Manufacturing method for multilayer ceramic capacitors

Abstract

A method for producing a multilayer ceramic capacitor according to the present invention, the multilayer ceramic capacitor being provided with a capacitor main body (1) which is obtained by stacking a plurality of dielectric layers (2), a plurality of first internal electrodes (3) and a plurality of second internal electrodes (4), a first via conductor (5) which is provided within the capacitor main body (1) and is electrically connected to the plurality of first internal electrodes (3), and a second via conductor (6) which is provided within the capacitor main body (1) and is electrically connected to the plurality of second internal electrodes (4), comprises: a step for forming a first material layer which is formed of a first material for the purpose of forming the first via conductor (5) and the second via conductor (6); and a step for forming a second material layer which is positioned at an end of at least one of the first via conductor (5) and the second via conductor (6), while being formed of a second material that is different from the first material and contains, as a main component, any one of Sn, Sn-Ag, Sn-Bi, Sn-In, Sn-Ag-Cu and Au.

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a multilayer ceramic capacitor. [Background technology]

[0002] Multilayer capacitors are known in which the ESL (equivalent series inductance) is reduced by widening the current route, shortening the current route, canceling out magnetic fields generated by currents of opposite polarity, etc. Patent Document 1 (JP 2006-135333 A) discloses an example of a multilayer capacitor with reduced ESL.

[0003] The multilayer capacitor disclosed in Patent Document 1 includes a capacitor body in which a plurality of dielectric layers, a plurality of first internal electrodes, and a plurality of second internal electrodes are laminated. The capacitor body is provided with a plurality of first via conductors electrically connected to the plurality of first internal electrodes and extending to one main surface of the capacitor body, and a plurality of second via conductors electrically connected to the plurality of second internal electrodes and extending to the one main surface of the capacitor body. The one main surface of the capacitor body is provided with a plurality of first external electrodes electrically connected to the plurality of first via conductors, respectively, and a plurality of second external electrodes electrically connected to the plurality of second via conductors, respectively. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-135333 Summary of the Invention [Problem to be solved by the invention]

[0005] The multilayer capacitor disclosed in Patent Document 1 is manufactured by fabricating a capacitor body and then performing a process of forming a first external electrode and a second external electrode on the surface of the capacitor body. Therefore, if the size of the multilayer capacitor is fixed, the thickness of the capacitor body must be reduced by the amount of the thickness of the external electrodes. This places a restriction on the number of layers of the internal electrodes, making it impossible to increase the capacitance.

[0006] The present disclosure is intended to solve the above-mentioned problems, and has an object to provide a method for manufacturing a multilayer ceramic capacitor having a large capacitance. [Means for solving the problem]

[0007] A method for manufacturing a multilayer ceramic capacitor according to the present disclosure is a method for manufacturing a multilayer ceramic capacitor including: a capacitor body in which a plurality of dielectric layers, a plurality of first internal electrodes, and a plurality of second internal electrodes are laminated; first via conductors provided inside the capacitor body and electrically connected to a plurality of the first internal electrodes; and second via conductors provided inside the capacitor body and electrically connected to a plurality of the second internal electrodes, The method comprises the steps of: forming a first material layer made of a first material to form the first via conductor and the second via conductor; and forming a second material layer made of a second material located at at least one end of the first via conductor and the second via conductor, the second material layer being different from the first material and containing any one of Sn, Sn-Ag, Sn-Bi, Sn-In, Sn-Ag-Cu, and Au as a main component. [Effects of the Invention]

[0008] According to the method for manufacturing a multilayer ceramic capacitor disclosed herein, a first material layer and a second material layer are formed at at least one end of the first and second via conductors within the capacitor body. The second material layer is made of a second material primarily composed of one of Sn, Sn-Ag, Sn-Bi, Sn-In, Sn-Ag-Cu, and Au. The second material has excellent oxidation resistance, preventing oxidation even when the surface is exposed, enabling highly reliable connection to external electrodes. This eliminates the need for separate external electrodes electrically connected to the first and second via conductors, allowing for a larger capacitor body. This allows for a larger number of layers to be laminated for the first and second internal electrodes, thereby increasing capacitance. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view of a multilayer ceramic capacitor manufactured by a method for manufacturing a multilayer ceramic capacitor according to the present disclosure. [Figure 2] 2 is a cross-sectional view taken along line II-II of the multilayer ceramic capacitor shown in FIG. [Figure 3] FIG. 2 is a cross-sectional view schematically showing a multilayer ceramic capacitor in which a second material layer is not exposed on a main surface of the capacitor body. [Figure 4] 1 is a cross-sectional view schematically showing a multilayer ceramic capacitor in which a second material layer protrudes outward beyond the main surface of the capacitor body. [Figure 5] 3 is a flowchart illustrating a method for manufacturing the multilayer ceramic capacitor according to the first embodiment of the present disclosure. [Figure 6] 6 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor according to a second embodiment of the present disclosure. [Figure 7] FIG. 4 is a cross-sectional view schematically showing a state in which a capacitor body and a first via conductor are formed. [Figure 8]10 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor according to a third embodiment of the present disclosure. [Figure 9] 10 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor according to a fourth embodiment of the present disclosure. [Figure 10] 10 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor according to a fifth embodiment of the present disclosure. [Figure 11] 4 is a cross-sectional view schematically showing a state in which the surface of the capacitor body is covered with a mask except for the position where the second material layer is to be formed. FIG. [Figure 12] 10 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor according to a sixth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be shown, and the features of the present disclosure will be specifically described.

[0011] First, an example of the configuration of a multilayer ceramic capacitor manufactured by the manufacturing method of a multilayer ceramic capacitor according to the present disclosure will be described, and then a manufacturing method of the multilayer ceramic capacitor will be described.

[0012] (multilayer ceramic capacitors) Fig. 1 is a plan view of a multilayer ceramic capacitor 100 manufactured by the manufacturing method of the multilayer ceramic capacitor of the present disclosure. Fig. 2 is a cross-sectional view of the multilayer ceramic capacitor 100 taken along line II-II of Fig. 1.

[0013] The multilayer ceramic capacitor 100 includes a capacitor body 1, a first via conductor 5, and a second via conductor 6.

[0014] The capacitor body 1 has a structure in which a plurality of dielectric layers 2, a plurality of first internal electrodes 3, and a plurality of second internal electrodes 4 are laminated. More specifically, the capacitor body 1 has a structure in which the first internal electrodes 3 and the second internal electrodes 4 are alternately laminated with the dielectric layers 2 interposed therebetween.

[0015] The dielectric layer 2 may be made of any material, such as a ceramic material containing BaTiO3, CaTiO3, SrTiO3, SrZrO3, or CaZrO3 as a main component. These main components may contain a minor component such as a Mn compound, an Fe compound, a Cr compound, a Co compound, or a Ni compound, the content of which is less than that of the main component.

[0016] The capacitor body 1 may have any shape. In this embodiment, the capacitor body 1 has a rectangular parallelepiped shape as a whole. A rectangular parallelepiped shape as a whole refers to a shape that is not a perfect rectangular parallelepiped shape, such as a shape in which the corners and ridges of a rectangular parallelepiped are rounded, but has six surfaces and can be regarded as a rectangular parallelepiped as a whole.

[0017] The dimensions of the capacitor body 1 are arbitrary, but for example, the rectangular vertical dimension in plan view can be 0.3 mm to 3.0 mm, the horizontal dimension can be 0.3 mm to 3.0 mm, and the dimension in the stacking direction T of the dielectric layers 2, first internal electrodes 3, and second internal electrodes 4 (hereinafter simply referred to as the stacking direction T) can be 50 μm to 200 μm. The dimension of the capacitor body 1 in the stacking direction T refers to the thickness of the capacitor body 1.

[0018] The first internal electrode 3 and the second internal electrode 4 may be made of any material, and may contain, for example, a metal such as Ni, Cu, Ag, Pd, Pt, Fe, Ti, Cr, Sn, or Au, or an alloy containing such a metal, as a main component. The first internal electrode 3 and the second internal electrode 4 may contain, as a common material, the same ceramic material as the dielectric ceramic contained in the dielectric layer 2. In this case, the proportion of the common material contained in the first internal electrode 3 and the second internal electrode 4 is, for example, 20 vol % or less.

[0019] The thickness of the first internal electrode 3 and the second internal electrode 4 is arbitrary, but can be, for example, about 0.3 μm or more and 1.0 μm or less. The number of layers of the first internal electrode 3 and the second internal electrode 4 is arbitrary, but can be, for example, about 10 layers or more and 150 layers or less in total.

[0020] The first inner electrode 3 has a plurality of first through holes 3a formed therein for inserting a plurality of second via conductors 6 (described later). The second inner electrode 4 has a plurality of second through holes 4a formed therein for inserting a plurality of first via conductors 5 (described later).

[0021] In the multilayer ceramic capacitor 100, a capacitance is formed by the first internal electrode 3 and the second internal electrode 4 facing each other with the dielectric layer 2 interposed therebetween.

[0022] 2, the first via conductors 5 are provided inside the capacitor body 1 and are electrically connected to the plurality of first internal electrodes 3. The first via conductors 5 pass through second through holes 4a formed in the second internal electrodes 4 and are insulated from the second internal electrodes 4.

[0023] 2, the second via conductors 6 are provided inside the capacitor body 1 and are electrically connected to the plurality of second internal electrodes 4. The second via conductors 6 pass through first through holes 3a formed in the first internal electrodes 3 and are insulated from the first internal electrodes 3.

[0024] Each of the first via conductor 5 and the second via conductor 6 includes a first material layer 11 made of a first material and a second material layer 12 made of a second material different from the first material, the second material being primarily composed of one of Sn, Sn-Ag, Sn-Bi, Sn-In, Sn-Ag-Cu, and Au. The "primary component" refers to the component that is most abundant by mass. The second material layer 12 is provided on at least one open end of the first via conductor 5 and the second via conductor 6 in the stacking direction T, where the surface is not covered. In the example shown in FIG. 2, the second material layer 12 is provided on the first principal surface 1a side of the capacitor body 1.

[0025] The first via conductor 5 and the second via conductor 6 are each provided inside the capacitor body 1 so as to extend in the stacking direction T. In the example shown in Fig. 2, the first via conductor 5 and the second via conductor 6 are each exposed on the first main surface 1a of the capacitor body 1, but not on the second main surface 1b. More specifically, the second material layers 12 of the first via conductor 5 and the second via conductor 6 are exposed on the first main surface 1a of the capacitor body 1, but the first material layers 11 are not exposed on the second main surface 1b.

[0026] As shown in FIG. 2, the first principal surface 1a and the second principal surface 1b of the capacitor body 1 are not provided with external electrodes electrically connected to the first via conductors 5 and made of a material different from that of the first via conductors 5, and external electrodes electrically connected to the second via conductors 6 and made of a material different from that of the second via conductors 6. Therefore, the dimensions of the multilayer ceramic capacitor 100 in the stacking direction T are the same as the dimensions of the capacitor body 1. Note that the dimensions of the multilayer ceramic capacitor 100 in the stacking direction T refer to the distance between the outermost portion of the components of the multilayer ceramic capacitor 100 on the first principal surface 1a side and the outermost portion of the components of the multilayer ceramic capacitor 100 on the second principal surface 1b side in the stacking direction T.

[0027] The first material contains, for example, Ni as a main component. The second material contains, as described above, any one of Sn, Sn—Ag, Sn—Bi, Sn—In, Sn—Ag—Cu, and Au as a main component. However, Sn—Ag is an alloy of Sn and Ag, Sn—Bi is an alloy of Sn and Bi, Sn—In is an alloy of Sn and In, and Sn—Ag—Cu is an alloy of Sn, Ag, and Cu. While the above-mentioned Ni is a metal that oxidizes easily, Sn, Sn—Ag, Sn—Bi, Sn—In, Sn—Ag—Cu, and Au are metals with excellent oxidation resistance. Therefore, by providing a second material layer 12 containing any one of Sn, Sn-Ag, Sn-Bi, Sn-In, Sn-Ag-Cu, and Au as a main component at the open end of at least one of the first via conductor 5 and the second via conductor 6, oxidation can be suppressed even when the surface of the second material layer 12 is exposed, enabling highly reliable connection to external electrodes, etc. For example, when the multilayer ceramic capacitor 100 is mounted on lands on a mounting board, the second material layers 12 of the first via conductor 5 and the second via conductor 6 are connected to the lands via solder, etc.

[0028] However, the main component of the first material is not limited to Ni, and may be a metal such as Cu, Ag, Pd, Pt, Fe, Ti, Cr, or Au, or an alloy containing these metals, etc. In other words, the first material may contain at least one of Ni, Cu, Ag, Pd, Pt, Fe, Ti, Cr, and Au as a main component.

[0029] Therefore, there is no need to provide separate external electrodes on the surface of the capacitor body 1, which are electrically connected to the first via conductors 5 and the second via conductors 6, respectively, and are made of a material different from that of the first via conductors 5 and the second via conductors 6, so the dimensions of the capacitor body 1 in the lamination direction T can be made larger than in conventional multilayer ceramic capacitors that have external electrodes. This allows the number of layers of the first internal electrodes 3 and the second internal electrodes 4 to be increased, thereby increasing the capacitance.

[0030] The first via conductors 5 and the second via conductors 6 can be provided at any positions. In this embodiment, as shown in Fig. 1, a plurality of first via conductors 5 and a plurality of second via conductors 6 are provided in a matrix. The number of first via conductors 5 and second via conductors 6 can be any number.

[0031] The first and second via conductors 5 and 6 may have any shape, for example, a cylindrical shape. In this case, the diameter of the first and second via conductors 5 and 6 is, for example, about 30 μm or more and 150 μm or less. The distance between adjacent first and second via conductors 5 and 6, more specifically, the distance L1 (see FIG. 2) between the centers of the first and second via conductors 5 and 6, is, for example, about 50 μm or more and 500 μm or less.

[0032] 3, the second material layer 12 does not have to be exposed on the first main surface 1a of the capacitor body 1. Even in such a configuration, it is possible to connect it to an external electrode or the like using a bonding material such as solder.

[0033] 4, the second material layer 12 may protrude outward in the stacking direction T from the first main surface 1a of the capacitor body 1. However, even in this case, the dimension of the portion of the second material layer 12 protruding outward from the first main surface 1a in the stacking direction T is preferably 5 μm or less. When the dimension of the portion of the second material layer 12 protruding outward from the first main surface 1a is 5 μm or less, the dimension of the capacitor body 1 in the stacking direction T can be increased when the size of the multilayer ceramic capacitor 100 is fixed, and the capacitance can be increased.

[0034] The first material layer 11 may be exposed on the second main surface 1b of the capacitor body 1. The second material layer 12 may be provided not only on the first main surface 1a side of the capacitor body 1 but also on the second main surface 1b side.

[0035] (Manufacturing method of multilayer ceramic capacitors) The method for manufacturing a multilayer ceramic capacitor according to the present disclosure is a method for manufacturing a multilayer ceramic capacitor 100 including a capacitor body 1 formed by stacking a plurality of dielectric layers 2, a plurality of first internal electrodes 3, and a plurality of second internal electrodes 4, first via conductors 5 provided inside the capacitor body 1 and electrically connected to the plurality of first internal electrodes 3, and second via conductors 6 provided inside the capacitor body 1 and electrically connected to the plurality of second internal electrodes 4. The method for manufacturing this multilayer ceramic capacitor includes the steps of forming a first material layer 11 made of a first material to form the first via conductors 5 and the second via conductors 6, and forming a second material layer 12 located at at least one end of the first via conductors 5 and the second via conductors 6 and made of a second material different from the first material, the second material layer 12 containing any one of Sn, Sn—Ag, Sn—Bi, Sn—In, Sn—Ag—Cu, and Au as a main component.

[0036] The method for manufacturing a multilayer ceramic capacitor according to the present disclosure allows for the manufacture of a multilayer ceramic capacitor 100 with a large capacitance. Specifically, the second material constituting the second material layer 12 has excellent oxidation resistance, which prevents oxidation even when the surface is exposed, enabling highly reliable connection to external electrodes, etc. This eliminates the need for separate external electrodes electrically connected to the first via conductors 5 and the second via conductors 6, allowing the dimensions of the capacitor body 1 to be increased when the size of the multilayer ceramic capacitor 100 is fixed. This allows for a larger number of layers of the first internal electrodes 3 and the second internal electrodes 4 to be stacked, thereby increasing the capacitance.

[0037] First Embodiment FIG. 5 is a flowchart illustrating a method for manufacturing the multilayer ceramic capacitor according to the first embodiment of the present disclosure.

[0038] 5, a laminate is produced by laminating a plurality of ceramic green sheets on which internal electrode patterns are formed. Known ceramic green sheets can be used, and can be obtained, for example, by applying a ceramic slurry containing ceramic powder, a resin component, and a solvent onto a substrate and drying it.

[0039] The internal electrode patterns can be formed by applying a conductive paste for internal electrodes to the ceramic green sheets by a method such as printing. An internal electrode pattern that allows a plurality of multilayer ceramic capacitors 100 to be manufactured at once may be formed. In this case, the laminate produced by stacking a plurality of ceramic green sheets on which the internal electrode patterns have been formed is a mother laminate.

[0040] The conductive paste for internal electrodes is a conductive paste for forming the first internal electrodes 3 and the second internal electrodes 4, and a known conductive paste can be used. The conductive paste for internal electrodes contains particles made of a metal such as Ni, Cu, Ag, Pd, Pt, Fe, Ti, Cr, Sn, or Au, or a precursor thereof, and a solvent. The conductive paste for internal electrodes may further contain a resin component that serves as a dispersant or binder.

[0041] The produced laminate is preferably pressed by a method such as a rigid press or a hydrostatic press.

[0042] In step S2 following step S1, holes for forming the first via conductors 5 and the second via conductors 6 are formed in the laminate. The holes can be formed by any method, for example, by irradiating with a laser beam. When manufacturing the multilayer ceramic capacitor 100 shown in FIG. 2, the holes formed are blind holes. In this case, the blind holes may be formed by adjusting the depth of the holes to be formed, or through holes may be formed and then a ceramic green sheet may be attached to one end side of the laminate in the stacking direction T. Note that the holes to be formed may be through holes depending on the shapes of the first via conductors 5 and second via conductors 6 to be formed.

[0043] In step S3 following step S2, the formed holes are filled with a conductive paste for via conductors containing a first material and a second material having a melting point lower than that of the first material. The first material contains, for example, Ni as a main component. As described above, the second material contains one of Sn, Sn-Ag, Sn-Bi, Sn-In, Sn-Ag-Cu, and Au as a main component. The amounts of the first and second materials contained in the conductive paste for via conductors are adjusted so that the ratio of the first material layer 11 to the second material layer 12 in the first via conductors 5 and second via conductors 6 to be formed is as shown in FIG. 2. The conductive paste for via conductors may contain a solvent, a dispersant, a resin component that serves as a binder, and the like.

[0044] After the mother laminate is produced, the holes of the mother laminate are filled with the conductive paste for via conductors, and the mother laminate is cut into individual pieces of a predetermined size by a cutting method such as press cutting, dicing, or laser cutting.

[0045] In step S4 following step S3, the laminate with the holes filled with the conductive paste for via conductors is fired to form the first material layer 11 and the second material layer 12 together with the capacitor body 1. That is, the firing causes the second material, which has a lower melting point than the first material, to appear on the surface side, thereby forming via conductors as shown in Fig. 2, i.e., the first via conductor 5 and the second via conductor 6, each including the first material layer 11 and the second material layer 12 located closer to the surface of the capacitor body 1 than the first material layer 11. That is, in this embodiment, step S4 is a process of forming the first material layer 11 and the second material layer 12.

[0046] Through the above-described steps, the multilayer ceramic capacitor 100 is manufactured.

[0047] When the multilayer ceramic capacitor 100 is manufactured using the above-described method, the first material layer 11 and the second material layer 12 do not form a neat two-layer structure as shown in FIG. 2, but are formed in such a manner that Ni is mainly present on the inside and Sn is mainly present on the outside.

[0048] As described above, the method for manufacturing a multilayer ceramic capacitor according to this embodiment does not include the step of separately providing external electrodes electrically connected to the first via conductors 5 and the second via conductors 6, respectively, and can increase the dimensions of the capacitor body 1, thereby manufacturing a multilayer ceramic capacitor 100 with a large capacitance. Furthermore, by firing a laminate in which holes are filled with a conductive paste for via conductors containing a first material and a second material having a melting point lower than that of the first material, the first material layer 11 and the second material layer 12 can be formed at the same time as the capacitor body 1, thereby simplifying the manufacturing process compared to a method in which the first material layer 11 and the second material layer 12 are formed separately.

[0049] <Second embodiment> In the method for manufacturing the multilayer ceramic capacitor according to the first preferred embodiment, the first material layer 11 and the second material layer 12 are simultaneously formed by firing an unfired laminate.

[0050] In contrast, in the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, the first material layer 11 is formed, and then the second material layer 12 is formed.

[0051] Fig. 6 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor according to a second embodiment of the present disclosure. Among the processes in the flowchart shown in Fig. 6, the same processes as those in the flowchart shown in Fig. 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0052] In step S1 of FIG. 6, a plurality of ceramic green sheets on which internal electrode patterns are formed are stacked to form a laminate.

[0053] In step S2 following step S1, holes for forming the first via conductors 5 and the second via conductors 6 are formed in the laminate.

[0054] In step S11 following step S2, the formed holes are filled with a conductive paste for via conductors containing a first material. The first material contains, for example, Ni as a main component. The conductive paste for via conductors may be filled up to the surface of the laminate, or may be filled up to a position inside the surface of the laminate in the stacking direction T. After the conductive paste for via conductors is filled into the holes, it may be pressed to provide a space for forming a second material layer 12.

[0055] In step S12 following step S11, the laminate with the holes filled with the conductive paste for via conductors is fired. By firing the laminate, the first material layer 11 is formed along with the capacitor body 1. That is, in this embodiment, step S12 is the step of forming the first material layer 11.

[0056] In either case, when the conductive paste for via conductors is filled up to the surface of the laminate, or when it is filled up to a position inside the surface of the laminate in the stacking direction T, the end of the first material layer 11 formed by firing is located inside the surface of the capacitor body 1 in the stacking direction T. In other words, even when the conductive paste for via conductors is filled up to the surface of the laminate, the end of the first material layer 11 formed by firing will be located inside the surface of the capacitor body 1 due to shrinkage caused by firing. In order to increase the amount of shrinkage caused by firing, the amount of components that disappear during firing may be increased by increasing the content of resin components in the conductive paste for via conductors.

[0057] In step S13 following step S12, a second material layer 12 is formed on the end of the first material layer 11. In this embodiment, the second material layer 12 is formed by placing a second material on the end of the first material layer 11 and heating it. As described above, the end of the first material layer 11 formed by firing is located inside the surface of the capacitor body 1, so a recess 20 is formed at the position where the first material layer 11 is formed, recessed inside the surface of the capacitor body 1 (see FIG. 7). A second material is placed in this recess 20 and heated to melt it, thereby forming a second material layer 12 connected to the first material layer 11.

[0058] Through the above-described steps, the multilayer ceramic capacitor 100 is manufactured.

[0059] According to the method for manufacturing the multilayer ceramic capacitor of the second embodiment, a conductive paste for via conductors containing a first material is filled into holes in the laminate and fired to form the first material layer 11 together with the capacitor body 1, and then the second material layer 12 is formed at the end of the first material layer 11, so that the second material layer 12 can be more reliably formed after the formation of the first material layer 11. Furthermore, the second material layer 12 is formed by disposing the second material at the end of the first material layer 11 and heating it, so that a strong second material layer 12 connected to the first material layer 11 can be formed.

[0060] <Third embodiment> In the method for manufacturing the multilayer ceramic capacitor according to the third embodiment, similarly to the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, a first material layer 11 is formed, and then a second material layer 12 is formed. The method for manufacturing the multilayer ceramic capacitor according to the third embodiment differs from the method for manufacturing the multilayer ceramic capacitor according to the second embodiment in the step of forming the second material layer 12.

[0061] Fig. 8 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor according to a third embodiment of the present disclosure. Among the processes in the flowchart shown in Fig. 8, the same processes as those in the flowchart shown in Fig. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0062] The processes from step S1 to step S12 in the flowchart shown in Fig. 8 are the same as the processes from step S1 to step S12 in the flowchart shown in Fig. 6. In step S21 following step S12, a second material layer 12 is formed on the end of the first material layer 11. In this embodiment, the second material layer 12 is formed by spraying a paste containing the second material in atomized form onto the surface of the capacitor body 1 and heating the paste attached to the end of the first material layer 11.

[0063] The paste containing the second material is, for example, a paste containing Sn. For example, the paste containing the second material can be atomized and sprayed by applying a voltage to a spray gun or the like. When the paste containing the second material is atomized and sprayed onto the capacitor body 1, the charged paste particles adhere to the end of the first material layer 11 due to static electricity. Then, the paste attached to the end of the first material layer 11 is heated and melted to form the second material layer 12 connected to the first material layer 11.

[0064] Like the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, the method for manufacturing the multilayer ceramic capacitor according to the third embodiment can more reliably form the second material layer 12 after forming the first material layer 11. Furthermore, the second material layer 12 is formed by spraying a mist of paste containing the second material onto the surface of the capacitor body 1 and heating the paste attached to the end of the first material layer 11, so that a strong second material layer 12 connected to the first material layer 11 can be formed.

[0065] <Fourth embodiment> In the method for manufacturing the multilayer ceramic capacitor according to the fourth embodiment, similarly to the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, a first material layer 11 is formed, and then a second material layer 12 is formed. The method for manufacturing the multilayer ceramic capacitor according to the fourth embodiment differs from the method for manufacturing the multilayer ceramic capacitor according to the second embodiment in the step of forming the second material layer 12.

[0066] Fig. 9 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor according to a fourth embodiment of the present disclosure. Among the processes in the flowchart shown in Fig. 9, the same processes as those in the flowchart shown in Fig. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0067] The processes from step S1 to step S12 in the flowchart shown in Fig. 9 are the same as the processes from step S1 to step S12 in the flowchart shown in Fig. 6. In step S31 following step S12, a second material layer 12 is formed on the end portion of the first material layer 11. In this embodiment, the capacitor body 1 is immersed in a molten bath containing the second material, thereby adhering the second material to the end portion of the first material layer 11 to form the second material layer 12.

[0068] That is, a melting tank containing melted second material is prepared, and the capacitor body 1 is immersed in the melting tank. As a result, the melted second material adheres only to the end of the conductive first material layer 11. After that, by cooling, the second material layer 12 connected to the first material layer 11 is formed.

[0069] Like the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, the method for manufacturing the multilayer ceramic capacitor according to the fourth embodiment also makes it possible to more reliably form the second material layer 12 after forming the first material layer 11. Furthermore, by immersing the capacitor body 1 in a molten tank containing the melted second material, the second material is adhered to the end of the first material layer 11 to form the second material layer 12, so that a strong second material layer 12 connected to the first material layer 11 can be formed.

[0070] <Fifth embodiment> In the method for manufacturing the multilayer ceramic capacitor according to the fifth embodiment, similarly to the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, a first material layer 11 is formed, and then a second material layer 12 is formed. The method for manufacturing the multilayer ceramic capacitor according to the fifth embodiment differs from the method for manufacturing the multilayer ceramic capacitor according to the second embodiment in the step of forming the second material layer 12.

[0071] The processes from step S1 to step S12 in the flowchart shown in Fig. 10 are the same as the processes from step S1 to step S12 in the flowchart shown in Fig. 6. In step S41 following step S12, a second material layer 12 is formed on the end portion of the first material layer 11. In this embodiment, the second material layer 12 is formed by depositing a second material on the end portion of the first material layer 11 by vapor deposition.

[0072] 11, for example, the surface of the capacitor body 1 is covered with a mask 30 except for the positions where the second material layer 12 is to be formed. In the example shown in FIG. 11, the second main surface 1b of the capacitor body 1 is the surface that comes into contact with the mounting table on which the capacitor body 1 is to be placed, and is therefore not covered with the mask 30, but it may be covered with the mask 30. Next, the second material is evaporated in a vacuum furnace to adhere to the end portions of the first material layer 11 that are not covered with the mask 30, thereby forming the second material layer 12. Then, the mask 30 is removed.

[0073] Like the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, the method for manufacturing the multilayer ceramic capacitor according to the fifth embodiment also makes it possible to more reliably form the second material layer 12 after forming the first material layer 11. Furthermore, since the second material layer 12 is formed by attaching the second material to the end portion of the first material layer 11 by vapor deposition, it is possible to form the second material layer 12 having a uniform dimension in the stacking direction T.

[0074] Sixth Embodiment In the method for manufacturing the multilayer ceramic capacitor according to the sixth embodiment, similarly to the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, a first material layer 11 is formed, and then a second material layer 12 is formed. The method for manufacturing the multilayer ceramic capacitor according to the sixth embodiment differs from the method for manufacturing the multilayer ceramic capacitor according to the second embodiment in the step of forming the second material layer 12.

[0075] 12 are the same as steps S1 to S12 in the flowchart shown in FIG. 6. In step S51 following step S12, a second material layer 12 is formed on the end of the first material layer 11. In this embodiment, the second material layer 12 is formed by performing an electroless plating process. That is, the capacitor body 1 is immersed in a plating solution in which the second material is dissolved, and the second material is deposited on the end of the first material layer 11, thereby forming the second material layer 12.

[0076] Like the method for manufacturing the multilayer ceramic capacitor according to the second embodiment, the method for manufacturing the multilayer ceramic capacitor according to the sixth embodiment also makes it possible to more reliably form the second material layer 12 after forming the first material layer 11. Furthermore, since the second material layer 12 is formed by performing an electroless plating process, the second material layer 12 can be easily formed by simply immersing the capacitor body 1 in a plating solution in which the second material has been dissolved.

[0077] The present disclosure is not limited to the above-described embodiments, and various applications and modifications can be made within the scope of the present disclosure. For example, the method for forming the second material layer 12 on the end portion of the first material layer 11 is not limited to the methods described in the second to sixth embodiments, and other methods are also possible.

[0078] After forming the first material layer 11 and the second material layer 12 together with the capacitor body 1 by the manufacturing method of the multilayer ceramic capacitor in the first embodiment, a step of forming the second material layer 12 in the second to sixth embodiments may be further carried out.

[0079] The method for manufacturing a multilayer ceramic capacitor in the present application is as follows. <1> A method for manufacturing a multilayer ceramic capacitor including: a capacitor body in which a plurality of dielectric layers, a plurality of first internal electrodes, and a plurality of second internal electrodes are laminated; first via conductors provided inside the capacitor body and electrically connected to a plurality of the first internal electrodes; and second via conductors provided inside the capacitor body and electrically connected to a plurality of the second internal electrodes, A method for manufacturing a multilayer ceramic capacitor, comprising: a step of forming a first material layer made of a first material to form the first via conductor and the second via conductor; and a step of forming a second material layer made of a second material that is different from the first material and contains any one of Sn, Sn--Ag, Sn--Ag--Cu, and Au as a main component, and is located at at least one end of the first via conductor and the second via conductor. <2> a step of laminating a plurality of ceramic green sheets on which internal electrode patterns are formed to prepare a laminate; forming holes in the laminate for forming the first via conductor and the second via conductor; filling the holes with a conductive paste for via conductors, the conductive paste including the first material and the second material having a melting point lower than that of the first material; Equipped with In the step of forming the first material layer and the step of forming the second material layer, the laminate in which the via conductor conductive paste is filled in the holes is fired to form the first material layer and the second material layer together with the capacitor body. <1> 10. A method for manufacturing the multilayer ceramic capacitor according to claim 9. <3> a step of laminating a plurality of ceramic green sheets on which internal electrode patterns are formed to prepare a laminate; forming holes in the laminate for forming the first via conductor and the second via conductor; filling the holes with a conductive paste for via conductors containing the first material; Equipped with In the step of forming the first material layer, the laminate in which the via conductor conductive paste is filled in the holes is fired to form the first material layer together with the capacitor body; In the step of forming the second material layer, the second material layer is formed on an end portion of the first material layer. <1> 10. A method for manufacturing the multilayer ceramic capacitor according to claim 9. <4> In the step of forming the second material layer, the second material is disposed and heated to form the second material layer. <1> ~ <3> 10. The method for manufacturing a multilayer ceramic capacitor according to claim 9, wherein the multilayer ceramic capacitor is a ceramic capacitor having a thickness of 1000 .mu.m.times. ... <5> In the step of forming the second material layer, a paste containing the second material is atomized and sprayed onto the surface of the capacitor body, and the adhered paste is heated to form the second material layer. <1> ~ <3> 10. The method for manufacturing a multilayer ceramic capacitor according to claim 9, wherein the multilayer ceramic capacitor is a ceramic capacitor having a thickness of 1000 .mu.m.times. ... <6> In the step of forming the second material layer, the second material is deposited by immersing the capacitor body in a molten layer of the second material, thereby forming the second material layer. <1> ~ <3> 10. The method for manufacturing a multilayer ceramic capacitor according to claim 9, wherein the multilayer ceramic capacitor is a ceramic capacitor having a thickness of 1000 .mu.m.times. ... <7> In the step of forming the second material layer, the second material layer is formed by depositing the second material by vapor deposition. <1> ~ <3> 10. The method for manufacturing a multilayer ceramic capacitor according to claim 9, wherein the multilayer ceramic capacitor is a ceramic capacitor having a thickness of 1000 .mu.m.times. ... <8> In the step of forming the second material layer, the second material layer is formed by performing an electroless plating process. <1> ~ <3> 10. The method for manufacturing a multilayer ceramic capacitor according to claim 9, wherein the multilayer ceramic capacitor is a ceramic capacitor having a thickness of 1000 .mu.m.times. ... <9> the first material contains at least one of Ni, Cu, Ag, Pd, Pt, Fe, Ti, Cr, and Au as a main component; <1> ~ <8> 10. The method for manufacturing a multilayer ceramic capacitor according to claim 9, wherein the multilayer ceramic capacitor is a ceramic capacitor having a thickness of 1000 .mu.m.times. ...

[0080] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0081] 1. Capacitor body 2. Dielectric layer 3 First inner electrode 4 Second internal electrode 5 First via conductor 6 Second via conductor 11 First material layer 12 Second material layer 20 recess 30 Mask 100 Multilayer ceramic capacitors

Claims

1. A method for manufacturing a multilayer ceramic capacitor including: a capacitor body in which a plurality of dielectric layers, a plurality of first internal electrodes, and a plurality of second internal electrodes are laminated; first via conductors provided inside the capacitor body and electrically connected to a plurality of the first internal electrodes; and second via conductors provided inside the capacitor body and electrically connected to a plurality of the second internal electrodes, The method includes the steps of: forming a first material layer made of a first material to form the first via conductor and the second via conductor; and forming a second material layer made of a second material that is different from the first material and contains any one of Sn, Sn—Ag, Sn—Bi, Sn—In, Sn—Ag—Cu, and Au as a main component, and that is located at at least one end of the first via conductor and the second via conductor; The method for manufacturing the multilayer ceramic capacitor further comprises: a step of laminating a plurality of ceramic green sheets on which internal electrode patterns are formed to prepare a laminate; forming holes in the laminate for forming the first via conductors and the second via conductors; filling the holes with a conductive paste for via conductors, the conductive paste including the first material and the second material having a melting point lower than that of the first material; and In the process of forming the first material layer and the process of forming the second material layer, the laminate in which the conductive paste for via conductors is filled in the holes is fired to form the first material layer and the second material layer together with the capacitor body.

2. 2. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein in the step of forming the second material layer, the second material layer is formed by disposing and heating the second material.

3. 2. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein in the step of forming the second material layer, the second material layer is formed by spraying a paste containing the second material in a mist form onto the surface of the capacitor body and heating the paste adhered to the end of the first material layer.

4. 2. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein in the step of forming the second material layer, the second material is adhered by immersing the capacitor body in a molten tank containing the melted second material, thereby forming the second material layer.

5. 2. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein in the step of forming the second material layer, the second material layer is formed by depositing the second material by vapor deposition.

6. 2. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein in the step of forming the second material layer, the second material layer is formed by performing an electroless plating process.

7. 7. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein the first material contains at least one of Ni, Cu, Ag, Pd, Pt, Fe, Ti, Cr, and Au as a main component.

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