Laminated ceramic electronic component and method for manufacturing the same

Abstract

The present invention provides a laminated ceramic electronic component and a method for manufacturing the same, which are capable of thinning an external electrode in a laminated ceramic electronic component without compromising reliability. The laminated ceramic electronic component includes a ceramic body and an external electrode. The ceramic body has: a first side surface facing a first axis direction; a second side surface facing a second axis direction orthogonal to the first axis; an edge connecting the first side surface and the second side surface; and a plurality of internal electrodes stacked along a third axis orthogonal to the first and second axes and led to a lead-out area. The external electrode covers the lead-out area and has: a protrusion disposed at a position along the edge and protruding in the first and second axis directions; and a first base portion and a second base portion extending from the protrusion along the first side surface and the second side surface, respectively.

Description

Technical Field

[0001] The present invention relates to a laminated ceramic electronic component having external electrodes and a method for manufacturing the same. Background Art

[0002] In high-frequency communication devices such as mobile terminals, multilayer ceramic capacitors are used for a wide range of applications such as decoupling of IC power lines. Multilayer ceramic capacitors have a structure in which a plurality of internal electrodes stacked in a ceramic body are alternately led out to a pair of external electrodes (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-24077 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] In multilayer ceramic capacitors, it is advantageous to thin the external electrodes in order to achieve lower height and higher performance, as well as to reduce ESR (equivalent series resistance) and ESL (equivalent series inductance). However, in multilayer ceramic capacitors, the thinner the external electrodes, the more likely it is that short circuits will occur due to moisture intrusion into the ceramic body.

[0008] In a ceramic body, cracks that form mainly from the surface to the inside serve as a path for moisture to enter. Therefore, in a laminated ceramic capacitor, a short circuit is particularly likely to occur when an excessively thin portion of an external electrode overlaps a portion of the ceramic body where a crack exists.

[0009] In view of the above circumstances, an object of the present invention is to provide a technology capable of reducing the thickness of external electrodes in a multilayer ceramic electronic component without impairing reliability.

[0010] Technical solutions for solving technical problems

[0011] In order to achieve the above object, one embodiment of the present invention provides a multilayer ceramic electronic component including a ceramic body and external electrodes.

[0012] The ceramic body comprises: a first side surface facing in a first axis direction; a second side surface facing in a second axis direction orthogonal to the first axis; an edge connecting the first side surface and the second side surface; and a plurality of internal electrodes stacked along a third axis orthogonal to the first axis and the second axis and led out to a lead-out region.

[0013] The external electrode covers the lead-out region and includes: a protrusion provided along the ridge and protruding in the first and second axis directions; and a first base portion and a second base portion extending from the protrusion along the first and second side surfaces, respectively.

[0014] Alternatively, the protrusion may extend along the edge.

[0015] The protrusion may be provided at least one of both end portions of the ridge portion in the third axis direction.

[0016] In the laminated ceramic electronic component, the thickness of the external electrode is larger at the protrusion formed along the edge of the ceramic body. As a result, in the ceramic body, the edge that is susceptible to external impact can be more reliably protected from the influence of the external environment by the protrusion of the external electrode, so even if there are cracks in the edge, it is possible to prevent moisture from intruding into the interior. Therefore, in the laminated ceramic electronic component, the occurrence of short circuits can be effectively suppressed. In addition, in the laminated ceramic electronic component, by ensuring that the thickness of the protrusion of the external electrode is large, on the other hand, the thickness of the first base part and the second base part is maintained small, it is possible to reduce ESR and ESL, and it is also possible to further suppress the occurrence of peeling of the external electrode.

[0017] Alternatively, the lead-out region may include the edge portion.

[0018] In a ceramic body in which the internal electrode is exposed at the edge portion, a short circuit caused by the intrusion of moisture into the edge portion is more likely to occur. Therefore, according to this structure, the effect of suppressing the short circuit as described above can be achieved more effectively.

[0019] The external electrode may further include a plating layer and a base layer located between the plating layer and the lead-out region.

[0020] The base layer may be formed of a sputtered film.

[0021] According to this structure, the base layer can be made thinner, so the thickness of the first base portion and the second base portion of the external electrode can be maintained smaller.

[0022] Alternatively, the maximum dimension in the third axis direction may be smaller than the maximum dimensions in the first axis direction and the second axis direction.

[0023] The maximum dimension in the third axis direction may be greater than or equal to 50 μm and less than or equal to 150 μm.

[0024] The maximum dimension in the third axis direction may be greater than or equal to 60 μm and less than or equal to 120 μm.

[0025] The maximum dimension in the third axis direction may be greater than or equal to 60 μm and less than or equal to 75 μm.

[0026] In a method for manufacturing a stacked ceramic electronic component according to one aspect of the present invention, a ceramic body is prepared, wherein the ceramic body has: a first side surface facing in a first axial direction; a second side surface facing in a second axial direction orthogonal to the first axis; an edge connecting the first side surface and the second side surface; and a plurality of internal electrodes stacked along a third axis orthogonal to the first axis and the second axis and led out to a lead-out area.

[0027] A base layer is formed in the lead-out region by a vacuum film forming method.

[0028] A plating layer is formed to cover the lead-out region via the base layer, the plating layer comprising: a protrusion extending along the ridge and protruding in the first and second axial directions; and a first base portion and a second base portion extending from the protrusion along the first and second side surfaces, respectively.

[0029] Alternatively, the lead-out region may include the edge portion.

[0030] Alternatively, the process of forming the plating layer may include: a process of forming a reinforcing layer extending along the ridge portion; and a process of forming a covering layer covering the lead-out region from above the reinforcing layer.

[0031] The vacuum film forming method may be a sputtering method.

[0032] Effects of the Invention

[0033] As described above, the present invention can provide a technology that can ensure reliability in a multilayer ceramic electronic component and reduce the thickness of the external electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a perspective view of a multilayer ceramic capacitor according to a first embodiment of the present invention.

[0035] Figure 2 It is a perspective view of the ceramic body of the above-mentioned multilayer ceramic capacitor.

[0036] Figure 3 It is an exploded perspective view of the ceramic body.

[0037] Figure 4 The above-mentioned multilayer ceramic capacitor is along Figure 1 Cross-sectional view along the diagonal line A-A'.

[0038] Figure 5 The above-mentioned multilayer ceramic capacitor is along Figure 1 Cross-sectional view along the diagonal line B-B'.

[0039] Figure 6 is a top view of the above-mentioned multilayer ceramic capacitor.

[0040] Figure 7 : is a flowchart showing a method for manufacturing the above-mentioned multilayer ceramic capacitor.

[0041] Figure 8 It is a perspective view showing the formation process of the base layer in the above-mentioned manufacturing method.

[0042] Fig. 9 It is a perspective view showing the formation process of the base layer in the above-mentioned manufacturing method.

[0043] Fig.10 This is a perspective view of a ceramic body on which a base layer is formed in the above-mentioned manufacturing method.

[0044] Fig.11 It is a perspective view showing the process of forming the reinforcing layer in the above-mentioned manufacturing method.

[0045] Fig.12 It is a perspective view showing the process of forming the reinforcing layer in the above-mentioned manufacturing method.

[0046] Fig.13 This is a perspective view of a ceramic body on which a reinforcement layer is formed in the above-mentioned manufacturing method.

[0047] Fig.14 This is a perspective view of the ceramic body on which the covering layer is formed in the above-mentioned manufacturing method.

[0048] Fig.15 It is a perspective view of a multilayer ceramic capacitor according to a second embodiment of the present invention.

[0049] Fig.16 It is a perspective view of the ceramic body of the above-mentioned multilayer ceramic capacitor.

[0050] Fig.17 It is an exploded perspective view of the ceramic body.

[0051] Fig.18 The above-mentioned multilayer ceramic capacitor is along Fig.15 Cross-sectional view along the diagonal line C-C'.

[0052] Fig.19 is a top view of the above-mentioned multilayer ceramic capacitor.

[0053] Fig. 20 It is a perspective view of a multilayer ceramic capacitor according to a modified example of the first embodiment.

[0054] Fig.21 The above-mentioned multilayer ceramic capacitor is along Fig. 20 Cross-sectional view along the diagonal line D-D'.

[0055] Fig. 22 The above-mentioned multilayer ceramic capacitor is along Fig. 20 Cross-sectional view along the diagonal line E-E'.

[0056] Description of Reference Numerals

[0057] 10...Multilayer ceramic capacitors

[0058] 11... Ceramic body

[0059] 12, 13...Internal electrodes

[0060] 12d, 13d...lead-out section

[0061] 14, 15...External electrodes

[0062] P... protrusion

[0063] E1, E2...base

[0064] S1, S2...side

[0065] R……Ring

[0066] D...lead-out area

[0067] L1...basal layer

[0068] L2……plating layer. DETAILED DESCRIPTION

[0069] Hereinafter, the multilayer ceramic capacitors 10 and 20 according to the first and second embodiments of the present invention will be described with reference to the drawings. In addition, the drawings appropriately show mutually orthogonal X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are the same in all the drawings, and define a fixed coordinate system fixed to the multilayer ceramic capacitors 10 and 20.

[0070] I. First Embodiment

[0071] 1. Structure of the Multilayer Ceramic Capacitor 10

[0072] 1.1 Overall structure

[0073] Figure 1 The multilayer ceramic capacitor 10 according to the first embodiment of the present invention is a perspective view. The multilayer ceramic capacitor 10 includes a ceramic body 11, a pair of first external electrodes 14, and a pair of second external electrodes 15. The external electrodes 14, 15 are provided on the outer surface of the ceramic body 11 at a distance from each other.

[0074] Figure 2: is a perspective view of the ceramic body 11. Typically, the ceramic body 11 is configured as a hexahedron. Specifically, the ceramic body 11 has a pair of first side surfaces S1 extending along the YZ plane, a pair of second side surfaces S2 extending along the XZ plane, and a pair of main surfaces M extending along the XY plane.

[0075] The first side surface S1, the second side surface S2 and the main surface M of the ceramic body 11 are all configured as flat surfaces. The flat surface of the present embodiment can be any surface that can be identified as flat when viewed as a whole, and may not be a plane in the strict sense, and may also include a surface having, for example, a shape with slight bumps on the surface or a shape that is slightly curved within a specified range.

[0076] In addition, the ceramic body 11 has four edges R that connect a pair of first side surfaces S1 and a pair of second side surfaces S2. Typically, the edges R are formed as convex curved surfaces that smoothly connect the first side surface S1 and the second side surface S2. However, the edges R are not limited to this structure, and may also be, for example, intersection lines that directly connect the first side surface S1 and the second side surface S2.

[0077] The ceramic body 11 has a rectangular planar shape along the XY plane, and has a structure in which a plurality of flat plate-shaped ceramic layers are stacked in the Z-axis direction. Figure 3 It is an exploded perspective view showing a part of the laminated structure of the ceramic body 11. The ceramic body 11 has a plurality of sheet-shaped first and second internal electrodes 12 and 13 extending along the XY plane.

[0078] The internal electrodes 12 and 13 are formed of a good electrical conductor. Typical examples of good electrical conductors forming the internal electrodes 12 and 13 include nickel (Ni), and other examples include metals or alloys mainly composed of copper (Cu), palladium (Pd), platinum (Pt), silver (Ag), gold (Au), etc.

[0079] In the ceramic body 11, the internal electrodes 12 and 13 are alternately arranged between the plurality of ceramic layers along the Z-axis direction and face each other in the Z-axis direction. The ceramic body 11 is provided with a lead-out region D extending from each edge portion R along the side surfaces S1 and S2 and leading out one of the internal electrodes 12 and 13.

[0080] Figure 1 2 shows the diagonal line AA′ and the diagonal line BB′ of the rectangular planar shape of the ceramic body 11 of the multilayer ceramic capacitor 10 . Figure 4 1 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along the diagonal line AA′. Figure 5 BB′ is a cross-sectional view of the multilayer ceramic capacitor 10 taken along the diagonal line BB′.

[0081] Each of the first and second internal electrodes 12, 13 includes a first lead portion 12d and a second lead portion 13d extending from an opposing portion opposed to the Z-axis direction to the lead region D. The first lead portion 12d is exposed in two lead regions D through which the diagonal line AA' passes. The second lead portion 13d is exposed in two lead regions D through which the diagonal line BB' passes.

[0082] The external electrodes 14 and 15 are provided in the lead regions D of the ceramic body 11. More specifically, the first external electrode 14 covers the two lead regions D where the first lead portion 12d is exposed, and is connected to the first internal electrode 12. The second external electrode 15 covers the two lead regions D where the second lead portion 13d is led, and is connected to the second internal electrode 13.

[0083] Thus, the pair of first external electrodes 14 are connected to the first lead portion 12d in each lead region D and are electrically connected to each other via the first internal electrode 12. In addition, the pair of second external electrodes 15 are connected to the second lead portion 13d in each lead region D and are electrically connected to each other via the second internal electrode 13.

[0084] In addition, the external electrodes 14 and 15 are not limited to the external electrodes 14 and 15 as long as they are separated from each other and cover the lead-out region D of the ceramic body 11. Figure 1 , Figure 4 , Figure 5 For example, the external electrodes 14 and 15 may not extend along the main surface M, and a gap may be formed on at least one of the upper side and the lower side of the side surfaces S1 and S2 in the Z-axis direction.

[0085] Thus, the multilayer ceramic capacitor 10 has a four-terminal structure with a pair of first external electrodes 14 and a pair of second external electrodes 15 as four terminals. According to this structure, the multilayer ceramic capacitor 10 can store charges corresponding to the potential difference between the pair of first external electrodes 14 and the pair of second external electrodes 15.

[0086] In the ceramic body 11, a dielectric ceramic with a high dielectric constant is used to increase the capacitance of each ceramic layer between the internal electrodes 12 and 13. Examples of dielectric ceramic with a high dielectric constant include perovskite materials containing barium (Ba) and titanium (Ti), such as barium titanate (BaTiO3).

[0087] In addition, the ceramic layer can also be composed of a group consisting of strontium titanate (SrTiO3), calcium titanate (CaTiO3), magnesium titanate (MgTiO3), calcium zirconate (CaZrO3), calcium zirconate titanate (Ca(Zr,Ti)O3), barium zirconate (BaZrO3), titanium oxide (TiO2), etc.

[0088] The outer dimensions of the multilayer ceramic capacitor 10 along the X-axis, Y-axis, and Z-axis directions may be, for example, 1.7×1.7×0.15 mm, 1.2×1.2×0.12 mm, 0.6×0.6×0.1 mm, 1.0×0.5×0.5 mm, 0.6×0.3×0.3 mm, 1.0×0.5×0.15 mm, or the like.

[0089] 1.2 Details of external electrodes 14 and 15

[0090] Figure 6 1 is a top view of the multilayer ceramic capacitor 10. The external electrodes 14 and 15 each include a first base portion E1, a second base portion E2, and a protrusion P. The first base portion E1 extends along the first side surface S1. The second base portion E2 extends along the second side surface S2. The protrusion P extends in a ridge shape along the ridge portion R in the Z-axis direction.

[0091] In each of the external electrodes 14 and 15, the protrusion P formed along the ridge R is formed thicker than the base parts E1 and E2. That is, in each of the external electrodes 14 and 15, the protrusion P thicker than the base parts E1 and E2 protrudes outward in the X-axis direction from the first base part E1 and protrudes outward in the Y-axis direction from the second base part E2.

[0092] Figure 6 , the thickness d1 of the first base portion E1, the thickness d2 of the second base portion E2, and the thicknesses dp1 and dp2 of the protrusion P are shown. The thickness dp1 of the protrusion P is defined as the maximum thickness in the X-axis direction based on the first side surface S1. The thickness dp2 of the protrusion P is defined as the maximum thickness in the Y-axis direction based on the second side surface S2.

[0093] When thicknesses d1, d2, dp1, and dp2 are used, each external electrode 14, 15 has the following structure: the thickness d1 of the first base portion E1 is smaller than the thickness dp1 of the protrusion P, and the thickness d2 of the second base portion E2 is smaller than the thickness dp2 of the protrusion P. That is, each external electrode 14, 15 satisfies the relationship of d1<dp1 and d2<dp2. d1 and d2 are, for example, not less than 10μm and not more than 50μm, preferably not less than 12μm and not more than 30μm. In addition, dp1 and dp2 can be set to be, for example, not less than 2μm and not more than 12μm larger than d1 and d2. That is, dp1 and dp2 are, for example, not less than 12μm and not more than 62μm, preferably not less than 14μm and not more than 42μm.

[0094] In the external electrodes 14 and 15, by forming the base parts E1 and E2 thinner, the current path in the current-carrying direction when using the multilayer ceramic capacitor 10 can be shortened. As a result, in the multilayer ceramic capacitor 10, ESR (equivalent series resistance) and ESL (equivalent series inductance) can be kept small.

[0095] In addition, since the base parts E1 and E2 of the external electrodes 14 and 15 are formed thinner, the internal stress is reduced accordingly. Therefore, in the multilayer ceramic capacitor 10, it is difficult for the base parts E1 and E2 of the external electrodes 14 and 15 to peel off due to thermal stress or mechanical stress applied during installation or use, so high reliability can be ensured.

[0096] On the other hand, in the ceramic body 11, stress caused by external impact is likely to be concentrated on the ridge R bent into a convex shape, so cracks are likely to be generated in the ridge R. In the ceramic body 11 where cracks are generated in the ridge R, due to the influence of moisture intrusion along the cracks from the ridge R, the internal electrodes 12 and 13 are likely to be short-circuited.

[0097] In this regard, in each external electrode 14, 15 of the laminated ceramic capacitor 10, the ridge R of the ceramic body 11 can be more reliably protected by the thick protrusion P. Therefore, in the laminated ceramic capacitor 10, the ridge R of the ceramic body 11 can be effectively isolated from the external environment by the protrusion P of each external electrode 14, 15.

[0098] Thus, in the ceramic body 11, moisture in the external environment is unlikely to reach the ridge R, so moisture is unlikely to enter the interior even if cracks are present in the ridge R. Therefore, in the multilayer ceramic capacitor 10, short circuits can be suppressed, thereby further ensuring high reliability.

[0099] like Figure 4 , Figure 5 As shown, each external electrode 14, 15 includes a base layer L1 and a plating layer L2. The base layer L1 constitutes the innermost layer of each external electrode 14, 15 adjacent to the lead-out region D of the ceramic body 11. The plating layer L2 is formed on the outside of the base layer L1, that is, covers the lead-out region D of the ceramic body 11 via the base layer L1.

[0100] The base layer L1 and the plating layer L2 constituting the external electrodes 14 and 15 are respectively formed of good electrical conductors. Examples of good electrical conductors constituting the external electrodes 14 and 15 include metals or alloys mainly composed of copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), silver (Ag), gold (Au), and the like.

[0101] The base layer L1 is provided as a base for forming the plating layer L2 by a wet plating method. In the external electrodes 14 and 15, by making the base layer L1 a sputtering film formed by a sputtering method, the overall thinning can be achieved. In addition, the method for forming the base layer L1 is not limited to the sputtering method, and other well-known methods can also be used.

[0102] For example, the base layer L1 may be a thin film formed by a vacuum film forming method other than sputtering. Examples of vacuum film forming methods other than sputtering that can form the base layer L1 include vacuum evaporation, CVD (Chemical Vapor Deposition), and ALD (Atomic Layer Deposition).

[0103] In the external electrodes 14 and 15, by giving a thickness distribution to the plating layer L2 on the base layer L1 formed thin by sputtering or the like, it is possible to form base parts E1 and E2 having a small thickness and protrusions P having a large thickness. Details of the method for forming the external electrodes 14 and 15 including the base parts E1 and E2 and the protrusions P will be described later.

[0104] 2. Method for Manufacturing Multilayer Ceramic Capacitor 10

[0105] Figure 7 1 is a flowchart showing an example of a method for manufacturing the multilayer ceramic capacitor 10 according to the present embodiment. Figure 8 to Figure 14 1 is a diagram showing a manufacturing process of the multilayer ceramic capacitor 10. Figure 7 and refer appropriately Figure 8 to Figure 14 , a method for manufacturing the multilayer ceramic capacitor 10 will be described.

[0106] 2.1 Step S01: Making the ceramic body

[0107] In step S01, make Figure 2 In step S01, for example, the ceramic body 11 can be fired according to Figure 3 The ceramic body 11 is produced by forming a laminate of dielectric green sheets on which the internal electrodes 12 and 13 are printed in the pattern shown. The method for producing the ceramic body 11 is not limited to this method.

[0108] 2.2 Step S02: Forming a base layer

[0109] In step S02, a base layer L1 is formed in each of the four lead-out regions D of the ceramic body 11 produced in step S01. The base layer L1 can be produced by, for example, the above-mentioned vacuum film forming method. As a material for forming the base layer L1, for example, copper (Cu) can be used. Figure 8 to Figure 10 It is a perspective view showing the process of forming the base layer L1 by the sputtering method in step S02.

[0110] First, if Figure 8As shown, a mask m1 is formed that opens only the region where the base layer L1 is provided including the lead-out region D on the outer surface of the ceramic body 11. The mask m1 can be formed by any known method. Thus, in the ceramic body 11, only the portion where the base layer L1 is provided can be exposed from the mask m1.

[0111] Then, if Fig. 9 As shown, by sputtering method to form Figure 8 The sputtering film s is formed on the entire periphery of the ceramic body 11 of the mask m1 shown. Thus, the sputtering film s is formed not only on the portion where the base layer L1 is provided in the ceramic body 11, but also on the mask m1.

[0112] Then, if Fig.10 As shown, the mask m1 is formed from Fig. 9 The ceramic body 11 of the sputtered film s is peeled off. Thus, in the ceramic body 11, the sputtered film s on the mask m1 is removed together with the mask m1, and the sputtered film s remaining on the region including the lead-out region D becomes the base layer L1.

[0113] 2.3 Step S03: Forming a reinforcement layer

[0114] In step S03, the reinforcing layer L2a is formed on the ceramic body 11 on which the base layer L1 is formed in step S02. The reinforcing layer L2a is formed as a part of the plating layer L2 in the area near the edge R of the ceramic body 11 by a wet plating method. The material for forming the reinforcing layer L2a can be the same as that for the base layer L1, for example, copper (Cu) can be used. Figure 11 to Figure 13 It is a perspective view showing the process of forming the reinforcement layer L2a in step S03.

[0115] First, if Fig.11 As shown, an insulating mask m2 is formed that opens only the region near the edge R where the reinforcing layer L2a is provided on the outer surface of the ceramic body 11. The mask m2 can be formed by any known method. Thus, in the ceramic body 11, only the region near the edge R where the reinforcing layer L2a is provided can be exposed from the mask m2.

[0116] Then, if Fig.12 As shown, by forming Fig.11 The ceramic body 11 with the mask m2 shown in FIG. 1 is subjected to a wet plating process to form a reinforcing layer L2a in the region near the ridge R exposed from the mask m2 of the ceramic body 11. Fig.13 As shown, the mask m2 is peeled off from the ceramic body 11.

[0117] 2.4 Step S04: Forming a covering layer

[0118] In step S04, the ceramic body 11 on which the reinforcement layer L2a is formed in step S03 forms a covering layer L2b. The covering layer L2b and the reinforcement layer L2a together constitute the plating layer L2. The covering layer L2b is formed from the reinforcement layer L2a by a wet plating method, that is, the lead-out area D and the base layer L1 are covered from the reinforcement layer L2a. The covering layer L2b may not be a single plating layer, and may be composed of a plurality of plating layers including a nickel (Ni) layer and a tin (Sn) layer, for example.

[0119] Therefore, if Fig.14 As shown, on the plated layer L2 are formed: base parts E1 and E2 formed only of the cover layer L2b; and a protrusion P thicker than the base parts E1 and E2 by the reinforcing layer L2a of the cover layer L2b. In this way, the multilayer ceramic capacitor 10 of this embodiment can be obtained.

[0120] II. Second Embodiment

[0121] Fig.15 2 is a perspective view of a laminated ceramic capacitor 20 according to a second embodiment of the present invention. The laminated ceramic capacitor 20 according to this embodiment has a two-terminal structure, unlike the four-terminal structure of the first embodiment. In the description of this embodiment, the description of the same structure as the first embodiment is appropriately omitted.

[0122] The multilayer ceramic capacitor 20 includes a ceramic body 21, a first external electrode 24, and a second external electrode 25. The external electrodes 24 and 25 are provided separately from each other on the outer surface of the ceramic body 21. Similar to the external electrodes 14 and 15 of the first embodiment, the external electrodes 24 and 25 include a base layer L1 and a plating layer L2.

[0123] Fig.16 : is a three-dimensional view of the ceramic body 21. The ceramic body 21 has a pair of first side surfaces S1 extending along the YZ plane, a pair of second side surfaces S2 extending along the XZ plane, and a pair of main surfaces M extending along the XY plane. In addition, the ceramic body 21 has four edges R connecting the pair of first side surfaces S1 and the pair of second side surfaces S2 to each other.

[0124] Fig.17 It is an exploded perspective view showing a part of the laminated structure of the ceramic body 21 in an exploded manner. Fig.18 is along Fig.15 The cross-sectional view of the multilayer ceramic capacitor 20 taken along the diagonal line CC' is shown. The ceramic body 21 has a plurality of first and second internal electrodes 22 and 23 including first and second lead portions 22d and 23d.

[0125] The ceramic body 21 has a pair of lead regions D extending from the first side surface S1 to the pair of second side surfaces S2 on one side and multiple sides of the pair of first side surfaces S1. In the pair of lead regions D, lead portions 22d and 23d of the internal electrodes 22 and 23 are alternately led out along the Z-axis direction.

[0126] The external electrodes 24 and 25 are provided in the lead regions D of the ceramic body 21. More specifically, the first external electrode 24 covers the lead region D where the first lead portion 22d is exposed, and is connected to the first internal electrode 22. The second external electrode 25 covers the lead region D where the second lead portion 23d is exposed, and is connected to the second internal electrode 23.

[0127] Thus, the multilayer ceramic capacitor 20 has a two-terminal structure with the first external electrode 24 and the second external electrode 25 as two terminals. With this structure, the multilayer ceramic capacitor 20 can store charges corresponding to the potential difference between the first external electrode 24 and the second external electrode 25 .

[0128] Fig.19 2 is a top view of the multilayer ceramic capacitor 20. The external electrodes 24 and 25 each include: a protrusion P extending in a ridge shape along two ridges R in the Z-axis direction; a first base portion E1 extending between the protrusions P along the first side surface S1; and a second base portion E2 extending from each protrusion P along the second side surface S2.

[0129] In the external electrodes 24 and 25, the protrusions P formed along the ridges R are formed thicker than the bases E1 and E2. That is, in each of the external electrodes 24 and 25, the protrusions P thicker than the bases E1 and E2 protrude outward in the X-axis direction from the first base E1 and protrude outward in the Y-axis direction from the second base E2.

[0130] Therefore, in the external electrodes 24, 25, as Fig.19 As shown, the thickness d1 of the first base portion E1 is smaller than the thickness dp1 of the protrusion P, and the thickness d2 of the second base portion E2 is smaller than the thickness dp2 of the protrusion P. That is, the external electrodes 24 and 25 both satisfy the relationship of d1<dp1 and d2<dp2. d1 and d2 are, for example, not less than 10μm and not more than 50μm, preferably not less than 12μm and not more than 30μm. In addition, dp1 and dp2 can be set to, for example, not less than 2μm and not more than 12μm larger than d1 and d2. That is, dp1 and dp2 are, for example, not less than 12μm and not more than 62μm, preferably not less than 14μm and not more than 42μm.

[0131] In the external electrodes 24 and 25, by forming the first and second base portions E1 and E2 thinner, the current path in the current-carrying direction when using the multilayer ceramic capacitor 20 can be shortened. As a result, in the multilayer ceramic capacitor 20, ESR (equivalent series resistance) and ESL (equivalent series inductance) can be kept small.

[0132] In addition, the base parts E1 and E2 of the external electrodes 24 and 25 are formed thinner, so the internal stress is reduced accordingly. Therefore, in the multilayer ceramic capacitor 20, it is not easy to peel off the base parts E1 and E2 of the external electrodes 24 and 25 due to thermal stress or mechanical stress applied during installation or use, so high reliability can be ensured.

[0133] Furthermore, the outer electrodes 24 and 25 can protect the ridges R of the ceramic body 21 more closely by the thick protrusions P. Therefore, in the multilayer ceramic capacitor 20, the protrusions P of the outer electrodes 24 and 25 can effectively isolate the ridges R of the ceramic body 21 from the external environment.

[0134] Thus, in the ceramic body 21, moisture in the external environment is unlikely to reach the ridge R, so moisture is unlikely to enter the interior even if cracks are present in the ridge R. Therefore, in the multilayer ceramic capacitor 20, short circuits can be suppressed, thereby further ensuring high reliability.

[0135] III Other Embodiments

[0136] As mentioned above, although embodiment of this invention is described, this invention is not limited to the said embodiment, It is a matter of course that various deformation|transformation is possible.

[0137] For example, the external electrode is not limited to the above structure as long as it is provided with a protrusion P extending along the edge R of the ceramic body and protruding in the X-axis and Y-axis directions. That is, the external electrode may include layers other than the base layer L1 and the plating layer L2, or may not include at least one of the base layer L1 and the plating layer L2.

[0138] In addition, in the ceramic body, the lead-out region D where the internal electrode is led out may not include the ridge R. That is, in the multilayer ceramic capacitor, even in the ceramic body in which the internal electrode is not led out to the ridge R, it is possible to prevent the intrusion of moisture along the cracks from the ridge R, thereby suppressing the occurrence of a short circuit.

[0139] Furthermore, the method for forming the reinforcing layer of the plating layer in each external electrode is not limited to the wet plating method, and may be a dry plating method such as a sputtering method, for example.

[0140] Furthermore, in each external electrode, the protrusion P may not extend to the entire range of the ridge R. For example, Figures 20-22 As shown, the protrusion P of each external electrode can be formed only at at least one of the two end portions in the Z-axis direction of the ridge portion R. Even in the multilayer ceramic capacitor of this structure, the portion of the ceramic body that is most susceptible to mechanical damage, that is, the corner where the main surface M and the side surfaces S1 and S2 intersect, can be reliably protected by the protrusion P of the external electrode, so that high reliability can be obtained.

[0141] In addition, in the multilayer ceramic capacitor, by setting the maximum dimension in the Z-axis direction to be smaller than the maximum dimensions in the X-axis and Y-axis directions, the ESR (equivalent series resistance) and ESL (equivalent series inductance) during substrate mounting can be further reduced. In this case, the maximum dimension in the Z-axis direction of the multilayer ceramic capacitor is preferably 50 μm to 150 μm, more preferably 60 μm to 120 μm, and even more preferably 60 μm to 75 μm.

[0142] In addition, in the above embodiment, a laminated ceramic capacitor is described as an example of a laminated ceramic electronic component, but the present invention can be applied to all laminated ceramic electronic components. Examples of such laminated ceramic electronic components include chip varistors, chip thermistors, and laminated inductors.

Claims

1. A laminated ceramic electronic component, characterized in that: include: A ceramic body having: a first side surface facing a first axis direction; a second side surface facing a second axis direction orthogonal to the first axis; an edge portion connecting the first side surface and the second side surface; and a plurality of internal electrodes stacked along a third axis direction orthogonal to the first axis and the second axis and led to the lead-out region; as well as An external electrode covering the lead-out region, comprising: a protrusion provided along the ridge and protruding in the first axis direction and the second axis direction; and a first base portion and a second base portion extending from the protruding portion along the first side surface and the second side surface, respectively, The protrusion extends along the ridge portion by a length of the external electrode in the third axis direction, The protrusion has a thickness greater than that of the first base portion and the second base portion, and the protrusion protrudes outward in the first axial direction from the first base portion and outward in the second axial direction from the second base portion.

2. The multilayer ceramic electronic component according to claim 1, wherein: The lead-out region includes the edge portion.

3. The multilayer ceramic electronic component according to claim 1 or 2, wherein: The external electrode further includes a plating layer and a base layer located between the plating layer and the lead-out region.

4. The multilayer ceramic electronic component according to claim 3, wherein: The base layer is composed of a sputtered film.

5. The multilayer ceramic electronic component according to claim 1 or 2, wherein: The maximum dimension of the multilayer ceramic electronic component in the third axis direction is smaller than the maximum dimensions in the first axis direction and the second axis direction.

6. The multilayer ceramic electronic component according to claim 5, wherein: The maximum dimension of the multilayer ceramic electronic component in the third axis direction is not less than 50 μm and not more than 150 μm.

7. The multilayer ceramic electronic component according to claim 5, wherein: The maximum dimension of the multilayer ceramic electronic component in the third axis direction is not less than 60 μm and not more than 120 μm.

8. The multilayer ceramic electronic component according to claim 5, wherein: The maximum dimension of the multilayer ceramic electronic component in the third axis direction is not less than 60 μm and not more than 75 μm.

9. A method for manufacturing a laminated ceramic electronic component, characterized in that: A ceramic body is manufactured, wherein the ceramic body has: a first side surface facing a first axis direction; a second side surface facing a second axis direction orthogonal to the first axis; an edge connecting the first side surface and the second side surface; and a plurality of internal electrodes stacked along a third axis direction orthogonal to the first axis and the second axis and led to a lead-out region, forming a base layer in the lead-out region by a vacuum film forming method, A plating layer is formed to cover the lead-out region via the base layer, the plating layer comprising: a protrusion extending along the ridge portion in the third axial direction and protruding in the first axial direction and the second axial direction; and a first base portion and a second base portion extending from the protrusion along the first side surface and the second side surface, respectively. When forming the plating layer, the protrusion is formed to have a thickness greater than that of the first base portion and the second base portion, and the protrusion protrudes outward in the first axial direction from the first base portion and outward in the second axial direction from the second base portion.

10. The method for manufacturing a laminated ceramic electronic component according to claim 9, wherein: The lead-out region includes the edge portion.

11. The method for manufacturing a laminated ceramic electronic component according to claim 9 or 10, wherein: The process of forming the plating layer includes: forming a reinforcing layer extending along the ridge portion; and forming a covering layer covering the lead-out region from above the reinforcing layer.

12. The method for manufacturing a laminated ceramic electronic component according to claim 9 or 10, wherein: The vacuum film forming method is a sputtering method.

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