Multilayer ceramic electronic component and manufacturing method therefor

Abstract

This multilayer ceramic electronic component comprises: an element body in which a plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic are alternately laminated in a first direction, and the laminated plurality of internal electrodes have end surfaces that are alternately exposed and opposed to each other in a second direction; a base metal layer that is in contact with some of the plurality of internal electrodes exposed from the end surfaces and is disposed at the end portion on the end surface side among four surfaces connected to the end surfaces of the element body; and a plating layer that is disposed so as to sandwich the base metal layer with the element body at the end portion and forms an external electrode together with the base metal layer, wherein θ1 is at most 30°, T1 is at most 0.9 times T2, and T3 is at least 1.1 times T2, where, when the distance between the tip and the end surface is L, θ1 is the angle between the surface of the element body and a line connecting a point on the element body at the tip and a point on the surface of the base metal layer at position P1 having a distance of 0.1 X L, T1 is the thickness of the base metal layer at position P1, T2 is the thickness of the base metal layer at position P2 having a distance of 0.5 X L, and T3 is the thickness of the base metal layer at position P3 having a distance of 0.9 X L.　

Description

Multilayer ceramic electronic component and its manufacturing method

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

[0002] It is known that in multilayer ceramic electronic components, the thickness of a plating layer covering a base metal layer of an external electrode becomes thinner with increasing distance from an end face of the element body (see, for example, Patent Document 1).

[0003] JP 2013-168526 A

[0004] Patent Document 1 does not describe the reason why the thickness of the plating layer is made thinner with increasing distance from the end face of the element body. Stress applied to the element body can cause cracks and the like in the element body near the tips of the external electrodes.

[0005] The present invention has been made in view of the above-mentioned problems, and has as its object to relieve stress applied to an element body.

[0006] The present invention provides an element body in which a plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic are alternately stacked in a first direction, the stacked internal electrodes being alternately exposed from the end faces facing each other in a second direction; an underlying metal layer in contact with a portion of the plurality of internal electrodes exposed from the end faces and provided on an end portion of four faces of the element body that are connected to the end faces, the end face side; and a plating layer provided at the end portion so as to sandwich the underlying metal layer between the element body and the element body, the plating layer forming an external electrode together with the underlying metal layer, wherein, on at least one of the four faces, when the distance in the second direction between a tip of the underlying metal layer and the end face is defined as L, When the angle between the surface of the element body and a line connecting a point on the surface of the base metal layer at a first position where the distance from the end to the end face in the second direction is 0.1 x L and a point on the surface of the element body at the tip of the base metal layer is θ1, the thickness of the base metal layer at the first position is T1, the thickness of the base metal layer at a second position where the distance from the tip to the end face in the second direction is 0.5 x L is T2, and the thickness of the base metal layer at a third position where the distance from the tip to the end face in the second direction is 0.9 x L is T3, θ1 is 30° or less, T1 is 0.9 times T2 or less, and T3 is 1.1 times T2 or more.

[0007] In the above configuration, θ1 may be 26° or less, T1 may be 0.8 times or less than T2, and T3 may be 1.2 times or more than T2.

[0008] In the above configuration, when the angle formed by the straight line connecting a point on the surface of the base metal layer at the third position and a point on the surface of the element body at the tip of the base metal layer and the surface of the element body is θ3, θ3 can be configured to be 10° or less.

[0009] In the above configuration, the thickness of the underlying metal layer at the center of the end face in the first direction may be at least twice the thickness of the underlying metal layer at the third position.

[0010] In the above configuration, the thickness of the underlying metal layer in a direction perpendicular to the second direction at the position of the end face in the second direction can be greater than the thickness of the underlying metal layer at the third position.

[0011] In the above configuration, θ1 may be 30° or less, T1 may be 0.9 times or less than T2, and T3 may be 1.1 times or more than T2 on the four surfaces.

[0012] The present invention relates to an element body in which a plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic are alternately stacked in a first direction, the stacked internal electrodes having end faces that are alternately exposed and opposed to each other in a second direction, and a metal layer on at least one of four faces of the element body other than the end face, at an end on the end face side of one of four faces connected to the end face so as to come into contact with parts of the plurality of internal electrodes exposed from the end face, the metal layer at a first position where the distance from the tip to the end face in the second direction is 0.1×L, where L is the distance between the tip of the metal layer and the end face in the second direction. forming a metal layer by a dipping method such that θ1 is 30° or less, T1 is 0.9 times or less T2, and T3 is 1.1 times or more T2, where θ1 is the angle formed by the surface of the element body and a line connecting a point on the surface of the metal layer and a point on the element body at the tip of the metal layer, T1 is the thickness of the metal layer at the first position, T2 is the thickness of the metal layer at a second position where the distance from the tip to the end face in the second direction is 0.5 × L, and T3 is the thickness of the metal layer at the second position where the distance from the tip to the end face in the second direction is 0.9 × L.

[0013] According to the present invention, the stress applied to the element body can be alleviated.

[0014] FIG. 1 is a partial cross-sectional perspective view of the multilayer ceramic capacitor according to Embodiment 1. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1. FIG. 4 is a flowchart illustrating a method for manufacturing the multilayer ceramic capacitor according to Embodiment 1. FIG. 5A is a cross-sectional view illustrating a method for manufacturing the multilayer ceramic capacitor according to Embodiment 1. FIG. 5B is a cross-sectional view illustrating a method for manufacturing the multilayer ceramic capacitor according to Embodiment 1. FIG. 5C is a cross-sectional view illustrating a method for manufacturing the multilayer ceramic capacitor according to Embodiment 1. FIG. 5D is a cross-sectional view illustrating a method for manufacturing the multilayer ceramic capacitor according to Embodiment 1. FIG. 6 is a cross-sectional view illustrating a method for manufacturing the multilayer ceramic capacitor according to Embodiment 1. FIG. 7 is a schematic diagram of a cross-sectional photograph illustrating a method for manufacturing the multilayer ceramic capacitor according to Embodiment 1. FIG. 8 is a cross-sectional view of a comparative multilayer ceramic capacitor mounted on a mounting substrate. FIG. 9 is a cross-sectional view of the multilayer ceramic capacitor of Embodiment 1 mounted on a mounting substrate. FIG. 10 is an enlarged cross-sectional view of an end portion of the multilayer ceramic capacitor according to Embodiment 1. FIG. 11 is an enlarged cross-sectional view of an end portion of the multilayer ceramic capacitor according to Embodiment 1. FIG. 12A is a diagram illustrating T1 / T2 and T3 / T2 with respect to position. FIG. 12B is a diagram showing angles θ1 to θ3 relative to the position.

[0015] Hereinafter, with reference to the drawings, a first embodiment will be described using a multilayer ceramic capacitor as an example of a multilayer ceramic electronic component.

[0016] 1 is a partial cross-sectional perspective view of a multilayer ceramic capacitor 100 according to embodiment 1. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. Fig. 3 is a cross-sectional view taken along line BB in Fig. 1.

[0017] 1 to 3 , the Z direction (first direction) is the stacking direction in which the dielectric layers 14 and the internal electrodes 12a and 12b are stacked, and is the direction in which the bottom surface 55 and top surface 56 of the element body 10 face each other. The X direction (second direction) is the length direction of the element body 10, and is the direction in which a pair of end surfaces 51 and 52 of the element body 10 face each other. The Y direction (third direction) is the width direction of the internal electrodes 12a and 12b, and is the direction in which a pair of side surfaces 53 and 54 of the element body 10 face each other. The X direction, Y direction, and Z direction intersect or are perpendicular to each other.

[0018] The multilayer ceramic capacitor 100 includes a substantially rectangular parallelepiped element body 10 and external electrodes 20a and 20b. The element body 10 includes a plurality of dielectric layers 14, a plurality of internal electrodes 12a and 12b, and a cover dielectric layer 16. The plurality of internal electrodes 12a (first internal electrodes) and a plurality of internal electrodes 12b (second internal electrodes) are alternately stacked. One of the plurality of dielectric layers 14 is provided between one of the plurality of internal electrodes 12a and one of the plurality of internal electrodes 12b. The outermost layers in the stacking direction (Z direction) of the laminate, in which the dielectric layer 14 and the internal electrodes 12a and 12b are stacked, are the internal electrodes 12a and 12b, and the bottom and top surfaces of the laminate are covered with a cover dielectric layer 16.

[0019] The internal electrodes 12a and 12b are alternately exposed on the end faces 51 and 52. The internal electrode 12a is exposed, but the internal electrode 12b is not, on the end face 51. The internal electrode 12b is exposed, but the internal electrode 12a is not, on the end face 52. That is, the internal electrodes 12a and 12b are connected to different end faces 51 and 52.

[0020] The external electrode 20a contacts the internal electrode 12a (i.e., a portion of the internal electrodes 12a and 12b) exposed from the element body 10 at the end face 51. The external electrode 20b contacts the internal electrode 12b exposed from the element body 10 at the end face 51. The external electrode 20a covers the end faces 40 in the -X direction of the side faces 53, 54, bottom face 55, and top face 56 in addition to the end face 51. The external electrode 20b contacts the internal electrode 12b at the end face 52. The external electrode 20b covers the end faces 40 in the +X direction of the side faces 53, 54, bottom face 55, and top face 56 in addition to the end face 52.

[0021] Each of the external electrodes 20a and 20b includes a metal base layer 22 and a plating layer 24 provided to cover the metal base layer 22. The metal base layer 22 is provided on the end portion 40. The thickness of the metal base layer 22 provided on the end portion 40 decreases with increasing distance from the end face 51 or 52 toward the tip 22c of the metal base layer 22. The thickness of the plating layer 24 is uniform compared to the metal base layer 22.

[0022] The size of the multilayer ceramic capacitor 100 is, for example, 0.25 mm in length (length in the X direction), 0.125 mm in width (width in the Y direction), and 0.125 mm in height (height in the Z direction), or 0.4 mm in length, 0.2 mm in width, and 0.2 mm in height, or 0.6 mm in length, 0.3 mm in width, and 0.3 mm in height, or 1.0 mm in length, 0.5 mm in width, and 0.5 mm in height, or 3.2 mm in length, 1.6 mm in width, and 1.6 mm in height, or 4.5 mm in length, 3.2 mm in width, and 2.5 mm in height, but is not limited to these sizes.

[0023] The internal electrodes 12a and 12b are primarily composed of base metals such as nickel (Ni), copper (Cu), and tin (Sn). The internal electrodes 12a and 12b may also be made of precious metals such as platinum (Pt), palladium (Pd), silver (Ag), and gold (Au), or alloys containing these metals. The thickness of the internal electrodes 12a and 12b is, for example, 0.1 μm to 1 μm.

[0024] The dielectric layer 14 is, for example, a compound represented by the general formula ABO ３ The main phase is a ceramic material having a perovskite structure represented by the formula: ３－α For example, the ceramic material includes barium titanate (BaTiO ３ ), calcium zirconate (CaZrO ３ ), calcium titanate (CaTiO ３ ), strontium titanate (SrTiO ３ ), magnesium titanate (MgTiO ３ ), and Ba, which forms a perovskite structure１-ｘ－ｙ Ca ｘ Sr ｙ Ti １－ｚ Zr ｚ O ３ (0≦x≦1, 0≦y≦1, 0≦z≦1) and the like. １-ｘ－ｙ Ca ｘ Sr ｙ Ti １－ｚ Zr ｚ O ３ Examples of the ceramic materials include barium strontium titanate, barium calcium titanate, barium zirconate, barium titanate zirconate, calcium titanate zirconate, and barium calcium titanate zirconate. For example, the dielectric layer 14 contains 90 at% or more of the main component ceramic. The thickness of the dielectric layer 14 is, for example, 0.3 μm or more and 2 μm or less.

[0025] An additive may be added to the dielectric layer 14. Examples of additives to the dielectric layer 14 include oxides of zirconium (Zr), hafnium (Hf), magnesium (Mg), manganese (Mn), molybdenum (Mo), vanadium (V), chromium (Cr), rare earth elements (yttrium (Y), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), and ytterbium (Yb)), oxides containing cobalt (Co), nickel (Ni), lithium (Li), boron (B), sodium (Na), potassium (K), or silicon (Si), or glasses containing cobalt, nickel, lithium, boron, sodium, potassium, or silicon.

[0026] The composition of the main ceramic component of the cover dielectric layer 16 may be the same as or different from the main ceramic component of the dielectric layer 14 .

[0027] The base metal layer 22 is primarily composed of a metal such as copper, nickel, aluminum (Al), or zinc (Zn), or an alloy of two or more of these metals (e.g., an alloy of copper and nickel), and also contains ceramics such as a glass component for densifying the base metal layer 22 and a co-material for controlling the sinterability of the external electrodes 20a and 20b. The glass component is an oxide of barium (Ba), strontium (Sr), calcium (Ca), zinc, aluminum, silicon, boron, or the like. The co-material is, for example, a ceramic component primarily composed of the same material as the main component of the dielectric layer 14. The thickness of the base metal layer 22 is, for example, 5 μm to 15 μm.

[0028] The plating layer 24 is primarily composed of a metal such as copper, nickel, aluminum, zinc, or tin, or an alloy of two or more of these metals. The plating layer 24 may be a single-metal layer or multiple layers of different metals. Furthermore, a conductive resin film such as epoxy resin or urethane resin may be formed on the surface of the plating layer. The thickness of the plating layer 24 is, for example, 5 μm to 12 μm.

[0029] (Manufacturing Method of First Embodiment) A method for manufacturing the multilayer ceramic capacitor 100 will be described below. Fig. 4 is a flowchart showing a method for manufacturing the multilayer ceramic capacitor of the first embodiment.

[0030] (Green Sheet Formation Process) First, a green sheet is formed (Step S10). In Step S10, a dielectric material is prepared by adding various additive compounds (such as sintering aids) to ceramic powder, for example. A binder such as polyvinyl butyral (PVB) resin, an organic solvent such as ethanol or toluene, and a plasticizer are added to the prepared dielectric material and wet-mixed to produce a slurry. The produced slurry is then applied to a substrate using, for example, a die coater method or a doctor blade method, to form a green sheet. The substrate is, for example, a PET (polyethylene terephthalate) film. The green sheet is then dried.

[0031] (Pattern Forming Process) Next, metal patterns that will become the internal electrodes 12a and 12b are formed on the green sheet (Process S12). In Process S12, a metal paste for forming the internal electrodes containing an organic binder is printed on the green sheet on the substrate using, for example, gravure printing. This results in multiple metal patterns corresponding to the internal electrodes 12a and 12b being formed on the green sheet at intervals. The metal paste contains a metal powder, such as nickel powder, as a main component, a binder, and an organic solvent. Ceramic particles may also be added to the metal paste as a co-material.

[0032] (Laminating Step) Next, the green sheets are laminated (Step S14). In Step S14, green sheets on which metal patterns that become the internal electrodes 12 a and 12 b are printed are laminated to form a laminate sheet. Green sheets corresponding to the cover dielectric layers 16 are laminated on both end faces of the laminate sheet in the lamination direction.

[0033] (Compression Bonding Step) Subsequently, the laminated sheet is compressed (Step S16). In Step S16, the laminated sheet formed in Step S14 is pressed to compress the green sheets together. As the compression bonding means, for example, a hydrostatic press is used.

[0034] (Cutting Step) Next, the laminated sheet is cut (step S18). In step S18, a cutting blade is used to cut the laminated sheet in the stacking direction along predetermined cutting lines, thereby preparing a plurality of element bodies 10. In each element body 10, the internal electrode 12a is exposed from an end face 51, and the internal electrode 12b is exposed from an end face 52. After step S18, the element body 10 may be polished by a technique such as barrel polishing. This rounds the corners of the element body 10.

[0035] (Firing Step) Next, the element body 10 is fired (Step S20). In Step S20, the element body 10 is subjected to a binder removal process in a nitrogen gas atmosphere at 250°C to 500°C, and then fired in a reducing atmosphere at 1300°C to 1400°C for about one hour. This sinters the particles of the element body 10 and the internal electrodes 12a and 12b.

[0036] (Base Metal Layer Forming Step) Next, the base metal layer 22 of the external electrodes 20a and 20b is formed (step S22). Figures 5A to 6 are cross-sectional views showing the method for manufacturing the multilayer ceramic capacitor according to the first embodiment.

[0037] 5A to 5D show a method for forming the base metal layer 22 using a dipping method. As shown in Fig. 5A, a paste 42 is prepared. The paste 42 contains a metal powder, such as copper powder, as a main component, glass frit, a binder, and an organic solvent. An end surface 51 or 52 of the element body 10 is placed on the liquid paste 42.

[0038] As shown in Figure 5B, the end 40 of the element body 10 is immersed in the paste 42. As shown in Figure 5C, the element body 10 is pulled up from the paste 42. The pulling speed at this time is slowed. For example, the pulling speed in the first embodiment is 1 / 50 of the pulling speed in the comparative example, which is 0.1 mm / sec to 1 mm / sec. The paste 43 attached to the end 40 of the element body 10 is pulled, and the paste 43 becomes thinner.

[0039] 5D , when element body 10 is further lifted up, paste 44 adheres to end 40 and end face 51 or 52. Tip 22c of paste 44 becomes thinner. When element body 10 is then further lifted up, paste 44 adheres to end 40 and end face 51 or 52. Thereafter, paste 44 is baked in a nitrogen atmosphere at, for example, 750°C to 850°C. As a result, base metal layer 22 is formed from paste 44.

[0040] Next, a plating layer 24 is formed on the surface of the base metal layer 22 (step S24). As shown in Fig. 6, in step S24, the plating layer 24 is formed to cover the base metal layer 22. The base metal layer 22 and the plating layer 24 form the external electrodes 20a and 20b. The plating layer 24 is, for example, a layer mainly composed of copper, a layer mainly composed of nickel, and a layer mainly composed of tin, from the base metal layer 22 side. The thickness of the plating layer 24 is uniform compared to the thickness of the base metal layer 22.

[0041] FIG. 7 is a schematic cross-sectional photograph illustrating the manufacturing method of the multilayer ceramic capacitor according to the first embodiment. The internal electrodes 12a and 12b are not shown in FIG. 7 . The size of the multilayer ceramic capacitor is 0201 size, i.e., the length in the X direction is 0.25 mm, the width in the Y direction is 0.125 mm, and the height in the Z direction is 0.125 mm. As shown in FIG. 7 , the portion 22a of the base metal layer 22 provided on the end portion 40 is thinner than the portion 22b of the base metal layer 22 provided on the end faces 51 and 52. The tip 22c of the portion 22a is thinner.

[0042] (Comparative Multilayer Ceramic Capacitor) FIG. 8 is a cross-sectional view of a comparative multilayer ceramic capacitor mounted on a mounting substrate. As shown in FIG. 8 , in the comparative multilayer ceramic capacitor 110, the base metal layer 22 has a thick portion 22a at the end 40, and the tip 22c of the portion 22a is rounded. The external electrodes 20a and 20b provided on the lower surface 55 are joined to the terminals 32 of the mounting substrate 30 with solder 34. The mounting substrate 30 may bend due to thermal stress or the like. In this case, stress concentrates on the tip 22c of the external electrodes 20a and 20b. This may cause cracks 46 to form in the element body 10 from the tip 22c of the external electrodes 20a and 20b. The Young's modulus of solder is 30 MPa to 50 MPa, while the Young's moduli of copper and nickel are large, approximately 200 MPa and 130 MPa, respectively. In this way, when the portion 22a, which is harder than the solder 34, is thick, stress tends to concentrate on the tip 22c of the portion 22a. In particular, when the size of the element body 10 is reduced, cracks 46 tend to occur due to the stress concentration on the tip 22c. Stress tends to concentrate on the tip 22c even when a multilayer ceramic capacitor is not mounted.

[0043] Furthermore, the coverage of the base metal layer 22 is poor at the corners 57 of the element body 10, and the base metal layer 22 is likely to become thin. This may result in problems when forming the plating layer 24, poor wetting of the solder 34 during mounting, or moisture entering through the corners 57, which may result in a deterioration in moisture resistance.

[0044] (Multilayer ceramic capacitor of embodiment) Figure 9 is a cross-sectional view of the multilayer ceramic capacitor of embodiment 1 mounted on a mounting substrate. As shown in Figure 9, in the multilayer ceramic capacitor 100 of the embodiment, the base metal layer 22 at the end 40 is thin, and the portion 22a gradually becomes thinner toward the tip 22c. This makes it difficult for stress to concentrate at the tip 22c of the external electrodes 20a and 20b, thereby preventing cracks 46 from occurring in the element body 10. In addition, the base metal layer 22 at the corners 57 of the element body 10 is thicker.

[0045] Furthermore, the coverage of the base metal layer 22 can be improved at the corners 57 of the element body 10, allowing the base metal layer 22 to be thickened. This makes it possible to prevent problems during the formation of the plated layer 24, poor wetting of the solder 34, and deterioration of moisture resistance.

[0046] 10 and 11 are enlarged cross-sectional views of the end portion of the multilayer ceramic capacitor according to the first embodiment. Internal electrodes 12a and 12b are not shown in FIGS. 10 and 11 . As shown in FIG. 10 , P0 denotes the position in the X direction of tip 22c of portion 22a of base metal layer 22. P4 denotes the position in the X direction of end face 51 or 52. The distance in the X direction between positions P0 and P4 is L. P1 (first position) denotes the position from tip 22c toward end face 51 or 52 that is 0.1×L. P2 (second position) denotes the position from tip 22c toward end face 51 or 52 that is 0.5×L. P3 (third position) denotes the position from tip 22c toward end face 51 or 52 that is 0.9×L. The thicknesses of base metal layer 22 at positions P1, P2, and P3 are T1, T2, and T3, respectively. At the position of the end face 51 or 52 in the X direction, the thickness of the underlying metal layer 22 in the direction perpendicular to the X direction is defined as T4.

[0047] 11 , points on the surface of the base metal layer 22 at positions P1 to P3 are designated S1 to S3, respectively, and the point on the surface of the element body 10 at position P0 is designated S0. The line connecting points S0 and S1 is designated L1, the line connecting points S0 and S2 is designated L2, and the line connecting points S0 and S3 is designated L3. The angle between surface S and line L1 is designated θ1, the angle between surface S and line L2 is designated θ2, and the angle between surface S and line L3 is designated θ3.

[0048] An experiment was conducted on an 0201 capacitor (i.e., a capacitor in which the element body 10 had a length of 0.25 mm in the X direction, a width of 0.125 mm in the Y direction, and a height of 0.125 mm in the Z direction) by slowing down the speed at which the element body 10 was pulled up from the paste 42 in FIG. 5C . The main component of the base metal layer 22 was nickel. Thicknesses T1 to T3 were measured for 12 samples, and angles θ1 to θ3 were measured for 11 samples.

[0049] FIG. 12A is a diagram showing T1 / T2 and T3 / T2 versus position, and FIG. 12B is a diagram showing angles θ1 to θ3 versus position. In FIG. 12A, the vertical axes at positions P1 and P3 are T1 / T2 and T3 / T2, respectively. In FIG. 12B, the vertical axes at positions P1 to P3 are θ1 to θ3, respectively. Measurement points are indicated by black circles. Straight lines connect the black circles. As shown in FIGS. 12A and 12B, T1 / T2 ranges from 0.4 to 0.92, with an average value of 0.64. T3 / T2 ranges from 1.01 to 1.56, with an average value of 1.31. θ1 ranges from 15° to 25°, with an average value of 21°. θ2 ranges from 5.1° to 8.9°, with an average value of 7.1°. θ3 ranges from 3.3° to 6.7°, with an average value of 5.1°. θ2 / θ3 is in the range of 1.16 to 1.78, with an average value of 1.41.

[0050] In order to relieve stress at the tip 22c, it is preferable that the tip 22c have an acute angle. However, in reality, as shown in FIG. 11, the tip 22c often does not have a perfectly acute angle. From the viewpoint of stress relief, it is preferable that the thicknesses T1 to T3 are all thin. However, if the thickness T3 is made too thin, the coverage of the corners of the element body 10 by the underlying metal layer 22 will be poor. Taking these factors into consideration, by making the thickness T1 small and making the thickness T2 larger than the thickness T1 and the thickness T3 larger than the thickness T2, it is possible to relieve stress at the tip 22c and suppress the occurrence of cracks, etc., and also to improve the coverage of the corners of the element body 10 by the underlying metal layer 22.

[0051] Therefore, as an index of thickness T1, angle θ1 is reduced, as an index of thickness T2, T1 / T2 is reduced, and as an index of thickness T3, T3 / T2 is increased. From this viewpoint, angle θ1 is preferably 30° or less, preferably 26° or less, and more preferably 22° or less. If angle θ1 is too small, thickness T1 becomes too thin. From this viewpoint, θ1 is preferably 5° or more, and more preferably 10° or more. Thickness T1 is preferably 0.9 times or less, more preferably 0.8 times or less, and even more preferably 0.7 times or less, of thickness T2. From the viewpoint of not making thickness T2 too large, thickness T1 is preferably 0.3 times or more of thickness T2. Thickness T3 is preferably 1.1 times or more of thickness T2, more preferably 1.2 times or more, and even more preferably 1.3 times or more. From the viewpoint of not making thickness T3 too large, thickness T3 is preferably 2 times or less of thickness T2.

[0052] From the viewpoint of stress relaxation, the angle θ2 is preferably equal to or less than 15°, more preferably equal to or less than 10°, and still more preferably equal to or less than 8°. From the viewpoint of preventing the thickness T2 from being too small, the angle θ2 is preferably equal to or greater than 2°, and more preferably equal to or greater than 4°.

[0053] From the viewpoint of stress relaxation, the angle θ3 is preferably equal to or less than 10°, more preferably equal to or less than 8°, and still more preferably equal to or less than 6°. From the viewpoint of preventing the thickness T2 from being too small, the angle θ2 is preferably equal to or greater than 1°, and more preferably equal to or greater than 3°.

[0054] By setting the angle θ2 to 1.7 times or less the angle θ3, the tip of the base metal layer 22 becomes sharp. This makes it difficult for stress to concentrate on the element body 10 at the tip 22c. This makes it possible to suppress the occurrence of cracks 46. The angle θ2 is preferably 1.6 times or less the angle θ3, and more preferably 1.5 times or less. θ2 may be smaller than θ3.

[0055] The thickness T5 of the base metal layer 22 at the center P5 of the end faces 51 and 52 is preferably at least twice the thickness T3. This allows the portion 22a to be thinner. This prevents stress applied to the element body 10 from concentrating on the tip 22c. The thickness T5 is more preferably at least 2.5 times the thickness T3. From the viewpoint of not making the thickness T3 too small, the thickness T5 is preferably, for example, 7 times or less the thickness T3. The center P5 is the center of the end faces 51 and 52 in the Z direction, and preferably the center of the end faces 51 and 52 in the Z direction and the Y direction.

[0056] It is preferable that thickness T4 be larger than T3. This improves the coverage of the base metal layer 22 at the corners 57 (see FIG. 9 ) of the element body 10. It is preferable that thickness T4 be 1.2 times or more, and more preferably 1.5 times or more, of thickness T3. From the viewpoint of not making thickness T3 too small, it is preferable that thickness T4 be no more than twice T3.

[0057] Portion 22a where angle θ1 is 10° or less, thickness T1 is 0.9 times T2 or less, and thickness T3 is 1.1 times T2 or more may be provided on at least one of the four surfaces (side surfaces 53, 54, bottom surface 55, and top surface 56) connected to end surface 51 or 52. Portion 22a where angle θ1 is 10° or less, thickness T1 is 0.9 times T2 or less, and thickness T3 is 1.1 times T2 or more may be provided on end portion 40 of at least one of end surfaces 51 and 52. When bottom surface 55 of element body 10 is mounted on mounting substrate 30 as shown in Figures 8 and 9 , stress tends to concentrate at tip 22c on bottom surface 55 of element body 10. Therefore, it is preferable that the portion 22a where the angle θ1 is 10° or less, the thickness T1 is 0.9 times or less than T2, and the thickness T3 is 1.1 times or more than T2 be provided on the lower surface 55 (the surface on which the multilayer ceramic component is mounted).

[0058] Portion 22a, in which angle θ1 is 10° or less, thickness T1 is 0.9 times or less than T2, and thickness T3 is 1.1 times or more than T2, is preferably provided on all four surfaces (side surfaces 53, 54, bottom surface 55, and top surface 56) connected to end surface 51 or 52, and is preferably provided on end portion 40 of both end surfaces 51 and 52.

[0059] As the element body 10 becomes smaller, cracks 46 are more likely to occur. From this perspective, in capacitors with a size of 0402 capacitors or smaller (i.e., capacitors in which the element body 10 has a length of 0.4 mm in the X direction, a width of 0.2 mm in the Y direction, and a height of 0.2 mm or less in the Z direction), it is preferable to sharpen the tip 22c of the portion 22a. In capacitors with a size of 0201 capacitors or smaller, it is more preferable to thin the tip of the portion 22a.

[0060] In the first embodiment, as shown in Fig. 4, the base metal layer 22 was formed after firing the element body 10. After the binder removal process of the element body 10, a paste 42 may be applied to the end portion 40 of the element body 10 using a dipping method, as shown in Figs. 5A to 5D, and then a firing process may be performed, so that firing of the element body 10 and baking of the base metal layer 22 are performed simultaneously. In this case, the main component metal element of the paste 42 is, for example, nickel. Furthermore, in the cutting step S18, the metal pattern may be exposed from the side surface of the laminate in the Y direction, and side green sheets may be formed on the side surface of the laminate.

[0061] Each dimension is measured by observing the cross section. It is sufficient to measure at least one location in the relevant area, but measurements at multiple locations can also be averaged. When a certain component contains a certain element or molecule as a main component, it is sufficient that the certain element or molecule is contained in the certain component to an extent that the effect of the embodiment is exhibited, and the concentration of the certain element or molecule in the certain component is, for example, 50 mol % or more, 80 mol % or more, or 90 mol % or more.

[0062] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims.

[0063] REFERENCE SIGNS LIST 10 Element body 12a, 12b Internal electrode 14 Dielectric layer 20a, 20b External electrode 22 Undercoat metal layer 22a, 22b Portion 22c Tip 24 Plated layer 30 Mounting substrate 32 Terminal 34 Solder 40 End 42 Paste 51, 52 End face 53, 54 Side face 55 Bottom face 56 Top face

Claims

1. An element body in which a plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic are alternately stacked in a first direction, the stacked internal electrodes having end faces that are alternately exposed and facing each other in a second direction; a base metal layer that contacts parts of the plurality of internal electrodes exposed from the end face and is provided on an end face side of one of four faces of the element body that is connected to the end face; and a plating layer that is provided at the end face so as to sandwich the base metal layer between the element body and the end face, and forms an external electrode together with the base metal layer, wherein, when the distance in the second direction between a tip of the base metal layer and the end face on at least one of the four faces is L, an angle formed by the surface of the element body and a straight line connecting a point on the surface of the base metal layer at a first position where the distance in the second direction from the tip to the end face is 0.1×L is θ1, a thickness of the base metal layer at the first position is T1, a thickness of the base metal layer at a second position where the distance in the second direction from the tip to the end face is 0.5×L is T2, and a thickness of the base metal layer at a third position where the distance in the second direction from the tip to the end face is 0.9×L is T3, wherein θ1 is 30° or less, T1 is 0.9 times T2 or less, and T3 is 1.1 times T2 or more.

2. A laminated ceramic electronic component according to claim 1, wherein θ1 is 26° or less, T1 is 0.8 times or less than T2, and T3 is 1.2 times or more than T2.

3. A multilayer ceramic electronic component as described in claim 1 or 2, wherein the angle θ3 formed by a straight line connecting a point on the surface of the base metal layer at the third position and a point on the surface of the element body at the tip of the base metal layer and the surface of the element body is θ3, and θ3 is 10° or less.

4. A multilayer ceramic electronic component according to claim 1 or 2, wherein the thickness of said base metal layer at the center of said end face in said first direction is at least twice the thickness of said base metal layer at said third position.

5. A multilayer ceramic electronic component as described in claim 1 or 2, wherein at the position of the end face in the second direction, the thickness of the base metal layer in a direction perpendicular to the second direction is greater than the thickness of the base metal layer at the third position.

6. A monolithic ceramic electronic component according to claim 1 or 2, wherein, in said four faces, θ1 is 30° or less, T1 is 0.9 times T2 or less, and T3 is 1.1 times T2 or more.

7. An element body in which a plurality of internal electrodes and a plurality of dielectric layers mainly composed of ceramic are alternately stacked in a first direction, the stacked internal electrodes having end faces that are alternately exposed and opposed to each other in a second direction, and a metal layer is provided on an end portion of the end face side of one of four faces of the element body connected to the end face of the element body so as to contact a portion of the plurality of internal electrodes exposed from the end face, the metal layer is provided on at least one of four faces of the element body other than the end face, the ... of the element body, the metal layer is provided on at least one of four faces of the element body other than the end face of the element body, the metal layer is provided on at least one of four faces of the element body other than the end face of the element body, the metal layer is provided on at least one of four faces of the element body other than the end face of the element body, the metal layer is provided on at least one of four faces of the element body other than the end face of the element body, the metal layer is provided on at least one of four faces of the element body other than the end face of the element body, the metal layer is provided on at least one of four faces of the element body other than the end face of forming, by a dipping method, a metal layer such that, when a thickness of the metal layer at a second position where a distance in the second direction from the tip to the end face is 0.9×L is T3, θ1 is 30° or less, T1 is 0.9 times T2 or less, and T3 is 1.1 times T2 or more.

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