JP2020004815A - Manufacturing method of chip-type electronic component - Google Patents

Abstract

To provide a manufacturing method of a chip-type electronic component that can reduce a defect when a protective layer is formed on a side surface of a laminate in which an internal electrode is exposed.SOLUTION: A manufacturing method of a chip-type electronic component according to the present invention includes a step of producing a laminate in which an internal electrode is exposed on a pair of side surfaces facing each other in the width direction orthogonal to the lamination direction, including a plurality of laminated internal electrodes, a step of arranging the laminate on an adhesive sheet, a step of removing the adhesive attached to the side surface of the laminate where the internal electrode is exposed by using a treatment liquid including a component that dissolves the adhesive included in the adhesive sheet, and a step of forming a protective layer on the side surface of the laminate after the adhesive has been removed.SELECTED DRAWING: Figure 9

Description

The present invention relates to a method for manufacturing a chip-type electronic component.

An example of a chip-type electronic component such as a multilayer ceramic electronic component is a multilayer ceramic capacitor. In order to manufacture a multilayer ceramic capacitor, for example, after laminating ceramic green sheets on which internal electrodes are formed and firing the obtained unsintered component main body, externally facing end faces of the sintered component main body are opposed to each other. Form electrodes. As a result, a multilayer ceramic capacitor is obtained in which the internal electrodes extended to both end surfaces are electrically connected to the external electrodes.

In recent years, as electronic components have become smaller and more sophisticated, multilayer ceramic capacitors have been required to be smaller and have higher capacitance. In order to reduce the size and increase the capacity of the multilayer ceramic capacitor, it is effective to increase the effective area of the internal electrodes occupying the ceramic green sheets, that is, the area of the internal electrodes facing each other.

For example, Patent Document 1 discloses a step of manufacturing a mother block including a plurality of stacked ceramic green sheets and internal electrode patterns respectively arranged along a plurality of interfaces between the ceramic green sheets; By cutting the mother block along a cutting line in a first direction and a cutting line in a second direction which are orthogonal to each other, a laminated structure including a plurality of unfired ceramic layers and a plurality of internal electrodes is formed. A cutting step of obtaining a plurality of green chips in which the internal electrodes are exposed on a cutting side surface that has appeared by cutting along the cutting line in the first direction, and applying a ceramic paste to the cutting side surface. Forming an unfired ceramic protective layer to obtain an unfired component body, and firing the unfired component body. Method of manufacturing a multilayer ceramic electronic component and a process is disclosed.

In the method for manufacturing a multilayer ceramic electronic component described in Patent Literature 1, a plurality of green chips arranged in a row and a column direction are rolled with a plurality of green chips being rolled in a state in which a distance between the green chips is widened. Further performing a rolling step of aligning each cut side surface of the green chip to an open surface, and, in the coating step, applying the ceramic paste simultaneously to the cut side surfaces of the plurality of green chips that are formed as open surfaces as a result of the rolling step. It is preferred to apply.

Japanese Patent No. 5678905

In the method described in Patent Literature 1, the rolling step is performed in a state where the green chip is stuck on the adhesive sheet. Therefore, when the green chip rotates on the adhesive sheet, the adhesive contained in the adhesive sheet may adhere to the green chip. In this case, if a ceramic protective layer is formed on the cut side surface of the green chip to which the adhesive has adhered, there is a possibility that the appearance may be determined to be poor when a structural defect inspection is performed from the surface of the ceramic protective layer.

In addition, the adhesive contained in the adhesive sheet is burned out when the component main body is fired and becomes a cavity. Since particles may enter into the hollow portion during firing, the internal electrodes may contact each other across the layers and short-circuit failure may occur.

The above problem is not limited to the case of manufacturing a multilayer ceramic capacitor, but is a problem common to the case of manufacturing a chip-type electronic component such as a multilayer ceramic electronic component other than the multilayer ceramic capacitor.

The present invention has been made to solve the above problems, and provides a method of manufacturing a chip-type electronic component capable of reducing defects when forming a protective layer on a side surface of a laminate in which internal electrodes are exposed. The purpose is to do.

The method for manufacturing a chip-type electronic component of the present invention includes a step of producing a laminate including a plurality of laminated internal electrodes, wherein the internal electrodes are exposed on a pair of side surfaces opposed in a width direction perpendicular to the lamination direction, Disposing the laminate on a pressure-sensitive adhesive sheet, and using a treatment liquid containing a component that dissolves the pressure-sensitive adhesive contained in the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive adhered to the side surface of the laminate where the internal electrodes are exposed And a step of forming a protective layer on a side surface of the laminate after the pressure-sensitive adhesive has been removed.

According to the present invention, it is possible to provide a method of manufacturing a chip-type electronic component that can reduce defects when forming a protective layer on a side surface of a laminate in which internal electrodes are exposed.

FIG. 1 is a perspective view schematically showing an example of a multilayer ceramic capacitor obtained by the method of manufacturing a chip-type electronic component according to the present invention. FIG. 2 is a perspective view schematically showing an example of a component body constituting the multilayer ceramic capacitor shown in FIG. FIG. 3 is a perspective view schematically showing an example of a green chip prepared for manufacturing the component body shown in FIG. FIG. 4 is a plan view schematically showing an example of a ceramic green sheet on which an internal electrode pattern prepared for manufacturing the green chip shown in FIG. 3 is formed. FIG. 5A is a perspective view for explaining a step of laminating the ceramic green sheets shown in FIG. FIGS. 5B and 5C are plan views for explaining a process of laminating the ceramic green sheets shown in FIG. FIG. 6 is a perspective view schematically illustrating an example of a plurality of green chips obtained by cutting the mother block. FIG. 7 is a perspective view showing a state in which a plurality of green chips arranged in the row and column directions are extended from each other. FIGS. 8A, 8B, and 8C are views from the end face direction of the green chip for explaining an example of the rolling process. FIG. 9 is a schematic diagram schematically illustrating an example of a method of performing a polishing process by polishing on a cut side surface. FIG. 10 is a schematic diagram schematically illustrating an example of a method of performing ultrasonic cleaning on a cut side surface. FIGS. 11 (a), 11 (b), 11 (c), 11 (d), and 11 (e) show that a plurality of green chips on which unfired ceramic protective layers are formed are rolled again. It is the figure shown from the end face direction of a green chip for explaining an example of a rolling process. FIG. 12 is a WT cross-sectional view schematically illustrating an example of a component body constituting the multilayer ceramic capacitor.

Hereinafter, a method for manufacturing a chip-type electronic component of the present invention will be described.
However, the present invention is not limited to the following configuration, and can be appropriately modified and applied without changing the gist of the present invention. Note that the present invention also includes a combination of two or more of the individual desirable configurations described below.

In the manufacturing process of the chip-type electronic component, when the laminate is placed on the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive contained in the pressure-sensitive adhesive sheet adheres to the laminate. In the method for manufacturing a chip-type electronic component according to the present invention, before forming a protective layer on the side surface of the laminated body where the internal electrodes are exposed, using a treatment liquid containing a component that dissolves the adhesive, It is characterized by removing the agent. As a result, defects such as defective appearance and short-circuit caused by the adhesive can be reduced.

In the treatment liquid used in the method for producing a chip-type electronic component of the present invention, it is preferable that the component that dissolves the adhesive does not substantially react with the resin component contained in the laminate. In this case, it is possible to dissolve the adhesive adhered to the laminate while causing little damage to the laminate and leaving the resin component in the laminate.

In selecting a processing solution, attention is paid to the Hansen solubility parameter. Specifically, the Hansen solubility parameter distance between the component that dissolves the adhesive and the adhesive included in the adhesive sheet is small, and the Hansen solubility parameter distance between the component that dissolves the adhesive and the resin component included in the laminate is large. To be. Therefore, the Hansen solubility parameter distance between the component that dissolves the adhesive and the adhesive included in the adhesive sheet is preferably smaller than the Hansen solubility parameter distance between the component that dissolves the adhesive and the resin component included in the laminate. .

The Hansen solubility parameter is a measure of the solubility of a substance in a certain other substance. The solubility parameter introduced by Hildebrand is a dispersion term δ _d , a polarity term δ _p , it is obtained by dividing the three components of the hydrogen bond [delta] _h. The dispersion term δ _d indicates the effect of the nonpolar interaction, the polar term δ _p indicates the effect of the dipole force, and the hydrogen bond term δ _h indicates the effect of the hydrogen bond force. The Hansen solubility parameter can be calculated by calculating the distance R of the two-component solubility parameter according to the following formula, and comparing the solubility.
R = {4 × (δ _d1 −δ _d2 ) ² + (δ _p1 −δ _p2 ) ² + (δ _h1 −δ _h2 ) ² } ^1/2
δ _d1 : dispersion term of component 1, δ _d2 : dispersion term of component 2, δ _p1 : polarity term of component 1, δ _p2 : polarity term of component 2, δ _h1 : hydrogen bonding term of component 1, δ _h2 : component Hydrogen bond term of 2

The definition and calculation method of the Hansen solubility parameter are described in the following documents.
Charles M. Hansen, Hansen Solubility Parameters: A User's Handbook, CRC Press (2007)

For a solvent for which the literature value of the Hansen solubility parameter is unknown, the Hansen solubility parameter can be easily estimated from its chemical structure by using computer software (Hansen Solubility Parameters in Practice (HSPiP)).

In addition, the Hansen solubility parameter of a specific polymer is usually determined by dissolving the polymer in a number of different organic solvents for which the Hansen solubility parameter is determined, and conducting a solubility test for measuring the solubility. Specifically, when the coordinates of the Hansen solubility parameters of all the organic solvents used for the solubility test of a certain polymer are shown in a three-dimensional space, all the coordinates of the organic solvent that dissolved the polymer are included inside the sphere, A sphere (solubility sphere) is searched for such that the coordinates of the organic solvent in which the polymer does not dissolve are outside the sphere, and the center coordinates of the solubility sphere are used as the Hansen solubility parameters of the polymer.

In the method of manufacturing a chip-type electronic component according to the present invention, it is preferable that the component that dissolves the pressure-sensitive adhesive is uniformly dispersed in the treatment liquid. Further, it is preferable that the component that dissolves the pressure-sensitive adhesive has a high affinity for the solvent in the treatment liquid.

The solubility of the pressure-sensitive adhesive and the like also changes depending on factors such as the temperature and pressure of the treatment using the treatment liquid and the content of the component that dissolves the pressure-sensitive adhesive. Therefore, even when a processing solution containing the same components is used, the solubility may change depending on how the laminate is processed. For example, it is difficult to dissolve the laminate simply by immersing the laminate in the treatment liquid. On the other hand, it becomes easier to dissolve when pressure is applied such as pressing an object containing the treatment liquid against the laminate.

In the method for manufacturing a chip-type electronic component of the present invention, examples of the adhesive contained in the adhesive sheet include an acrylate-based adhesive. The acrylate-based pressure-sensitive adhesive is a pressure-sensitive adhesive containing a polymer containing an alkyl (meth) acrylate as a monomer unit. (Meth) acrylate means acrylate or methacrylate. The polymer may be a homopolymer or a copolymer obtained by copolymerizing two or more kinds of alkyl (meth) acrylates. Further, the polymer may further contain another monomer unit copolymerizable with the alkyl (meth) acrylate. The alkyl group constituting the alkyl (meth) acrylate preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms. Examples of such (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, and the like. Examples of the acrylate-based pressure-sensitive adhesive include a polybutyl acrylate-based pressure-sensitive adhesive.

In the method for producing a chip-type electronic component according to the present invention, when the pressure-sensitive adhesive contained in the pressure-sensitive adhesive sheet is an acrylate-based pressure-sensitive adhesive, the treatment liquid is represented by the general formula R ¹ COOR ² or R ¹ COR ² (R ¹ and R ² Are each independently a solution containing a compound represented by an alkyl group). The acrylate-based pressure-sensitive adhesive has a structure called COOR (R is an alkyl group constituting alkyl (meth) acrylate). Therefore, by using an ester-based compound represented by R ¹ COOR ² or a ketone-based compound represented by R ¹ COR ² similar to the structure of the pressure-sensitive adhesive as a treatment liquid, an acrylate-based pressure-sensitive adhesive is used. It can be easily dissolved.

In the general formula R ¹ COOR ² , R ¹ is preferably an alkyl group having 1 to ² carbon atoms, and R ² is preferably an alkyl group having 1 to 4 carbon atoms. In the general formula R ¹ COR ² , R ¹ is preferably an alkyl group having 1 to ² carbon atoms, and R ² is preferably an alkyl group having 1 to 4 carbon atoms. R ¹ and R ² may be the same alkyl group or different alkyl groups.

In particular, the compound contained in the treatment liquid is preferably any one selected from the group consisting of n-butyl acetate, n-propyl acetate, ethyl acetate, methyl acetate, and methyl ethyl ketone.

The content of the compound in the treatment liquid is not particularly limited, but the treatment liquid preferably contains the compound in an amount of 20% by weight or more and 75% by weight or less.

Note that, even when an adhesive other than the acrylate-based adhesive is used, the same concept as described above can be applied.

Hereinafter, a method of manufacturing a multilayer ceramic capacitor will be described as an embodiment of a method of manufacturing a chip-type electronic component according to the present invention. The manufacturing method of the present invention can be applied to chip-type electronic components such as multilayer ceramic electronic components other than the multilayer ceramic capacitor.

First, a multilayer ceramic capacitor obtained by the method for manufacturing a chip-type electronic component of the present invention will be described.
FIG. 1 is a perspective view schematically showing an example of a multilayer ceramic capacitor obtained by the method of manufacturing a chip-type electronic component according to the present invention. FIG. 2 is a perspective view schematically showing an example of a component body constituting the multilayer ceramic capacitor shown in FIG.

In the present specification, the laminating direction, width direction, and length direction of the multilayer ceramic capacitor and the component body are defined by arrows T, W, and L in the multilayer ceramic capacitor 11 shown in FIG. 1 and the component body 12 shown in FIG. 2, respectively. Direction. Here, the laminating direction, the width direction, and the length direction are orthogonal to each other. The laminating direction is a direction in which a plurality of ceramic layers 25 and a plurality of pairs of internal electrodes 26 and 27 are stacked.

The multilayer ceramic capacitor 11 shown in FIG. As shown in FIG. 2, the component body 12 has a rectangular parallelepiped shape or a substantially rectangular parallelepiped shape, and has a pair of main surfaces 13 and 14 facing the laminating direction T and a width direction W orthogonal to the laminating direction T. And a pair of end surfaces 17 and 18 facing in a length direction L perpendicular to the laminating direction T and the width direction W.

In this specification, a cross section of the multilayer ceramic capacitor 11 or the component body 12 that intersects the pair of end faces 17 and 18 and that is along the lamination direction T is referred to as an LT cross section. Further, a cross section of the multilayer ceramic capacitor 11 or the component body 12 that intersects the side surface 15 or the side surface 16 and extends along the lamination direction T is referred to as a WT cross section. Further, a cross section of the multilayer ceramic capacitor 11 or the component body 12 that intersects the side surface 15, the side surface 16, the end surface 17 or the end surface 18 and is orthogonal to the lamination direction T is referred to as an LW cross section.

FIG. 3 is a perspective view schematically showing an example of a green chip prepared for manufacturing the component body shown in FIG.
As will be described later, the component body 12 shown in FIG. 2 includes an unfired ceramic protective layer 22 and a pair of mutually facing side surfaces (hereinafter, referred to as cut side surfaces) 20 and 21 of the green chip 19 shown in FIG. It is obtained by baking the product in which each of 23 is formed. In the following description, a portion derived from the green chip 19 in the fired component body 12 will be referred to as a laminate 24. In addition, in the present specification, the concept of the laminate includes a green chip that is in an unfired state.

As shown in FIGS. 2 and 3, the laminate 24 in the component body 12 includes a plurality of ceramic layers 25 extending in the directions of the main surfaces 13 and 14 and stacked in a direction orthogonal to the main surfaces 13 and 14. It has a laminated structure constituted by a plurality of pairs of internal electrodes 26 and 27 formed along the interface between the layers 25. The component body 12 has a pair of ceramic protective layers 22 and 23 disposed on the cut side surfaces 20 and 21 of the laminate 24 to provide the side surfaces 15 and 16 respectively. The thicknesses of the ceramic protective layers 22 and 23 are preferably the same.

In FIGS. 1 and 2, for convenience of description, boundaries between the stacked body 24 and each of the ceramic protective layers 22 and 23 are clearly illustrated, but such boundaries are not clearly illustrated. You may.

As shown in FIGS. 2 and 3, the internal electrode 26 and the internal electrode 27 face each other with the ceramic layer 25 interposed therebetween. When the internal electrode 26 and the internal electrode 27 face each other, electrical characteristics are developed. That is, in the multilayer ceramic capacitor 11 shown in FIG. 1, capacitance is formed.

The internal electrode 26 has an exposed end exposed on the end face 17 of the component body 12, and the internal electrode 27 has an exposed end exposed on the end face 18 of the component body 12. On the other hand, the internal electrodes 26 and 27 are not exposed on the side surfaces 15 and 16 of the component body 12 because the ceramic protective layers 22 and 23 described above are arranged.

As shown in FIG. 1, the multilayer ceramic capacitor 11 is further provided on at least one pair of end faces 17 and 18 of the component body 12 so as to be electrically connected to the exposed ends of the internal electrodes 26 and 27, respectively. External electrodes 28 and 29 are formed respectively.

The external electrodes 28 and 29 are formed on at least one pair of end surfaces 17 and 18 of the component main body 12, respectively. In FIG. 1, the external electrodes 28 and 29 extend to a part of each of the main surfaces 13 and 14 and the side surfaces 15 and 16. Has a part.

As the conductive material forming the internal electrode, for example, a metal material such as Ni, Cu, Ag, Pd, an Ag-Pd alloy, or Au can be used.

As a ceramic material constituting the ceramic layer and the ceramic protective layer, for example, a dielectric ceramic containing BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , CaZrO _3, or the like as a main component can be used.

It is preferable that the ceramic material forming the ceramic protective layer has at least the same main component as the ceramic material forming the ceramic layer. In this case, it is particularly preferable that ceramic materials having the same composition are used for both the ceramic layer and the ceramic protective layer.

As described above, the manufacturing method of the present invention can be applied to multilayer ceramic electronic components other than the multilayer ceramic capacitor. For example, when the multilayer ceramic electronic component is a piezoelectric component, a piezoelectric ceramic such as a PZT ceramic is used, and when a thermistor is used, a semiconductor ceramic such as a spinel ceramic is used.

The external electrode is preferably composed of a base layer and a plating layer formed on the base layer. As the conductive material forming the underlayer, for example, Cu, Ni, Ag, Pd, an Ag-Pd alloy, Au, or the like can be used. The base layer may be formed by applying a conductive paste to the unfired component body and applying a cofiring method of simultaneously firing the component body, and applying the conductive paste to the fired component body. It may be formed by applying a post-fire method of baking. Alternatively, the underlayer may be formed by direct plating, or may be formed by curing a conductive resin including a thermosetting resin.

The plating layer formed on the underlayer preferably has a two-layer structure of Ni plating and Sn plating thereon.

Next, a method of manufacturing the multilayer ceramic capacitor 11 shown in FIG. 1 will be described as one embodiment of a method of manufacturing a chip-type electronic component according to the present invention.

Each embodiment described below is an exemplification, and it is needless to say that partial replacement or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, description of items common to the first embodiment will be omitted, and only different points will be described. In particular, the same operation and effect of the same configuration will not be sequentially described for each embodiment.

[First Embodiment]
In the first embodiment, a grinding process or a cutting process is performed on the side surface of the stacked body where the internal electrodes are exposed.

First, a ceramic green sheet to be a ceramic layer is prepared. The ceramic green sheet contains a binder resin, a solvent, and the like, in addition to the ceramic raw material including the above-described dielectric ceramic and the like. For example, a ceramic slurry containing a ceramic powder, a binder resin, and a solvent is prepared, and the ceramic slurry is formed into a sheet shape on a carrier film using a die coater, a gravure coater, a micro gravure coater, or the like, thereby forming a ceramic green. A sheet is obtained. The ceramic slurry may contain various additives such as a plasticizer, a dispersant, and an antistatic agent.

As the binder resin contained in the ceramic green sheet, for example, a cellulose-based, acrylic-based, polyvinyl alcohol (PVA) -based, polyvinyl butyral (PVB) -based resin, or the like can be used. Further, as a plasticizer contained in the ceramic green sheet, for example, a phthalate ester such as dioctyl phthalate (DOP) or the like can be used.

The thickness of the ceramic green sheet is usually 3 μm or less, preferably 1 μm or less, and more preferably 0.6 μm or less.

Next, a conductive paste is printed on the ceramic green sheet in a predetermined pattern. The conductive paste contains a binder resin, a solvent, and the like, in addition to the above-described metal materials. The conductive paste is applied on the ceramic green sheet using, for example, a screen printing method, an inkjet method, a gravure printing method, or the like.

FIG. 4 is a plan view schematically showing an example of a ceramic green sheet on which an internal electrode pattern prepared for manufacturing the green chip shown in FIG. 3 is formed.
As shown in FIG. 4, an internal electrode pattern 32 to be each of the internal electrodes 26 and 27 is formed by printing a conductive paste in a predetermined pattern on a ceramic green sheet 31 to be the ceramic layer 25. Is done. Specifically, a plurality of strip-shaped internal electrode patterns 32 are formed on the ceramic green sheet 31.

The thickness of the internal electrode pattern is not particularly limited, but is preferably 1.5 μm or less.

Thereafter, a laminating step is performed in which a predetermined number of ceramic green sheets on which the internal electrode patterns are formed are stacked while being shifted, and a predetermined number of ceramic green sheets on which no internal electrode patterns are formed are stacked above and below the ceramic green sheets.

FIG. 5A is a perspective view for explaining a step of laminating the ceramic green sheets shown in FIG.
As shown in FIG. 5A, the ceramic green sheets 31 on which the internal electrode patterns 32 are formed are shifted by a predetermined distance along the width direction of the internal electrode patterns 32, that is, by half the width of the internal electrode patterns 32. While stacking a predetermined number of sheets. Further, a predetermined number of ceramic green sheets on which no internal electrode pattern is printed are laminated on the upper and lower sides.

FIGS. 5B and 5C are plan views for explaining a process of laminating the ceramic green sheets shown in FIG. FIGS. 5B and 5C show enlarged ceramic green sheets of the first and second layers, respectively.
FIGS. 5B and 5C show cutting lines 33 in a first direction (vertical direction in FIGS. 5B and 5C) orthogonal to the direction in which the strip-shaped internal electrode patterns 32 extend. In addition, each part of a cutting line 34 in a second direction (the left-right direction in FIGS. 5B and 5C) orthogonal to this is shown. The band-shaped internal electrode pattern 32 has a shape in which two internal electrodes 26 and 27 are connected to each other at the respective lead portions, and are connected in the second direction. 5 (b) and 5 (c), the cutting lines 33 and 34 are shown in common.

As a result of the laminating step, a mother block including a plurality of laminated ceramic green sheets and internal electrode patterns arranged along a plurality of interfaces between the ceramic green sheets is obtained. The obtained mother block is pressed in the laminating direction by means such as a hydrostatic press.

By cutting the pressed mother block along a cutting line in the first direction and a cutting line in the second direction that are orthogonal to each other, a plurality of green chips (laminates) can be obtained. For this cutting, for example, a method such as dicing, pressing and laser cutting is applied.

FIG. 6 is a perspective view schematically illustrating an example of a plurality of green chips obtained by cutting the mother block.
As shown in FIG. 6, the mother block 35 is cut along a cutting line 33 in a first direction and a cutting line 34 in a second direction orthogonal to each other, and a plurality of green chips 19 arranged in the row and column directions are formed. can get. In FIG. 6, the uppermost internal electrode pattern 32 located inside the mother block 35 is indicated by a broken line. In FIG. 6, six green chips 19 are taken out from one mother block 35. However, actually, a larger number of green chips 19 are taken out. Further, the mother block 35 shown in FIG. 6 is merely an example, and in actuality, the number of stacked ceramic green sheets 31 and the internal electrode patterns 32 and the number of rows forming the band-shaped internal electrode patterns 32 are larger. Become.

As shown in FIG. 3, each green chip 19 has a laminated structure including a plurality of ceramic layers 25 in an unfired state and a plurality of internal electrodes 26 and 27. The cutting side surfaces 20 and 21 of the green chip 19 are surfaces that have appeared by cutting along the cutting line 33 in the first direction, and the cutting end surfaces 36 and 37 are surfaces that have appeared by cutting along the cutting line 34 in the second direction. is there. All of the internal electrodes 26 and 27 are exposed on the cut side surfaces 20 and 21. Further, only the internal electrode 26 is exposed on one cut end surface 36, and only the internal electrode 27 is exposed on the other cut end surface 37.

As shown in FIG. 6, the plurality of green chips 19 arranged in the row and column directions are pasted on an expandable adhesive sheet 38. The adhesive sheet 38 is expanded by an expanding device (not shown).

FIG. 7 is a perspective view showing a state in which a plurality of green chips arranged in the row and column directions are extended from each other.
By expanding the pressure-sensitive adhesive sheet 38 shown in FIG. 6, as shown in FIG. 7, the plurality of green chips 19 arranged in the row and column directions are in a state where the intervals between them are widened.

At this time, in a rolling step described later, the pressure-sensitive adhesive sheet 38 is expanded to such an extent that the plurality of green chips 19 do not collide with each other and can be rolled smoothly.

The pressure-sensitive adhesive sheet 38 preferably has plasticity that does not return to its original shape once expanded. In this case, the handling of the expanded adhesive sheet 38 is easy. For example, after a plurality of green chips 19 are obtained by cutting the mother block 35, the cut side surfaces 20 and 21 or the cut end surfaces 36 and 37 of the adjacent green chips 19 are re-adhered by the binder resin contained in the green chip 19. However, if the expanded pressure-sensitive adhesive sheet 38 does not completely return to its original shape, the cut side surfaces 20 and 21 or the cut end surfaces 36 and 37 do not come into contact with each other. Adhesion can be avoided.

The adhesive sheet 38 includes, for example, a base material and an adhesive layer provided on the base material. As a material constituting the base material, for example, vinyl chloride resin and the like can be mentioned. The pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer includes, for example, an acrylate-based pressure-sensitive adhesive.

Thereafter, a rolling step of rolling the plurality of green chips to make the cut side surfaces of the plurality of green chips uniform and open surfaces is performed.

FIGS. 8A, 8B, and 8C are views from the end face direction of the green chip for explaining an example of the rolling process.

As shown in FIG. 8A, a plurality of green chips 19 stuck on the adhesive sheet 38 are placed on the support 40 together with the adhesive sheet 38, while the rolling plate 41 is attached to the green chip 19. It is placed in a state where it can act from above. The support 40 and the rolling plate 41 are preferably made of silicone rubber.

By moving the support 40 in the direction of the arrow with respect to the rolling plate 41, the plurality of green chips 19 are rotated 90 degrees as shown in FIGS. The cutting side surface 20 is in a state of facing upward. If the rolling plate 41 is removed in this state, the cut side surface 20 becomes an open surface.

In order to smooth the rolling of the green chips, the rolling operation may be performed after transferring the green chips from the adhesive sheet to the adhesive rubber sheet.

In the first embodiment, a grinding process using abrasive grains or a cutting process using a cutting tool is performed on the cut side surface facing upward by the rolling process. Note that the grinding process and the cutting process may be performed in combination. In this case, the order in which the grinding process and the cutting process are performed is not particularly limited.

As the grinding process, for example, a grinding process using fixed abrasives (dicing, grinding, etc.), a polishing process using fixed abrasives (dry polishing, tape polishing, etc.), a polishing process using free abrasives (lapping) , Polishing, etc.). These grinding processes may be combined. Examples of the cutting process include cutting by rotating a cutting tool, cutting by rotating a green chip, cutting by linear motion of a cutting tool, and cutting by linear motion of a green tip. These cutting processes may be combined. Specifically, a cutting process using a cutting device such as a surface planar is exemplified.

FIG. 9 is a schematic diagram schematically illustrating an example of a method of performing a polishing process by polishing on a cut side surface.
As shown in FIG. 9, the plurality of green chips 19 held by the polishing head 230 are pressed against and brought into contact with the polishing pad 220, and while the polishing liquid (grinding liquid) A is dropped from the supply pipe 240, the polishing head 230 and the polishing head 230 are polished. By rotating the platen 210 relatively, the cut side surface is polished. As shown in FIG. 9, it is preferable that a cut side surface of each green chip 19 is polished while the plurality of green chips 19 are stuck on the adhesive sheet 38.

When the pressure-sensitive adhesive contained in the pressure-sensitive adhesive sheet adheres to the cut side surface, it is preferable that the grinding fluid used for the grinding treatment or the cutting fluid used for the cutting treatment contains a component that dissolves the pressure-sensitive adhesive. The adhesive adhered to the cut side surface can be removed by the grinding fluid used for the grinding process or the cutting fluid used for the cutting process.

During the grinding process or the cutting process, pressure is applied to the cut side surface of the green chip, so that the dissolution of the adhesive is promoted. At the time of the grinding process or the cutting process, it is preferable that a grinding fluid or a cutting fluid does not adhere to the adhesive sheet to which the green chip is fixed. However, even when the grinding fluid or the cutting fluid adheres to the pressure-sensitive adhesive sheet due to unexpected scattering, the pressure is not applied as compared to the cut side surface, so that the pressure-sensitive adhesive dissolution rate is low. Therefore, while the grinding process or the cutting process is being performed, the situation in which the adhesive fixing the green chip is dissolved and the green chip falls off does not occur.

In the first embodiment, a cleaning process may be performed on the cut side surface after the grinding process or the cutting process is performed. In this case, the cleaning liquid used for the cleaning process may contain a component that dissolves the adhesive. The adhesive adhered to the cut side surface can be removed by the cleaning liquid used for the cleaning process.

As the cleaning treatment, for example, ultrasonic cleaning or the like can be mentioned. Ultrasonic cleaning can be performed by a known method, for example, using an ultrasonic cleaning machine, immersing a plurality of green chips held by a holder in a cleaning liquid, ultrasonic wave provided in a cleaning tank The plurality of green chips can be cleaned with the cleaning liquid to which vibration is applied by the vibrator. At this time, it is preferable to swing the holder along a direction parallel to the direction of the vibration wave traveling in the cleaning liquid. Thereby, a further cleaning effect can be obtained.

FIG. 10 is a schematic diagram schematically illustrating an example of a method of performing ultrasonic cleaning on a cut side surface.
As shown in FIG. 10, the plurality of green chips 19 held by the holder 330 are immersed in the cleaning liquid B. The cut side surface is ultrasonically cleaned by the cleaning liquid B vibrated by the vibration plate 320 installed in the cleaning tank 310 and the ultrasonic vibrator 321 assembled thereto. As shown in FIG. 10, it is preferable that the cut side surface of each green chip 19 is subjected to ultrasonic cleaning while the plurality of green chips 19 are stuck on the adhesive sheet 38.

In the first embodiment, a rinsing process for washing off the liquid (a grinding liquid or a cutting liquid and, if necessary, a cleaning liquid) attached to the green chip is performed as needed. In the rinsing treatment, it is preferable to perform cleaning using water, and it is more preferable to perform ultrasonic cleaning using water.

After the rinsing treatment, a drying step is preferably performed. As a method of the drying step, for example, a method of blowing water by air, a method of rotating an object to fly water by centrifugal force, a method of flying water by air and centrifugal force, and setting a temperature of 40 ° C or more and 100 ° C or less Drying in a baked oven.

Subsequently, an unfired ceramic protective layer is formed on the cut side surface. The unfired ceramic protective layer is formed by, for example, attaching a green sheet for a ceramic protective layer, or applying a paste for a ceramic protective layer.

The green sheet for the ceramic protective layer or the paste for the ceramic protective layer preferably contains, as a main component, the same ceramic material as the ceramic green sheet for producing the mother block.

After forming the unfired ceramic protective layer, a drying step is performed, if necessary. In the drying step, the green chip on which the unfired ceramic protective layer is formed is placed in, for example, an oven set at 120 ° C. for 5 minutes.

Thereafter, a rolling step of rolling the green chips on which the unfired ceramic protective layers are formed again is performed.

FIGS. 11 (a), 11 (b), 11 (c), 11 (d), and 11 (e) show that a plurality of green chips on which unfired ceramic protective layers are formed are rolled again. It is the figure shown from the end face direction of a green chip for explaining an example of a rolling process.

As shown in FIG. 11A, a plurality of green chips 19 each having a cut side surface 20 on which an unfired ceramic protective layer 22 is formed are supported by a support 40 via an adhesive sheet 38, and a plurality of green chips 19 are formed. Is placed in a state in which the rolling plate 41 can act from above.

By moving the support 40 in the direction of the arrow with respect to the rolling plate 41, as shown in FIGS. 11 (b), 11 (c), 11 (d) and 11 (e), The green chip 19 is rotated twice by 90 degrees, and the other cut side surface 21 is directed upward. If the rolling plate 41 is removed in this state, the cut side surface 21 becomes an open surface.

As shown in FIG. 11A, before the second rolling step, the cut side surface 21 is in contact with the adhesive sheet 38. Therefore, as shown in FIG. 11B, FIG. 11C, FIG. 11D and FIG. 11E, after the green chip 19 is rotated on the adhesive sheet 38, The adhesive contained in the sheet 38 is attached.

Then, a grinding process or a cutting process is also performed on the cut side opposite to the open side. For example, when the grinding process is performed for the first time (one cut side surface), the grinding process may be performed for the second time (the other cut side surface), or the cutting process may be performed.

As described above, since the adhesive is attached to the cut side surface, the grinding fluid used for the second grinding process or the cutting fluid used for the cutting process contains a component that dissolves the adhesive. Is preferred. The grinding fluid used for the second grinding process or the cutting fluid used for the cutting process may be the same as or different from the grinding fluid used for the first grinding process or the cutting fluid used for the cutting process. Is also good.

A cleaning process may be performed on the cut side surface after the second grinding process or the cutting process is performed. In this case, the cleaning solution used for the second cleaning process may contain a component that dissolves the adhesive. The cleaning solution used in the second cleaning process may be the same as or different from the cleaning solution used in the first cleaning process.

As before, an unfired ceramic protective layer is formed on the opposite cut side. After forming the unfired ceramic protective layer, a drying step is performed, if necessary. As described above, an unsintered component body is obtained.

Subsequently, after removing the plurality of unfired component bodies together with the adhesive sheet from the support base and peeling the adhesive sheet from the unfired component body, the unfired component body is fired. The firing temperature is, for example, in the range of 900 ° C. or more and 1300 ° C. or less, although it depends on the ceramic material or metal material contained in the unsintered component body.

External electrodes are formed by applying a conductive paste to both end surfaces of the fired component body, baking, and, if necessary, plating. The application of the conductive paste may be performed on the unsintered component body, and the conductive paste may be baked simultaneously with the unsintered component body.

Thus, the multilayer ceramic capacitor 11 shown in FIG. 1 is manufactured.

[Second embodiment]
In the second embodiment, unlike the first embodiment, the cleaning process is performed on the side surface of the stacked body where the internal electrodes are exposed, without performing the grinding process or the cutting process.

First, according to the method described in the first embodiment, a mother block including a plurality of stacked ceramic green sheets and internal electrode patterns arranged along a plurality of interfaces between the ceramic green sheets is manufactured. . The obtained mother block is pressed in the laminating direction by means such as a hydrostatic press.

By cutting the pressed mother block along a cutting line in the first direction and a cutting line in the second direction orthogonal to each other, a plurality of green chips can be obtained. For this cutting, for example, a method such as dicing, pressing and laser cutting is applied.

As described in the first embodiment, the plurality of green chips arranged in the row and column directions are pasted on an expandable adhesive sheet. Then, by expanding the pressure-sensitive adhesive sheet, the plurality of green chips arranged in the row and column directions are in a state where the interval between them is widened. Thereafter, a rolling step of rolling the plurality of green chips to make the cut side surfaces of the plurality of green chips uniform and open surfaces is performed.

In the second embodiment, a cleaning process is performed on the cut side surface facing upward by the rolling process. The method of the cleaning process is as described in the first embodiment.

When the pressure-sensitive adhesive contained in the pressure-sensitive adhesive sheet adheres to the cut side surface, it is preferable that the cleaning liquid used for the cleaning treatment contains a component that dissolves the pressure-sensitive adhesive. The adhesive adhered to the cut side surface can be removed by the cleaning liquid used for the cleaning process.

In the second embodiment, a rinsing process for washing off the cleaning liquid adhering to the green chip is performed as necessary. In the rinsing treatment, it is preferable to perform cleaning using water, and it is more preferable to perform ultrasonic cleaning using water.

After the rinsing treatment, a drying step is preferably performed. Examples of the method of the drying step include the method described in the first embodiment.

Subsequently, an unfired ceramic protective layer is formed on the cut side surface. The method for forming the unfired ceramic protective layer is as described in the first embodiment.

After forming the unfired ceramic protective layer, a drying step is performed, if necessary. Thereafter, a rolling step of rolling the green chips on which the unfired ceramic protective layers are formed again is performed.

Then, it is preferable that the cleaning process is also performed on the cut side opposite to the open side. Since the pressure-sensitive adhesive is attached to the cut side surface, it is preferable that the cleaning liquid used in the second cleaning treatment contains a component that dissolves the pressure-sensitive adhesive. The cleaning solution used in the second cleaning process may be the same as or different from the cleaning solution used in the first cleaning process.

Similarly to the above, after forming the unfired ceramic protective layer on the opposite cut side surface, a drying step is performed as necessary. As described above, an unsintered component body is obtained.

After firing the obtained unfired component body, external electrodes are formed on both end surfaces of the fired component body, whereby the multilayer ceramic capacitor 11 shown in FIG. 1 is manufactured.

[Other embodiments]
As described in the above embodiments, the method for manufacturing a chip-type electronic component of the present invention is such that the internal electrodes are exposed by rolling the laminate on the adhesive sheet before the step of removing the adhesive. It is preferable that the method further includes a step of setting a side surface of the laminated body as an open surface.

The method for manufacturing a chip-type electronic component of the present invention may further include a step of peeling the laminate from the pressure-sensitive adhesive sheet before the step of removing the pressure-sensitive adhesive.

In the method of manufacturing a chip-type electronic component according to the present invention, a method of removing a pressure-sensitive adhesive adhered to a side surface of a laminate in which an internal electrode is exposed using a treatment liquid containing a component that dissolves a pressure-sensitive adhesive contained in a pressure-sensitive adhesive sheet However, the present invention is not limited to the method described in the above-described embodiment, and the adhesive may be removed using a processing liquid other than a grinding liquid, a cutting liquid, or a cleaning liquid. In that case, it is not necessary to perform a grinding process, a cutting process, or a cleaning process on the side surface of the laminate in which the internal electrodes are exposed.

In the embodiment described above, the mother block is cut into a cutting line in the first direction and a cutting line in the second direction to obtain a plurality of green chips, and then the unfired ceramic protective layer is formed on the cut side surface. In this case, before forming the ceramic protective layer on the side surface of the green chip where the internal electrodes are exposed, the adhesive adhered to the side surface was removed. However, it is also possible to make the following changes.

That is, by cutting the mother block along only the cutting line in the first direction, a plurality of rod-shaped green block bodies are obtained in which the internal electrodes are exposed on the cutting side surfaces that appear by cutting along the cutting line in the first direction. Then, after forming the unfired ceramic protective layer on the cut side surface, cutting along the cutting line in the second direction to obtain a plurality of unfired component bodies, and then firing the unfired component body Good. In this case, before forming the ceramic protective layer on the side surface of the green block body where the internal electrodes are exposed, the adhesive adhered to the side surface may be removed. After firing, a multilayer ceramic electronic component such as a multilayer ceramic can be manufactured by performing the same steps as in the above-described embodiment.

Also, in the case of manufacturing a chip-type electronic component other than the multilayer ceramic electronic component, the adhesive adhered to the side surface of the laminate with the internal electrodes exposed may be removed in the same manner as described above.

[Example of experiment]
In the following experimental examples, an adhesive layer made of a polybutyl acrylate-based adhesive was formed on a polyvinyl chloride (PVC) substrate, and a resin made of polyvinyl butyral (PVB), which is a resin component contained in a green chip. What prepared the layer on the glass plate was prepared.

(Examples 1 to 10)
As a component for dissolving the pressure-sensitive adhesive, a treatment liquid was prepared by adding a liquid shown in Table 1 to water in a predetermined amount.
In selecting a component for dissolving the pressure-sensitive adhesive, the Hansen solubility parameter distance to the pressure-sensitive adhesive to be dissolved was small, and the Hansen solubility parameter distance to PVB, which is a resin component not to be dissolved, was large. Further, those having high affinity with water as a solvent and being easily dissolved were selected.

Table 1 shows the Hansen solubility parameter distance Δδ1 between the component that dissolves the adhesive and the polybutyl acrylate-based adhesive, and the Hansen solubility parameter distance Δδ2 between PVB that is the resin component and the component that dissolves the adhesive.

The prepared adhesive layer and resin layer were rubbed for 1 minute at room temperature using a waste cloth containing the prepared treatment liquid. Thereafter, the treatment liquid was washed away with water and dried, and the surfaces of the adhesive layer and the resin layer were touched with a finger. At that time, it was determined that "dissolve" if no adhesive force was felt, and "not dissolved" if adhesive force remained.

(Comparative Example 1)
The same evaluation as above was performed using water instead of the treatment liquids prepared in Examples 1 to 10.

In Table 1, when the result was "the adhesive dissolves but the resin component did not dissolve", it was judged as "O", and otherwise, it was judged as "x".

From Table 1, it was confirmed that when the treatment solutions prepared in Examples 1 to 10 were used, the polybutyl acrylate-based pressure-sensitive adhesive was dissolved, and the resin component PVB was not dissolved. From these results, it is considered that when the components contained in the treatment liquid and the structure of the pressure-sensitive adhesive are close to each other, they have high affinity and are easily dissolved.

[Structure of chip-type electronic components]
Not only in the method of manufacturing a chip-type electronic component according to the present invention, but also when a grinding process such as a polishing process is performed on a side surface of the laminate where the internal electrodes are exposed, the corners of the laminate are rounded. Note that the corner of the laminate is a portion where three surfaces of the laminate intersect.

As an embodiment of such a chip-type electronic component, a multilayer ceramic capacitor will be described as an example.

FIG. 12 is a WT cross-sectional view schematically illustrating an example of a component body constituting the multilayer ceramic capacitor. 12, the names and reference numerals of the respective parts correspond to those in FIG.
As shown in FIG. 12, on one end face of the laminated body 24, the upper and lower four corners are all rounded. Similarly, on the other end face of the laminate 24, the four corners at the top and bottom are all rounded. Therefore, a virtual line L ₁ connecting the ends of the internal electrodes 26, the angle formed between the virtual line L ₂ is formed by connecting the end nearest the internal electrodes 26 on the outermost side and the corner portion of the corner of the stack 24 (The angle indicated by θ in FIG. 12) is greater than 0 °.

As described above, when at least one corner of the laminate is rounded, the corners of the protective layer formed thereafter are also rounded, so that impact resistance is improved.

(In FIG. 12, the length indicated by X ₁₎ thickness from the nearest inner electrode at the corner portions of the laminate to the surface of the protective layer is preferably 10μm or more.
If the thickness of the protective layer close to the internal electrode is 10 μm or more, it is difficult for moisture to enter the internal electrode from the outside, so that it is possible to prevent a decrease in moisture resistance reliability.

(In FIG. 12, the length indicated by X ₂₎ the distance between the outermost corners of the stack and the virtual line connecting the ends of the internal electrodes is preferably less than 15 [mu] m.
If the roundness of the corners of the laminate is too large, a gap is likely to be formed between the protective layer and the laminate after forming the protective layer. When moisture enters through the gap, the moisture resistance reliability is reduced. When the above distance is less than 15 μm, the protective layer can be formed so as to firmly follow the roundness of the corners of the laminate.

Reference Signs List 11 multilayer ceramic capacitor 12 component body 13, 14 main surface 15, 16 side surface 17, 18 end surface 19 green chip 20, 21 cutting side surface 22, 23 ceramic protective layer 24 laminated body 25 ceramic layer 26, 27 internal electrode 28, 29 external electrode 31 Ceramic Green Sheet 32 Internal Electrode Pattern 33 Cutting Line 34 in First Direction 34 Cutting Line 35 in Second Direction Mother Block 36, 37 Cutting End Face 38 Adhesive Sheet 40 Support 41 Rolling Plate 210 Polishing Plate 220 Polishing Pad 230 Polishing Head 240 Supply pipe 310 Cleaning tank 320 Vibration plate 321 Ultrasonic vibrator 330 Holder A Polishing liquid (grinding liquid)
B Cleaning liquid

Claims (11)

Including a plurality of laminated internal electrodes, a step of producing a laminate in which the internal electrodes are exposed on a pair of side surfaces opposed in a width direction orthogonal to the laminating direction,
Arranging the laminate on an adhesive sheet,
Using a treatment solution containing a component that dissolves the adhesive contained in the adhesive sheet, removing the adhesive attached to the side surface of the laminate where the internal electrodes are exposed,
Forming a protective layer on the side surface of the laminate after the pressure-sensitive adhesive is removed. The pressure-sensitive adhesive is an acrylate-based pressure-sensitive adhesive,
The chip-type electronic component according to claim 1, wherein the treatment liquid is a solution containing a compound represented by a general formula R ¹ COOR ² or R ¹ COR ² (R ¹ and R ² are each independently an alkyl group). Manufacturing method. The method for manufacturing a chip-type electronic component according to claim 2, wherein the compound is any one selected from the group consisting of n-butyl acetate, n-propyl acetate, ethyl acetate, methyl acetate, and methyl ethyl ketone. 4. The method for manufacturing a chip-type electronic component according to claim 2, wherein the treatment liquid contains the compound in an amount of 20% by weight or more and 75% by weight or less. 5. The Hansen solubility parameter distance between the component that dissolves the pressure-sensitive adhesive and the pressure-sensitive adhesive is smaller than the Hansen solubility parameter distance between the component that dissolves the pressure-sensitive adhesive and the resin component included in the laminate. The method for manufacturing a chip-type electronic component according to any one of the above. 2. The method according to claim 1, further comprising, before the step of removing the pressure-sensitive adhesive, rolling the laminate on the pressure-sensitive adhesive sheet so that a side surface of the laminate in which the internal electrodes are exposed is an open surface. 6. The method for manufacturing a chip-type electronic component according to any one of claims 5 to 5. The method for manufacturing a chip-type electronic component according to any one of claims 1 to 5, further comprising, before the step of removing the adhesive, a step of peeling the laminate from the adhesive sheet. In the step of removing the adhesive, a grinding process using abrasive grains or a cutting process using a cutting tool is performed on the side surface of the laminate before forming the protective layer,
The method for manufacturing a chip-type electronic component according to any one of claims 1 to 7, wherein a component that dissolves the adhesive is contained in a grinding fluid used for the grinding process or a cutting fluid used for the cutting process. In the step of removing the adhesive, a cleaning process is performed on the side surface of the laminate before forming the protective layer,
9. The method of manufacturing a chip-type electronic component according to claim 1, wherein a component that dissolves the pressure-sensitive adhesive is included in a cleaning liquid used for the cleaning process. 10. The chip-type electronic component is a multilayer ceramic electronic component,
In the step of producing the laminate, after producing a mother block including a plurality of laminated ceramic green sheets and the unfired internal electrodes disposed between the ceramic green sheets, the mother block is cut. The chip-type electronic device according to any one of claims 1 to 9, wherein a plurality of stacked bodies are produced, and the internal electrodes are exposed on side surfaces of the stacked body that appear when the mother block is cut. The method of manufacturing the part. The method of manufacturing a chip-type electronic component according to claim 10, wherein the multilayer ceramic electronic component is a multilayer ceramic capacitor.

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