Multilayer ceramic electronic component and manufacturing method of the same

Abstract

To provide a multilayer ceramic electronic component capable of controlling a shape of an external electrode at an end part thereof.SOLUTION: A multilayer ceramic electronic component includes: an element body 10 in which a plurality of internal electrodes and a plurality of dielectric layers having a ceramic as a main component are alternately laminated in a first direction, and the laminated plurality of internal electrodes are alternately exposed and have end surfaces facing each other in a second direction; and an external electrode provided at an end part on the end surface side in four surfaces which are in contact with a part of the plurality of internal electrodes exposed from the end surfaces and are connected to the end surfaces of the element body. A surface roughness of at least a part of a rough surface region of an end part 40 of at least the surface facing in the first direction among the four surfaces is larger than the surface roughness of a central part 42 of the facing surface other than the end part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] It is known that in multilayer ceramic electronic components, the roughness of the surface of a part of the element body is increased (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-76995 [Patent Document 2] Japanese Patent Publication No. 2022-85196 Summary of the Invention [Problem to be solved by the invention]

[0004] When external electrodes are formed on the ends and end surfaces of the side, bottom, and top surfaces of the element body, the lengths of the external electrodes at the ends may vary, which makes it difficult to apply paste to form the external electrodes and to control the shape, such as the length, of the external electrodes, particularly in multilayer ceramic electronic components.

[0005] The present invention has been made in view of the above-mentioned problems, and has as its object to control the shape of the external electrode at the end portion. [Means for solving the problem]

[0006] The present invention is a multilayer ceramic electronic component comprising: 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 and having end faces facing each other in a second direction; and external electrodes in contact with some of the plurality of internal electrodes exposed from the end faces and provided at ends on the end face side of four faces connected to the end faces of the element body, wherein the surface roughness of at least a roughened surface region of at least a portion of the end of at least faces facing each other in the first direction is greater than the surface roughness of central portions of the facing faces other than the ends.

[0007] In the above configuration, the external electrode comprises a base metal layer provided on the end portion and a plating layer provided to cover the base metal layer, and the end opposite the end face of the roughened surface region can be configured to approximately coincide with the end of the base metal layer.

[0008] In the above configuration, the roughened surface area may be provided on the entire surface of the end portion.

[0009] In the above configuration, the roughened surface region can be provided in a region of the end portion closer to the tip of the external electrode, and the surface roughness of the roughened surface region can be greater than the surface roughness of a region of the end portion closer to the end face.

[0010] In the above configuration, the end portion has a first corner portion where the corner between the end face and the four faces is rounded, the roughened surface region is provided at the first corner portion of the end portion, and the surface roughness of the roughened surface region can be greater than the surface roughness of the region of the end portion opposite the end face.

[0011] In the above configuration, the end portion has a second corner portion between the four faces, the roughened surface region is provided at the second corner portion of the end portion, and the surface roughness of the roughened surface region can be greater than the surface roughness of the region of the end portion other than the second corner portion.

[0012] In the above configuration, the arithmetic mean roughness of the at least part of the edge portion may be at least twice as large as the arithmetic mean roughness of the central portion.

[0013] In the above configuration, the arithmetic mean roughness at the end portion may be 50 nm or more.

[0014] In the above configuration, the roughened surface area may be provided on all of the four surfaces.

[0015] The present invention provides a method for manufacturing a multilayer ceramic electronic component, comprising: an element body in which a plurality of internal electrodes and a plurality of dielectric layers primarily 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 process for forming rough surfaces on the end faces of at least four faces of the element body that are connected to the end faces, without forming a rough surface in the center other than the end face side of the end face; and a process for applying a paste to the end faces and end faces of the four faces, and forming external electrodes from the paste that contact portions of the plurality of internal electrodes exposed from the end faces.

[0016] In the above configuration, the process of forming the element body includes a process of forming a laminated sheet in which multiple green sheets and metal patterns are alternately stacked, and a process of cutting the laminated sheet to form multiple element bodies, and the process of forming a rough surface on the end portion can be configured to be performed before cutting the laminated sheet. [Effects of the Invention]

[0017] According to the present invention, the shape of the external electrode at the end can be controlled. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a partial cross-sectional perspective view of the multilayer ceramic capacitor according to the first embodiment. [Figure 2]FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 4 is a flowchart showing a method 1 for manufacturing the multilayer ceramic capacitor according to the first embodiment. [Figure 5] 5(a) and 5(b) are cross-sectional views illustrating a method 1 for manufacturing the multilayer ceramic capacitor according to the first embodiment. [Figure 6] 6(a) and 6(b) are cross-sectional views illustrating a method 1 for manufacturing the multilayer ceramic capacitor according to the first embodiment. [Figure 7] 7(a) to 7(c) are cross-sectional views showing the paste on the element body. [Figure 8] FIG. 8 is a flowchart showing a second method for manufacturing the multilayer ceramic capacitor according to the first embodiment. [Figure 9] FIG. 9(a) is a plan view showing a second manufacturing method of the multilayer ceramic capacitor according to the first embodiment, and FIG. 9(b) is a cross-sectional view taken along line AA in FIG. 9(a). [Figure 10] FIG. 10 is a cross-sectional view of the multilayer ceramic capacitor of the first embodiment mounted on a mounting substrate. [Figure 11] 11(a) to 11(c) are perspective views showing regions of the element body where a rough surface is to be formed in the first embodiment. [Figure 12] 12(a) to 12(c) are perspective views showing regions of the element body in which rough surfaces are to be formed in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

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

[0020] (Embodiment 1) Fig. 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.

[0021] 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 the 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 the 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.

[0022] The multilayer ceramic capacitor 100 includes an element body 10 having a substantially rectangular parallelepiped shape 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 the plurality of internal electrodes 12b (second internal electrodes) are alternately stacked. One of the plurality of dielectric layers 14 is provided between one of the plurality of internal electrodes 12a and one of the plurality of internal electrodes 12b. 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.

[0023] 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.

[0024] The external electrode 20a contacts the internal electrode 12a exposed from the element body 10 at the end face 51. The external electrode 20b contacts the internal electrode 12b (parts of the internal electrodes 12a and 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. The external electrodes 20a and 20b are not provided on the central portion 42 in the X direction of the side faces 53, 54, bottom face 55, and top face 56 of the element body 10. The end faces 40 are rough surfaces, and the central portion 42 is flat. Here, a flat surface does not only mean a completely flat surface with no irregularities, but also means a substantially flat surface (approximately flat surface) with slight irregularities formed so as to satisfy the arithmetic mean roughness described below. The surface roughness at the end portions 40 is greater than the surface roughness at the central portion 42. Each of the external electrodes 20a and 20b includes a metal base layer 22 and a plating layer 24 provided so as to cover the metal base layer 22. The metal base layer 22 is provided at the end portions 40.

[0025] 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.

[0026] The internal electrodes 12a and 12b are mainly composed of base metals such as nickel (Ni), copper (Cu), and tin (Sn). The internal electrodes 12a and 12b may 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 or more and 1 μm or less.

[0027] The dielectric layer 14 has a main phase made of a ceramic material having a perovskite structure represented by the general formula ABO3. 3-α For example, the ceramic material includes barium titanate (BaTiO3), calcium zirconate (CaZrO3), calcium titanate (CaTiO3), strontium titanate (SrTiO3), magnesium titanate (MgTiO3), and BaTiO3, which forms a perovskite structure. 1-x-y Ca x Sr y Ti 1-z Zr z At least one of the following can be selected and used: O3 (0≦x≦1, 0≦y≦1, 0≦z≦1). 1-x-y Ca x Sr y Ti 1-z Zr z O3 is barium strontium titanate, barium calcium titanate, barium zirconate, barium titanate zirconate, calcium titanate zirconate, barium calcium titanate zirconate, etc. 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.

[0028] 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.

[0029] The composition of the main ceramic of the cover dielectric layer 16 may be the same as or different from the main ceramic of the dielectric layer 14 .

[0030] 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 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), trontium (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 base metal layer 22 has a thickness of, for example, 20 to 200 μm.

[0031] The plating layer 24 is mainly 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 plating layer of a single metal component, or may be a plating layer of multiple layers of different metal components. Furthermore, a film of conductive resin 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, 2 to 50 μm.

[0032] (Manufacturing Method 1 of Embodiment 1) A description will now be given of a method 1 for manufacturing the multilayer ceramic capacitor 100. Fig. 4 is a flowchart showing the method 1 for manufacturing the multilayer ceramic capacitor according to the first embodiment.

[0033] (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.

[0034] (Pattern formation process) Next, metal patterns that will become the internal electrodes 12a and 12b are formed on the green sheet (step S12). In step S12, a metal paste for forming the internal electrodes, containing an organic binder, is printed on the green sheet on the base material 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.

[0035] (Lamination process) Next, the green sheets are stacked (step S14). In step S14, a laminate sheet is formed by stacking green sheets on which metal patterns that become the internal electrodes 12a and 12b are printed. Green sheets corresponding to the cover dielectric layer 16 are stacked on both end surfaces of the laminate sheet in the stacking direction.

[0036] (Crimping process) Next, the laminated sheet is pressure-bonded (step S16). In step S16, the laminated sheet formed in step S14 is pressed to pressure-bond the plurality of green sheets together. As the pressure-bonding means, for example, a hydrostatic press is used.

[0037] (cutting process) Next, the laminated sheet is cut (step S18). In step S18, a cutting blade is used to cut the laminated sheet along predetermined cutting lines in the stacking direction, 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.

[0038] (Surface roughening process) Next, a roughening treatment is performed on the surface of the end portion 40 of the element body 10 (step S20). FIGS. 5(a) to 6(b) are cross-sectional views showing a method 1 for manufacturing a multilayer ceramic capacitor according to embodiment 1. As shown in FIG. 5(a), in step S20, a laser beam is irradiated onto the surface of the end portion 40 of the element body 10 to form a roughened surface on the surface of the end portion 40. At this time, no roughened surface is formed on the surfaces of the central portion 42 and the end faces 51 and 52. A roughened surface may be formed by blasting or rubbing with coarse sandpaper, in addition to irradiating with laser beam. The roughened surface may also be formed after sintering the element body 10.

[0039] (Firing process) Next, the element body 10 is fired (step S22). In step S22, 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 an hour. This sinters the particles of the element body 10 and the internal electrodes 12a and 12b.

[0040] (External electrode formation process) Next, the external electrodes 20a and 20b are formed (step S24). Figures 5(b) to 6(b) show a method for forming the base metal layer 22 of the external electrodes 20a and 20b using a dipping method. As shown in Figure 5(b), a paste 43 is prepared. The paste 43 contains a metal powder, such as copper powder, as a main component, glass frit, a binder, and an organic solvent. The end surface 51 or 52 of the element body 10 is placed on the liquid paste 43.

[0041] As shown in FIG. 6(a), the end portion 40 of the element body 10 is immersed in the paste 43. The element body 10 is then pulled out of the paste 43. Due to the surface tension at this time, the paste 44 adheres to the end portion 40, which has an uneven surface, but does not adhere to the central portion 42. Therefore, the top portion 44a of the paste 44 reaches the end 40a of the end portion 40 opposite the end faces 51 and 52, but does not spread above the end 40a.

[0042] As shown in FIG. 6(b), when the element body 10 is further lifted up, the paste 45 adheres to the end portion 40 and the end surface 51 or 52. At this time, the uppermost portion 45a of the paste 45 is substantially located at the end 40a of the end portion 40, as described above. The paste 45 is then baked in a nitrogen atmosphere at, for example, 750°C to 850°C. As a result, the base metal layer 22 is formed from the paste 45. Next, the plating layer 24 is formed on the surface of the base metal layer 22. As a result, the external electrodes 20a and 20b are formed from the base metal layer 22 and the plating layer 24.

[0043] 7(a) to 7(c) are cross-sectional views showing the paste on the element body. As shown in FIG. 7(a), when the paste 44 is brought into contact with the flat surface of the element body 10, the contact angle θ is less than 90°. In this case, the paste 44 has good wettability to the surface of the element body 10. As shown in FIG. 7(b), when the contact angle θ on the flat surface is less than 90°, roughening the surface of the element body 10 to provide irregularities increases the surface area, and the contact angle θ of the paste 44 becomes smaller than that shown in FIG. 7(a) due to surface tension. This allows the paste 44 to more easily wet and spread over the surface of the element body 10.

[0044] Therefore, as shown in FIG. 5(a), unevenness is formed on the end portion 40. As shown in FIG. 6(a), the end surface 51 or 52 is immersed in paste 43. At this time, as shown in FIG. 7(b), the paste 44 spreads over the uneven end portion 40. However, the substantially flat central portion 42 has a lower surface free energy than the uneven end portion 40, so the paste 44 does not spread over it easily. Therefore, as shown in FIGS. 6(a) and 6(b), the external electrodes 20a and 20b can be formed accurately on the uneven end portion 40. Although an example in which the paste 44 is formed using a dip method has been described, even when the paste 44 is applied using a roller or the like, forming unevenness on the end portion 40 allows the paste 44 to be applied accurately to the end portion 40. As such, the paste 44 can be applied by methods other than the dip method.

[0045] (Manufacturing Method 2 of Embodiment 1) A description will now be given of a method 2 for manufacturing the multilayer ceramic capacitor 100. Fig. 8 is a flowchart showing a method 2 for manufacturing the multilayer ceramic capacitor according to embodiment 1. As shown in Fig. 8, steps S10 to S16 are the same as those in Fig. 4.

[0046] A surface roughening step S20 is performed before the cutting step S18. Fig. 9(a) is a plan view showing a method for manufacturing a multilayer ceramic capacitor according to embodiment 1, and Fig. 9(b) is a cross-sectional view taken along line AA in Fig. 9(a).

[0047] As shown in FIGS. 9(a) and 9(b), after the surface roughening step S20 is completed, laminate sheets 38a and 38b are alternately stacked between cover green sheets 35 that will become cover dielectric layers 16 in laminate sheet 48. In laminate sheet 38a, metal pattern 37a is provided on green sheet 36, and in laminate sheet 38b, metal pattern 37b is provided on green sheet 36. Cutting lines 47 are the lines along which laminate sheet 48 is cut in step S18. A roughened surface is formed in region 46 of lower surface 55 of laminate sheet 48 that straddles cutting line 47. The roughened surface can be formed using methods such as laser light irradiation or blasting.

[0048] Subsequently, in step S18, the element body 10 is cut, after which steps S22 and S24, which are the same as those in FIG.

[0049] Fig. 10 is a cross-sectional view of the multilayer ceramic capacitor of embodiment 1 mounted on a mounting substrate. As shown in Fig. 10, the multilayer ceramic capacitor 100 has unevenness formed on the end portions 40. 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. To prevent the external electrodes 20a and 20b from shorting out due to excessive wetting and spreading of the solder 34 during solder mounting, the length L of the end portions 40 of the external electrodes 20a and 20b is appropriately set, and the shape (fillet) of the solder 34 is also appropriately controlled accordingly.

[0050] Therefore, of the four surfaces, namely, the side surfaces 53, 54, the bottom surface 55, and the top surface 56 connected to the end surface 51 or 52, the surface roughness of at least the bottom surface 55 and the top surface 56 at the end 40 is made larger than the surface roughness of the central portion 42 other than the end 40. This allows the paste 44 to wet and spread over the rough surface of the end 40, as shown in FIG. 6(a), thereby improving the accuracy of the distance L in the X direction between the external electrodes 20a and 20b.

[0051] When the paste 45 is formed as shown in FIGS. 5(a) to 6(b), the top 45a of the paste 45 is located at the edge 40a of the end face 40, as described above. Therefore, the edge 40a of the roughened end face 40 approximately coincides with the edge of the base metal layer 22, as shown by the symbol Ea in FIG. 2 and the symbol Eb in FIG. 3. "Almost coincident" allows for manufacturing errors, for example, differences due to shrinkage of the paste 45 when the paste 45 is baked. The distance between the edge of the roughened surface and the edge of the base metal layer 22 is, for example, 0.1 times or less, or 0.05 times or less, the length L.

[0052] From the viewpoint of improving the wettability of the paste 44 at the end portion 40, the arithmetic mean roughness at the end portion 40 is preferably, for example, 50 nm or more, more preferably 100 nm or more, and even more preferably 500 nm or more. If the arithmetic mean roughness is too large, the wettability of the paste 44 at the end portion 40 will not improve. From this viewpoint, the arithmetic mean roughness at the end portion 40 is preferably, for example, 10 μm or less, and more preferably 5 μm or less. The arithmetic mean roughness at the central portion 42 is, for example, 20 nm to 500 nm. The arithmetic mean roughness at the end portion 40 is preferably at least twice the arithmetic mean roughness at the central portion 42, more preferably at least 5 times, and even more preferably at least 10 times. The arithmetic mean roughness at the end portion 40 is, for example, 200 times or less the arithmetic mean roughness at the central portion 42.

[0053] In manufacturing methods 1 and 2, as shown in Figures 5(a), 9(a), and 9(b), a rough surface is formed only on the end portion 40, without forming a rough surface in the central portion 42 other than the end portion 40. As shown in Figures 6(a) and 6(b), paste 44 is applied to the end portion 40 on the side surfaces 53, 54, bottom surface 55, and top surface 56, and external electrodes 20a and 20b are formed from the paste 44. This makes it possible to improve the accuracy of the distance L in the X direction between the external electrodes 20a and 20b at least on the bottom surface 55.

[0054] In manufacturing method 2, as shown in Figures 9(a) and 9(b), a laminated sheet 48 is formed in which multiple green sheets 36 and multiple metal patterns 37a and 37b for internal electrodes 12a and 12b are alternately stacked. Then, rough surfaces are formed in regions 46 that will become end portions 40 on the surfaces that will become the lower surface 55 and upper surface 56, and no rough surfaces are formed in regions between the regions 46. Then, in step S18, the laminated sheet 48 is cut to form multiple element bodies 10. This simplifies the process compared to manufacturing method 1, in which the surface is roughened after the element body 10 is formed.

[0055] In manufacturing methods 1 and 2, as shown in FIGS. 4 and 8, the base metal layer 22 is formed after firing the element body 10. After the binder removal process of the element body 10, a paste 45 may be applied to the end portion 40 of the element body 10 using a dipping method, as shown in FIGS. 5(b) to 6(b), followed by a firing process, 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 45 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.

[0056] 11(a) to 12(c) are perspective views showing regions of the element body in embodiment 1 where rough surfaces are to be formed. In FIGS. 11(a) to 12(c), cross-hatching is used to indicate rough surface regions 50 on the surface of element body 10. An example is shown in which the corners of element body 10 are rounded. As shown in FIG. 11(a), the edge portions 40 of side surfaces 53, 54, bottom surface 55, and top surface 56 of element body 10 are rough surface regions 50, and the rough surface regions 50 are provided over the entire surface of edge portions 40. End surfaces 51, 52 and a central portion 42 are flat surfaces. By forming edge portions 40 as rough surface regions 50, the length L of external electrodes 20a and 20b can be formed with high precision. Furthermore, because end surfaces 51 and 52 are not roughened, the manufacturing process for forming the rough surfaces can be reduced.

[0057] 11(b), end faces 51 and 52 may be roughened in addition to end portion 40. This allows for further improvement in the adhesion between external electrodes 20a and 20b and element body 10.

[0058] As shown in FIG. 11(c), the end 40 has rounded corners 41 (first corners) between the end faces 51 and 52 and the side faces 53 and 54, the lower face 55, and the upper face 56. The roughened surface region 50 may be provided at a location other than the corner 41 of the end 40. In FIG. 6(a), the paste 44 is less likely to wet the portion of the end 40 near the central portion 42. The end of the base metal layer 22 is determined by the position of the edge of the roughened surface region 50. Therefore, the roughened surface region 50 is provided in the region of the end 40 near the central portion 42 (the region on the tip side of the external electrodes 20a and 20b). The surface roughness of the roughened surface region 50 is greater than the surface roughness of the region of the end 40 on the end faces 51 and 52 side. This allows the length L of the external electrodes 20a and 20b to be formed accurately and reduces the manufacturing process for forming the roughened surface. The arithmetic mean roughness of the rough surface region 50 is preferably at least twice, more preferably at least five times, and even more preferably at least ten times, the arithmetic mean roughness of the region of the end 40 on the side of the end faces 51 and 52 .

[0059] As shown in FIG. 12( a), the roughened surface region 50 may be provided at the corner 41. Coverage of the metal base layer 22 at the corner 41 may be poor. Therefore, the roughened surface region 50 is provided at the corner 41. The surface roughness of the roughened surface region 50 is greater than the surface roughness of the region of the end 40 opposite the end faces 51 and 52. This improves coverage of the metal base layer 22 at the corner 41. Furthermore, by not providing the roughened surface region 50 at the end 40 other than the corner 41, the manufacturing process for forming the roughened surface can be reduced. The arithmetic mean roughness of the roughened surface region 50 is preferably at least twice, more preferably at least five times, and even more preferably at least ten times, the arithmetic mean roughness of the region of the end 40 opposite the end faces 51 and 52.

[0060] As shown in FIG. 12(b), the roughened surface regions 50 may be provided at corners 58 of the end portion 40 between the side surfaces 53 and 54 and the bottom surface 55 and top surface 56. Corners 58 are the locations of the end portion 40 where the wettability of the paste 44 is poor. Therefore, roughened surface regions 50 are provided at corners 58 of the end portion 40, and no roughened surface regions 50 are provided outside corners 58. This allows the length L of the external electrodes 20a and 20b to be formed with high precision, and also reduces the manufacturing process for forming the roughened surfaces.

[0061] 12(c), the roughened surface region 50 may be provided at a corner 59 of the corner 41, where the side surfaces 53 and 54 meet the lower surface 55 and upper surface 56. The coverage of the metal base layer 22 at the corner 59 of the corner 41 may be poor. Therefore, by providing the roughened surface region 50 at the corner 59, the coverage of the metal base layer 22 at the corner 59 can be improved. Furthermore, by not providing the roughened surface region 50 at the end 40 other than the corner 59, the manufacturing process for forming the roughened surface can be reduced.

[0062] 12(b) and 12(c), the roughened surface region 50 is provided at a corner 58 or 59 (second corner) of the end portion 40, and the surface roughness of the roughened surface region 50 is greater than the surface roughness of the region of the end portion 40 other than the corner 58 or 59. The arithmetic mean roughness of the roughened surface region 50 is preferably at least two times, more preferably at least five times, and even more preferably at least ten times.

[0063] 11(c) to 12(c), a portion of the end portion 40 is made into a roughened region 50, and the remaining portion of the end portion 40 is made into a flat surface. This makes it possible to control the shape of the underlying metal layer 22. By controlling the shape of the underlying metal layer 22, it is also possible to control the shape of the solder 34 in FIG.

[0064] 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 variations are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0065] 10 Base 12a, 12b internal electrode 14 Dielectric layer 20a, 20b external electrode 24 plating layer 30 Mounting board 32 terminals 34 Solder 40 End 42 Central part 43, 44, 45 Paste 51, 52 End face 53, 54 Side 55 Bottom side 56 Top

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 face each other in a second direction; external electrodes that contact parts of the plurality of internal electrodes exposed from the end faces and are provided on the end faces of four surfaces of the element body that are connected to the end faces; Equipped with A multilayer ceramic electronic component in which the surface roughness of at least a roughened surface region at the end of at least one of the four surfaces that opposes each other in the first direction is greater than the surface roughness of a central portion of the opposing surface other than the end.

2. the external electrode includes a base metal layer provided on the end portion and a plating layer provided to cover the base metal layer, 2. The multilayer ceramic electronic component according to claim 1, wherein an end of the roughened surface region opposite the end face is substantially aligned with an end of the base metal layer.

3. 3. The multilayer ceramic electronic component according to claim 1, wherein the roughened surface region is provided over the entire surface of the end portion.

4. 3. The multilayer ceramic electronic component according to claim 1, wherein the roughened surface region is provided in a region of the end portion closer to the tip of the external electrode, and the surface roughness of the roughened surface region is greater than the surface roughness of a region of the end portion closer to the end face.

5. the end portion has a first corner portion where the corners between the end surface and the four surfaces are rounded, 2. The multilayer ceramic electronic component according to claim 1, wherein the roughened surface region is provided at the first corner of the end portion, and the surface roughness of the roughened surface region is greater than the surface roughness of a region of the end portion opposite the end face.

6. the end portion has a second corner portion between the four faces; 3. The multilayer ceramic electronic component according to claim 1, wherein the roughened surface region is provided at the second corner of the end portion, and the surface roughness of the roughened surface region is greater than the surface roughness of the end portion other than the second corner.

7. 3. The multilayer ceramic electronic component according to claim 1, wherein the arithmetic mean roughness of said at least one portion of said edge is at least twice as large as the arithmetic mean roughness of said central portion.

8. 3. The multilayer ceramic electronic component according to claim 1, wherein the arithmetic mean roughness at the end portion is 50 nm or more.

9. 3. The multilayer ceramic electronic component according to claim 1, wherein the roughened surface region is provided on all of the four surfaces.

10. 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 face each other in a second direction; forming a roughened surface on at least one of four surfaces connected to the end surface of the element body that opposes the end surface in the first direction, without forming a roughened surface on a central portion other than the end portion on the end surface side; applying a paste to the end faces and end portions of the four surfaces, and forming external electrodes from the paste in contact with portions of the plurality of internal electrodes exposed from the end faces; A method for manufacturing a multilayer ceramic electronic component comprising:

11. The step of forming the element body includes: forming a laminated sheet in which a plurality of green sheets and metal patterns are alternately laminated; cutting the laminated sheet to form a plurality of the element bodies; Including, The method for manufacturing a multilayer ceramic electronic component according to claim 10, wherein the step of forming a rough surface on the end portion is carried out before cutting the laminated sheet.

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