Multilayer ceramic capacitor

Abstract

To provide multilayer ceramic capacitors with superior reliability. [Solution] The multilayer ceramic capacitor 1 comprises a laminate 2 and an external electrode 3. The external electrode 3 has an inner base electrode 311 disposed on at least one of the first end face CA and the second end face CB and containing glass and conductive metal, an outer base electrode 312 disposed on the inner base electrode 311 and containing glass and conductive metal, and containing a component different from the main component metal of the inner base electrode 311 as the main component metal, and a plating layer 32 disposed on the outer base electrode 312.

Description

Technical Field

[0001] The present invention relates to a multilayer ceramic capacitor.

Background Art

[0002] Multilayer ceramic capacitors are one of the important components for electronic devices such as portable terminals and precision equipment. In order to improve the performance of electronic devices and achieve stable operation of machines, it is urgent to improve the reliability of multilayer ceramic capacitors.

[0003] Among the factors related to the reliability of multilayer ceramic capacitors, the reliability against corrosion components is one of the particularly important ones. Patent Document 1 discloses a technique for improving the reliability of multilayer ceramic capacitors against corrosion components.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the reliability regarding electrical connectivity such as the reliability of the connection between the internal electrode and the external electrode is also an important factor related to the reliability of the multilayer ceramic capacitor, along with the reliability against corrosion components. However, in the multilayer ceramic capacitor of Patent Document 1, the reliability regarding electrical connectivity has not been improved. Development of a multilayer ceramic capacitor having excellent reliability against corrosion components and excellent reliability regarding electrical junction is desired.

[0006] An object of the present invention is to provide a multilayer ceramic capacitor with more excellent reliability.

Means for Solving the Problems

[0007] To solve the above problems, the present invention provides a multilayer ceramic capacitor comprising a laminated body including stacked dielectric layers and internal electrodes, having a first main surface and a second main surface facing each other in the stacking direction, a first side surface and a second side surface facing each other in the width direction intersecting the stacking direction, and a first end surface and a second end surface facing each other in the length direction intersecting the stacking direction and the width direction, and an external electrode provided on the laminated body and connected to the internal electrode, wherein the external electrode is disposed on at least one of the first end surface and the second end surface and contains glass and conductive metal on the inside bottom The electrode comprises a ground electrode, an outer base electrode disposed on the inner base electrode and containing glass and a conductive metal, and containing a metal component different from the main component metal of the inner base electrode as its main component metal, and a plating layer disposed on the outer base electrode, wherein the outer base electrode has an outer diffusion portion which is a region containing the main component metal of the inner base electrode at a concentration of 1 / 10 or more of the main component metal content of the outer base electrode, the outer diffusion portion is adjacent to the inner base electrode, and the maximum thickness of the outer diffusion portion is 1.0 μm or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a multilayer ceramic capacitor with superior reliability. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic perspective view of a multilayer ceramic capacitor according to an embodiment. [Figure 2] This is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 1. [Figure 4] This is an enlarged view of section IV in Figure 2. [Figure 5] This is a schematic diagram showing the results of EDX measurements of the inner and outer substrate electrodes. [Modes for carrying out the invention]

[0010] Hereinafter, a multilayer ceramic capacitor 1 according to an embodiment of the present invention will be described with reference to Figures 1 to 4.

[0011] (Multilayer ceramic capacitor) As shown in Figure 1, the multilayer ceramic capacitor 1 is a so-called two-terminal multilayer ceramic capacitor. The multilayer ceramic capacitor 1 comprises a laminate 2 and a pair of external electrodes 3. The laminate 2 is substantially rectangular in shape and has six outer surfaces. The laminate 2 includes an inner layer 11 in which a dielectric layer 14 and an internal electrode 15 are laminated.

[0012] In this specification, the direction in which the dielectric layer 14 and the internal electrode 15 are stacked in a multilayer ceramic capacitor 1 is defined as the stacking direction T. One of the directions perpendicular to the stacking direction T is defined as the length direction L. The directions perpendicular to the length direction L and the stacking direction T are defined as the width direction W.

[0013] Of the six outer surfaces of the laminate 2, a pair of outer surfaces provided on both sides in the lamination direction T are designated as the first main surface AA and the second main surface AB, a pair of outer surfaces extending in the lamination direction T and provided on both sides in the width direction W are designated as the first side surface BA and the second side surface BB, and a pair of outer surfaces extending in the lamination direction T and provided on both sides in the length direction L are designated as the first end surface CA and the second end surface CB.

[0014] The first main surface AA and the second main surface AB are sometimes collectively referred to as "each main surface A". The first side surface BA and the second side surface BB are sometimes collectively referred to as "each side surface B". The first end surface CA and the second end surface CB are sometimes collectively referred to as "each end surface C".

[0015] A cross-section parallel to the stacking direction T and the length direction L is defined as the "LT cross-section". The cross-section in Figure 2 is the LT cross-section passing through the center of the width direction W of the multilayer ceramic capacitor 1. A cross-section parallel to the stacking direction T and the width direction W is defined as the "WT cross-section". The cross-section in Figure 3 is the WT cross-section passing through the center of the length direction L of the multilayer ceramic capacitor 1.

[0016] (Multilayer Body) The multilayer body 2 includes an inner layer portion 11 formed by laminating a dielectric layer 14 and an internal electrode 15, an outer layer portion 12 disposed sandwiching the inner layer portion 11 in the lamination direction T, and a side margin portion 20 disposed sandwiching the inner layer portion 11 and the outer layer portion 12 in the width direction W. A portion where three outer surfaces of the multilayer body 2 intersect is defined as a "corner portion". A portion where two outer surfaces of the multilayer body 2 intersect is defined as an "edge line portion". It is preferable that the corner portion and the edge line portion of the multilayer body 2 are rounded.

[0017] (Inner Layer Portion) As shown in FIGS. 2 and 3, the inner layer portion 11 includes a plurality of dielectric layers 14 and a plurality of internal electrodes 15. The dielectric layers 14 and the internal electrodes 15 are laminated alternately.

[0018] The dielectric layer 14 is composed of a perovskite-type compound. As the material of the dielectric layer 14, for example, dielectric ceramics mainly composed of BaTiO3, CaTiO3, SrTiO3, CaZrO3, etc. are used. To the material of the dielectric layer 14, Mn compounds, Mg compounds, Si compounds, Fe compounds, Cr compounds, Co compounds, Ni compounds, Al compounds, V compounds, rare earth compounds, etc. may be added as sub-components. The average grain size of the grains of the dielectric layer 14 is, for example, 0.05 μm or more and 0.15 μm.

[0019] The internal electrode 15 is formed by sintering a conductive paste containing a metal powder serving as a conductor, an organic solvent, a binder, and a dispersant on the dielectric layer 14. As the metal powder serving as a conductor, for example, metals such as Ni, Cu, Ag, Pd, Ag-Pd alloy, Au, Sn, etc. are used. These metals may be compounds containing these metal elements or alloys with other metals. The main component metal of the internal electrode 15 is, for example, Ni. The total number of sheets of the internal electrode 15 is, for example, 100 or more and 500 or less. Note that the main component metal of the internal electrode 15 is the metal having the largest content among the metals contained in the internal electrode 15.

[0020] The internal electrode 15 has a plurality of first internal electrodes 15A and a plurality of second internal electrodes 15B. The first internal electrode 15A is exposed only on the first end face CA. The second internal electrode 15B is exposed only on the second end face CB. The first internal electrode 15A and the second internal electrode 15B are alternately arranged.

[0021] Among the internal electrodes 15, the one closest to the first main surface AA is, for example, the first internal electrode 15A. Among the internal electrodes 15, the one closest to the second main surface AB is, for example, the second internal electrode 15B. However, it is not limited to this. Among the internal electrodes 15, the one closest to the first main surface AA may be the second internal electrode 15B, or the one closest to the second main surface AB may be the first internal electrode 15A.

[0022] The first internal electrode 15A has a first opposing portion 15Aa and a first lead-out portion 15Ab. The first opposing portion 15Aa is the portion of the first internal electrode 15A that faces the adjacent second internal electrode 15B. The first lead-out portion 15Ab is the portion of the first internal electrode 15A that is drawn out from the first opposing portion 15Aa toward the first external electrode 3A. The first lead-out portion 15Ab is exposed on the first end face CA. The first lead-out portion 15Ab is electrically connected to the first external electrode 3A.

[0023] The second internal electrode 15B has a second opposing portion 15Ba and a second lead-out portion 15Bb. The second opposing portion 15Ba is the portion of the second internal electrode 15B that faces the adjacent first internal electrode 15A (the first opposing portion 15Aa). The second lead-out portion 15Bb is the portion of the second internal electrode 15B that is drawn out toward the second external electrode 3B. The second lead-out portion 15Bb is exposed on the second end face CB. The second lead-out portion 15Bb is electrically connected to the second external electrode 3B.

[0024] Incidentally, the first internal electrode 15A and the second internal electrode 15B may be collectively referred to as the "internal electrode 15". The first opposing portion 15Aa and the second opposing portion 15Ba may be collectively referred to as the "opposing portion 15a". The first lead-out portion 15Ab and the second lead-out portion 15Bb may be collectively referred to as the "lead-out portion 15b".

[0025] (outer layer) The outer layer 12 is formed of the same material as, for example, the dielectric layer 14 of the inner layer 11. Note that the inner electrodes 15 are not located in the outer layer 12.

[0026] (Side margin area) The side margin portion 20 is formed of the same material as the dielectric layer 14 of the inner layer portion 11, for example. The side margin portion 20 is provided sandwiching the inner layer portion 11 and the outer layer portion 12 in the width direction W.

[0027] (external electrode) The external electrode 3 is positioned on the laminate 2, specifically on the end face C. The external electrode 3 is connected to the internal electrode 15. The external electrode 3 includes a first external electrode 3A positioned on the first end face CA and connected to the first internal electrode 15A, and a second external electrode 3B positioned on the second end face CB and connected to the second internal electrode 15B. The first external electrode 3A covers not only the first end face CA, but also a portion of the main surface A and a portion of the side surface B. The second external electrode 3B covers not only the second end face CB, but also a portion of the main surface A and a portion of the side surface B.

[0028] Here, the external electrode 3 includes an inner base electrode 311 disposed on at least one of the first end face CA and the second end face CB and containing glass and conductive metal, an outer base electrode 312 disposed on the inner base electrode 311 and containing glass and conductive metal, and containing a different component as the main metal than the main metal of the inner base electrode 311, and a plating layer 32 disposed on the outer base electrode 312. The plating layer 32 includes, for example, an inner plating layer 321 disposed on the outer base electrode 312 and an outer plating layer 322 disposed on the inner plating layer 321.

[0029] The inner substrate electrode 311 has an inner diffusion portion 311a, which is a region containing the main component metal of the outer substrate electrode 312 at a concentration of 1 / 10 or more of the main component metal content of the inner substrate electrode 311. The inner diffusion portion 311a is adjacent to the outer substrate electrode 312. However, the inner diffusion portion 311a is not an essential component.

[0030] The inner base electrode 311 is, for example, a baked layer. The inner base electrode 311 is, for example, located only on the end face C of the outer surface of the outer electrode 3, and is not located on a part of the main surface A or a part of the side surface B. The thickness of the inner base electrode 311 is, for example, 5 μm to 10 μm. The glass content of the inner base electrode 311 is, for example, 5% to 10%. The inner base electrode 311 contains, for example, Cu, Sn, Zn, Ni, Ag, Pd, Au, Ag-Pd alloy, etc. The main component metal of the inner base electrode 311 is the metal with the largest content among the metals contained in the inner base electrode 311.

[0031] The outer base electrode 312 is, for example, a baked layer. The outer base electrode 312 is, for example, positioned on the first end face CA, a part of the main face A, and a part of the side surface B. The thickness of the outer base electrode 312 is, for example, 5.5 μm to 20 μm. The glass content of the outer base electrode 312 is, for example, 15% to 30%. The outer base electrode 312 contains, for example, Cu, Sn, Zn, Ni, Ag, Pd, Au, Ag-Pd alloy, etc. However, the main component metal of the outer base electrode 312 is different from the main component metal of the inner base electrode 311. The main component metal of the outer base electrode 312 is the metal with the highest content among the metals contained in the outer base electrode 312.

[0032] Note that the inner base electrode 311 and the outer base electrode 312 are sometimes collectively referred to as "base electrode 31".

[0033] The plating layer 32 is composed of, for example, one metal selected from the group consisting of Cu, Ni, Ag, Pd, Au, and Sn, or an alloy containing this metal. The inner plating layer 321 is, for example, a Ni plating layer. The outer plating layer 322 is, for example, a Sn plating layer. The plating layer 32 may have a single-layer structure. The thickness of each layer constituting the plating layer 32 is preferably 2 μm or more and 7 μm or less.

[0034] The first external electrode 3A includes a first inner base electrode 311A ​​disposed on the first end face CA and containing glass and a conductive metal, a first outer base electrode 312A disposed on the first inner base electrode 311A ​​and containing glass and a conductive metal, and containing a different component as the main metal than the main metal of the first inner base electrode 311A, and a first plating layer 32A disposed on the first outer base electrode 312A. The first plating layer 32A includes, for example, a first inner plating layer 321A disposed on the first outer base electrode 312, and a first outer plating layer 322A disposed on the first inner plating layer 321A.

[0035] The second external electrode 3B includes a second inner underlayer electrode 311B disposed on the second end face CB and containing glass and conductive metal, a second outer underlayer electrode 312B disposed on the second inner underlayer electrode 311B and containing glass and conductive metal, and containing a different component as the main metal than the main metal of the second inner underlayer electrode 311B, and a second plating layer 32 disposed on the second outer underlayer electrode 312B. The second plating layer 32 includes, for example, a second inner plating layer 321 disposed on the second outer underlayer electrode 312B and a second outer plating layer 322 disposed on the second inner plating layer 321.

[0036] The configuration of the second external electrode 3B is, for example, generally similar to that of the first external electrode 3A. For this reason, the explanation of the second external electrode 3B may be omitted. In addition, the second inner base electrode 311B corresponds to the first inner base electrode 311A, the second outer base electrode 312B corresponds to the first outer base electrode 312A, and the second plating layer 32 corresponds to the first plating layer 32.

[0037] As shown in Figure 4, the outer substrate electrode 312 has an outer diffusion portion 312a, which is a region containing the main component metal of the inner substrate electrode 311 at a concentration of 1 / 10 or more of the main component metal content of the outer substrate electrode 312. The outer diffusion portion 312a is adjacent to the inner substrate electrode 311. The maximum thickness of the outer diffusion portion 312a is 1.0 μm or less.

[0038] For example, the first outer substrate electrode 312A has a first outer diffusion portion 312a which is a region containing the main component metal of the first inner substrate electrode 311A ​​at a concentration of 1 / 10 or more of the main component metal content of the first outer substrate electrode 312A. The first outer diffusion portion 312a is adjacent to the inner substrate electrode 311. The maximum thickness of the first outer diffusion portion 312a is 1.0 μm or less.

[0039] The main component metal of the inner base electrode 311 is preferably at least one metal selected from the group consisting of Ni, Ag, and Pd, and the main component metal of the outer base electrode 312 is preferably at least one metal selected from the group consisting of Cu, Sn, and Zn. The main component metal of the inner base electrode 311 is more preferably Ni, and the main component metal of the outer base electrode 312 is more preferably Cu. The main component metal of the inner base electrode 311 is preferably substantially the same as the main component metal of the internal electrode 15.

[0040] For example, the main component metal of the first inner base electrode 311A ​​is preferably at least one metal selected from the group consisting of Ni, Ag, and Pd, and the main component metal of the first outer base electrode 312A is preferably at least one metal selected from the group consisting of Cu, Sn, and Zn. The main component metal of the first inner base electrode 311A ​​is more preferably Ni, and the main component metal of the first outer base electrode 312A is more preferably Cu.

[0041] The maximum thickness of the inner substrate electrode 311 is thinner than the maximum thickness of the outer substrate electrode 312.

[0042] For example, the maximum thickness of the first inner substrate electrode 311A ​​is thinner than the maximum thickness of the first outer substrate electrode 312A.

[0043] The shortest distance from a point on the lower surface of the inner base electrode 311 (the bonding surface with the laminate 2) to the outer surface of the inner base electrode 311 (the bonding surface with the outer base electrode 312) is defined as the thickness of the inner base electrode 311 at that point. The shortest distance from a point on the lower surface of the outer base electrode 312 (the bonding surface with the inner base electrode 311) to the outer surface of the outer base electrode 312 (the bonding surface with the plating layer 32) is defined as the thickness of the outer base electrode 312 at that point.

[0044] The ratio of the maximum thickness of the inner base electrode 311 to the maximum thickness of the outer base electrode 312 is between 0.5 and 0.9.

[0045] For example, the ratio of the maximum thickness of the first inner base electrode 311A ​​to the maximum thickness of the first outer base electrode 312A is between 0.5 and 0.9.

[0046] Furthermore, the glass content of the inner substrate electrode 311 is lower than that of the outer substrate electrode 312.

[0047] For example, the glass content of the first inner substrate electrode 311A ​​is lower than that of the first outer substrate electrode 312A.

[0048] The ratio of the glass content of the inner substrate electrode 311 to the glass content of the outer substrate electrode 312 is between 0.33 and 0.66.

[0049] For example, the ratio of the glass content of the first inner substrate electrode 311A ​​to the glass content of the first outer substrate electrode 312A is between 0.33 and 0.66.

[0050] In the WT cross-section, of the three regions obtained by dividing the portion of the inner substrate electrode 311 located on the first end face CA into three equal parts in the width direction W, the glass content of the region closest to the outer substrate electrode 312 is greater than that of the central region.

[0051] Furthermore, all internal electrodes 15 satisfy the condition that the distance in the width direction W between one end of an internal electrode 15 and one end of an adjacent internal electrode 15 is 0.5 μm or less. All internal electrodes 15 also satisfy the condition that the distance in the width direction W between the other end of an internal electrode 15 and the other end of an adjacent internal electrode 15 is 0.5 μm or less.

[0052] The laminate 2 has a recess 21 on its outer surface that is concave toward the center of the laminate 2 in the stacking direction T, and is provided in the portion that overlaps with the end of the internal electrode 15 in the width direction W.

[0053] The recesses 21 are provided, for example, on the outer surface of the first main surface AA, in the portion that overlaps with the end of the first side surface BA of the internal electrode 15 in the width direction W and the stacking direction T; on the outer surface of the first main surface AA, in the portion that overlaps with the end of the second side surface BB of the internal electrode 15 in the width direction W and the stacking direction T; on the outer surface of the second main surface AB, in the portion that overlaps with the end of the first side surface BA of the internal electrode 15 in the width direction W and the stacking direction T; and on the outer surface of the second main surface AB, in the portion that overlaps with the end of the second side surface BB of the internal electrode 15 in the width direction W and the stacking direction T. The recesses 21 extend, for example, over the entire length L of the laminate 2. The ends of the recesses 21 in the length direction L overlap with the external electrodes 3.

[0054] The recess 21 may be provided only on the first main surface AA, or only on the second main surface AB. In this case, it is possible to easily distinguish between the first main surface AA and the second main surface AB of the multilayer ceramic capacitor 1, making it easier to mount the multilayer ceramic capacitor 1 on the substrate with the second main surface AB facing the substrate.

[0055] Pores (voids) are formed in the dielectric layer 14. Preferably, the pore ratio (void ratio) in the dielectric layer 14 is 1% or more and 5% or less. Preferably, the pore ratio in the portion of the dielectric layer 14 facing the internal electrode 15 in the stacking direction T is 1% or more and 5% or less. Note that the pore ratio refers to the proportion of voids present in the dielectric layer 14.

[0056] The width W dimension of the laminate 2 at the center of the laminate direction T is smaller than any of the width W dimensions of the laminate 2 at each end of the laminate direction T. The shape of the first side surface BA as viewed in the longitudinal direction L is such that the middle part of the first side surface BA in the laminate direction T is convex toward the center of the width W of the laminate 2. The shape of the second side surface BB as viewed in the longitudinal direction L is such that the middle part of the second side surface BB in the laminate direction T is convex toward the center of the width W of the laminate 2.

[0057] The shape of the line connecting all the ends of each internal electrode 15 in the width direction W, viewed along the length direction L, is an arc shape that is convex toward the center of the laminate 2 in the width direction W. The shape of the line connecting all the other ends of each internal electrode 15 in the width direction W, viewed along the length direction L, is an arc shape that is convex toward the center of the laminate 2 in the width direction W. In other words, the shape of the surface of the inner layer 11 facing the side margin 20, viewed along the length direction L, is an arc shape that is convex toward the center of the laminate 2 in the width direction W.

[0058] In the LT cross-section passing through the center of the width direction W of the laminate 2, the curvature of the lead portion 15b of the internal electrode 15 closest to the first main surface AA is greater than the curvature of the lead portion 15b of the internal electrode 15 closest to the second main surface AB.

[0059] For example, in a cross section LT passing through the center of the width direction W of the laminate 2, the lead portion 15b (specifically, the first lead portion 15Ab) of the internal electrode 15 closest to the first main surface AA (specifically, the first internal electrode 15A) is curved so as it approaches the second end surface CB, it approaches the center of the laminate 2 in the stacking direction T. The lead portion 15b (specifically, the second lead portion 15Bb) of the internal electrode 15 closest to the second main surface AB (specifically, the second internal electrode 15B) is either not curved in the stacking direction T, or it is slightly curved so as it approaches the first end surface CA, it approaches the center of the laminate 2 in the stacking direction T.

[0060] The dimension of the laminate 2 in the stacking direction T is greater than the dimension of the laminate 2 in the width direction W. The dimension of the laminate 2 in the length direction L is, for example, between 0.6 mm and 1.2 mm. The dimension of the laminate 2 in the width direction W is, for example, between 0.3 mm and 0.6 mm. The dimension of the laminate 2 in the stacking direction T is, for example, between 0.3 mm and 0.6 mm.

[0061] However, the dimension of the laminate 2 in the stacking direction T does not necessarily have to be larger than the dimension of the laminate 2 in the width direction W, and may be less than or equal to the dimension of the laminate 2 in the width direction W.

[0062] (Measurement method) Next, we will explain the methods for measuring various parameters.

[0063] (Content of metallic elements) The metallic element content is determined by measuring a predetermined cross-section of the multilayer ceramic capacitor 1, exposed by polishing, using EDX. The predetermined cross-section is defined as the LT cross-section, which passes through the center of the width W of the multilayer ceramic capacitor 1.

[0064] The position of the boundary between the inner substrate electrode 311 and the outer substrate electrode 312, the range of the inner diffusion section 311a, and the range of the outer diffusion section 312a can be determined based on the EDX measurement results. The method for setting the position of the boundary between the inner substrate electrode 311 and the outer substrate electrode 312, the range of the inner diffusion section 311a, and the range of the outer diffusion section 312a will be described below.

[0065] First, in the cross-section LT of the multilayer ceramic capacitor 1, while keeping the position in the stacking direction T constant, we determine the relationship between the shortest distance from the measurement point to the outer surface of the stacked body 2 and the content of the metal element at that measurement point.

[0066] Figure 5 shows the results of EDX analysis of the inner substrate electrode 311 and the outer substrate electrode 312. Figure 5 shows the relationship between the shortest distance from the measurement point to the outer surface of the laminate 2 and the content of the metal element at that measurement point, for each metal element. In Figure 5, the horizontal axis represents the shortest distance from the measurement point to the outer surface of the laminate 2, and the vertical axis represents the content of the metal element at that measurement point. For ease of explanation, only the measurement results for Ni and Cu are shown in Figure 5; however, in reality, various metal elements other than Ni and Cu are also measured. Furthermore, if granular glass is present at a measurement point, the measurement value at that point is discarded. Therefore, the line showing the EDX analysis results may be partially interrupted.

[0067] First, in the inner and outer base electrodes 311 and 312, the portion near the outer surface of the laminate 2 (see the left edge of the graph in Figure 5) has the highest Ni content among all the metal elements. The main metal component of the inner base electrode 311 is Ni.

[0068] In the inner and outer base electrodes 311 and 312, the portion near the plating layer 32 (see the right edge of the graph in Figure 5) has the highest Cu content among all the metal elements. The main metal component of the outer base electrode 312 is Cu.

[0069] The Ni content remains approximately constant as the measurement point moves away from the outer surface of the laminate 2, then begins to decrease at a certain point, stops decreasing at another point, and then remains approximately constant. The Cu content remains approximately constant as the measurement point moves away from the outer surface of the laminate 2, then begins to increase at a certain point, stops increasing at another point, and then remains approximately constant.

[0070] The boundary between the inner substrate electrode 311 and the outer substrate electrode 312 is the point where the content of the main component metal (e.g., Ni) in the inner substrate electrode 311 is equal to the content of the main component metal (e.g., Cu) in the outer substrate electrode 312.

[0071] The point where the content of the main component metal (e.g., Cu) in the outer substrate electrode 312 is 1 / 10 of the content of the main component metal (e.g., Ni) in the inner substrate electrode 311 marks the boundary between the inner diffusion portion 311a and the portion of the inner substrate electrode 311 that is not the inner diffusion portion 311a. The region between the boundary between the inner diffusion portion 311a and the portion of the inner substrate electrode 311 that is not the inner diffusion portion 311a, and the boundary between the inner substrate electrode 311 and the outer substrate electrode 312, constitutes the inner diffusion portion 311a.

[0072] The boundary between the outer diffusion portion 312a and the portion of the outer substrate electrode 312 that is not the inner diffusion portion 311a is the point where the content of the main component metal (e.g., Ni) of the inner substrate electrode 311 is 1 / 10 of the content of the main component metal (e.g., Cu) of the outer substrate electrode 312. The region between the boundary between the outer diffusion portion 312a and the portion of the inner substrate electrode 311 that is not the outer diffusion portion 312a, and the boundary between the inner substrate electrode 311 and the outer substrate electrode 312, constitutes the outer diffusion portion 312a.

[0073] In Figure 5, the shortest distance from the measurement point to the outer surface of the laminate 2 at the boundary between the inner substrate electrode 311 and the outer substrate electrode 312 is shown as "D1". The shortest distance from the measurement point to the outer surface of the laminate 2 at the boundary between the inner diffusion portion 311a and the portion of the inner substrate electrode 311 that is not the inner diffusion portion 311a is shown as "D2". The shortest distance from the measurement point to the outer surface of the laminate 2 at the boundary between the outer diffusion portion 312a and the portion of the outer substrate electrode 312 that is not the outer diffusion portion 312a is shown as "D3".

[0074] Next, the EDX analysis described above is performed continuously while moving the position in the stacking direction T. This makes it possible to determine the boundary line between the inner substrate electrode 311 and the outer substrate electrode 312, the boundary line between the inner diffusion portion 311a and the portion of the inner substrate electrode 311 that is not the inner diffusion portion 311a, and the boundary line between the outer diffusion portion 312a and the portion of the inner substrate electrode 311 that is not the outer diffusion portion 312a.

[0075] Note that the boundary lines obtained by the above method may be interrupted where they overlap with glass. The parts of the boundary line that are interrupted by glass are connected and completed with the shortest possible line segments.

[0076] Furthermore, the range of the inner substrate electrode 311, the range of the outer substrate electrode 312, the range of the inner diffusion section 311a, and the range of the outer diffusion section 312a may be set by the following method.

[0077] In a predetermined cross-section, the base electrode 311 is divided into multiple meshes. EDX measurement is performed for each mesh. This allows the metal content of each mesh to be obtained. The main metal component of the inner base electrode 311 and the main metal component of the outer base electrode 312 are identified. For each mesh, the ratio of the main metal component of the inner base electrode 311 to that of the outer base electrode is calculated. Based on the obtained ratio, it is determined whether the mesh corresponds to the inner base electrode 311 or the outer base electrode 312 region, and whether the mesh corresponds to the inner diffusion region 311a or the outer diffusion region 312a.

[0078] The set of meshes determined to correspond to the inner substrate electrode 311 is designated as the inner substrate electrode 311. The set of meshes determined to correspond to the outer substrate electrode 312 is designated as the outer substrate electrode 312. The set of meshes within the inner substrate electrode 311 that are determined to correspond to the inner diffusion portion 311a is designated as the inner diffusion portion 311a. The set of meshes within the outer substrate electrode 312 that are determined to correspond to the outer diffusion portion 312a is designated as the outer diffusion portion 312a.

[0079] (Thickness of the inner substrate electrode and thickness of the outer substrate electrode) The thickness of the inner base electrode 311 and the thickness of the outer base electrode 312 are determined in the LT cross section that passes through the center of the width W of the multilayer ceramic capacitor 1. The multilayer ceramic capacitor 1 is polished to expose a predetermined cross section. By observing the predetermined cross section with a scanning electron microscope, the thickness of the inner base electrode 311 and the thickness of the outer base electrode 312 can be determined.

[0080] (Glass content) The glass content is determined in the LT cross-section that passes through the center of the width W of the multilayer ceramic capacitor 1. The multilayer ceramic capacitor 1 is polished to expose a predetermined cross-section. The glass content can be determined by performing a WDX measurement in the predetermined cross-section. The glass content is calculated using the following formula (1). When determining the glass content of the inner base electrode 311, the target area is the entire inner base electrode 311 in the LT cross-section that passes through the center of the width W of the multilayer ceramic capacitor 1. When determining the glass content of the outer base electrode 312, the target area is the entire outer base electrode 312 in the LT cross-section that passes through the center of the width W of the multilayer ceramic capacitor 1. The area of ​​glass is measured as the area of ​​Si. Glass content (%) = Total area of ​​Si in the target area / Total area of ​​the target area × 100 ... (1)

[0081] (Pore rate) The pore ratio is measured in a cross-section parallel to the length L and width W of the dielectric layer 14. The laminate is polished to expose a predetermined cross-section. The pore ratio can be determined by calculating the percentage of the area occupied by pores in the predetermined cross-section. The predetermined cross-section is imaged using a scanning electron microscope (SEM). The obtained SEM image is analyzed to determine the area of ​​the field of view and the area occupied by pores. The pore ratio is calculated using the obtained area and the calculation formula in (2). The region imaged by the SEM is the part of the dielectric layer 14 sandwiched between adjacent internal electrodes 15, and more specifically, the central part in the length L and width W of that portion. The magnification during imaging is set to a magnification that fits within a plate with a field of view of 12 μm × 9 μm. Pore ​​ratio (%) = Area occupied by pores / Area of ​​field of view × 100 ... (2)

[0082] (Misalignment of the ends of the internal electrodes) The magnitude of the widthwise displacement W at the widthwise ends of adjacent internal electrodes 15 can be measured using a scanning electron microscope (SEM).

[0083] Specifically, first, the cross-section of the multilayer ceramic capacitor is polished from the first end face CA or the second end face CB to the center in the length direction L of the multilayer ceramic capacitor to expose the WT cross-section. Next, the WT cross-section is observed using a SEM. The observation conditions at this time are a magnification of 2000x and an acceleration voltage of 5kV, and the ends in the width direction W of the internal electrode 15 are imaged along the stacking direction T at the top, bottom, and center with a field of view of 50μm × 50μm. Based on the above observation conditions, images are taken and the distance between the ends in the width direction W of adjacent internal electrodes 15 is measured using the scale in the SEM image, so the magnitude of the displacement in the width direction W of adjacent internal electrodes 15 can be confirmed.

[0084] (Dimensions of the laminate) The external dimensions of the multilayer ceramic capacitor 1 can be measured using a micrometer.

[0085] (Method for manufacturing a multilayer ceramic capacitor 1) Next, the manufacturing method of the multilayer ceramic capacitor 1 according to this embodiment will be described.

[0086] (Printing process) First, a ceramic green sheet is prepared, which is a ceramic slurry formed into a sheet. The ceramic green sheet contains ceramic raw materials, including dielectric ceramic material, as well as a binder and a solvent. Additives containing rare earth elements may be added to the ceramic raw materials. Next, a conductive paste for the internal electrodes is prepared. The conductive paste for the internal electrodes contains metal powder, as well as a binder and a solvent.

[0087] Next, a conductive paste for the internal electrodes is printed onto the ceramic green sheet. The conductive paste for the internal electrodes is printed, for example, by screen printing or gravure printing. Multiple conductive pastes for the internal electrodes are printed at intervals along the length L. Each conductive paste for the internal electrodes is printed in a stripe pattern with the width W as the longitudinal direction. This results in a ceramic green sheet for the inner layer.

[0088] For the outer layer, a ceramic green sheet without an internal electrode pattern printed on it is prepared. The components contained in the ceramic green sheet for the inner layer and the components contained in the ceramic green sheet for the outer layer may be different.

[0089] (Lamination process) A predetermined number of ceramic green sheets for the outer layer are stacked. A predetermined number of ceramic green sheets for the inner layer are stacked. Next, the ceramic green sheets for the inner layer are stacked while being alternately offset in the length direction L. Next, a predetermined number of ceramic green sheets for the outer layer are stacked. Next, ceramic green sheets for the outer layer are stacked on both sides of the stacked ceramic green sheets for the inner layer in the stacking direction. The ceramic green sheets for the outer layer are heat-pressed onto the stacked ceramic green sheets for the inner layer. This gives rise to the mother block. Note that each outer layer 12 may consist of multiple stacked ceramic green sheets or may consist of a single ceramic green sheet.

[0090] (Pressing process) The mother block is pressed in the stacking direction T by means of a hydrostatic press or the like. A plate made of a hard material (e.g., steel plate) is pressed against the first main surface AA of the mother block, and a plate made of a soft material (e.g., rubber) is pressed against the second main surface AB of the mother block. This makes it possible to curve only the internal electrodes 15 located near the first main surface AA toward the second main surface AB.

[0091] (Mother block cutting process) Next, the mother block is cut along cutting lines corresponding to the dimensions of the laminate 2. The mother block is cut by, for example, a push-cutting blade. The mother block is cut, for example, in the length direction L and the width direction W. This yields multiple rectangular blocks (referred to as "laminated chips").

[0092] Furthermore, the curvature of the ends of the internal electrodes 15 in the longitudinal direction L can also be formed by adjusting the cutting speed when the mother block is cut. The mother block is cut by pressing with a cutting blade, for example. When the mother block is cut by pressing with a cutting blade, if the cutting speed is relatively high, it is possible to curve the ends of the internal electrodes 15 toward the direction of the cutting blade's movement, and if the cutting speed is relatively low, it is possible to suppress the curvature of the ends of the internal electrodes 15. When the mother block is cut in the width direction W, the cutting blade is inserted into the mother block from the first main surface AA side toward the second main surface AB side. The cutting speed is set to be relatively high near the first main surface AA and relatively low near the second main surface AB. This makes it possible to curve the ends of the internal electrodes 15 in the longitudinal direction L near the first main surface AA toward the center of the stacking direction T of the stacked chip, and to suppress the curvature of the internal electrodes 15 near the second main surface AB. Furthermore, the cutting speed when the mother block is cut in the length direction L is set to be relatively slow. This makes it possible to suppress the curvature of the ends of the internal electrodes 15 in the width direction W.

[0093] (Rounding process) It is preferable that the corners and edges of the laminated chips be rounded, for example, by barrel polishing.

[0094] (Side margin formation process) A ceramic green sheet for the side margin portion 20 is prepared. The ceramic green sheet for the side margin portion 20 contains Si in addition to the components contained in the ceramic green sheet for the dielectric layer 14. The ceramic green sheet for the side margin portion 20 may also contain additives such as Mg, Mn, Sn, Ho, and Tb. Next, the ceramic green sheet for the side margin portion 20 is attached to each surface of the outer surface of the laminated chip where the internal electrodes 15 are exposed (in other words, each surface opposite in the width direction W). This forms the side margin portion 20 on the laminated chip. The corners and edges of the laminated chip are rounded prior to the side margin portion formation process. As a result, a recess 21 is formed at the boundary between the laminated chip and the side margin portion 20. Note that one side margin portion 20 may be composed of one ceramic green sheet or multiple ceramic green sheets.

[0095] Next, the laminated chip with the side margin portion 20 formed on it is pressed in the width direction W. The central part of the laminated chip with the side margin portion 20 formed on it in the stacking direction T is pressed more strongly than the edges of the laminated chip with the side margin portion 20 formed on it in the stacking direction T. As a result, the outer surface of the side margin portion 20 in the width direction W becomes concave towards the center of the laminated chip in the width direction W. In addition, the surface of the outer surface of the laminated chip where the internal electrodes 15 are exposed also becomes concave towards the center of the laminated chip in the width direction W.

[0096] Furthermore, by pressing the central part of the side margin portion 20 in the stacking direction T toward the central part of the stacked body 2 in the width direction W, the side margin portion 20 as a whole is curved into an arc, thereby separating each end of the side margin portion 20 in the stacking direction T from the stacked chip. For this reason, rounding the stacked chip is not an essential step in forming the recess 21 at the boundary between the stacked chip and the side margin portion 20.

[0097] (Laminate firing process) The laminated chips are heated in a nitrogen atmosphere at a predetermined firing temperature for a predetermined time. This yields the laminated body 2.

[0098] (Inner base electrode formation process) A conductive paste containing glass and metal is prepared as the conductive paste for the inner base electrode 311. The main component metal of the conductive paste for the inner base electrode 311 contains at least one metal selected from the group consisting of Ni, Ag, and Pd, for example, Ni. The glass content of the conductive paste for the inner base electrode 311 is, for example, 5% by mass or more and 10% by mass or less of the total conductive paste for the inner base electrode 311. Next, the conductive paste for the inner base electrode 311 is applied to each end face C. The conductive paste for the inner base electrode 311 is applied, for example, only to each end face C of the outer surface of the laminate 2. After drying the conductive paste for the inner base electrode 311, the laminate 2 on which the conductive paste for the inner base electrode 311 is placed is heated in a nitrogen atmosphere at a predetermined firing temperature for a predetermined time. The predetermined firing temperature is, for example, in the range of 900°C to 1000°C. As a result, the conductive paste for the inner base electrode 311 is baked onto the laminate 2, and the inner base electrode 311 is formed on the laminate 2.

[0099] (Outer base electrode formation process) A conductive paste containing glass and metal is provided as the conductive paste for the outer base electrode 312. The main component metal of the conductive paste for the outer base electrode 312 is at least one metal selected from the group consisting of Cu, Sn, and Zn, for example, Cu. The glass content in the conductive paste for the outer base electrode 312 is, for example, in the range of 15% to 30% by mass relative to the total conductive paste for the outer base electrode 312.

[0100] Next, a conductive paste for the outer base electrode 312 is applied onto the inner base electrode 311. The conductive paste for the outer base electrode 312 is applied so as to cover, for example, each end face B, a part of each main face A, and a part of each side face B. After the conductive paste for the outer base electrode 312 is dried, the laminate 2 on which the conductive paste for the outer base electrode 312 is placed is heated in a nitrogen atmosphere at a predetermined firing temperature for a predetermined time. The predetermined firing temperature is, for example, in the range of 750°C to 850°C. As a result, the conductive paste for the outer base electrode 312 is baked onto the inner base electrode 311, and the outer base electrode 312 is formed on the laminate 2.

[0101] During the curing of the outer base electrode 312, components of the inner base electrode 311 diffuse into the outer base electrode 312, and components of the outer base electrode 312 diffuse into the inner base electrode 311. As a result, an inner diffusion portion 311a is formed in the inner base electrode 311, and an outer diffusion portion 312a is formed in the outer base electrode 312.

[0102] The glass content in the conductive paste for the outer base electrode 312 is set to within the range of 15% to 30% by mass relative to the total conductive paste for the outer base electrode 312, which allows the curing temperature of the outer base electrode 312 to be relatively low. This suppresses excessive diffusion of components from the inner base electrode 311 into the outer base electrode 312.

[0103] The arrangement of the conductive paste is not limited to these examples. The conductive paste for the inner base electrode 311 may extend to each main surface A and each side surface B, or both the conductive paste for the inner base electrode 311 and the conductive paste for the outer base electrode 312 may be arranged only on each end face C of the outer surface of the laminate 2.

[0104] (Plating process) A plating layer 32 is formed on the base electrode 31. First, a first plating layer 321 is formed on the base electrode 31. Next, a second plating layer 322 is formed on the first plating layer 321. The first plating layer 321 is formed, for example, by Ni plating. The second plating layer 322 is formed, for example, by Sn plating. The first plating layer 321 and the second plating layer 322 are formed sequentially, for example, by an electroplating method.

[0105] Based on the above, the multilayer ceramic capacitor 1 shown in Figure 1 is obtained.

[0106] (Effects according to the embodiment) According to this embodiment, the following effects can be obtained.

[0107] According to this embodiment, the outer substrate electrode 312 has an outer diffusion portion 312a which is a region containing the main component metal of the inner substrate electrode 311 at a concentration of 1 / 10 or more of the main component metal content of the outer substrate electrode 312. The outer diffusion portion 312a is adjacent to the inner substrate electrode 311. The maximum thickness of the outer diffusion portion 312a is 1.0 μm or less.

[0108] With this configuration, since the main component metal of the inner base electrode 311 and the main component metal of the outer base electrode 312 are different from each other, the functions of the inner base electrode 311 and the outer base electrode 312 can be made different. For this reason, by making the main component metal of the inner base electrode 311 easy to connect with the internal electrode 15, the connectivity between the inner base electrode 311 and the internal electrode 15 can be improved. By making the main component metal of the outer base electrode 312 easy to suppress the penetration of corrosive components, it is possible to suppress the penetration of corrosive components contained in the plating solution for the plating layer 32 into the interior of the laminate 2.

[0109] However, the diffusion of the main component metal of the inner substrate electrode 311 to the outer substrate electrode 312 may reduce the corrosion resistance of the outer substrate electrode 312. However, since the maximum thickness of the outer diffusion portion 312a is 1.0 μm or less, the penetration of corrosive components into the laminate 2 can be sufficiently suppressed by the outer substrate electrode 312.

[0110] Therefore, it is possible to improve reliability regarding electrical connectivity while also improving reliability against corrosive components, thereby providing a more reliable multilayer ceramic capacitor 1.

[0111] According to this embodiment, the main component metal of the inner base electrode 311 is preferably at least one metal selected from the group consisting of Ni, Ag, and Pd, and the main component metal of the outer base electrode 312 is preferably at least one metal selected from the group consisting of Cu, Sn, and Zn.

[0112] With this configuration, the connectivity between the inner base electrode 311 and the internal electrode 15 can be more effectively improved. The penetration of corrosive components into the laminate 2 can be effectively suppressed by the outer base electrode 312.

[0113] According to this embodiment, the maximum thickness of the inner base electrode 311 is thinner than the maximum thickness of the outer base electrode 312.

[0114] With this configuration, the diffusion of the main component metal of the inner substrate electrode 311 to the outer substrate electrode 312 can be suppressed, thereby preventing a decrease in the corrosive component penetration suppression function of the outer substrate electrode 312.

[0115] According to this embodiment, the ratio of the maximum thickness of the inner base electrode 311 to the maximum thickness of the outer base electrode 312 is 0.5 or more and 0.9 or less.

[0116] With this configuration, it is possible to suppress the decrease in the corrosive component penetration suppression function of the outer substrate electrode 312.

[0117] However, if the main component metal of the outer substrate electrode 312 is Cu and the main component metal of the inner electrode 15 is Ni, for example, if the main component metal of the outer substrate electrode 312 is prone to forming an alloy with the main component metal of the inner electrode 15, there is a risk that the main component metal of the outer substrate electrode 312 will form an alloy with the main component metal of the inner electrode 15 when it reaches the laminate 2 through the inner substrate electrode 311. Furthermore, if the formed alloy expands, there is a risk that it will cause cracks in the laminate 2.

[0118] However, with this configuration, since the thickness of the inner base electrode 311 is relatively large, it is possible to suppress the main component metal of the outer base electrode 312 from reaching the laminate 2 through the inner base electrode 311. This makes it possible to suppress the occurrence of cracks in the laminate 2.

[0119] According to this embodiment, the glass content of the inner substrate electrode 311 is lower than that of the outer substrate electrode 312.

[0120] With this configuration, increasing the glass content of the outer substrate electrode 312 allows for a lower temperature during the baking process of the outer substrate electrode 312. As a result, during the baking process of the outer substrate electrode 312, the main component metal of the outer substrate electrode 312 (e.g., Cu) can diffuse into the inner substrate electrode 311, and the main component metal of the inner substrate electrode 311 (e.g., Ni) can diffuse into the outer substrate electrode 312. This suppresses a decrease in the content of the main component metal of the outer substrate electrode 312, thereby suppressing a decrease in the corrosion component penetration suppression function of the outer substrate electrode 312. Furthermore, it suppresses a decrease in the content of the main component metal of the inner substrate electrode 311, thereby suppressing a decrease in connectivity between the inner substrate electrode 311 and the internal electrode 15.

[0121] According to this embodiment, the ratio of the glass content of the inner base electrode 311 to the glass content of the outer base electrode 312 is 0.33 or more and 0.66 or less.

[0122] If the ratio of the glass content of the inner substrate electrode 311 to the glass content of the outer substrate electrode 312 is excessive, the sintering temperature of the outer substrate electrode 312 will become too high compared to the sintering temperature of the inner substrate electrode 311, and the outer substrate electrode 312 may not be sufficiently sintered by low-temperature sintering alone. Conversely, if the ratio of the glass content of the inner substrate electrode 311 to the glass content of the outer substrate electrode 312 is insufficient, the glass content of the outer substrate electrode 312 will become excessive, and the resistance value (ESR) of the outer substrate electrode 312 may become excessive. However, with this configuration, it is possible to sufficiently sinter the outer substrate electrode 312 while suppressing an excessive ESR.

[0123] According to this embodiment, in the WT cross-section, of the three regions obtained by dividing the portion of the inner substrate electrode 311 that is placed on the first end face CA into three equal parts in the width direction W, the glass content of the region closest to the outer substrate electrode 312 is greater than the glass content of the central region.

[0124] With this configuration, the diffusion of the main component of the inner substrate electrode 311 from the inner substrate electrode 311 to the outer substrate electrode 312 can be suitably suppressed by the glass present at the boundary between the inner substrate electrode 311 and the outer substrate electrode 312. Furthermore, the glass present at the boundary between the inner substrate electrode 311 and the outer substrate electrode 312 acts as an anchor, thereby improving the bonding strength between the inner substrate electrode 311 and the outer substrate electrode 312.

[0125] According to this embodiment, in the WT cross-section of the laminate 2, all internal electrodes 15 satisfy the relationship that the distance in the width direction W between one end of an internal electrode 15 and one end of an adjacent internal electrode 15 in the width direction W is 0.5 μm or less. All internal electrodes 15 also satisfy the relationship that the distance in the width direction W between the other end of an internal electrode 15 and the other end of an adjacent internal electrode 15 in the width direction W is 0.5 μm or less.

[0126] With this configuration, by aligning one end of the internal electrode 15 in the width direction W with the stacking direction T, it becomes possible to accurately set the capacitance of the multilayer ceramic capacitor 1.

[0127] According to this embodiment, the laminate 2 has a recess 21 on its outer surface that is provided in a portion that overlaps with the end of the internal electrode 15 in the width direction W and the stacking direction T, and which is concave toward the center of the laminate 2 in the stacking direction T.

[0128] With this configuration, the inner base electrode 311 or the outer base electrode 312 can be embedded in the recess 21, thereby suppressing peeling of the ends of the inner base electrode 311 or the outer base electrode 312.

[0129] According to this embodiment, the pore ratio in the dielectric layer 14 is preferably 1% or more and 5% or less.

[0130] With this configuration, the pore ratio of the dielectric layer 14 is relatively high, which makes it easier for the internal electrodes 15 to bite into the pores of the dielectric layer 14, thereby suppressing delamination of the internal electrodes 15. In addition, the pore ratio of the dielectric layer 14 is relatively low, which suppresses the occurrence of cracks inside the laminate 2.

[0131] According to this embodiment, in a cross-section WT passing through the center of the laminate 2 in the width direction W, the dimension of the laminate 2 in the width direction W at the center of the laminate 2 in the stacking direction T is smaller than any of the dimensions of the laminate 2 in the width direction W at each end of the laminate 2 in the stacking direction T.

[0132] With this configuration, the flexural strength of the laminate 2 in the direction perpendicular to the substrate can be improved.

[0133] According to this embodiment, in the LT cross section passing through the central part of the width direction W of the laminate 2, the curvature of the lead portion 15b of the internal electrode 15 closest to the first main surface AA is greater than the curvature of the lead portion 15b of the internal electrode 15 closest to the second main surface AB.

[0134] When mounting the multilayer ceramic capacitor 1, the portion of the laminate 2 closer to the substrate is more susceptible to stress than the portion further away from the substrate. However, with this configuration, when the multilayer ceramic capacitor 1 is mounted on the substrate with the second main surface AB facing the substrate, the internal electrodes 15 with less curvature are positioned on the substrate side of the laminate 2. The less curvature the internal electrodes 15 have, the higher their strength. As a result, the internal electrodes 15 with higher strength can be placed in the portion of the laminate 2 that is relatively prone to stress, thereby suppressing the occurrence of defects inside the laminate 2 due to substrate deflection during the mounting of the multilayer ceramic capacitor 1.

[0135] On the other hand, with this configuration, when the multilayer ceramic capacitor 1 is mounted on the substrate with the second main surface AB facing the substrate, the internal electrodes 15 with greater curvature are positioned in the portion of the laminate 2 that is separated from the substrate. By curving the internal electrodes 15, the adhesion between the internal electrodes 15 and the dielectric layer 14 can be improved. Therefore, peeling of the internal electrodes 15 can be suppressed in the portion of the laminate 2 that is relatively less stressed.

[0136] According to this embodiment, the dimension of the laminate 2 in the stacking direction T is larger than the dimension of the laminate 2 in the width direction W.

[0137] With this configuration, the number of stacked internal electrodes 15 can be increased, thereby providing a high-capacitance multilayer ceramic capacitor 1.

[0138] Furthermore, since it is easier to distinguish between the stacking direction T and the width direction W, it is easier to mount the multilayer ceramic capacitor 1 on the substrate in the desired orientation.

[0139] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications and variations are possible.

[0140] Furthermore, the present invention includes the following combinations.

[0141] <1> A laminate comprising stacked dielectric layers and internal electrodes, having a first main surface and a second main surface facing each other in the stacking direction, a first side surface and a second side surface facing each other in the width direction intersecting the stacking direction, and a first end surface and a second end surface facing each other in the length direction intersecting the stacking direction and the width direction; and an external electrode provided on the laminate and connected to the internal electrode, wherein the external electrode comprises an inner base electrode disposed on at least one of the first end surface and the second end surface and containing glass and a conductive metal, and a glass disposed on the inner base electrode. A multilayer ceramic capacitor comprising: an outer base electrode containing a conductive metal and a metal component different from the main component metal of the inner base electrode as the main component metal; and a plating layer disposed on the outer base electrode, wherein the outer base electrode has an outer diffusion portion which is a region containing the main component metal of the inner base electrode at a content of 1 / 10 or more of the content of the main component metal of the outer base electrode; the outer diffusion portion is adjacent to the inner base electrode; and the maximum thickness of the outer diffusion portion is 1.0 μm or less.

[0142] <2> The main component metal of the inner substrate electrode is at least one metal selected from the group consisting of Ni, Ag, and Pd, and the main component metal of the outer substrate electrode is at least one metal selected from the group consisting of Cu, Sn, and Zn. <1> The multilayer ceramic capacitor described above.

[0143] <3> The maximum thickness of the inner substrate electrode is thinner than the maximum thickness of the outer substrate electrode. <1> or <2> The multilayer ceramic capacitor described above.

[0144] <4> The ratio of the maximum thickness of the inner substrate electrode to the maximum thickness of the outer substrate electrode is 0.5 or more and 0.9 or less. <3> The multilayer ceramic capacitor described above.

[0145] <5> In a cross-section of the laminate parallel to the stacking direction and the width direction, all internal electrodes satisfy the relationship that the distance in the width direction between one end of an internal electrode in the width direction and one end of an adjacent internal electrode in the width direction is 0.5 μm or less, and all internal electrodes satisfy the relationship that the distance in the width direction between the other end of an internal electrode in the width direction and the other end of an adjacent internal electrode in the width direction is 0.5 μm or less. <1> ~ <4> A multilayer ceramic capacitor as described in any one of the following:

[0146] <6> The laminate has a recess provided on its outer surface in a portion that overlaps with the end of the internal electrode in the width direction and the stacking direction, and which is concave toward the center of the laminate in the stacking direction. <1> ~ <5> A multilayer ceramic capacitor as described in any one of the following:

[0147] <7> The pore ratio in the dielectric layer is 1% or more and 5% or less. <1> ~ <6> A multilayer ceramic capacitor as described in any one of the following:

[0148] <8> The width dimension of the laminate at the center of the laminate in the stacking direction is smaller than any of the width dimensions of the laminate at each end of the laminate in the stacking direction. <1> ~ <7> A multilayer ceramic capacitor as described in any one of the following:

[0149] <9> Each internal electrode has a facing portion which is the portion facing an adjacent internal electrode in the stacking direction, and a leading portion which is the portion drawn out from the facing portion toward the external electrode, and in a cross section parallel to the length direction and the stacking direction at the center of the width direction of the stack, the curvature of the leading portion of the internal electrode closest to the first main surface is greater than the curvature of the leading portion of the internal electrode closest to the second main surface. <1> ~ <8> A multilayer ceramic capacitor as described in any one of the following:

[0150] <10> The dimension of the laminate in the stacking direction is greater than the dimension of the laminate in the width direction. <1> ~ <10> A multilayer ceramic capacitor as described in any one of the following: [Explanation of Symbols]

[0151] 1. Multilayer ceramic capacitor 2 Laminate 3 External electrode 32 Plating layer 14 Dielectric layer 15 Internal electrode 15a Opposite part 15b Drawer part 20 recesses 311 Outer base electrode 312 Inner base electrode AA First Main Surface AB Second Main Surface BA First side BB 2nd side CA 1st end face CB 2nd end face G Glass

Claims

1. A laminate comprising stacked dielectric layers and internal electrodes, having a first main surface and a second main surface facing each other in the stacking direction, a first side surface and a second side surface facing each other in the width direction intersecting the stacking direction, and a first end surface and a second end surface facing each other in the length direction intersecting the stacking direction and the width direction, The laminate comprises an external electrode provided on the laminate and connected to the internal electrode, The external electrode comprises an inner base electrode disposed on at least one of the first end face and the second end face and containing glass and a conductive metal; an outer base electrode disposed on the inner base electrode and containing glass and a conductive metal, and containing a metal component different from the main metal component of the inner base electrode as its main metal component; and a plating layer disposed on the outer base electrode. The outer base electrode has an outer diffusion portion which is a region containing the main component metal of the inner base electrode at a concentration of 1 / 10 or more of the main component metal content of the outer base electrode. The outer diffusion portion is adjacent to the inner substrate electrode, A multilayer ceramic capacitor in which the maximum thickness of the outer diffusion portion is 1.0 μm or less.

2. The main component metal of the inner base electrode is at least one metal selected from the group consisting of Ni, Ag, and Pd. The multilayer ceramic capacitor according to claim 1, wherein the main component metal of the outer substrate electrode is at least one metal selected from the group consisting of Cu, Sn, and Zn.

3. The multilayer ceramic capacitor according to claim 1 or 2, wherein the maximum thickness of the inner substrate electrode is thinner than the maximum thickness of the outer substrate electrode.

4. The multilayer ceramic capacitor according to claim 3, wherein the ratio of the maximum thickness of the inner base electrode to the maximum thickness of the outer base electrode is 0.5 or more and 0.9 or less.

5. In a cross-section of the laminate parallel to the stacking direction and the width direction, The multilayer ceramic capacitor according to claim 1 or 2, wherein all internal electrodes satisfy the relationship that the distance in the width direction between one end of the internal electrode in the width direction and one end of the internal electrode adjacent to the internal electrode in the width direction is 0.5 μm or less, and all internal electrodes satisfy the relationship that the distance in the width direction between the other end of the internal electrode in the width direction and the other end of the internal electrode adjacent to the internal electrode in the width direction is 0.5 μm or less.

6. The laminated body has a recess provided on the outer surface of the laminated body in a portion that overlaps with the end of the internal electrode in the width direction and the lamination direction, and the recess is concave toward the center of the laminated body in the lamination direction, according to claim 1 or 2.

7. The multilayer ceramic capacitor according to claim 1 or 2, wherein the pore ratio in the dielectric layer is 1% or more and 5% or less.

8. The multilayer ceramic capacitor according to claim 1 or 2, wherein the width dimension of the laminate at the center of the laminate in the stacking direction is smaller than any of the width dimensions of the laminate at each end of the laminate in the stacking direction.

9. Each internal electrode has a facing portion which is the portion facing an adjacent internal electrode in the stacking direction, and a leading portion which is the portion drawn out from the facing portion toward the external electrode. In the cross-section of the laminated body in the central part in the width direction, parallel to the length direction and the stacking direction, The multilayer ceramic capacitor according to claim 1 or 2, wherein the curvature of the lead portion of the internal electrode closest to the first main surface is greater than the curvature of the lead portion of the internal electrode closest to the second main surface.

10. The multilayer ceramic capacitor according to claim 1 or 2, wherein the dimension of the laminate in the stacking direction is greater than the dimension of the laminate in the width direction.

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