanate zirconate, etc. For example, in the dielectric layer 14, the main component ceramic is contained at 90 at% or more. The thickness of the dielectric layer 14 is, for example, 0.3 μm or more and 2 μm or less.

[0029] An additive may be added to the dielectric layer 14. Examples of additives to the dielectric layer 14 include oxides of zirconium (Zr), hafnium (Hf), magnesium (Mg), manganese (Mn), molybdenum (Mo), vanadium (V), chromium (Cr), rare earth elements (yttrium (Y), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), and ytterbium (Yb)), or oxides containing cobalt (Co), nickel (Ni), lithium (Li), boron (B), sodium (Na), potassium (K), or silicon (Si), or glasses containing cobalt, nickel, lithium, boron, sodium, potassium, or silicon.

[0030] The materials of the insulator layers 16a to 16e are, for example, metal oxides or metal nitrides such as aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), silicon carbide (SiC), zirconium oxide (ZrO2), yttrium oxide (Y2O3), forsterite (2MgO, SiO2), or mixtures thereof, or diamond-like carbon (DLC). The insulator layers 16a to 16e are, for example, amorphous or polycrystalline such as glass. The respective thicknesses T1 to T5 of the insulator layers 16a to 16e are, for example, 10 nm or more and 100 μm or less, and 100 nm or more and 5 μm or less.

[0031] The external electrodes 20a and 20b are mainly composed of metals such as copper, nickel, aluminum (Al), zinc (Zn), or alloys of two or more of these (for example, an alloy of copper and nickel), and contain ceramics such as a glass component for densifying the external electrodes 20a and 20b, a co-material for controlling the sinterability of the external electrodes 20a and 20b, and the like. The glass component is an oxide such as barium (Ba), strontium (Sr), calcium (Ca), zinc, aluminum, silicon, or boron. The co-material is, for example, a ceramic component mainly composed of the same material as the main component of the dielectric layer 14. Note that a plating film mainly composed of a base metal such as nickel, copper, or tin may be formed on the surfaces of the external electrodes 20a and 20b. Further, a film of a conductive resin such as an epoxy resin and a urethane resin may be formed on the surface of the plating film.

[0032] (Method for manufacturing a multilayer ceramic capacitor) A method for manufacturing the multilayer ceramic capacitor 100 will be described. FIG. 10 is a flowchart showing the method for manufacturing a multilayer ceramic capacitor.

[0033] (Green sheet forming step) First, a green sheet 30 is formed (step S10). In step S10, for example, a dielectric material is prepared by adding various additive compounds (such as a sintering aid) to ceramic powder. A slurry is generated by adding a binder, an organic solvent such as ethanol or toluene, and a plasticizer to the prepared dielectric material and performing wet mixing. The binder is, for example, polyvinyl butyral (PVB).

[0034] (Pattern forming step) Subsequently, a metal pattern 32 and a dielectric pattern 33 are formed on the green sheet 30 (step S12). FIG. 11(a) is a plan view showing the method for manufacturing a multilayer ceramic capacitor according to an embodiment, and FIG. 11(b) is a cross-sectional view taken along line A-A in FIG. 11(a). The cutting line 36 in FIGS. 11(a) and 11(b) is a cutting line for cutting the laminated sheet 35 in step S18.

[0035] In step S12, first, a metal paste containing metal powder, an organic binder, and an organic solvent is prepared. The metal paste may contain ceramic particles as a co-material. As shown in FIGS. 11(a) and 11(b), a metal pattern 32 is formed by printing the metal pattern 32 on the green sheet 30 using, for example, the gravure printing method. The metal pattern 32 is provided with a rectangular opening that is long in the X direction in plan view. The plurality of openings are arranged in a matrix in the X direction and the Z direction.

[0036] Next, a dielectric paste containing ceramic powder such as sodium titanate powder, an organic binder, an organic solvent, and a plasticizer is prepared. The dielectric pattern 33 is formed by printing the dielectric paste on the green sheet 30 using, for example, the gravure printing method. The dielectric pattern 33 is the reverse pattern of the metal pattern 32, and the dielectric pattern 33 is formed within the opening of the metal pattern 32. It is preferable that there is almost no gap between the dielectric pattern 33 and the metal pattern 32. Thus, a laminated sheet 34 having the metal pattern 32 and the dielectric pattern 33 formed thereon is formed on the green sheet 30.

[0037] (Lamination step) Subsequently, the green sheets are laminated (step S14). FIG. 12 is a cross-sectional view showing a method for manufacturing a laminated ceramic capacitor according to an embodiment, and corresponds to the A-A cross-section of FIG. 11(a). In step S14, the laminated sheets 34 are laminated in the Y direction. At this time, the laminated sheets 34 are laminated such that the center in the X direction of the dielectric pattern 33 and the center in the X direction of the metal pattern 32 in the lower laminated sheet 34 are respectively positioned above the center in the X direction of the metal pattern 32 and the center in the X direction of the dielectric pattern 33 of the upper laminated sheet. A laminated sheet 35 formed by laminating a plurality of laminated sheets 34 is formed.

[0038] (Pressing step) Subsequently, the laminated sheet 35 is pressure-bonded (step S16). In step S16, the laminated sheet 35 formed in step S14 is pressurized to pressure-bond between the plurality of laminated sheets 34. As the pressure-bonding means, for example, a hydrostatic press is used.

[0039] (Cutting step) Subsequently, the laminated sheet 35 is cut (step S18). In step S18, the laminated sheet is cut in the lamination direction along a predetermined cutting line 36 by a cutting blade to prepare a plurality of element bodies 10. After step S18, the element bodies 10 may be polished by a method such as barrel polishing. Thereby, the corners of the element bodies 10 are rounded.

[0040] (Firing step) Subsequently, the element bodies 10 are fired (step S20). In step S20, the element bodies 10 are subjected to a debinding treatment in a nitrogen gas atmosphere at 250°C to 500°C and then fired in a reducing atmosphere at 1300°C to 1400°C. Thereby, each particle in the element bodies 10 is sintered.

[0041] (Insulator layer forming step) Subsequently, insulator layers 16a to 16e are formed (step S22). FIGS. 13(a) and 13(b) are side views showing a method for manufacturing a multilayer ceramic capacitor according to an embodiment. As shown in FIG. 13(a), a plurality of element bodies 10 are arranged on a sheet 38. At this time, the upper surface 56a of the element body 10 faces upward.

[0042] As shown in FIG. 13(b), an insulator layer 16e is formed on the upper surface 56a of the plurality of element bodies 10. Similarly, a plurality of element bodies 10 are arranged on the sheet 38 with the end faces 51a facing upward, and an insulator layer 16a is formed on the end faces 51a. A plurality of element bodies 10 are arranged with the end faces 52a facing upward, and an insulator layer 16b is formed on the end faces 52a. A plurality of element bodies 10 are arranged with the side faces 53a facing upward, and an insulator layer 16c is formed on the side faces 53a. A plurality of element bodies 10 are arranged with the side faces 54a facing upward, and an insulator layer 16d is formed on the side faces 54a. In this way, the insulator layers 16a to 16e are formed. For the formation of the insulator layers 16a to 16e, for example, a sputtering method, a CVD (Chemical Vapor Deposition) method, or a vacuum evaporation method is used. Also, the insulator layers 16a to 16e may be formed using a method such as a barrel sputtering method that can form insulator layers on a plurality of surfaces at once.

[0043] (External electrode forming process) Subsequently, external electrodes 20a and 20b are formed (step S24). In step S24, a conductive paste containing, for example, metal powder, glass frit, a binder, and a solvent is applied to the end portions 40a and 40b of the lower surface 55. After applying the conductive paste, baking is performed to form the base metal layers of the external electrodes 20a and 20b. Note that the binder and the solvent evaporate by baking. The conductive paste is applied using, for example, a dipping method. A plating film may be formed on the base metal layer.

[0044] In the multilayer ceramic capacitor 100 of Embodiment 1, the insulator layers 16a to 16e are formed using a sputtering method, a CVD method, or a vacuum evaporation method after sintering of the element body 10. Therefore, the main components of the insulator layers 16a to 16e are different from the main components of the dielectric layer 14. By using the sputtering method, the CVD method, or the vacuum evaporation method, the thicknesses T1 to T5 of the insulator layers 16a to 16e can be reduced. Thus, miniaturization is possible.

[0045] Table 1 is a table showing the relative permittivity, resistivity, thermal conductivity, and toughness in examples of materials used as the insulator layers 16a to 16e.

Table 1

[0046] When the insulator layers 16a to 16e are formed using a sputtering method, a CVD method, or a vacuum evaporation method, an insulator with a high dielectric constant cannot be formed. For example, when the ceramic having the perovskite structure is used as the dielectric layer 14, the relative dielectric constant is 30 or more. On the other hand, the relative dielectric constants of aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, zirconia, yttrium oxide, and forsterite are 12.5 or less. Thus, the dielectric constant of the insulator layers 16a to 16e is 1 / 2 or less of that of the dielectric layer 14. The dielectric constant of the insulator layers 16a to 16e is, for example, 1 / 3 times or less, and 1 / 5 times or less of that of the dielectric layer 14.

[0047] The main components of the insulator layers 16a to 16e may be the same as each other or different from each other. For example, the main components of the insulator layers 16a to 16e are aluminum oxide or silicon nitride. As shown in Table 1, since aluminum oxide or silicon nitride has a high resistivity and is easy to form a film, the insulation property of the insulator layers 16a to 16e can be increased and the thicknesses T1 to T5 can be decreased.

[0048] For example, the main components of the insulator layers 16a to 16e are aluminum nitride or silicon carbide. Since aluminum nitride or silicon carbide has a high thermal conductivity, a capacitor with excellent heat dissipation can be realized.

[0049] For example, the main components of the insulator layers 16a to 16e are silicon nitride or zirconia. Since silicon nitride or zirconia has a large toughness, a capacitor with high mechanical strength can be realized.

[0050] For example, the main components of the insulator layers 16a to 16e are forsterite. Since forsterite has a high adhesion to the base body 10, the adhesion between the insulator layers 16a to 16e and the base body 10 can be improved.

[0051] The main components of the insulator layers 16a to 16e may be diamond-like carbon with high water repellency. On the surface of diamond-like carbon with high water repellency, the wettability of the molten solder deteriorates. Therefore, when mounting the external electrodes 20a and 20b, it is possible to suppress the adhesion of the solder to the surface of the element body 10. Thereby, it is possible to suppress an electrical short circuit between the external electrodes 20a and 20b, or an electrical short circuit between the external electrode 20a or 20b and other components.

[0052] The main components of the insulator layers 16a to 16e may be different from each other. On the end faces 51a, 52a and the upper face 56a of the element body 10, the internal electrodes 12a and 12b that sandwich the thickness T0 of the dielectric layer 14 are exposed. Therefore, the insulator layers 16a, 16b and 16e are preferably made of a material with high insulation. Also, in order to efficiently release the heat of the internal electrodes 12a and 12b, the insulator layers 16a, 16b and 16e are preferably made of a material with high thermal conductivity. On the side faces 53a and 54a of the element body 10, the internal electrodes of different potentials are not exposed. Therefore, the insulator layers 16c and 16d may be made of a material with low insulation. Also, the insulator layers 16c and 16d may be made of a material with low thermal conductivity.

[0053] In the stacking direction (Y direction) of the internal electrodes 12a, 12b and the dielectric layer 14, stress caused by electrostriction is applied. Therefore, the insulator layers 16c and 16d are preferably made of a material with high toughness. On the other hand, the stress caused by electrostriction in the X direction and the Z direction is not so large. Therefore, the insulator layers 16a, 16b and 16e may be made of a material with low toughness.

[0054] Thus, the main components of the insulator layers 16c and 16d (first insulator layers) may be different from the main components of the insulator layers 16a, 16b, and 16e (second insulator layers). For example, the thermal conductivity of the insulator layers 16a, 16b, and 16e is made higher than the thermal conductivity of the insulator layers 16c and 16d. Heat generated in the element body 10 is transmitted through the internal electrodes 12a and 12b and released to the outside. Therefore, when the thermal conductivity of the insulator layers 16a, 16b, and 16e in contact with the end faces 51a, 52a where the internal electrodes 12a and 12b are exposed and the upper face 56a is high, the heat dissipation property from the element body 10 can be enhanced. The thermal conductivity of the insulator layers 16a, 16b, and 16e is preferably 2 times or more, more preferably 5 times or more, the thermal conductivity of the insulator layers 16c and 16d. The thermal conductivity of the insulator layers 16a, 16b, and 16e is, for example, 100 times or less the thermal conductivity of the insulator layers 16c and 16d.

[0055] The electrical resistivity of the insulator layers 16a, 16b, and 16e is higher than the electrical resistivity of the insulator layers 16c and 16d. The internal electrodes 12a and 12b are exposed from the end faces 51a, 52a, and the upper face 56a. For this reason, if the resistivity of the insulator layers 16a, 16b, and 16e is low, a current flows between the internal electrodes 12a and 12b. Therefore, by increasing the electrical resistivity of the insulator layers 16a, 16b, and 16e, the current between the internal electrodes 12a and 12b can be suppressed. The electrical resistivity of the insulator layers 16a, 16b, and 16e is preferably 2 times or more, more preferably 3 times or more, the electrical resistivity of the insulator layers 16c and 16d. The electrical resistivity of the insulator layers 16a, 16b, and 16e is, for example, 100 times or less or 10000 times or less the electrical resistivity of the insulator layers 16c and 16d.

[0056] The toughness of the insulator layers 16c and 16d is greater than the toughness of the insulator layers 16a, 16b, and 16e. Thereby, breakage of the insulator layers 16c and 16d due to electrostrain can be suppressed. The toughness of the insulator layers 16c and 16d is preferably 1.2 times or more, more preferably 1.5 times or more, the toughness of the insulator layers 16a, 16b, and 16e.

[0057] By setting the main components of the insulator layers 16c and 16d to silicon nitride or zirconium oxide, and the main components of the insulator layers 16a, 16b, and 16e to aluminum nitride or silicon carbide, it is possible to increase the strength against electrostrain and improve the heat dissipation performance.

[0058] By setting the main components of the insulator layers 16c and 16d to silicon nitride or zirconium oxide, and the main components of the insulator layers 16a, 16b, and 16e to aluminum oxide, aluminum nitride, or silicon carbide, it is possible to increase the strength against electrostrain and improve the insulation performance.

[0059] By setting the main components of the insulator layers 16c and 16d to silicon nitride or zirconium oxide, and the main components of the insulator layers 16a, 16b, and 16e to forsterite, it is possible to increase the strength against electrostrain and improve the adhesion between the base body 10 and the insulator layers 16a, 16b, and 16e.

[0060] The thicknesses T1 to T5 of the insulator layers 16a to 16e are preferably not more than twice, more preferably not more than 1.5 times, and even more preferably not more than 1 time the thickness T0 of at least one layer of the dielectric layer 14. Thereby, the capacitor can be miniaturized. In order for the insulator layers 16a to 16e to function as a protective film, the thicknesses T1 to T5 are preferably not less than 0.1 times the thickness T0.

[0061] The thicknesses T1 to T5 of the insulator layers 16a to 16e are preferably uniform. Thereby, the heat dissipation performance and insulation performance of the insulator layers 16a to 16e can be made uniform, enabling miniaturization. When the maximum thickness and the minimum thickness of the insulator layers 16a to 16e are Tmax and Tmin, respectively, (Tmax - Tmin) / (Tmax + Tmin) is preferably not more than 0.5, more preferably not more than 0.25, and even more preferably not more than 0.1.

[0062] (Embodiment 2) FIG. 14 is a partial cross-sectional view of the multilayer ceramic capacitor according to Embodiment 2. As shown in FIG. 14, in the multilayer ceramic capacitor 102 of Embodiment 2, the thicknesses T3 and T4 of the insulator layers 16c and 16d are larger than the thicknesses T1, T2, and T5 of the insulator layers 16a, 16b, and 16e. Other configurations are the same as those in FIGS. 1 to 9 of Embodiment 1, and the description thereof is omitted.

[0063] As in Embodiment 2, the thicknesses T1 to T5 of the insulator layers 16a to 16e may be different from each other. For example, stress due to electrostriction is applied to the insulator layers 16c and 16d. No stress due to electrostriction is applied to the insulator layers 16a, 16b, and 16e. Therefore, the thicknesses T3 and T4 of the insulator layers 16b and 16c are made larger than the thicknesses T1, T2, and T5 of the insulator layers 16a, 16b, and 16e. Thereby, the strength against the stress caused by electrostriction is increased and miniaturization is possible. The thicknesses T3 and T4 are preferably 1.5 times or more, more preferably 2 times or more, of the thicknesses T1, T2, and T5. From the viewpoint of miniaturization, the thicknesses T3 and T4 are preferably 3 times or less of the thicknesses T1, T2, and T5.

[0064] When the main components of the insulator layers 16a to 16e are silicon nitride or zirconium oxide, by making the thicknesses T3 and T4 larger than the thicknesses T1, T2, and T5, the strength against the stress caused by electrostriction can be further increased.

[0065] When the main components of the insulator layers 16c and 16d are silicon nitride or zirconium oxide and the main components of the insulator layers 16a, 16b, and 16e are aluminum oxide, aluminum nitride, or silicon carbide, the thicknesses T3 and T4 are made larger than the thicknesses T1, T2, and T5. Thereby, the strength against electrostriction can be further increased, the heat dissipation can be increased, and miniaturization can be achieved.

[0066] In Embodiments 1 and 2, when a certain member is mainly composed of a certain material, it only needs to contain the certain material in the member to such an extent that the effects of the embodiment are achieved. The content of the certain material in the certain member is, for example, 50 mol% or more, 80 mol% or more, or 90 mol% or more. The lower surface 55 and the upper surface 56 are used in the sense of surfaces facing each other in the Z direction, and do not necessarily mean surfaces facing in the vertical direction.

[0067] As described above in detail regarding the embodiments of the present invention, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

Explanation of Reference Numerals

[0068] 10 Substrate 12a, 12b Internal electrodes 14 Dielectric layer 16a~16e Insulator layers 20a, 20b External electrodes 30 Green sheet 32 Metal pattern 33 Dielectric pattern 34, 35 Laminated sheets 40a, 40b Ends 42 Capacitance region 51, 52, 51a, 52a End faces 53, 54, 53a, 54a Side faces 55 Lower surface 56, 56a Upper surfaces

Claims

1. A plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic are alternately laminated in a first direction. In the first direction, the plurality of internal electrodes are alternately provided with a first internal electrode and a second internal electrode. It has a pair of side surfaces facing each other in the first direction, a pair of end surfaces facing each other in the second direction, and an upper surface and a lower surface facing each other in the third direction. At a first end of the lower surface in the second direction, the first internal electrode is exposed and the second internal electrode is not exposed. At a second end of the lower surface in the second direction, the second internal electrode is exposed and the first internal electrode is not exposed. The first internal electrode and the second internal electrode are in a capacitance region facing each other in the first direction, and the first internal electrode and the second internal electrode are exposed from the pair of end surfaces and the upper surface, and a body; A first insulator layer provided on the pair of side surfaces and mainly composed of a material different from the ceramic; A second insulator layer provided on the pair of end surfaces and the upper surface and mainly composed of a material different from the ceramic; A pair of external electrodes respectively contacting the first internal electrode and the second internal electrode exposed from the first end and the second end; A multilayer ceramic electronic component comprising:

2. The multilayer ceramic electronic component according to claim 1, wherein the dielectric constant of the first insulator layer and the second insulator layer is 1 / 2 times or less of that of the plurality of dielectric layers.

3. The multilayer ceramic electronic component according to claim 2, wherein the thicknesses of the first insulator layer and the second insulator layer are 2 times or less of the thickness of at least one of the plurality of dielectric layers.

4. The multilayer ceramic electronic component according to claim 3, when the maximum thickness and the minimum thickness of the first insulator layer and the second insulator layer are Tmax and Tmin respectively, (Tmax - Tmin) / (Tmax + Tmin) < 0.

5.

5. The multilayer ceramic electronic component according to any one of claims 1 to 3, wherein the main component of the first insulator layer is different from the main component of the second insulator layer.

6. The multilayer ceramic electronic component according to any one of claims 1 to 3, wherein the toughness of the first insulator layer is higher than the toughness of the second insulator layer.

7. The multilayer ceramic electronic component according to claim 6, wherein the thermal conductivity of the second insulator layer is higher than the thermal conductivity of the first insulator layer.

8. The multilayer ceramic electronic component according to claim 6, wherein the resistivity of the second insulator layer is higher than that of the first insulator layer.

9. The multilayer ceramic electronic component according to any one of claims 1 to 3, wherein the thickness of the first insulator layer is larger than the thickness of the second insulator layer.

10. The multilayer ceramic electronic component according to any one of claims 1 to 3, wherein the first insulator layer and the second insulator layer are mainly composed of aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, zirconium oxide, yttrium oxide, forsterite or diamond-like carbon.

11. A step of preparing a body in which a plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic are alternately laminated in a first direction, the first internal electrode and the second internal electrode are alternately provided in the plurality of internal electrodes in the first direction, and the body has a pair of side surfaces facing each other in the first direction, a pair of end surfaces facing each other in a second direction, and an upper surface and a lower surface facing each other in a third direction, the first internal electrode is exposed at a first end of the lower surface in the second direction and the second internal electrode is not exposed, the second internal electrode is exposed at a second end of the lower surface in the second direction and the first internal electrode is not exposed, and the first internal electrode and the second internal electrode are exposed from the pair of end surfaces and the upper surface in a capacitance region where the first internal electrode and the second internal electrode face each other in the first direction; A step of forming a first insulator layer provided on the pair of side surfaces and mainly composed of a material different from the ceramic, a second insulator layer provided on the pair of end surfaces and the upper surface and mainly composed of a material different from the ceramic, by using a sputtering method, a CVD method or a vacuum evaporation method; A step of forming a pair of external electrodes that respectively contact the first internal electrode and the second internal electrode exposed from the first end and the second end; A method for manufacturing a multilayer ceramic electronic component, comprising the steps above.

Images