JP2017034146A - Manufacturing method of multilayer ceramic electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer ceramic electronic component in which both moisture resistance reliability and compaction are made compatible by a base electrode layer, while suppressing occurrence of crack by a conductive resin layer.SOLUTION: In a manufacturing method of a multilayer ceramic capacitor 10 including a laminate 20, and a pair of external electrodes 140a, 140b including a base electrode layer 142 formed at the first and second end faces 26a, 26b of the laminate 20, and a conductive resin layer 144 formed on the surface of the base electrode layer 142, a step of applying a base electrode layer paste 280 includes a paste storage section 220 filled with a lower electrode layer paste 280, a plurality of recesses 230 are formed in the bottom face 222 of the paste storage section 220, and a step of preparing a platen 210, where a treatment film 240 is formed only on the inner surface of the plurality of recesses 230, is included.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method for manufacturing a multilayer ceramic electronic component.

  In recent years, a multilayer ceramic electronic component (for example, a multilayer ceramic capacitor) has been used in a harsher environment as compared with the conventional one. Therefore, it is required to withstand such an environment. For example, multilayer ceramic electronic components used in mobile devices such as mobile phones and portable music players are required not to fall off the mounting substrate even when subjected to an impact at the time of dropping, and to be free from cracks. In addition, multilayer ceramic electronic components used in in-vehicle devices such as EUC are subjected to impacts (for example, bending stress generated by linear expansion / contraction of the mounting substrate, tensile stress applied to the external electrode, etc.) generated during thermal cycling. However, it is required that cracks do not occur.

  For the purpose of meeting the above-described requirements, a technique has been proposed in which an external electrode including a conductive thermosetting resin layer is provided to relieve stress received from a mounting substrate or the like. An example of such a multilayer ceramic electronic component is the multilayer ceramic capacitor disclosed in Patent Document 1.

  The multilayer ceramic capacitor of Patent Document 1 includes a baked electrode layer connected to an internal electrode and a thermosetting resin layer formed on the surface of the baked electrode layer. The baked electrode layer has a function of ensuring moisture resistance reliability, and the thermosetting resin layer has a function of suppressing cracks.

  Here, the size of the multilayer ceramic electronic component has been further reduced. Therefore, a multilayer ceramic capacitor having a thermosetting resin layer as in Patent Document 1 is also required to have good moisture resistance reliability and a crack suppression function in the chip size.

  When miniaturizing a multilayer ceramic electronic component, it is conceivable to reduce the thickness of the external electrode. In such a case, in the multilayer ceramic capacitor as in Patent Document 1, it is necessary to secure the thickness of the main thermosetting resin layer to some extent, so that the baking electrode layer is thinned. Here, the multilayer ceramic capacitor as in Patent Document 1 has a trade-off relationship that the size of the baked electrode layer decreases as the thickness of the baked electrode layer decreases, but the moisture resistance reliability decreases.

  In order to avoid such a trade-off relationship, a base electrode layer capable of ensuring moisture resistance reliability at a portion where moisture easily enters on the surface of the laminate (corresponding to “capacitor body” in Patent Document 1) (Patent Document) 1) (corresponding to “baked electrode layer”). FIG. 12 is a cross-sectional view showing the thickness of a base electrode layer formed on the surface of a multilayer body included in a conventional multilayer ceramic electronic component. In the base electrode layer 3 formed on the end surface 2 of the multilayer body 1, the portion where moisture is most likely to enter is the outermost portion 4 where the internal electrode 6 closest to the main surface is located. That is, forming the flat base electrode layer 3 having the same thickness at the outermost portion 4 and the central portion 5 is an ideal state in which both moisture resistance reliability and miniaturization are achieved.

  FIG. 13 is a schematic view showing a state in which the base electrode layer paste is applied to the end face of the laminate by the dipping method described in Patent Document 2, and (A) immerses the laminate in the base electrode layer paste. It is the state in the middle of pulling up after making it, and (B) is a figure which shows the state pulled up after making a laminated body immerse in the paste for base electrode layers. Conventionally, there is a dipping method as described in Patent Document 2 as a method conventionally used for forming an external electrode. However, in the dipping method as in Patent Document 2, as shown in FIG. 13A, when pulling up the laminated body 1 (corresponding to the “electronic component body” in Patent Document 2), the center of the end surface 2 of the laminated body 1 is used. A force toward the portion 5 is applied to the base electrode layer paste 7 (corresponding to “conductive paste” in Patent Document 2). Therefore, as shown in FIG. 13B, the external electrode formed by the dipping method has a thick dome shape at the central portion 5 of the end face 2 and a thin portion at the other portions as compared with the central portion 5. In other words, the external electrode formed by the dipping method does not achieve both the moisture resistance reliability and the downsizing as described above.

  Therefore, Patent Document 3 discloses a method for manufacturing an electronic component for the purpose of forming a terminal electrode having a uniform film thickness. FIG. 14 is a schematic view showing a state in which a base electrode layer paste is applied and formed on the end face of the laminate by the method for manufacturing an electronic component of Patent Document 3, and the base electrode layer paste filled with (A) is laminated. It is a figure which shows the state where the end surface of the body was immersed, and the state where (B) pulled up the layered product. In Patent Document 3, a base electrode layer paste 7 (corresponding to the “metallized paste film” in Patent Document 3) is formed on a support having a roughened surface, and a laminate 1 (“Lamination” in Patent Document 3). It is described that the base electrode layer paste 7 is applied and formed on the end surface 2 of the laminate 1 by dipping the end surface 2 until the end surface 2 comes into contact with the convex portion of the support and pulling it up. Yes.

Japanese Patent Application Laid-Open No. 11-162771 JP 2002-151367 A JP-A-8-273972

  FIG. 15 is a schematic view showing a state in which the base electrode layer paste is applied and formed on the end face of the laminate by the manufacturing method of Patent Document 3, wherein (A) shows a state immediately after the application and formation, and (B) shows a fixed time. This is the state after elapse. Here, the paste used for forming the external electrode generally has a low viscosity. Therefore, even if the base electrode layer paste 7 having a uniform film thickness is applied and formed on the end face 2 of the laminate 1 as shown in FIG. The central portion 5 of the end face 2 becomes gradually thicker. Then, after a predetermined time has elapsed, the base electrode layer paste 7 eventually has a thick dome shape at the center portion 5 of the end face 2 as compared with other portions as shown in FIG.

  FIG. 16 is a schematic view showing a state in which a paste having a high viscosity is applied and formed on the end face of the laminate by the manufacturing method of Patent Document 3. In order to suppress the shape change of the base electrode layer paste 7 due to the surface tension as described above, it is conceivable to increase the viscosity of the base electrode layer paste 7. However, if the viscosity of the base electrode layer paste 7 is increased, when the laminate 1 is pulled up, the base electrode layer paste 7 falls or the transferability is lowered. As a result, there is a concern that even the laminated body 1 to which the high-viscosity base electrode layer paste 7 is applied may not have a uniform film thickness, as shown in FIG. It will not be in the state.

  SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a multilayer ceramic electronic component that is compatible with moisture resistance reliability and miniaturization by a base electrode layer while suppressing the generation of cracks by a conductive resin layer.

The method for manufacturing a multilayer ceramic electronic component according to the present invention is formed in a rectangular parallelepiped shape by alternately laminating a plurality of ceramic layers and a plurality of internal electrodes, and the first main surface and the second main surface facing each other in the laminating direction. A main surface, a first side surface and a second side surface facing each other in the width direction orthogonal to the stacking direction, and a stack including the first end surface and the second end surface facing each other in the length direction orthogonal to the stacking direction and the width direction A base electrode layer formed to be electrically connected to the internal electrode at the first and second end faces of the laminate, and a thermosetting resin and a conductive metal formed on the surface of the base electrode layer A method of manufacturing a multilayer ceramic electronic component comprising a pair of external electrodes including a conductive resin layer including a plurality of ceramic green sheets having internal electrode patterns formed thereon Forming a laminated body block, cutting the laminated body block to prepare a raw laminated body, firing the raw laminated body to prepare the laminated body, and at least a first of the laminated body And a step of applying a base electrode layer paste on the second end face, a step of baking a laminate coated with the base electrode layer paste to form a base electrode layer, and a conductive resin layer on the surface of the base electrode layer And the step of applying the base electrode layer paste includes a paste storage unit filled with the base electrode layer paste, and a plurality of recesses are formed on the bottom surface of the paste storage unit, and a plurality of recesses are formed. The method includes a step of preparing a surface plate in which a treatment film is formed only on the inner surface of the recess, and a step of pressing the first and second end surfaces of the laminated body against the bottom surface of the paste storage unit.
Preferably, the step of forming the conductive resin layer includes a step of applying a paste for a conductive resin layer containing a thermosetting resin and a conductive metal to the surface of the base electrode layer, and a thermosetting by performing a heat treatment. Curing the functional resin.
Preferably, the treatment film is formed from 20% to 80% of the height dimension of the side surface from the bottom surface of the inner surface of the recess.
Preferably, the treatment film is formed of a film made of Teflon (registered trademark), a film containing a silane coupling agent, a film containing a silicone compound or a fluorine compound.

  The method for manufacturing a multilayer ceramic electronic component according to the present invention provides oil repellency to a plurality of recesses by using a surface plate provided with a paste storage part in which a treatment film is formed only on the inner surfaces of the plurality of recesses formed on the bottom surface. Can be granted. Therefore, the transferability of the base electrode layer paste to the laminated body is improved, and the moisture content of the base electrode layer formed on the first and second end faces of the laminated body is the highest without changing the viscosity of the base electrode layer paste. Can sufficiently secure the thickness of the outermost portion (a portion where the first and second internal electrodes closest to the main surface at the first and second end faces are located). That is, since the base electrode layer paste can be applied to the first and second end faces of the laminate with a uniform thickness, the base electrode layer can achieve both moisture resistance reliability and miniaturization. Furthermore, the formation of a conductive resin layer on the surface of the base electrode layer can also suppress the occurrence of cracks in the multilayer ceramic electronic component.

  According to the present invention, it is possible to manufacture a multilayer ceramic electronic component that is compatible with moisture resistance reliability and downsizing by the base electrode layer while suppressing the generation of cracks by the conductive resin layer.

  The above-described object, other objects, features, and advantages of the present invention will become more apparent from the following description of embodiments for carrying out the invention with reference to the drawings.

1 is an external perspective view showing a multilayer ceramic capacitor manufactured by a manufacturing method according to an embodiment of the present invention. It is II-II sectional drawing of FIG. 1 which shows the laminated ceramic capacitor manufactured by the manufacturing method which concerns on one embodiment of this invention. It is sectional drawing which shows the surface plate used with the manufacturing method which concerns on one embodiment of this invention. It is a cross-sectional perspective view of the recessed part formed in the surface plate used with the manufacturing method which concerns on one embodiment of this invention. It is sectional drawing which shows a mode that the process film was formed in the inner surface of the recessed part formed in the surface plate used with the manufacturing method which concerns on one embodiment of this invention. It is sectional drawing which shows a mode that after forming the process film in the inner surface of the recessed part formed in the surface plate used with the manufacturing method which concerns on one embodiment of this invention, it filled with the paste for base electrode layers. It is sectional drawing which shows a mode that the jig | tool holding the some laminated body was arrange | positioned above the surface plate used with the manufacturing method which concerns on one embodiment of this invention. It is sectional drawing which shows a mode that the end surface of the laminated body was pressed on the bottom face of the paste storage part with which the surface plate used with the manufacturing method which concerns on one embodiment of this invention is equipped. In the manufacturing method which concerns on one embodiment of this invention, it is sectional drawing which shows a mode when the paste for base electrode layers is apply | coated to the end surface of a some laminated body. In the manufacturing method which concerns on one embodiment of this invention, it is an expanded sectional view of the end surface vicinity when the paste for base electrode layers is apply | coated to the end surface of a laminated body. It is sectional drawing which shows a mode that the process film was formed in the inner surface whole region of the recessed part formed in the paste storage part in the manufacturing method which concerns on one embodiment of this invention. It is sectional drawing which shows the thickness of the base electrode layer formed in the surface of the laminated body with which the conventional multilayer ceramic electronic component is provided. It is the schematic which shows a mode that the paste for base electrode layers is apply | coated to the surface of a laminated body by the immersion method described in patent document 2, (A) pulls up after immersing a laminated body in the paste for base electrode layers It is a figure in the middle, (B) is a figure which shows the state pulled up, after immersing a laminated body in the paste for base electrode layers. It is the schematic which shows a mode that the paste for base electrode layers is applied and formed in the end surface of a laminated body by the manufacturing method of patent document 3, and the end surface of the laminated body was immersed in the paste for base electrode layers with which (A) was filled. It is a figure which shows the state which pulled up the laminated body in the state and (B). It is the schematic which shows a mode that the paste for base electrode layers was apply | coated to the end surface of a laminated body by the manufacturing method of patent document 3, (A) is the state immediately after apply | coating, (B) is the state which fixed time passed after application | coating. FIG. It is the schematic which shows a mode that the paste with high viscosity was apply | coated and formed on the end surface of a laminated body by the manufacturing method of patent document 3. FIG.

1. Multilayer Ceramic Electronic Component Hereinafter, a multilayer ceramic electronic component manufactured by a manufacturing method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view showing a multilayer ceramic capacitor manufactured by a manufacturing method according to an embodiment of the present invention. 2 is a cross-sectional view taken along the line II-II of FIG. 1 showing the multilayer ceramic capacitor manufactured by the manufacturing method according to one embodiment of the present invention.

  Here, the multilayer ceramic capacitor 10 manufactured by the manufacturing method according to one embodiment of the present invention will be described. The multilayer ceramic capacitor 10 includes a multilayer body 20 and a first external electrode 140a and a second external electrode 140b (a pair of external electrodes).

(Laminated body 20)
The multilayer body 20 is formed in a rectangular parallelepiped shape by laminating a plurality of ceramic layers 30, and a plurality of first internal electrodes 40a and second internal electrodes 40b, and is opposed to the first in the stacking (T) direction. Main surface 22a and second main surface 22b, first side surface 24a and second side surface 24b opposed in the width (W) direction orthogonal to the T direction, and length orthogonal to the T direction and W direction (L The first end face 26a and the second end face 26b are opposed in the direction).

  Here, the rectangular parallelepiped shape of the laminate 20 is a general shape including the first and second main faces 22a and 22b, the first and second side faces 24a and 24b, and the first and second end faces 26a and 26b. I mean. For example, it is preferable that the laminated body 20 has roundness in the corner part and the ridge part. Further, the laminate 20 has irregularities formed on part or all of the first and second main surfaces 22a and 22b, the first and second side surfaces 24a and 24b, and the first and second end surfaces 26a and 26b. May be.

(Ceramic layer 30)
The ceramic layer 30 is laminated in the T direction so as to be sandwiched between the first internal electrode 40a and the second internal electrode 40b. The thickness of the ceramic layer 30 is preferably about 0.5 μm to 10 μm.

As the ceramic material of the ceramic layer 30, for example, a dielectric ceramic made of a main component such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , CaZrO ₃ can be used. In addition, you may add subcomponents, such as a Mn compound, Fe compound, Cr compound, Co compound, Ni compound, to these main components.

  When the multilayer ceramic electronic component is a piezoelectric component, the multilayer body 20 can be formed of piezoelectric ceramics. Examples of the piezoelectric ceramic include a PZT (lead zirconate titanate) ceramic. When the multilayer ceramic electronic component is a thermistor, the multilayer body 20 can be formed of semiconductor ceramics. Examples of semiconductor ceramics include spinel ceramics. Furthermore, when the multilayer ceramic electronic component is an inductor, the multilayer body 20 can be formed of magnetic ceramics. Examples of magnetic ceramics include ferrite ceramics.

(First and second internal electrodes 40a and 40b)
The first internal electrode 40 a extends in a flat plate shape at the interface of the ceramic layer 30, and its end is exposed at the first end surface 26 a of the multilayer body 20. On the other hand, the second internal electrode 40b extends in a flat plate shape at the interface of the ceramic layer 30 so as to face the first internal electrode 40a via the ceramic layer 30, and its end is exposed to the second end face 26b. To do. Accordingly, the first and second internal electrodes 40a, 40b include a facing portion that faces each other with the ceramic layer 30 interposed therebetween, and a lead portion that is led out to the first or second end face 26a, 26b. The first internal electrode 40a and the second internal electrode 40b are opposed to each other with the ceramic layer 30 interposed therebetween, thereby generating a capacitance. The thickness of the first and second internal electrodes 40a, 40b is preferably about 0.2 μm or more and 2.0 μm or less.

  The first and second internal electrodes 40a and 40b are made of a suitable conductive material such as a metal such as Ni, Cu, Ag, Pd, or Au, an Ag—Pd alloy, or an alloy containing at least one of these metals. It can be made of a material.

(First and second external electrodes 140a and 140b)
The first external electrode 140a extends from the first end face 26a of the multilayer body 20 to a part of each of the first and second main faces 22a and 22b and a part of each of the first and second side faces 24a and 24b. And is electrically connected to the first internal electrode 40a at the first end face 26a. On the other hand, the second external electrode 140b extends from the second end surface 26b of the stacked body 20 to a part of each of the first and second main surfaces 22a and 22b and each of the first and second side surfaces 24a and 24b. It is formed so as to reach a part, and is electrically connected to the second internal electrode 40b at the second end face 26b.

(First and second external electrodes 140a and 140b)
Each of the first and second external electrodes 140a and 140b has a multilayer structure including a base electrode layer 142, a conductive resin layer 144, and an upper electrode layer 146. The first and second external electrodes 140a and 140b may not include the upper electrode layer 146.

(Base electrode layer 142)
The base electrode layer 142 is formed on the first or second end face 26a, 26b of the multilayer body 20 so as to be connected to the lead portions of the first and second internal electrodes 40a, 40b. The base electrode layer 142 is formed from the first or second end face 26a, 26b of the stacked body 20, a part of each of the first and second main faces 22a, 22b, and each of the first and second side faces 24a, 24b. It is preferable to be formed so as to reach a part of. The base electrode layer 142 may be formed only on the first or second end face 26a, 26b of the stacked body 20. The thickness of the thickest portion of the base electrode layer 142 is preferably, for example, 10 μm or more and 50 μm or less.

  The base electrode layer 142 is formed, for example, by applying and baking a conductive paste containing a conductive metal and glass. As the conductive metal, for example, Cu, Ni, Ag, Pd, Ag-Pd alloy, Au, or the like can be used. As the glass, for example, glass containing B, Si, Ba, Mg, Al, Li, or the like can be used. The base electrode layer 142 is formed by applying and baking a base electrode layer paste on the laminate 20.

(Conductive resin layer 144)
The conductive resin layer 144 is formed on the surface so as to cover the base electrode layer 142. Specifically, the conductive resin layer 144 is formed on the surface of the base electrode layer 142 formed on the first or second end face 26a, 26b of the multilayer body 20, and from there, the first and second main layers are formed. It is preferably formed so as to reach the surface of the base electrode layer 142 formed on a part of each of the surfaces 22a and 22b and a part of each of the first and second side surfaces 24a and 24b. The conductive resin layer 144 may be formed only on the surface of the base electrode layer 142 formed on the first or second end face 26a, 26b of the stacked body 20. The thickness of the conductive resin layer 144 is preferably 10 μm or more and 150 μm or less, for example.

  The conductive resin layer 144 includes a thermosetting resin and a conductive metal.

  As the thermosetting resin included in the conductive resin layer 144, for example, a known thermosetting resin such as an epoxy resin, a phenol resin, a urethane resin, a silicone resin, or a polyimide resin can be used. In particular, the epoxy resin is excellent in heat resistance, moisture resistance, adhesion, and the like, and is one of the most suitable resins.

  The conductive resin layer 144 preferably contains a curing agent together with the thermosetting resin. As a curing agent for the epoxy resin, for example, a known compound such as phenol, amine, acid anhydride, and imidazole can be used.

  Since the conductive resin layer 144 includes a resin, the conductive resin layer 144 is more flexible than, for example, a conductive layer made of a fired product of a plating film or a conductive paste. Thereby, the conductive resin layer 144 functions as a buffer layer when a physical impact or an impact caused by a thermal cycle is applied to the multilayer ceramic capacitor 10. Thereby, it can suppress that a crack arises in the multilayer ceramic capacitor 10.

  The conductive metal contained in the conductive resin layer 144 is preferably powdered conductive metal powder. The shape of the conductive metal powder may be spherical or flat, but is not particularly limited. Preferably, the conductive metal powder is used by mixing a spherical shape and a flat shape. The average particle diameter of the conductive metal may be, for example, about 1.0 μm or more and 10 μm or less, but is not particularly limited.

  As the conductive metal powder, one type of metal powder may be used, or a plurality of types, for example, a metal powder consisting of a first metal component and a second metal component may be used. As the conductive metal powder, when one kind of metal powder is used, at least one metal powder selected from Ag, Pd, Pt, Au, Cu, Ni and the like can be used. Further, when using a plurality of types of conductive metal powder, as the conductive metal powder, a first metal powder made of at least one metal powder selected from Ag, Pd, Pt, Au, Cu, Ni, etc., At least one metal selected from Sn, In, Bi, or the like, or a second metal powder made of an alloy thereof can be used.

  The conductive metal powder is mainly responsible for the conductivity of the conductive resin layer 144. Specifically, a conductive path is formed inside the conductive resin layer 144 by contact between the conductive metal powders.

(Upper electrode layer 146)
The upper electrode layer 146 is composed of a plating layer. The plating layer is formed on the surface so as to cover the conductive resin layer 144. Specifically, the plating layer is formed on the surface of the conductive resin layer 144 formed on the first or second end face 26a, 26b of the laminate 20, and from there, the first and second main faces 22a are formed. , 22b and the surface of the conductive resin layer 144 formed on each of the first and second side surfaces 24a, 24b. The plating layer may be formed only on the surface of the conductive resin layer 144 formed on the first or second end face 26a, 26b of the stacked body 20.

  As the plating layer, for example, Cu, Ni, Sn, Ag, Pd, Ag—Pd alloy, Au, or the like can be used. The plating layer may have a multilayer structure. Preferably, the plating layer has a two-layer structure including Ni plating formed on the surface of the conductive resin layer 144 and Sn plating formed on the surface of the Ni plating. The Ni plating can prevent the base electrode layer 142 and the conductive resin layer 144 from being eroded by the solder used for mounting when the multilayer ceramic capacitor 10 is mounted on the mounting substrate. Moreover, Sn plating can improve the wettability with respect to the external electrodes 140a and 140b of the solder used for mounting when the multilayer ceramic capacitor 10 is mounted on the mounting substrate. Therefore, the multilayer ceramic capacitor 10 can be easily mounted on a substrate or the like by including Ni plating and Sn plating. The thickness of each plating layer is preferably 1 μm or more and 15 μm or less. The plating layer may have a single layer structure or a multilayer structure of three or more layers.

2. Manufacturing Method of Multilayer Ceramic Capacitor Next, a manufacturing method of the multilayer ceramic capacitor will be described.

(Process of preparing a raw laminate)
First, the process of forming a laminated body block by laminating a plurality of ceramic green sheets on which internal electrode patterns are formed and cutting the laminated body block to prepare a raw laminated body will be described.

  First, a ceramic slurry is obtained by dispersing and mixing ceramic powder, additive powder and binder resin solution. The ceramic slurry may be solvent-based or water-based. When the ceramic slurry is used as a water-based paint, the ceramic raw material may be mixed with a solution in which a water-soluble binder or dispersant is dissolved in water. The ceramic slurry is formed into a sheet shape on the surface of a support film such as PET, and becomes a ceramic green sheet. The ceramic slurry is dried after being applied to the support film. When molding into a sheet, various methods are employed. For example, the ceramic slurry may be formed into a sheet by being extruded from the coating head while moving the support film. Moreover, it is preferable to perform drying by combining atmosphere drying, freeze drying, far-infrared rays, and the like. The thickness of the ceramic green sheet is determined by the moving speed of the support film and the extrusion amount of the ceramic slurry. Thus, the ceramic green sheet used as a ceramic layer is obtained.

  Next, the conductive paste for forming an internal electrode is applied to the surface of the ceramic green sheet in a predetermined pattern by, for example, a screen printing method to obtain a ceramic green sheet on which the internal electrode pattern is formed. Moreover, a ceramic green sheet on which no internal electrode pattern is formed is also obtained. The ceramic paste and the internal electrode forming conductive paste may contain, for example, a known binder or solvent.

  Then, a predetermined number of ceramic green sheets on which no internal electrode pattern is formed are laminated, ceramic green sheets on which internal electrode patterns are formed are sequentially laminated on the surface, and further, ceramic green on which no internal electrode pattern is formed. A laminate block is obtained by laminating a predetermined number of sheets.

  If necessary, the laminated body block may be pressed in the laminating direction. For example, the laminate block may be housed in a mold and pressed by an isostatic press. Thereby, the adhesive force between ceramic green sheets improves. Note that there may be a difference in the adhesion between the ceramic green sheets due to the steps of the internal electrodes formed on the surface of the ceramic green sheets. Therefore, a uniform pressure may be applied by pressing after pressing an elastic body between the laminate block and the mold.

  Furthermore, a raw laminated body is obtained by cutting a laminated body block. Specifically, first, a thermal foam release sheet is attached to the main surface of the laminate block, and the thermal foam release sheet is fixed to the table, thereby fixing the laminate block to the table upper surface. Next, the end of the laminated body block is cut out, the electrode embedded in the inside is exposed, and the cut blade is pressed against the laminated body block while being aligned, and is divided into individual chips. In addition, the cutting by a dicer may be sufficient and the division | segmentation by a laser may be sufficient.

  At this time, the raw laminated body may be subjected to barrel polishing or the like to round the ridge line portion or the corner portion. Specifically, the raw laminate is accommodated in a small pod together with the polishing media, and an external force is applied to the small pod so that the raw laminate is polished by the polishing media and the corners are formed so as to have a certain radius of curvature. Round. In addition, you may perform barrel polishing after baking a raw laminated body.

(Process of preparing a laminate)
Next, the process of baking a raw laminated body and preparing a laminated body is demonstrated.

First, the binder removal process which removes the binder contained in a raw laminated body is performed. Specifically, the raw laminate is placed on a setter for firing and heated to remove the organic binder contained in the ceramic layer and the internal electrode of the raw laminate. The atmosphere in the furnace is an air atmosphere, but may be performed by adjusting the amount of gas such as N ₂ , H ₂ , H ₂ O or the like.

Next, the green laminate is sintered. Specifically, the raw laminate is placed on a setter and heated at a temperature in the furnace of 900 ° C. to 1300 ° C. for a predetermined time. Note that the firing temperature at this time can be set as appropriate according to the ceramic material and conductive material used. Further, the firing is performed by adjusting the amount of gas such as N ₂ , H ₂ , H ₂ O in the furnace.

  As described above, the first and second internal electrodes 40a and 40b are arranged inside, and the ends of the first and second internal electrodes 40a and 40b are drawn out to the first or second end surfaces 26a and 26b. The laminated body 20 prepared is prepared. The laminated body 20 thus obtained is preferably annealed (after firing). The annealing process is a process for reoxidizing the ceramic layer 30. Thereby, the laminated body 20 can lengthen the lifetime of insulation resistance, and reliability improves. Note that the annealing treatment is preferably performed under an oxygen partial pressure higher than that in the reducing atmosphere. However, if the oxygen concentration is too high, the internal electrodes tend to be insulated.

(Process of applying the base electrode layer paste)
First, a surface plate is prepared, which includes a paste storage unit filled with a base electrode layer paste, a plurality of recesses are formed on the bottom surface of the paste storage unit, and a treatment film is formed only on the inner surfaces of the plurality of recesses. The process will be described with reference to FIGS.

  FIG. 3 is a sectional view showing a surface plate used in the manufacturing method according to the embodiment of the present invention. FIG. 4 is a cross-sectional perspective view of a recess formed in a surface plate used in the manufacturing method according to one embodiment of the present invention. FIG. 5 is a cross-sectional view showing a state in which a treatment film is formed on the inner surface of the recess formed in the surface plate used in the manufacturing method according to one embodiment of the present invention. FIG. 6 is a cross-sectional view showing a state in which a base film layer paste is filled after a treatment film is formed on the inner surface of a recess formed in a surface plate used in a manufacturing method according to an embodiment of the present invention.

  For the formation of the base electrode layer 142, an external electrode paste storage jig 200 is used. The external electrode paste storage jig 200 includes a surface plate 210.

  The surface plate 210 includes a paste storage unit 220 that is filled with the base electrode layer paste 280. A plurality of recesses 230 are formed on the bottom surface 222 of the paste storage unit 220. The plurality of recesses 230 are continuously formed side by side in the left-right direction on the paper surface in FIGS. 3 and 4, each of the plurality of recesses 230 is formed so as to extend in a substantially rectangular parallelepiped shape in a direction from the front side to the back side of the sheet.

  As shown in FIG. 5, a treatment film 240 is formed on the inner surface 232 of each of the plurality of recesses 230. The treatment film 240 can impart oil repellency to the plurality of recesses 230. Therefore, transferability is improved when the base electrode layer paste 280 is applied to the laminate 20, and the first and second end faces 26a and 26b of the laminate 20 are not changed without changing the viscosity of the base electrode layer paste 280. In the base electrode layer 142 formed on the outermost portion, the outermost portion where moisture can easily enter (the first and second inner electrodes 40a, 40b closest to the main surfaces 22a, 22b in the first and second end surfaces 26a, 26b are positioned). The thickness of the portion to be sufficiently ensured. That is, since the base electrode layer paste 280 can be applied to the first and second end faces 26a, 26b of the multilayer body 20 with a uniform thickness, both the moisture resistance reliability and the miniaturization can be achieved by the base electrode layer 142. Can do. Furthermore, the formation of the conductive resin layer 144 on the surface of the base electrode layer 142 can also suppress the occurrence of cracks in the multilayer ceramic capacitor 10 (multilayer ceramic electronic component).

  Here, the treatment film 240 is formed only on the inner surface 232 of each of the plurality of recesses 230, and is applied to the bottom surface 222 (surface located at the same height as the upper ends of each of the plurality of recesses 230) and other portions of the paste storage unit 220. Is not formed. This is because the following problem is a concern when the treatment film 240 is formed on the bottom surface 222 of the paste storage unit 220.

  That is, since the entire bottom surface 222 of the paste storage unit 220 repels the base electrode layer paste 280, the base electrode paste 280 filled in the paste storage unit 220 is turned into a ball. As a result, the bottom surface 222 of the paste storage unit 220 has a so-called sea-island shape in which a portion filled with the base electrode layer paste 280 and a portion not filled are mixed. As a result, the base electrode layer paste 280 is applied with variations in thickness and shape. Furthermore, the treatment film 240 is easily brought into direct contact with the squeegee used when the base electrode layer paste 280 is scraped off and the laminated body 20 pressed against the bottom surface 222, and is thus scraped off. Then, there is a concern that the treatment film 240 scraped off in this way may be mixed as impurities (contamination) in the base electrode layer paste 280. If the base electrode layer paste 280 mixed with impurities is applied to the laminate 20, the impurities burn out during baking, resulting in a large defect, and there is a concern that the moisture resistance reliability may be significantly reduced.

  In addition, it is preferable that the process film 240 is formed from 20% to 80% of the height dimension of the side surface from the bottom surface of the inner surface 232 of the recess 230. By forming the treatment film 240 to 20% or more of the height dimension of the side surface from the bottom surface of the inner surface 232 of the recess 230, sufficient transferability to the laminate 20 of the base electrode layer paste 280 is obtained, and Since the treatment film 240 is not formed on the inner surface 232 of the recess 230 at a portion exceeding 80% of the height dimension of the side surface from the bottom surface, the filling property of the base electrode layer paste 280 inside the recess 230 is sufficiently secured. Is done.

  The treatment film 240 is formed of, for example, a film made of Teflon (registered trademark), a film containing a silane coupling agent, a film containing a silicone compound or a fluorine compound, or the like.

  As shown in FIG. 6, the base electrode layer paste 280 is filled in the paste storage unit 220 on which the treatment film 240 is formed as described above.

  Next, the process of pressing the first and second end faces of the laminate on the bottom surface of the paste storage unit will be described with reference to FIGS.

  FIG. 7 is a cross-sectional view showing a state in which a jig holding a plurality of laminated bodies is arranged above a surface plate used in the manufacturing method according to one embodiment of the present invention. FIG. 8 is a cross-sectional view showing a state in which the end surface of the laminate is pressed against the bottom surface of the paste storage section provided in the surface plate used in the manufacturing method according to the embodiment of the present invention. FIG. 9 is a cross-sectional view showing a state when the base electrode layer paste is applied to the end faces of a plurality of laminated bodies in the manufacturing method according to one embodiment of the present invention. FIG. 10 is an enlarged cross-sectional view of the vicinity of the end face of the laminate when the base electrode layer paste is applied to the end face of the laminate in the manufacturing method according to one embodiment of the present invention.

  The external electrode paste storage jig 200 further includes a jig 290 above the surface plate 210.

  First, as shown in FIG. 7, the jig 290 sandwiches each of the plurality of stacked bodies 20 above the surface plate 210 so that the first or second end surfaces 26 a and 26 b face the paste storage unit 220.

  Next, by moving the jig 290 downward, the first or second end face 26a, 26b of the laminate 20 is immersed in the base electrode layer paste 280 as shown in FIG. And the 1st or 2nd end surface 26a, 26b of the laminated body 20 is pressed against the bottom face 222 of the paste storage part 220. FIG.

  Then, by moving the jig 290 upward, as shown in FIGS. 9 and 10, a part of the first or second end face 26a, 26b and the first and second main faces 22a, 22b of the laminate 20 The base electrode layer paste 280 is applied to a part of the first and second side surfaces 24a and 24b. The base electrode layer paste 280 may be applied only to the first or second end face 26a, 26b of the stacked body 20 by adjusting the amount of the base electrode layer paste 280 filled.

(Step of forming the base electrode layer)
The step of baking the laminate on which the base electrode layer paste is applied to form the base electrode layer includes drying the base electrode layer paste applied to the laminate 20 and then, for example, 700 ° C. or more and 900 ° C. or less. This is done by baking at temperature.

(Process for forming conductive resin layer)
First, the process of apply | coating the paste for conductive resin layers containing a thermosetting resin and a conductive metal to the surface of a base electrode layer is performed.

  Finally, a heat treatment is performed to cure the thermosetting resin, thereby forming a conductive resin layer. Specifically, the resin is cured by performing a heat treatment at a temperature of 150 ° C. or higher and 300 ° C. or lower. Thereby, a conductive resin layer is formed. Note that the atmosphere during the heat treatment may be an air atmosphere or a nitrogen gas atmosphere. In addition, when forming the conductive resin layer containing Cu powder, in order to prevent that a metal component will oxidize, it is preferable to make oxygen concentration at the time of heat processing into 100 ppm or less.

(Formation of upper electrode layer)
If necessary, a step of forming an upper electrode layer on the surface of the conductive resin layer is performed. The upper electrode layer is formed by an electrolytic plating method or an electroless plating method.

(effect)
The method for manufacturing a multilayer ceramic capacitor 10 (multilayer ceramic electronic component) according to an embodiment of the present invention includes a paste storage unit 220 in which a treatment film 240 is formed only on the inner surfaces of a plurality of recesses 230 formed on a bottom surface 222. By using the surface plate 210 provided, oil repellency can be imparted to the plurality of recesses 230. Therefore, the transferability of the base electrode layer paste 280 to the laminate 20 is improved, and the base electrode layer paste 280 is formed on the first and second end faces 26a and 26b of the laminate 20 without changing the viscosity. In the base electrode layer 142, the outermost portion in which moisture is most likely to enter (portions where the first and second inner electrodes 40a, 40b closest to the main surfaces 22a, 22b are located on the first and second end surfaces 26a, 26b). Can be sufficiently secured. That is, since the base electrode layer paste 280 can be applied to the first and second end faces 26a, 26b of the multilayer body 20 with a uniform thickness, both the moisture resistance reliability and the miniaturization can be achieved by the base electrode layer 142. Can do. Furthermore, the formation of the conductive resin layer 144 on the surface of the base electrode layer 142 can also suppress the occurrence of cracks. As described above, according to one embodiment of the present invention, a multilayer ceramic capacitor that achieves both moisture resistance reliability and downsizing by the base electrode layer 142 while suppressing the generation of cracks by the conductive resin layer 144. 10 can be manufactured.

  Further, in the method of manufacturing the multilayer ceramic capacitor 10 (multilayer ceramic electronic component) according to one embodiment of the present invention, the step of forming the conductive resin layer includes the step of forming a thermosetting resin and a conductive material on the surface of the base electrode layer. Conduction for appropriately suppressing the occurrence of cracks in the multilayer ceramic capacitor 10 by including a step of applying a conductive resin layer paste containing metal and a step of curing the thermosetting resin by performing a heat treatment. The conductive resin layer 144 can be formed.

  In the method of manufacturing the multilayer ceramic capacitor 10 (multilayer ceramic electronic component) according to the embodiment of the present invention, the treatment film 240 is 20% of the height dimension of the inner surface 232 of the recess 230 from the bottom surface to the side surface. It has been described that it is preferably formed to 80% or less. By forming the treatment film 240 to 20% or more of the height dimension of the side surface from the bottom surface of the inner surface 232 of the recess 230, sufficient transferability to the laminate 20 of the base electrode layer paste 280 is obtained, and Since the treatment film 240 is not formed on the inner surface 232 of the recess 230 at a portion exceeding 80% of the height dimension of the side surface from the bottom surface, the filling property of the base electrode layer paste 280 inside the recess 230 is sufficiently secured. Is done.

  As shown in FIG. 11, the treatment film 240 may be formed from the bottom surface to the upper end of the side surface (that is, 100% of the height dimension of the side surface) of the inner surface 232 of the recess 230, or the bottom surface thereof. May be formed from over 80% to less than 100%, from the bottom surface to less than 20% of the height of the side surface, or only on the bottom surface and not on the side surface. .

  Further, in the method of manufacturing the multilayer ceramic capacitor 10 (multilayer ceramic electronic component) according to one embodiment of the present invention, the treatment film 240 is a film made of Teflon (registered trademark), a film containing a silane coupling agent, a silicone-based film By being formed of a film containing a compound or a fluorine-based compound, sufficient oil repellency can be imparted to the plurality of recesses 230. As a result, the transferability of the base electrode layer paste 280 to the laminate 20 is improved, and the base electrode layer paste 280 is formed on the first and second end faces 26a and 26b without changing the viscosity of the base electrode layer paste 280. The outermost portion where the moisture is most likely to enter in the underlying electrode layer 142 (the first and second end faces 26a and 26b where the first and second inner electrodes 40a and 40b closest to the main surfaces 22a and 22b are located). ) Can be sufficiently secured.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is carried out within the range of the summary.

DESCRIPTION OF SYMBOLS 10 Multilayer ceramic capacitor 20 Laminated body 22a 1st main surface 22b 2nd main surface 24a 1st side surface 24b 2nd side surface 26a 1st end surface 26b 2nd end surface 30 Ceramic layer 40a 1st internal electrode 40b 1st Two internal electrodes 140a First external electrode 140b Second external electrode 142 Base electrode layer 144 Conductive resin layer 146 Upper electrode layer 200 External electrode paste storage jig 210 Surface plate 220 Paste storage portion 222 Bottom surface 230 Recessed portion 232 Inner surface 240 treatment film 280 base electrode layer paste 290 jig

Claims (4)

A plurality of ceramic layers and a plurality of internal electrodes are alternately stacked to form a rectangular parallelepiped shape. The first main surface and the second main surface are opposed to each other in the stacking direction, and are opposed in the width direction orthogonal to the stacking direction. A laminated body including a first side surface and a second side surface, and a first end surface and a second end surface facing each other in a length direction perpendicular to the laminating direction and the width direction;
A base electrode layer formed so as to be electrically connected to the internal electrode at the first and second end faces of the laminate, and a thermosetting resin and a conductive metal formed on the surface of the base electrode layer A method for manufacturing a multilayer ceramic electronic component comprising a pair of external electrodes including a conductive resin layer including:
By laminating a plurality of ceramic green sheets with internal electrode patterns formed thereon, forming a laminate block, cutting the laminate block to prepare a raw laminate, and
Firing the raw laminate and preparing the laminate;
Applying a base electrode layer paste to at least the first and second end faces of the laminate;
Baking the laminate on which the paste for the base electrode layer is applied to form a base electrode layer;
Forming a conductive resin layer on the surface of the base electrode layer,
The step of applying the base electrode layer paste includes
A surface plate is provided, comprising a paste storage unit filled with the base electrode layer paste, wherein a plurality of recesses are formed on a bottom surface of the paste storage unit, and a treatment film is formed only on the inner surfaces of the plurality of recesses. And a process of
And a step of pressing the first and second end faces of the multilayer body against the bottom surface of the paste storage unit. The step of forming the conductive resin layer includes:
Applying a paste for a conductive resin layer containing the thermosetting resin and the conductive metal to the surface of the base electrode layer;
The manufacturing method of the multilayer ceramic electronic component of Claim 1 including the process of hardening the said thermosetting resin by performing heat processing.   3. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein the treatment film is formed from 20% to 80% of a height dimension of a side surface from a bottom surface of an inner surface of the concave portion.   The multilayer ceramic electronic equipment according to claim 1, wherein the treatment film is formed of a film made of Teflon (registered trademark), a film containing a silane coupling agent, a film containing a silicone compound or a fluorine compound. Production method.

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