JP2018113300A - Manufacturing method of multilayer electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of multilayer electronic component capable of preventing a laminate from cracking in a crimp step.SOLUTION: A manufacturing method of multilayer electronic component including a lamination step of making a laminate by laminating multiple green sheets on which an internal electrode layer is formed, and a crimp step of placing a first elastic body sheet on the upper surface of the laminate in the lamination direction, placing a second elastic body sheet on the lower surface of the laminate in the lamination direction, and then crimping the laminate in the lamination direction, satisfies following relational expressions (1) and (2). (Thickness of the internal electrode layer×number of laminations of the internal electrode layers)/2>thickness of the first elastic body sheet (1), (Thickness of the internal electrode layer×number of laminations of the internal electrode layers)/2>thickness of the second elastic body sheet (2).SELECTED DRAWING: Figure 6

Description

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

In multilayer ceramic capacitors, there is a great demand for small size and large capacity, and green sheets are becoming thinner and internal electrodes are becoming more multilayered.
In the production process of a multilayer ceramic capacitor, there is a crimping process in which a large number of green sheets on which internal electrode layers are formed are laminated to form a laminate, and the laminate is crimped.
In the laminated body, a step is generated in the laminated thickness between a portion where the internal electrode layer is formed and a portion where the internal electrode layer is not formed. And in the part in which the internal electrode layer is not formed, adhesion becomes insufficient.
Moreover, as the number of layers increases, the effect of the step becomes larger.
And in order to ensure the adhesiveness in the part in which the internal electrode layer is not formed, an elastic body sheet | seat may be arrange | positioned at the upper and lower sides of a laminated body in a crimping | compression-bonding process.

Patent Document 1 describes a method for manufacturing a multilayer ceramic electronic component, which includes a step of pressing a multilayer body using an elastic sheet that exhibits greater stretchability in the thickness direction than in the plane direction. ing.

JP-A-9-190948

In Patent Document 1, in the step of crimping the green sheet at the time of manufacturing the multilayer ceramic capacitor, the step amount of the internal electrode layer (= the thickness of the internal electrode layer × the number of green sheets laminated) is 150 μm (3 μm × 50 sheets), The document describes that the thickness of polyethylene terephthalate as an elastic sheet is 200 μm.

When the pressure-bonding process is performed under the conditions described in Patent Document 1, a crack may occur in a part of the surface of the laminate, particularly in the peripheral portion of the surface of the laminate.
In particular, there is a tendency that cracks are likely to occur in a laminated electronic component having internal electrode lead portions on the side surfaces of the laminated body.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method for manufacturing a laminated electronic component that can prevent a laminate from being cracked in a crimping process.

The present inventors examined a means that can eliminate the occurrence of cracks in the crimping process, and found that the relationship between the thickness of the elastic sheet disposed above and below the laminate and the step amount of the internal electrode layer is within an appropriate range. Thus, the inventors have found that it is possible to reduce the force applied at the boundary between the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed, and to prevent the occurrence of cracks, and have arrived at the present invention. .
That is, the method for manufacturing a laminated electronic component according to the present invention includes a lamination step of producing a laminate by laminating a plurality of green sheets on which internal electrode layers are formed, and a first elastic body on an upper surface in the lamination direction of the laminate. A method of manufacturing a laminated electronic component including a crimping step in which a sheet is disposed, a second elastic sheet is disposed on a lower surface in the stacking direction of the stacked body, and the stacked body is crimped in the stacking direction. (1) and (2) are satisfied.
(Thickness of internal electrode layer x number of laminated internal electrode layers) / 2> thickness of first elastic sheet (1)
(Thickness of internal electrode layer x number of laminated internal electrode layers) / 2> thickness of second elastic sheet (2)

When the thicknesses of the first elastic sheet and the second elastic sheet used in the pressure-bonding process satisfy the above relational expressions (1) and (2), the portion where the internal electrode layer is formed and the internal electrode Generation of cracks can be prevented by reducing the force applied at the boundary between the portions where the layer is not formed.

In the method for manufacturing a laminated electronic component according to the present invention, the thicknesses of the first elastic sheet and the second elastic sheet are respectively determined by (the thickness of the internal electrode layer × the number of laminated internal electrode layers). The thickness is preferably 20% or more of the level difference.
When the thickness of the elastic sheet is reduced, the pressure applied to the portion where the internal electrode layer is formed becomes relatively high, and the dielectric thickness tends to be reduced. Thereby, although the insulation resistance failure rate (short failure rate) increases, the insulation resistance failure rate can be lowered by setting the thickness of the elastic sheet in the above range.

In the method for manufacturing a laminated electronic component of the present invention, it is preferable that the durometer A hardness of the first elastic sheet and the second elastic sheet is 40 or more and 80 or less, respectively.
It is preferable that the hardness of the elastic sheet is 40 or more because the step between the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed in the laminated body after pressure bonding does not become too large. Moreover, it is preferable that the hardness of the elastic sheet is 80 or less because the effect of improving the adhesion at the portion where the internal electrode layer is not formed can be sufficiently exhibited.

In the method for manufacturing a laminated electronic component of the present invention, it is preferable that the step amount determined by (thickness of internal electrode layer × number of laminated internal electrode layers) is 50 μm or more and 200 μm or less.
It is preferable that the step amount is 50 μm or more because the effects of the present invention are more remarkably exhibited. Moreover, when the amount of steps exceeds 200 μm, it may be difficult to ensure adhesion between the green sheets.

In the method for manufacturing a laminated electronic component according to the present invention, it is preferable that a rigid body pressing step is further performed after the crimping step.
By further performing the rigid body pressing after the crimping step, it is possible to reduce a step between the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed. If the level difference is large, it is preferable to reduce the level difference because there is a concern that stability is insufficient when mounting the multilayer electronic component on the substrate and soldering failure occurs.

In the method for manufacturing a multilayer electronic component of the present invention, the multilayer electronic component is preferably a multilayer ceramic capacitor.
Since the multilayer ceramic capacitor tends to have a large number of laminated layers and a step is likely to occur, the method for manufacturing a multilayer electronic component of the present invention is particularly effective.

In the method for manufacturing a multilayer electronic component according to the present invention, the multilayer electronic component is preferably a multilayer electronic component having two or more internal electrode lead portions on one side surface.
When the laminated electronic component is a laminated electronic component having two or more internal electrode lead portions on one side surface, cracks are particularly likely to occur when the conventional crimping process is performed. And if the crimping | compression-bonding process in the manufacturing method of the multilayer electronic component of this invention is applied, generation | occurrence | production of a crack can be prevented.
That is, the effect of the present invention is particularly remarkable for a multilayer electronic component having two or more internal electrode lead portions on one side surface.

In the method for manufacturing a laminated electronic component according to the present invention, the pressure bonding temperature in the pressure bonding step is preferably 60 ° C. or higher and 85 ° C. or lower.
When the pressure bonding temperature is 60 ° C. or higher, the effect of improving the adhesion at the portion where the internal electrode layer is not formed is more fully exhibited, and the possibility of generating structural defects such as delamination is reduced. Further, when the pressure bonding temperature is 85 ° C. or less, the amount of strain due to temperature deformation of the laminated body that has undergone the pressure bonding process is less likely to increase. For this reason, in the step of cutting the laminated body into chip pieces later, the internal electrode exposure defect rate due to a decrease in cutting position accuracy is lowered.

According to the method for producing a laminated electronic component of the present invention, it is possible to produce a laminated electronic component while preventing the laminate from being cracked in the crimping step.

FIG. 1 is a perspective view schematically showing an example of a multilayer ceramic capacitor that can be manufactured by the method for manufacturing a multilayer electronic component of the present invention. 2 (a) and 2 (b) schematically illustrate a green sheet having an internal electrode layer having an internal electrode pattern for manufacturing a laminated electronic component having three internal electrode lead portions on one side surface. FIG. FIG. 2C is a plan view showing the internal electrode patterns shown in FIG. 2A and FIG. FIGS. 3A and 3B schematically show a green sheet having an internal electrode layer having an internal electrode pattern for manufacturing a laminated electronic component having two internal electrode lead portions on one side surface. FIG. FIG. 3C is a plan view showing the internal electrode patterns shown in FIG. 3A and FIG. 4 (a) and 4 (b) schematically illustrate a green sheet having an internal electrode layer having an internal electrode pattern for manufacturing a laminated electronic component having one internal electrode lead portion on one side surface. FIG. FIG. 4C is a plan view showing the internal electrode patterns shown in FIG. 4A and FIG. FIG. 5 is a schematic diagram showing a multi-chamfer pattern of a laminate in which the green sheet shown in FIG. 2A and the green sheet shown in FIG. 2B are laminated. FIG. 6 is a cross-sectional view schematically showing a state in which elastic sheets are arranged above and below the laminate in the crimping step.

Hereinafter, a method for manufacturing a multilayer electronic component according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following configurations, and can be applied with appropriate modifications without departing from the scope of the present invention. Note that the present invention also includes a combination of two or more desirable configurations of the present invention described below.

Hereinafter, a method for manufacturing a multilayer electronic component according to the present invention will be described with reference to an example of manufacturing a multilayer ceramic capacitor.

FIG. 1 is a perspective view schematically showing an example of a multilayer ceramic capacitor that can be manufactured by the method for manufacturing a multilayer electronic component of the present invention.
A multilayer ceramic capacitor 1 shown in FIG. 1 includes an external electrode 21a, an external electrode 22a, and an external electrode 23a on a first side surface 11 of a multilayer body 10, and an external electrode 21b and an external electrode on a second side surface 12 of the multilayer body 10. An electrode 22b and an external electrode 23b are provided. The portion where each external electrode is provided is a portion where the internal electrode is drawn from the side surface of the laminate. In FIG. 1, the internal electrode in the back of the external electrode is schematically shown by a dotted line. It can be said that the multilayer ceramic capacitor 1 shown in FIG. 1 is a multilayer electronic component having three internal electrode lead portions on one side surface.
Hereinafter, a method for manufacturing a multilayer electronic component capable of manufacturing such a multilayer ceramic capacitor will be described.

First, a green sheet on which an internal electrode layer is formed is prepared.
By applying ceramic slurry, which is a dielectric layer ceramic mixed with organic substances and solvent, onto a carrier film such as PET film in a sheet form by spray coating, die coating, screen printing, etc., ceramic green Get a sheet.
Subsequently, a conductive paste for forming an internal electrode layer made of a metal material such as Ni powder, a solvent, a dispersant, a binder, and the like is prepared. A conductive paste for forming an internal electrode layer is printed on the ceramic green sheet by a method such as screen printing or gravure printing to form an internal electrode pattern.
In this way, a green sheet on which the internal electrode layer is formed is prepared.

Examples of the ceramic used as the dielectric layer include ceramic materials mainly composed of barium titanate (BaTiO ₃ ), calcium titanate (CaTiO ₃ ), strontium titanate (SrTiO ₃ ), or calcium zirconate (CaZrO ₃ ). including. Further, the ceramic material may contain Mn, Mg, Si, Co, Ni, rare earth, or the like as an auxiliary component having a lower content than the main component.
Examples of organic substances contained in the ceramic slurry include polyvinyl butyral binders and phthalate ester binders as binders.
The thickness of the ceramic green sheet is preferably 0.6 μm or more and 1.2 μm or less.

The conductive paste for forming the internal electrode layer preferably contains a metal material such as Ni, Cu, Ag, Pd, an Ag—Pd alloy, or Au. Moreover, it is also preferable that the dielectric material of the same composition system as the ceramic material contained in a ceramic green sheet is included.
The thickness of the internal electrode layer formed on the green sheet is preferably 0.2 μm or more and 1.5 μm or less. When the thickness of the internal electrode layer is 0.2 μm or more, the continuity of the internal electrode is improved, so that the acquisition capacity does not decrease. Moreover, when the thickness of the internal electrode layer is 1.5 μm or less, the adhesion between the green sheets is not lowered, and the occurrence of structural defects such as delamination can be prevented.

Although the internal electrode pattern drawn on the ceramic green sheet differs depending on the specifications of the laminated electronic component to be manufactured, some examples will be described.
The multilayer electronic component manufactured by the multilayer electronic component manufacturing method of the present invention is preferably a multilayer electronic component having two or more internal electrode lead portions on one side surface.
The internal electrode patterns for manufacturing such a laminated electronic component are shown in FIGS. 2A, 2B and 2C, and FIGS. 3A, 3B and 3C. c).

2 (a) and 2 (b) schematically illustrate a green sheet having an internal electrode layer having an internal electrode pattern for manufacturing a laminated electronic component having three internal electrode lead portions on one side surface. FIG. FIG. 2C is a plan view showing the internal electrode patterns shown in FIG. 2A and FIG.

In the green sheet 110a shown in FIG. 2 (a), the internal electrode lead-out portion 121a and the internal electrode lead-out portion 123a reach the first long side 111a that is the first side surface when the laminate is formed. In this case, the internal electrode lead-out portion 122b reaches the second long side 112a serving as the second side surface. On the other hand, in the green sheet 110b shown in FIG. 2B, the internal electrode lead-out portion 122a reaches the first long side 111b which is the first side surface when the laminated body is formed. The internal electrode lead-out part 121b and the internal electrode lead-out part 123b reach the second long side 112b serving as the second side face.

In FIG. 2C, the internal electrode pattern when the two green sheets 110a and 110b are overlapped is shown. From the shape obtained by stacking two green sheets, the first side surface of the laminate obtained by the first long side 111 when the laminate is formed is provided with an internal electrode lead portion 121a, an internal electrode lead portion 122a, and an internal portion. It can be seen that the electrode lead-out portion 123a is located. It can also be seen that the internal electrode lead-out portion 121b, the internal electrode lead-out portion 122b, and the internal electrode lead-out portion 123b are located on the second side surface of the laminate obtained by the second long side 112 when the laminate is formed.
FIG. 2C schematically shows a portion where a crack is likely to occur when the laminated body having the internal electrode pattern is pressure-bonded by a conventional method. According to the method for manufacturing a laminated electronic component of the present invention, it is possible to prevent a crack from occurring at this portion.

FIGS. 3A and 3B schematically show a green sheet having an internal electrode layer having an internal electrode pattern for manufacturing a laminated electronic component having two internal electrode lead portions on one side surface. FIG. FIG. 3C is a plan view showing the internal electrode patterns shown in FIG. 3A and FIG.

In the green sheet 210a shown in FIG. 3A, the internal electrode lead-out portion 221a reaches the first long side 211a, which is the first side surface when the laminate is formed, and the second when the laminate is formed. The internal electrode lead-out portion 222b reaches the second long side 212a which is the side surface of the inner electrode. On the other hand, in the green sheet 210b shown in FIG. 3B, the internal electrode lead-out portion 222a reaches the first long side 211b which is the first side surface when the laminated body is formed. The internal electrode lead-out portion 221b reaches the second long side 212b serving as the second side surface.

In FIG. 3C, the internal electrode pattern when the two green sheets 210a and 210b are overlapped is shown. The internal electrode lead-out part 221a and the internal electrode lead-out part 222a are located on the first side surface of the laminate obtained by the first long side 211 from the shape obtained by stacking the two green sheets. I understand that Further, it can be seen that the internal electrode lead-out portion 221b and the internal electrode lead-out portion 222b are located on the second side surface of the laminate obtained by the second long side 212 when the laminate is formed.
FIG. 3C schematically shows a portion where a crack is likely to occur when the laminated body having the internal electrode pattern is pressure-bonded by a conventional method. According to the method for manufacturing a laminated electronic component of the present invention, it is possible to prevent a crack from occurring at this portion.

Moreover, the multilayer electronic component manufactured by the method for manufacturing the multilayer electronic component of the present invention may be a multilayer electronic component having one internal electrode lead portion on one side surface.
An internal electrode pattern for manufacturing such a laminated electronic component is shown in FIGS. 4 (a), 4 (b) and 4 (c).

4 (a) and 4 (b) schematically illustrate a green sheet having an internal electrode layer having an internal electrode pattern for manufacturing a laminated electronic component having one internal electrode lead portion on one side surface. FIG. FIG. 4C is a plan view showing the internal electrode patterns shown in FIG. 4A and FIG.

In the green sheet 310a shown in FIG. 4A, the internal electrode lead-out portion 321a reaches the first long side 311a serving as the first side face when the laminated body is formed, and the second sheet when the laminated body is formed. The internal electrode lead-out portion 322a reaches the second long side 312a that is the side surface of the inner electrode. On the other hand, in the green sheet 310b shown in FIG. 4B, when it is formed into a laminated body, the first long side 311b serving as the first side surface and the second long side 312b serving as the second side surface are both inside. The electrode lead-out part has not reached. In the green sheet 310b shown in FIG. 4B, the end face internal electrode lead-out part 323b reaches the first short side 313b which becomes the first end face when the laminate is formed, and the second sheet when the laminate is formed. The end face internal electrode lead-out portion 324b reaches the second short side 314b serving as the end face of the first end face.

In FIG. 4C, the internal electrode pattern when the two green sheets 310a and 310b are overlapped is shown. From the shape obtained by stacking the two green sheets, it can be seen that the internal electrode lead-out portion 321a is located on the first side surface of the multilayer body obtained by the first long side 311 when the multilayer body is formed. Further, it can be seen that the internal electrode lead-out portion 322a is located on the second side surface of the multilayer body obtained by the second long side 312 when the multilayer body is formed.
It can also be seen that the end face internal electrode lead-out portion 323b is located on the first end face of the laminate obtained by the first short side 313 when the laminate is formed. It can also be seen that the end face internal electrode lead-out portion 324b is located on the second end face of the laminate obtained by the second short side 314 when the laminate is formed.
FIG. 4C schematically shows a portion where a crack is likely to occur when the laminated body having the internal electrode pattern is pressure-bonded by the method of the prior art. According to the method for manufacturing a laminated electronic component of the present invention, it is possible to prevent a crack from occurring at this portion.

The length of the long side of the green sheet constituting the laminate is preferably 0.7 mm or more and 1.3 mm or less. Moreover, it is preferable that the length of a short side is 0.4 mm or more and 0.8 mm or less.

A green body having an internal electrode layer as described above is laminated to produce a laminate. The number of stacked layers is preferably 100 or more and 300 or less.
The thickness obtained by (thickness of internal electrode layer × number of stacked internal electrode layers) is referred to as a step amount. This level difference is a difference in thickness between a portion where the internal electrode layer is formed and a portion where the internal electrode layer is not formed.
In the method for manufacturing a laminated electronic component according to the present invention, the thickness of the elastic sheet is determined in consideration of the level difference in the crimping process.
The step amount is preferably 50 μm or more and 200 μm or less.

When producing a laminated body, it laminates so that two types of green sheets may overlap, and the internal electrode pattern of the laminated body is as shown in FIG. 2 (c), FIG. 3 (c) or FIG. 4 (c). The internal electrode pattern is used.
FIG. 5 shows a schematic diagram of this multi-chamfering method in which a multi-chamfered green sheet on which internal electrode patterns are repeatedly drawn is produced and laminated by shifting the position of the internal electrode pattern.
FIG. 5 schematically shows a multi-chamfer pattern of a laminate 100 in which the green sheet 110a shown in FIG. 2A and the green sheet 110b shown in FIG. 2B are stacked. FIG. 5 shows a pattern for four multilayer ceramic capacitors, and each region divided by a one-dot chain line in FIG. 5 corresponds to a pattern for one multilayer ceramic capacitor.

Moreover, when producing a laminated body, it is preferable to laminate | stack the outer layer green sheet for forming an outer layer in the further outer side of the green sheet in which the internal electrode layer was formed.
The outer green sheet is a ceramic green sheet having no electrode layer. The thickness of the outer green sheet is preferably 1 μm or more and 10 μm or less.

Subsequently, the first elastic sheet is disposed on the upper surface in the stacking direction of the stacked body, the second elastic sheet is disposed on the lower surface in the stacking direction of the stacked body, and a crimping process is performed to press the stacked body in the stacking direction. .

FIG. 6 is a cross-sectional view schematically showing a state in which elastic sheets are arranged above and below the laminate in the crimping step. FIG. 6 schematically shows a state in which elastic sheets are arranged above and below a cross section cut at a position corresponding to the line AA ′ in the multi-face pattern of the laminate shown in FIG. 5.

In FIG. 6, the first elastic sheet 101 is disposed on the upper surface of the laminate 100, and the second elastic sheet 102 is disposed on the lower surface of the laminate 100.
In the laminated body 100, the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed alternately exist in the left-right direction, and the portion where the internal electrode layer is not formed is (internal The thickness is reduced by an amount corresponding to the level difference obtained by (thickness of electrode layer × number of stacked internal electrode layers). Since the elastic sheet has elasticity (flexibility), it can follow a step and can contact a portion where the internal electrode layer is not formed.

The material of the first elastic sheet and the second elastic sheet is not particularly limited as long as the material has elasticity that allows pressure to be applied to a portion where the internal electrode layer is not formed. Specifically, styrene butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber, butyl rubber, ethylene propylene rubber, ethylene propylene diene rubber, urethane rubber, silicone rubber, fluorine rubber, acrylic rubber, epichlorohydrin rubber, polysulfide Examples thereof include rubber materials such as rubber and chlorosulfonated polyethylene rubber.
Moreover, resin materials, such as polyethylene, a polystyrene, and a polyurethane, are mentioned.
Of these materials, silicone rubber is preferred.

The durometer A hardness of the first elastic sheet and the second elastic sheet is preferably 40 or more and 80 or less, respectively. The durometer A hardness is a hardness measured with a type A indenter (cylindrical shape).

The thicknesses of the first elastic sheet and the second elastic sheet satisfy the following relational expressions (1) and (2).
(Thickness of internal electrode layer x number of laminated internal electrode layers) / 2> thickness of first elastic sheet (1)
(Thickness of internal electrode layer x number of laminated internal electrode layers) / 2> thickness of second elastic sheet (2)
(Thickness of internal electrode layer × number of stacked internal electrode layers) is the above-described step amount, and the first elastic sheet and the second elastic sheet are thinner than half the step amount. This is meant by the equations (1) and (2).
When the thicknesses of the first elastic sheet and the second elastic sheet satisfy the above relational expressions (1) and (2), the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed Generation of cracks can be prevented by reducing the force applied at the boundary.
Moreover, the thickness of the first elastic sheet and the second elastic sheet is 20% or more of the step amount obtained by (the thickness of the internal electrode layer × the number of stacked internal electrode layers). It is preferable.
Moreover, it is preferable that the thickness of the 1st elastic body sheet and the 2nd elastic body sheet is 20 micrometers or more, respectively.

Each of the first elastic sheet and the second elastic sheet may be used, or a plurality of sheets may be used in an overlapping manner. The thickness of the elastic sheet when a plurality of elastic sheets are used is determined as the total thickness.
The material of the first elastic sheet and the material of the second elastic sheet may be the same or different. Further, the thickness of the first elastic sheet and the thickness of the second elastic sheet may be different as long as each satisfies the relational expressions (1) and (2).

The pressure bonding conditions in the pressure bonding step are not particularly limited, but the pressure bonding temperature (mold temperature) is preferably 60 ° C. or higher and 85 ° C. or lower. Moreover, it is preferable that a press pressure shall be 20 Mpa or more and 60 Mpa or less. The pressing time is preferably 30 seconds or more and 180 seconds or less. Crimping can be performed using any pressing device.
By pressure bonding using an elastic sheet, it is possible to ensure adhesion at a portion where the internal electrode layer is not formed.

It is preferable to perform a rigid body pressing process after the crimping process.
In the rigid body pressing step, pressing is performed without using an elastic sheet, and a step between the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed is reduced.
It is preferable to arrange a PET film between the mold (rigid body) and the laminate. Moreover, a rigid body press process may be performed without providing a mold release agent on the surface of the mold and disposing a PET film.
The pressing conditions in the rigid body pressing step are not particularly limited, but the pressure bonding temperature (mold temperature) is preferably 60 ° C. or higher and 85 ° C. or lower. Moreover, it is preferable that a press pressure shall be 70 Mpa or more and 150 Mpa or less. The pressing time is preferably 30 seconds or more and 300 seconds or less. The rigid body pressing step can be performed using any pressing device.
In addition, when the level | step difference of the part in which the internal electrode layer was formed in the laminated body which passed through the crimping process and the part in which the internal electrode layer is not formed is small, it is not necessary to perform a rigid body press process.

Thereafter, a multilayer ceramic capacitor can be obtained by firing the multilayer body and forming external electrodes. These steps can be performed by a known method.

So far, the method of manufacturing the multilayer electronic component of the present invention has been described by taking the case of manufacturing a multilayer ceramic capacitor as an example, but the multilayer electronic component manufactured by the method of manufacturing the multilayer electronic component of the present invention is limited to the multilayer ceramic capacitor. Is not to be done.
In the case of an electronic component other than a multilayer ceramic capacitor, a piezoelectric ceramic such as a PZT ceramic, a semiconductor ceramic such as a spinel ceramic, or a magnetic ceramic such as ferrite can be used as the ceramic constituting the dielectric layer.
When a piezoelectric ceramic is used, it functions as a piezoelectric component, when a semiconductor ceramic is used, it functions as a thermistor, and when a magnetic ceramic is used, it functions as an inductor.

Examples in which the electronic component of the present invention is disclosed more specifically are shown below. In addition, this invention is not limited only to these Examples.

Example 1
1) Production of Green Sheet with Internal Electrode Layers To BaTiO ₃ as a ceramic raw material, a polyvinyl butyral binder, a plasticizer and ethanol as an organic solvent were added, and these were wet mixed by a ball mill to produce a ceramic slurry. . Next, this ceramic slurry was formed into a sheet by a lip method to obtain a rectangular ceramic green sheet.
The average thickness of the ceramic green sheet was 1.0 μm.
Next, a conductive paste containing Ni was screen-printed on the ceramic green sheet to form an internal electrode pattern containing Ni as a main component.
The internal electrode pattern is an internal electrode pattern for manufacturing a laminated electronic component having three internal electrode lead portions on one side as shown in FIGS. 2 (a) and 2 (b).

2) Measurement of internal electrode layer thickness The printed internal electrode layer thickness was measured with a fluorescent X-ray film thickness meter. The measurement was performed for 25 green sheets per sheet (5 columns × 5 rows in the center of the internal electrode pattern) (total of 125 points for 5 sheets).
The average thickness was 0.5 μm.

3) Lamination process Two types of green sheets on which the internal electrode layers were formed were alternately laminated to form a laminate. The number of stacked layers is 200.
Further, on the top and bottom of the laminate, outer green sheets having the same composition as the ceramic green sheets and an average thickness of 50 μm were laminated.
The level difference in the laminated body is the internal electrode layer thickness of 0.5 μm × the number of laminated layers of 200 = 100 μm.

4) Pressure bonding process Silicone rubber having a durometer A hardness of 60 was used as the first elastic sheet and the second elastic sheet. In Example 1, an elastic sheet having a thickness of 40 μm was used.
The first elastic sheet was disposed on the upper surface of the laminate and the second elastic sheet was disposed on the lower surface, and pressure bonding was performed at a mold temperature of 70 ° C., a press pressure of 40 MPa, and a press time of 60 seconds.

5) Rigid body pressing step Subsequently, a PET film having a thickness of 50 μm is disposed on the upper and lower surfaces of the laminate in place of the elastic sheet, and is pressed (rigid body pressing) at a mold temperature of 70 ° C., a pressing pressure of 100 MPa, and a pressing time of 60 seconds. Step).

6) Cutting and firing step The pressed laminate was divided by dicing to obtain a chip. The obtained chip was heated in an N ₂ atmosphere to burn the binder, and then fired and sintered at 1250 ° C. in a reducing atmosphere containing H ₂ , N ₂ and H ₂ O gas. Got.
The size of the produced laminate was L × W × T = 1.0 mm × 0.5 mm × 0.4 mm.

(Observation of the number of cracks after firing)
The surface of the laminated body which passed through the baking process was observed and the presence or absence of the crack was confirmed.
The presence or absence of cracks is determined by observing a surface (upper surface or lower surface) perpendicular to the stacking direction of the stacked body after firing with a microscope. In particular, cracks are likely to occur at a portion corresponding to the boundary between the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed.
Cracks having a length of 10 μm or more were counted as cracks.

(Measurement of insulation resistance failure rate)
A voltage of 40 V and 30 ms was applied to the laminate, and the insulation having a resistance value lower than 50 MΩ was defined as an insulation failure. The number of measurements was 3000, and the defect rate was expressed in%.
As a sample for measuring the insulation resistance defect rate, a sample subjected to a firing step after the crimping step without a rigid pressing step (shown as “after the crimping step” in Table 1), a crimping step and a rigid pressing step Two types were prepared, ones that had undergone a firing step (shown as “after rigid body pressing” in Table 1).

(Measurement of level difference)
The laminated body before dicing before the baking process through the pressure bonding process was resin-filled and end-face polished to prepare a sample for cross-sectional observation.
Then, the difference in height between the lowest portion where the internal electrode layer was not formed and the highest portion where the internal electrode layer was formed was measured to obtain the step amount.
The height was measured at four locations (positions indicated by B, C, D, and E in FIG. 6) for one chip, and five chips were randomly extracted from the laminate. .
As a sample for measuring the amount of the step, a sample subjected to a firing process without a rigid pressing step after the crimping step (shown as “after the crimping step” in Table 1), and a firing after the crimping step and the rigid pressing step Two types of those that had undergone the process (shown as “after rigid body pressing” in Table 1) were prepared.

(Examples 2 to 4)
A laminate was prepared and evaluated in the same manner as in Example 1 except that the thickness of the elastic sheet was changed as shown in Table 1.

(Comparative Example 1)
A laminate was prepared and evaluated in the same manner as in Example 1 except that the crimping process was performed without using an elastic sheet.

(Comparative Examples 2 and 3)
A laminate was prepared and evaluated in the same manner as in Example 1 except that the thickness of the elastic sheet was changed as shown in Table 1.

Table 1 summarizes the evaluation results of each example and each comparative example.

In each example shown in Table 1, since [(thickness of internal electrode layer × number of laminated internal electrode layers) / 2] = 50 μm, if the thickness of the elastic sheet is less than 50 μm, the relational expression (1 ) And (2) are satisfied.
In each of Examples 1 to 4, an elastic sheet was used, and the thickness satisfied the relational expressions (1) and (2), so that the occurrence of cracks could be prevented.
Moreover, the insulation resistance defect rate was also low, and the insulation resistance defect rate was particularly low in Examples 3, 4 and 1 in which the thickness of the elastic sheet was 20 μm or more.

In Comparative Example 1, since the elastic sheet was not used, the insulation resistance defect rate was high.
In Comparative Examples 2 and 3, although an elastic sheet was used, cracks occurred because the thickness thereof was large and did not satisfy the relational expressions (1) and (2).

It was found that the level difference was small after the rigid press, and the level difference could be reduced by the rigid press.

(Example 5, Comparative Example 4)
The internal electrode layer is used as an internal electrode pattern for manufacturing a laminated electronic component having two internal electrode lead portions on one side as shown in FIGS. 3 (a) and 3 (b). Two types of green sheets on which were formed were prepared.
A laminate was prepared and evaluated as Example 5 in which the thickness of the elastic sheet was 40 μm and Comparative Example 4 in which the thickness was 100 μm. As an evaluation, only the number of cracks after firing was observed.

(Example 6, Comparative Example 5)
The internal electrode layer is used as an internal electrode pattern for manufacturing a laminated electronic component having one internal electrode lead-out portion on one side as shown in FIGS. 4 (a) and 4 (b). Two types of green sheets on which were formed were prepared.
A laminate was prepared and evaluated as Example 6 in which the thickness of the elastic sheet was 40 μm and Comparative Example 5 in which the thickness was 100 μm. As an evaluation, only the number of cracks after firing was observed.

Table 2 shows the results of Example 1 and Comparative Example 3 together, and shows the relationship between the number of side surface internal extraction electrode portions and the number of cracks.
The size of the produced laminate was L × W × T = 1.0 mm × 0.5 mm × 0.4 mm.

As shown in Table 2, no crack was generated in each of the examples in which the thickness of the elastic sheet satisfied the relational expressions (1) and (2), but the thickness of the elastic sheet In each comparative example that does not satisfy the relational expressions (1) and (2), cracks are generated. Since the number of cracks generated increases as the number of side surface internal electrode lead portions increases, it can be seen that the method of the present invention is particularly effective when the number of side surface internal electrode lead portions is large.

DESCRIPTION OF SYMBOLS 1 Multilayer ceramic capacitor 10, 100 Multilayer body 11 1st side surface 12 2nd side surface 21a, 21b, 22a, 22b, 23a, 23b External electrode 101 1st elastic body sheet 102 2nd elastic body sheet 110a, 110b, 210a, 210b, 310a, 310b Green sheets 111, 111a, 111b, 211, 211a, 211b, 311, 311a, 311b First long sides 112, 112a, 112b, 212, 212a, 212b, 312, 312a, 312b Second Long sides 121a, 121b, 122a, 122b, 123a, 123b, 221a, 221b, 222a, 222b, 321a, 322a Internal electrode lead-out portions 130, 230, 330 Wavy lines (prone to cracks)
313, 313b 1st short side 314, 314b 2nd short side 323b, 324b End surface internal electrode extraction part

Claims (8)

A laminating step of laminating a plurality of green sheets each having an internal electrode layer to produce a laminate;
A pressure bonding step in which a first elastic sheet is disposed on a top surface in the stacking direction of the stacked body, a second elastic sheet is disposed on a bottom surface in the stacking direction of the stacked body, and the stacked body is pressure-bonded in the stacking direction. A method for manufacturing a laminated electronic component, comprising:
A method for manufacturing a laminated electronic component, characterized by satisfying the following relational expressions (1) and (2):
(Thickness of internal electrode layer x number of laminated internal electrode layers) / 2> thickness of first elastic sheet (1)
(Thickness of internal electrode layer x number of laminated internal electrode layers) / 2> thickness of second elastic sheet (2) The thicknesses of the first elastic sheet and the second elastic sheet are equal to or greater than 20% of the step amount determined by (thickness of internal electrode layer × number of stacked internal electrode layers). The manufacturing method of the multilayer electronic component of Claim 1. 3. The method for manufacturing a laminated electronic component according to claim 1, wherein the durometer A hardness of the first elastic sheet and the second elastic sheet is 40 or more and 80 or less, respectively. The method for manufacturing a laminated electronic component according to any one of claims 1 to 3, wherein a step amount obtained by (thickness of internal electrode layer x number of laminated internal electrode layers) is 50 µm or more and 200 µm or less. The manufacturing method of the multilayer electronic component according to any one of claims 1 to 4, wherein a rigid body pressing step is further performed after the crimping step. The method for manufacturing a multilayer electronic component according to claim 1, wherein the multilayer electronic component is a multilayer ceramic capacitor. The method for manufacturing a laminated electronic component according to claim 1, wherein the laminated electronic component is a laminated electronic component having two or more internal electrode lead portions on one side surface. The method for manufacturing a laminated electronic component according to any one of claims 1 to 7, wherein a pressure bonding temperature in the pressure bonding step is 60 ° C or higher and 85 ° C or lower.

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