JP2019160963A - Manufacturing method of multilayer ceramic electronic component - Google Patents

Abstract

To provide a manufacturing method of multilayer ceramic electronic component in which exfoliation between ceramic layers is less likely to occur, without specially increasing the pressing pressure.SOLUTION: In a manufacturing method of multilayer ceramic electronic component having a step of preparing a ceramic green sheet, a step of forming a conductive pattern for forming the internal electrode by coating the ceramic green sheet with conductive paste for internal electrode, a step of obtaining a lamination sheet by laminating ceramic green sheets and multiple ceramic green sheets where the conductive pattern for forming the internal electrode is formed, and a step of obtaining a lamination block by pressing the lamination sheet in the lamination direction, the ceramic green sheet composing the lamination sheet contains microcapsules including solvent.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for manufacturing a multilayer ceramic electronic component including, for example, a multilayer ceramic capacitor.

  Generally, in the manufacturing process of a multilayer ceramic electronic component, there is a process of bonding ceramic green sheets together by pressing (see Patent Document 1).

  More specifically, for example, a plurality of ceramic green sheets having internal electrode forming conductive patterns are stacked and sandwiched between forming dies (not shown), and a temporary press and a main press are performed by an isostatic press or the like. After that, the press pressure is released. Thereby, the plurality of ceramic green sheets having the conductive pattern for forming the internal electrode are brought into close contact with each other, and a laminated block is obtained.

JP 2009-277800 A

  However, in the above-described press, generally, the ceramic green sheet and the internal electrode forming conductive pattern are often pressed at a pressure that only deforms the interface, and the ceramic having the internal electrode forming conductive pattern is often pressed. There was a limit to the adhesion between green sheets, and voids were likely to occur between adjacent ceramic green sheets.

  In addition, the adhesion between ceramic green sheets can be increased by increasing the pressing pressure, but if the pressing pressure is too high, the laminated block will be greatly deformed, and the laminated electronic component can guarantee the quality. There was a problem that the structure could not be obtained.

  As a result, the press pressure within a range where the above-mentioned problems do not occur cannot sufficiently secure the adhesion between the ceramic green sheets having the internal electrodes, and therefore, there may occur peeling between the ceramic layers in the final product. .

  Further, a method of simply adding an adhesive component to the internal electrode forming conductive pattern or the ceramic green sheet to increase the adhesion between the ceramic green sheets having the internal electrode forming conductive pattern is also conceivable. However, in this case, the ceramic green sheet itself having the conductive pattern for internal electrode formation adheres to the manufacturing process equipment (molding machine, printing machine, laminating machine) and auxiliary materials (PET film), and sheet tearing occurs. There is a worry.

  Therefore, a main object of the present invention is to provide a method for manufacturing a multilayer ceramic electronic component in which peeling between ceramic layers is unlikely to occur without specially increasing the pressing pressure.

  The method for manufacturing a multilayer ceramic electronic component according to the present invention includes a step of preparing a ceramic green sheet, a step of applying a conductive paste for internal electrodes on the ceramic green sheet to form a conductive pattern for forming internal electrodes, and a ceramic. A multilayer ceramic comprising: a step of laminating a plurality of ceramic green sheets on which green sheets and conductive patterns for forming internal electrodes are formed to obtain a laminated sheet; and a step of pressing the laminated sheet in the laminating direction to obtain a laminated block. A method of manufacturing a multilayer ceramic electronic component, wherein the ceramic green sheet constituting the multilayer sheet contains a microcapsule containing a solvent.

  Moreover, the method for manufacturing a multilayer ceramic electronic component according to the present invention includes a step of cutting a multilayer block to obtain a laminate before firing, a step of firing the laminate before firing, and obtaining a laminate after firing, It is preferable to further include a step of forming external electrodes on the fired laminate.

  In addition, the method for producing a multilayer ceramic electronic component according to the present invention is such that the microcapsule is crushed when the laminated sheet is pressed in the laminating direction, the interface between the ceramic green sheets at the time of lamination, and the conductive for forming the ceramic green sheet and the internal electrode The solvent in the microcapsule is supplied to the interface with the pattern so that the binder between the ceramic green sheets is compatible, and the binder of the conductive pattern for forming the internal electrode is compatible with the binder of the ceramic green sheet.

  In the method for producing a multilayer ceramic electronic component according to the present invention, the area ratio of the microcapsules in the cross section of the ceramic green sheet is preferably 1% or more and 20% or less.

  In the method for producing a multilayer ceramic electronic component according to the present invention, the solvent is preferably selected from any one of n-octanol and ethanol.

  According to the present invention, it is possible to obtain a method for manufacturing a multilayer ceramic electronic component in which peeling between ceramic layers hardly occurs without particularly increasing the press pressure.

  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 an example of a multilayer ceramic capacitor as a multilayer ceramic electronic component according to an embodiment of the present invention. It is sectional drawing in line II-II of FIG. It is sectional drawing in line III-III of FIG. It is sectional drawing in line IV-IV of FIG. It is a flowchart for demonstrating an example of the manufacturing method of the multilayer ceramic electronic component which concerns on embodiment of this invention. It is a schematic cross section for demonstrating an example of the manufacturing method of the multilayer ceramic electronic component which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the manufacturing method of the multilayer ceramic electronic component which concerns on embodiment of this invention, Comprising: (A) is a model expanded sectional view which shows the state of the interface of a ceramic green sheet and the conductive pattern for internal electrode formation (B) is a schematic enlarged cross-sectional view showing the state of the interface between the ceramic green sheets.

1. Multilayer Ceramic Electronic Component A multilayer ceramic electronic component according to an embodiment of the present invention will be described. FIG. 1 is an external perspective view showing an example of a multilayer ceramic capacitor as a multilayer ceramic electronic component according to an embodiment of the present invention. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is a sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

  Hereinafter, a multilayer ceramic capacitor will be described as an example of the multilayer ceramic electronic component. Although the present embodiment will be described using a normal two-terminal capacitor as an example, the present embodiment is not limited to this and can be applied to a multi-terminal capacitor.

  As shown in FIGS. 1 to 3, the multilayer ceramic capacitor 10 includes a rectangular parallelepiped multilayer body 12.

  The multilayer body 12 includes a plurality of laminated ceramic layers 14 and a plurality of internal electrode layers 16. Furthermore, the laminate 12 includes a first main surface 12a and a second main surface 12b that are opposed to the lamination direction x, and a first side surface 12c and a second side surface that are opposed to the width direction y orthogonal to the lamination direction x. 12d, and a first end surface 12e and a second end surface 12f that are opposed to a length direction z orthogonal to the stacking direction x and the width direction y. The dimension of the laminated body 12 is not specifically limited. However, the laminated body 12 does not necessarily have the dimension of the length direction z longer than the dimension of the width direction y.

  The laminated body 12 is preferably rounded at corners and ridge lines. In addition, a corner | angular part is a part where three adjacent surfaces of a laminated body cross, and a ridgeline part is a part where two adjacent surfaces of a laminated body intersect.

  The ceramic layer 14 includes an outer layer portion 14a composed of a plurality of ceramic layers 14, an inner layer portion 14b composed of one or more ceramic layers 14, and a plurality of internal electrode layers 16 disposed thereon. including. The outer layer portion 14a is located on the first main surface 12a side and the second main surface 12b side of the laminate 12, and is formed between the first main surface 12a and the internal electrode layer 16 closest to the first main surface 12a. It is an aggregate of a plurality of ceramic layers 14 positioned between them, and a plurality of ceramic layers 14 positioned between the second main surface 12b and the internal electrode layer 16 closest to the second main surface 12b. The region sandwiched between both outer layer portions 14a is the inner layer portion 14b.

The ceramic layer 14 can be formed of a dielectric material, for example. As the dielectric material, for example, a dielectric ceramic containing a component such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , or CaZrO ₃ can be used. When the above dielectric material is included as a main component, depending on the desired characteristics of the laminate 12, for example, a component having a lower content than the main component such as a Mn compound, Fe compound, Cr compound, Co compound, Ni compound, etc. You may use what added.

  When a piezoelectric ceramic is used for the multilayer body 12, the multilayer ceramic electronic component functions as a ceramic piezoelectric element. Specific examples of the piezoelectric ceramic material include, for example, a PZT (lead zirconate titanate) ceramic material.

  Moreover, when a semiconductor ceramic is used for the laminated body 12, the laminated ceramic electronic component functions as a thermistor element. Specific examples of the semiconductor ceramic material include spinel ceramic materials.

  When a magnetic ceramic is used for the multilayer body 12, the multilayer ceramic electronic component functions as an inductor element. When functioning as an inductor element, the internal electrode layer 16 is a coiled conductor. Specific examples of the magnetic ceramic material include a ferrite ceramic material.

  The thickness of the ceramic layer 14 after firing is preferably 0.5 μm or more and 10 μm or less.

  As illustrated in FIG. 2, the multilayer body 12 includes, as the plurality of internal electrode layers 16, for example, a plurality of first internal electrode layers 16 a and a plurality of second internal electrode layers 16 b having a substantially rectangular shape. The plurality of first internal electrode layers 16 a and the plurality of second internal electrode layers 16 b are embedded so as to be alternately arranged at equal intervals along the stacking direction x of the stacked body 12.

  One end side of the first internal electrode layer 16 a has a first extraction electrode portion 18 a that is extracted to the first end face 12 e of the multilayer body 12. On one end side of the second internal electrode layer 16b, there is a second extraction electrode portion 18b that is extracted to the second end surface 12f of the multilayer body 12. Specifically, the first extraction electrode portion 18 a on one end side of the first internal electrode layer 16 a is exposed on the first end face 12 e of the multilayer body 12. Further, the second lead electrode portion 18 b on one end side of the second internal electrode layer 16 b is exposed on the second end face 12 f of the multilayer body 12.

  The multilayer body 12 includes a counter electrode portion 20a in which the first internal electrode layer 16a and the second internal electrode layer 16b face each other in the inner layer portion 14b of the ceramic layer 14. The stacked body 12 is formed between one end in the width direction y of the counter electrode portion 20a and the first side surface 12c and between the other end in the width direction y of the counter electrode portion 20a and the second side surface 12d. The side part (W gap) 20b of the laminated body 12 is included. Further, the multilayer body 12 includes the second internal surface of the second internal electrode layer 16b between the end portion of the first internal electrode layer 16a opposite to the first extraction electrode portion 18a and the second end surface 12f. It includes an end portion (L gap) 20c of the multilayer body 12 formed between the end portion on the opposite side to the extraction electrode portion 18b and the first end face 12e.

The internal electrode layer 16 is made of, for example, a metal such as Ni, Cu, Ag, Pd, or Au, or an alloy containing at least one of these metals such as an Ag—Pd alloy containing one of these metals. It contains an appropriate conductive material. The internal electrode layer 16 may further include dielectric particles having the same composition system as the ceramic contained in the ceramic layer 14.
The thickness of the internal electrode layer 16 is preferably 0.2 μm or more and 2 μm or less. The number of the first internal electrode layers 16a and the second internal electrode layers 16b is not particularly limited.

External electrodes 22 are disposed on the first end surface 12 e side and the second end surface 12 f side of the multilayer body 12. The external electrode 22 has a first external electrode 22a and a second external electrode 22b.
The first external electrode 22a is disposed on the surface of the first end surface 12e of the multilayer body 12, and extends from the first end surface 12e to form the first main surface 12a, the second main surface 12b, and the first side surface. 12c and second side surface 12d are formed so as to cover each part. In this case, the first external electrode 22a is electrically connected to the first extraction electrode portion 18a of the first internal electrode layer 16a.
The second external electrode 22b is disposed on the surface of the second end surface 12f of the multilayer body 12, and extends from the second end surface 12f to the first main surface 12a, the second main surface 12b, and the first side surface. 12c and second side surface 12d are formed so as to cover each part. In this case, the second external electrode 22b is electrically connected to the second extraction electrode portion 18b of the second internal electrode layer 16b.

  In the laminated body 12, the electrostatic capacity is formed by the first internal electrode layer 16a and the second internal electrode layer 16b facing each other with the ceramic layer 14 in each counter electrode portion 20a. Therefore, a capacitance can be obtained between the first external electrode 22a to which the first internal electrode layer 16a is connected and the second external electrode 22b to which the second internal electrode layer 16b is connected. .

  As shown in FIG. 2, the first external electrode 22a includes, in order from the stacked body 12 side, a first base electrode layer 24a and a first plating layer 26a disposed on the surface of the first base electrode layer 24a. Have Similarly, the second external electrode 22b includes a second base electrode layer 24b and a second plating layer 26b disposed on the surface of the second base electrode layer 24b in this order from the stacked body 12 side.

The first base electrode layer 24a is disposed on the surface of the first end surface 12e of the multilayer body 12, and extends from the first end surface 12e to form the first main surface 12a, the second main surface 12b, and the first main surface 12e. It is formed so as to cover a part of each of the side surface 12c and the second side surface 12d.
The second base electrode layer 24b is disposed on the surface of the second end surface 12f of the multilayer body 12, and extends from the second end surface 12f to form the first main surface 12a, the second main surface 12b, and the first main surface 12b. It is formed so as to cover a part of each of the side surface 12c and the second side surface 12d.

  Each of the first base electrode layer 24a and the second base electrode layer 24b includes at least one selected from a baking layer, a thin film layer, and the like. Here, the first base electrode layer 24a formed of the baking layer is used. The second base electrode layer 24b will be described.

  The baking layer includes glass and metal. Examples of the metal of the baking layer include at least one selected from Cu, Ni, Ag, Pd, an Ag—Pd alloy, Au, and the like. Moreover, as a glass of a baking layer, at least 1 chosen from B, Si, Ba, Mg, Al, Li etc. is included. The baking layer may be a plurality of layers. The baking layer is obtained by applying a conductive paste containing glass and metal to the laminated body 12 and baking it. The baking layer may be fired simultaneously with the ceramic layer 14 and the internal electrode layer 16. It may be baked after firing. The thickness of the thickest part in the baking layer is preferably 10 μm or more and 50 μm or less.

The first plating layer 26a is disposed so as to cover the first base electrode layer 24a. Specifically, the first plating layer 26a is disposed on the first end surface 12e on the surface of the first base electrode layer 24a, and the first main surface 12a and the first main surface 12a on the surface of the first base electrode layer 24a. Preferably, the second main surface 12b, the first side surface 12c, and the second side surface 12d are provided.
The second plating layer 26b is disposed so as to cover the second base electrode layer 24b. Specifically, the second plating layer 26b is disposed on the second end surface 12f on the surface of the second base electrode layer 24b, and the first main surface 12a and the second main surface 12a on the surface of the second base electrode layer 24b. Preferably, the second main surface 12b, the first side surface 12c, and the second side surface 12d are provided.

  Further, as the first plating layer 26a and the second plating layer 26b (hereinafter also simply referred to as a plating layer), for example, at least selected from Cu, Ni, Sn, Ag, Pd, an Ag—Pd alloy, Au, and the like. Contains one. The plating layer may be formed of a plurality of layers. In this case, the plating layer preferably has a two-layer structure of a Ni plating layer and a Sn plating layer. By providing the Ni plating layer so as to cover the surface of the base electrode layer, the base electrode layer can be prevented from being eroded by the solder when the multilayer ceramic capacitor 10 is mounted. Further, by providing the Sn plating layer on the surface of the Ni plating layer, the wettability of the solder when the multilayer ceramic capacitor 10 is mounted can be improved and can be easily mounted.

  The thickness per plating layer is not particularly limited, but is preferably 1 μm or more and 15 μm or less.

The multilayer ceramic capacitor 10 including the multilayer body 12, the first external electrode 22a, and the second external electrode 22b has a dimension Z in the length direction z, and the multilayer body 12, the first external electrode 22a, and the second external electrode. The dimension in the stacking direction x of the multilayer ceramic capacitor 10 including the electrode 22b is T, and the dimension in the width direction y of the multilayer ceramic capacitor 10 including the multilayer body 12, the first external electrode 22a and the second external electrode 22b is W. Dimension.
The dimensions of the multilayer ceramic capacitor 10 are not particularly limited. For example, the L dimension in the length direction z is 0.4 mm to 6 mm, the W dimension in the width direction y is 0.2 mm to 6 mm, and the T dimension in the stack direction x. Is preferably 0.2 mm or more and 3 mm or less.

2. Next, an embodiment of a method for manufacturing a multilayer ceramic electronic component having the above configuration will be described. FIG. 5 is a flowchart for explaining an example of a method for manufacturing a multilayer ceramic electronic component according to an embodiment of the present invention. FIG. 6 is a schematic cross-sectional view for explaining an example of a method for manufacturing a multilayer ceramic electronic component according to an embodiment of the present invention. FIG. 7 is a diagram for explaining a method of manufacturing a multilayer ceramic electronic component according to an embodiment of the present invention, wherein (A) shows the state of the interface between the ceramic green sheet and the conductive pattern for forming internal electrodes. It is a model expanded sectional view, (B) is a model expanded sectional view which shows the state of the interface of ceramic green sheets. Here, a method for manufacturing the multilayer ceramic capacitor 10 will be described as an example.

  First, in step S1, a ceramic green sheet containing microcapsules containing a solvent is prepared. Specifically, ceramic powder (dielectric powder), additive powder, binder resin and microcapsule solution are prepared and dispersed and mixed to obtain ceramic slurry (dielectric slurry). Accordingly, the ceramic slurry contains microcapsules.

  A microcapsule is composed of a capsule membrane material and an encapsulation material encapsulated in the capsule membrane material. The diameter of the microcapsule is, for example, 0.1 μm or more and 10 μm or less.

  The inner packaging material comprises a solvent, such as methanol, ethanol, n-propanol, iso-propanol (IPA), n-butanol, sec-butanol, n-octanol, diacetone alcohol benzyl alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve. , Acetone, methyl ethyl ketone (MEK), cyclohexanone, isophorone, N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, methyl acetate, n-hexyl acetate, dioxane, tetrahydrofuran, toluene, xylene, terpineol , Butyl carbitol and the like. Among these, as the encapsulating material, an alcohol solvent is preferable. By using the alcohol-based solvent, the binder resin in the ceramic green sheet is dissolved with a small amount of the inner packaging material, and the effect of improving the adhesion can be obtained only by dissolving the surface of the ceramic green sheet. In particular, it is more preferably selected from any one of n-octanol and ethanol, and the effect of the present invention can be made more remarkable.

  As for the amount of the solvent that is the inner packaging material, the ratio of the inner packaging material (wt%) to the total mass of the microcapsules is desirably 30 wt% or more and 70 wt% or less. Further, the amount of the solvent as the encapsulating material is desirably 1% or more and 20% or less according to the area ratio of the microcapsules in the cross section of the ceramic green sheet. Thereby, in a multilayer ceramic capacitor, peeling between the ceramic layers 14 can be suppressed more reliably.

  The capsule membrane material is made of, for example, gelatin, urea resin, melamine resin, urethane resin, or polyurea resin. The capsule membrane material is preferably crushed by a pressure of 1 Mpa or more. Thereby, the solvent which is an inclusion material can be reliably supplied at the time of lamination | stacking of a ceramic green sheet, and the effect of this invention can be made reliable.

  The ceramic slurry is formed into a sheet shape on a support film such as PET to form a ceramic green sheet. There are various methods for forming into a sheet shape. For example, the ceramic slurry may be extruded from the coating head while moving the support film, and then formed into a sheet shape. 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. The ceramic slurry applied to the support film is dried by combining atmosphere drying, freeze drying, far-infrared rays, etc., and a ceramic green sheet to be the ceramic layer 14 is produced.

  The ceramic slurry may be solvent-based or water-based. When the ceramic slurry is used as a water-based paint, a ceramic raw material in which a water-soluble binder resin or a dispersant is dissolved in water is mixed.

  Next, in step S2, an internal electrode conductive paste for forming the internal electrode layer 16 is applied to a predetermined pattern on the ceramic green sheet containing the microcapsules by, for example, a screen printing method or the like. A plurality of ceramic green sheets 30 on which internal electrode forming conductive patterns 31 are formed are prepared (see FIG. 6A).

  Further, a plurality of outer-layer ceramic green sheets on which no internal electrode forming conductive pattern is formed are prepared. The outer layer ceramic green sheet may not contain microcapsules.

  The ceramic slurry and the internal electrode conductive paste contain a binder resin and a solvent, but a known binder resin or solvent may be used.

  Next, in step S3, a predetermined number of outer layer ceramic green sheets (which may or may not contain microcapsules) in which the internal electrode forming conductive pattern is not formed are stacked, The ceramic green sheets 30 including the microcapsules on which the internal electrode forming conductive patterns 31 are formed are sequentially laminated, and the outer layer ceramic green sheets on which the internal electrode forming conductive patterns are not formed (microcapsules are contained). A predetermined number of sheets may be laminated to produce a laminated sheet (also referred to as a mother laminate) 32 (see FIG. 6B).

  Next, in step S4, the laminated sheet 32 is temporarily pressed in the laminating direction x by means such as an isostatic press or a rigid press and is temporarily pressed (see FIG. 6C). At the time of this temporary pressing, as shown in FIG. 7A, the microcapsules 40 contained in the ceramic green sheet 30 in contact with the internal electrode forming conductive pattern 31 are crushed, and the ceramic at the time of lamination The solvent in the microcapsule 40 is supplied to the interface between the green sheet 30 and the internal electrode forming conductive pattern 31, and the binder resin of the internal electrode forming conductive pattern 31 and the binder resin of the ceramic green sheet 30 are compatible. become. As a result, a portion 34 where the ceramic green sheet 30 and the internal electrode forming conductive pattern 31 are familiar is formed between the ceramic green sheet 30 and the internal electrode forming conductive pattern 31.

  Thereafter, the laminated sheet 32 is pressed by means such as a hydrostatic press or a rigid press to form a laminated block 38 (see FIG. 6D). At the time of this press, as shown in FIG. 7B, the microcapsules 40 contained in the ceramic green sheet 30 in the portion where the internal electrode forming conductive pattern 31 is not formed are crushed, and the ceramic at the time of lamination The solvent in the microcapsule 40 is supplied to the interface between the green sheets 30 and the binder resin between the ceramic green sheets 30 is compatible. Thereby, between the ceramic green sheets 30, a portion 36 in which the ceramic green sheets 30 are familiar with each other is formed.

  As a result, the adhesion between the ceramic green sheet 30 and the internal electrode forming conductive pattern 31 and the adhesion between the ceramic green sheets 30 can be dramatically improved without particularly increasing the pressing pressure. Therefore, it is possible to suppress peeling between the ceramic layers 14 in the multilayer ceramic capacitor.

  Further, in the present invention, when the adhesive component is simply mixed in the internal electrode forming conductive pattern or the ceramic green sheet to increase the adhesion between the ceramic green sheets having the internal electrode forming conductive pattern. No sheet tearing occurs.

  Thereafter, the press pressure is released (see FIG. 6E).

  In addition, when pressing, the lamination sheet 32 is stored in a metal mold | die, for example, it presses by an isostatic press or a rigid body press. Further, a step is likely to occur between the internal electrode forming conductive pattern 31 formed on the ceramic green sheet 30 and the portion of the ceramic green sheet 30 where the internal electrode forming conductive pattern 31 is not formed. An elastic body may be sandwiched between the mold and the laminated sheet 32 so that pressure is applied uniformly.

Next, in step S5, the laminated block 38 is cut into a predetermined shape and a plurality of laminated bodies before firing are cut out. Specifically, in order to fix the laminated block 38 on the table, an adhesive sheet or the like is attached to the main surface of the laminated block 38 and fixed to the table. The end portion of the laminated block 38 is cut away to expose the internal electrode forming conductive pattern 31 embedded therein. While aligning, the cutting blade is pressed against the laminated block 38 to cut it, and the laminated block 38 is divided into individual laminates before firing.
In addition, the division | segmentation by a dicer may be sufficient and the division | segmentation by a laser may be sufficient.

  At this time, the laminated body before firing may be subjected to barrel polishing or the like to round the ridge line part or the corner part. Specifically, the laminate before firing is accommodated in the small pod together with the polishing media, and by applying an external force to the small pod, the laminate before firing is polished with the abrasive media, and the ridge line portion of the laminate before firing or By rounding the corners, the ridges and corners have a certain radius of curvature. This barrel polishing may be performed on the laminate before firing or may be performed on the laminate after firing.

  Next, in step S6, the laminate before firing is fired, and the fired laminate 12 (also simply referred to as laminate 12) is created. The fired laminate 12 has the first internal electrode layer 16a and the second internal electrode layer 16b disposed therein, and the first lead electrode portion 18a of the first internal electrode layer 16a is the fired laminate. The second extraction electrode portion 18b of the second internal electrode layer 16b is extracted to the second end surface 12f of the laminated body 12 after firing.

Specifically, the laminate before firing is set in a firing apparatus. First, a binder removal step of heating and removing the binder contained in the laminate before firing is performed. In the binder removal step, the binder resin contained in the ceramic green sheet and the internal electrode forming conductive pattern of the laminate before firing is removed. At this time, the solvent supplied by the microcapsules is also completely removed.
Although the atmosphere in the furnace is an air atmosphere, it may be adjusted by mixing an appropriate amount of gas such as N ₂ , H ₂ , H ₂ O or the like.

Next, the baking process in which the laminated body before baking is sintered is performed. The laminate before firing is heated for a predetermined time at the set firing temperature. Although the firing temperature of the laminate before firing depends on the ceramic material and the material of the internal electrode conductive paste, it is preferably 900 ° C. or higher and 1300 ° C. or lower. Note that the furnace atmosphere is prepared by adjusting an appropriate amount of gas such as N ₂ , H ₂ , or H ₂ O. In this way, the sintered laminated body 12 is obtained.

  After firing, it is preferable to anneal. Annealing is a process for re-oxidizing the ceramic layer 14, thereby extending the life of the insulation resistance and improving the reliability. The annealing treatment is preferably performed in an oxygen partial pressure atmosphere higher than the reducing atmosphere. However, if the oxygen concentration is too high, the internal electrode layer 16 tends to be insulated.

Next, in step S7, the first external electrode 22a and the second external electrode 22b are formed on the first end surface 12e and the second end surface 12f of the fired laminate 12.
Specifically, first, the base electrode layer paste is applied and baked on the first end surface 12e and the second end surface 12f of the fired laminate 12, and the first base of the first external electrode 22a is baked. A second base electrode layer 24b of the electrode layer 24a and the second external electrode 22b is formed. For forming the first base electrode layer 24a and the second base electrode layer 24b, a dip method, a screen printing method, a roller coating method, or the like is used. In this embodiment mode, the dip method is used.

In the dip method, a base electrode layer paste is applied in a film form on a table to form a base electrode layer paste film.
Here, when the internal electrode layer 16 is shrunk by firing and the internal electrode layer 16 is not exposed at the first end surface 12e and the second end surface 12f of the laminate 12, the first end surface 12e and the second end surface 12e are not exposed. The end face 12f is polished so that the internal electrode layer 16 is exposed.

  Next, the laminated body 12 is held so that the first end face 12e where the internal electrode layer 16 is exposed faces the base electrode layer paste film on the table. As a holding method, the first side surface 12c and the second side surface 12d of the laminated body 12 may be elastically held by an elastic body, or the other second end face 12f of the laminated body 12 may be held by an adhesive. Good. Thereafter, the first end face 12e of the laminate 12 is immersed in the base electrode layer paste film on the table, and the first end face 12e is covered with the base electrode layer paste.

  The excess base electrode layer paste covering the first end surface 12e is formed by pressing the first end surface 12e covered with the base electrode layer paste against a flat plate on which the base electrode layer paste film is not formed. May be removed. Moreover, you may immerse in the paste film | membrane for base electrode layers on a table in multiple times. When the base electrode layer paste is excessively wetted, the laminate 12 may be treated in advance to repel the base electrode layer paste to prevent excessive wettability.

  Similarly, the second end face 12f where the internal electrode layer 16 is exposed is covered with the base electrode layer paste.

  Next, the first plating layer 26a is formed on the surface of the first base electrode layer 24a, and the second plating layer 26b is formed on the surface of the second base electrode layer 24b. If necessary, a metal and a resin are provided between the first base electrode layer 24a and the first plating layer 26a and between the second base electrode layer 24b and the second plating layer 26b. A resin electrode layer containing may be provided.

  The first plating layer 26a and the second plating layer 26b are formed by preparing a plating bath filled with a plating solution, a cathode electrode and an anode electrode, and applying a plating voltage between the cathode electrode and the anode electrode in the plating solution. Then, the first base electrode layer 24a and the second base electrode are formed by energizing the first base electrode layer 24a and the second base electrode layer 24b formed in the stacked body 12 so that the cathode electrodes are in contact with each other. It can be deposited on layer 24b.

  Note that a conductive medium may be placed in the plating bath together with the laminated body 12, and the first ground electrode layer 24a and the second ground electrode layer 24b formed on the laminated body 12 may be energized via the conductive medium. In addition, there are various methods for conducting, and the vibration plating method in which the laminate 12 and the conductive media are stirred and plated by vibration, or the conductive media and the laminate 12 placed in the barrel are rotated. A rotating barrel plating method in which plating is performed while stirring, or a centrifugal plating method in which the laminate 12 is stirred and plated by a centrifugal force of the barrel may be used.

  As described above, the multilayer ceramic capacitor 10 shown in FIG. 1 is manufactured.

3. Experimental Example Next, in order to confirm the effect of the above-described manufacturing method of the multilayer ceramic electronic component according to the present invention, a multilayer ceramic capacitor was manufactured based on the manufacturing method of the present invention. Area ratio (%) ”,“ average diameter of microcapsules (μm) ”,“ ratio of encapsulating material to total mass of microcapsules (wt%) ”,“ number of peeling occurrences (pieces) ”and“ short ratio (%) ” Was evaluated.

(A) Examples and Comparative Examples In Examples 1 to 9, monolithic ceramic capacitors having specifications described later were produced according to the above-described monolithic ceramic electronic component manufacturing method. In particular, in Examples 1 to 9, dielectric slurry was prepared by preparing and dispersing and mixing dielectric powder, additive powder for adjusting electrical characteristics, and binder resin solution. To the dielectric slurry, 0.04 wt% to 1.64 wt% of microcapsules were added to BaTiO ₃ , and then mixed to prepare a dielectric slurry containing microcapsules. Using this dielectric slurry, a dielectric green sheet was molded.

  In Comparative Example 1, a multilayer ceramic capacitor having the specifications described later was manufactured according to a conventional method for manufacturing a multilayer ceramic electronic component. In particular, in Comparative Example 1, a dielectric slurry was prepared by preparing and dispersing and mixing a dielectric powder, an additive powder for adjusting electrical characteristics, and a binder resin solution. Therefore, the dielectric slurry does not contain microcapsules. Using this dielectric slurry, a dielectric green sheet was molded.

  The specifications of the multilayer ceramic capacitor of Comparative Example 2 are as described later. In particular, in Comparative Example 2, a dielectric slurry was prepared by preparing and dispersing and mixing a dielectric powder, an additive powder for adjusting electrical characteristics, and a binder resin solution. A predetermined amount of n-octanol was added to the dielectric slurry and mixed to prepare a dielectric slurry. Therefore, the dielectric slurry does not contain microcapsules. Using this dielectric slurry, a dielectric green sheet was molded.

Specifications of Multilayer Ceramic Capacitor ・ Size L × W × T (design value): 3.2 mm × 2.5 mm × 2.5 mm
・ Ceramic material: BaTiO ₃
・ Capacitance: 10μF
・ Rated voltage: 25V
Internal electrode layer: Ni
External electrode: composed of a base electrode layer and a plating layer The base electrode layer is an electrode layer containing Cu and glass. The plating layer is a two-layer structure of a Ni plating layer and a Sn plating layer.

(B) Evaluation For Example 1 to Example 9 and Comparative Example 1 and Comparative Example 2, “area ratio (%) of microcapsules in dielectric green sheet cross section”, “average diameter of microcapsules (μm)” ”,“ Ratio of encapsulating material in 1 g of microcapsule (wt%) ”,“ number of peelings (number) ”,“ short rate (%) ”and the like were evaluated.

The “area ratio (%) of microcapsules in the cross section of the dielectric green sheet” is obtained by processing the dielectric green sheet with a focused ion beam (FIB) device to obtain the cross section of the dielectric green sheet, and the SEM cross section in the reflected electron mode Observations were made. From the obtained image, the area ratio of the microcapsules in the cross section of the dielectric green sheet was determined. At that time, the particle state that appeared black was used as a microcapsule, and the area of each particle was obtained from image analysis. The measurement range was 10 fields with 40 μm ² as one field. The area of all the microcapsules with respect to the measurement area was defined as “area ratio (%) of microcapsules in cross section of dielectric green sheet”. However, in Example 1, since the amount of microcapsules was small, the measurement range was 50 visual fields.

  “The average diameter of microcapsules (μm)” was obtained by separately observing the used microcapsules with an SEM, measuring the particle diameter of 100 particles, and taking the average value as the diameter.

  The “ratio of the encapsulating material to the total mass of the microcapsule (wt%)” was measured at about 5.0 g of the microcapsule mass containing the encapsulating material and then heated at 150 ° C. for 3 hours. Thereafter, the mass was measured again, and the ratio of the encapsulating material (wt%) to the total mass of the microcapsule was determined from the mass reduction rate and the mass of the microcapsule containing the original encapsulating material.

  The “number of occurrences of peeling (pieces)” was 10000 on the WT surface of the fired laminate, and peeling occurred when the peeling between the ceramic layers was 1 μm or more.

  "Short-circuit rate (%)" confirmed whether or not 10,000 multilayer ceramic capacitors formed up to the plating layer of the external electrode were short-circuited under a measurement condition of 2.5 V using a measurement sorter.

  The evaluation results are shown in Tables 1 and 2.

  From Table 2, it was found that Comparative Example 1 and Comparative Example 2 did not contain microcapsules in the dielectric green sheet, and thus “the number of occurrences of peeling (pieces)” and “short ratio (%)” were high. .

  On the other hand, according to Table 1, Examples 1 to 9 have low “number of peelings (number)” and “short ratio (%)” because microcapsules are contained in the dielectric green sheet. I understood.

  As described above, according to the method for manufacturing a multilayer ceramic electronic component according to the present invention, since the microcapsules containing the solvent are contained in the ceramic green sheet, the microcapsules are crushed when pressing the multilayer sheet in the stacking direction. The solvent in the microcapsule is supplied to the ceramic green sheet interface at the time of lamination or the interface between the ceramic green sheet and the internal electrode layer. As a result, the internal electrode layer and the binder of the ceramic green sheet are compatible with each other, and the adhesion can be improved dramatically. Therefore, it was confirmed that it was possible to suppress the peeling between the ceramic green sheets in the multilayer ceramic electronic component.

  In particular, it is clear that peeling between the dielectric layers can be completely suppressed by using n-octanol or ethanol as the solvent of the microcapsules and setting the area ratio of the microcapsules in the cross section of the dielectric green sheet to 1% to 20%. It became.

As described above, the embodiment of the present invention has been disclosed in the above description, but the present invention is not limited to this.
That is, various modifications can be made to the embodiment described above with respect to the mechanism, shape, material, quantity, position, arrangement, etc., without departing from the scope of the technical idea and object of the present invention. Which are included in the present invention.

DESCRIPTION OF SYMBOLS 10 Multilayer ceramic capacitor 12 Laminated body 14 Ceramic layer 14a Outer layer part 14b Inner layer part 16 Internal electrode layer 16a 1st internal electrode layer 16b 2nd internal electrode layer 18a 1st extraction electrode part 18b 2nd extraction electrode part 20a Opposite Electrode 20b Side (W gap)
20c End (L gap)
22 external electrode 22a first external electrode 22b second external electrode 24a first base electrode layer 24b second base electrode layer 26a first plating layer 26b second plating layer 30 ceramic green sheet 31 for internal electrode formation Conductive pattern 32 Laminated sheet 34 Part where ceramic green sheet and conductive pattern for internal electrode formation are familiar 36 Part where ceramic green sheet is familiar 38 Laminated block 40 Microcapsule x Laminating direction y Width direction z Length direction

Claims (5)

Preparing a ceramic green sheet;
Applying a conductive paste for internal electrodes on the ceramic green sheet to form a conductive pattern for forming internal electrodes;
Laminating a plurality of ceramic green sheets and ceramic green sheets on which the internal electrode forming conductive pattern is formed, to obtain a laminated sheet;
Pressing the laminated sheet in the laminating direction to obtain a laminated block;
A method for producing a multilayer ceramic electronic component comprising:
The ceramic green sheet constituting the laminated sheet contains microcapsules containing a solvent,
A method for producing a multilayer ceramic electronic component, characterized in that: Cutting the laminated block to obtain a laminated body before firing;
Firing the laminate before firing, and obtaining a laminate after firing;
Forming an external electrode on the fired laminate;
The method for producing a multilayer ceramic electronic component according to claim 1, further comprising:   The microcapsule is crushed when the laminated sheet is pressed in the laminating direction, and the solvent in the microcapsule is present at the interface between the ceramic green sheets and the interface between the ceramic green sheet and the internal electrode forming conductive pattern during lamination. The binder of the ceramic green sheets is supplied, and the binder of the conductive pattern for internal electrode formation and the binder of the ceramic green sheet are compatible with each other. The manufacturing method of the multilayer ceramic electronic component of 2.   4. The method for manufacturing a multilayer ceramic electronic component according to claim 1, wherein an area ratio of the microcapsules in a cross section of the ceramic green sheet is 1% or more and 20% or less. 5.   The method for manufacturing a multilayer ceramic electronic component according to any one of claims 1 to 4, wherein the solvent is selected from any one of n-octanol and ethanol.

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