KR20180082342A - Method of manufacturing multilayer electronic component - Google Patents

Abstract

Provided is a method for manufacturing a multilayer electronic component capable of preventing cracking from occurring in a stacked body in a pressing process. The method for manufacturing a multilayer electronic component comprises: a stacking step of forming a stacked body by stacking a plurality of green sheets having internal electrode layers formed thereon; and a pressing step of disposing a first elastic sheet on an upper surface of the stacked body in the stacking direction, disposing a second elastic sheet on a lower surface of the stacked body in the stacking direction, and pressing the stacked body in the stacking direction. The present invention satisfies relational expression (1), (Thickness of Internal electrode layer x Number of Stacked internal electrode layers)/2 > Thickness of First elastic sheet, and relational expression (2), (Thickness of Internal electrode layer x Number of Stacked internal electrode layers)/2 > Thickness of Second elastic sheet.

Description

[0001] METHOD OF MANUFACTURING MULTILAYER ELECTRONIC COMPONENT [0002]

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

In multilayer ceramic capacitors, there is a great demand for miniaturization of large capacity, thinning of green sheets and multilayering of internal electrodes are progressing.

In the production process of a multilayer ceramic capacitor, there is a compression process in which a plurality of green sheets having internal electrode layers are laminated to form a laminate, and the laminate is compressed.

There is a step difference in the lamination thickness in the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed in the laminate. Then, adhesion at the portion where the internal electrode layer is not formed becomes insufficient.

Further, when the multilayer structure is progressed, the influence of the step becomes larger.

In order to ensure adhesion at a portion where the internal electrode layer is not formed, an elastic sheet may be disposed above and below the laminate in the pressing step.

Patent Document 1 discloses a method for producing a multilayer ceramic electronic device including a step of pressing a laminate by using an elastic sheet having a greater stretchability in the thickness direction as compared with the surface direction.

Japanese Patent Application Laid-Open No. 9-190948

Patent Document 1 discloses a method for manufacturing a multilayer ceramic capacitor wherein the step of pressing the green sheet at the time of manufacturing the multilayer ceramic capacitor has a stepped portion of the inner electrode layer (the thickness of the inner electrode layer x the number of laminated green sheets) is 150 탆 (3 탆 x 50 sheets) The thickness of the polyethylene terephthalate as the base material is 200 mu m.

When the compression step under the same conditions as described in Patent Document 1 is carried out, there is a case where a part of the surface of the layered product, particularly, the peripheral portion of the surface of the layered product, is cracked.

Particularly, there is a tendency that cracks tend to occur in the laminated electronic component having the internal electrode lead-out portion on the side surface of the laminate.

An object of the present invention is to provide a method for manufacturing a laminated electronic component which is capable of preventing cracks in the laminate in the pressing process.

The inventors of the present invention have studied means for eliminating the occurrence of cracks in the pressing process and found that by setting the relationship between the thickness of the elastic sheet disposed above and below the laminate and the end of the internal electrode layer within an appropriate range, It has been found that 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 can be reduced and cracks can be prevented from occurring.

That is, a method of manufacturing a laminated electronic component of the present invention includes: a lamination step of laminating a plurality of green sheets on which internal electrode layers are formed to form a laminate; And a pressing step of disposing a second elastic sheet on the lower face of the laminate in the lamination direction and pressing the laminate in the laminating direction, characterized by satisfying the following relational expressions (1) and (2) .

(Thickness of the internal electrode layer x number of laminated internal electrode layers) / 2 > thickness of the first elastic sheet (1)

(The thickness of the internal electrode layer x the number of laminated internal electrode layers) / 2 > the thickness of the second elastic sheet (2)

If the thicknesses of the first and second elastic sheet used in the pressing process satisfy the relational expressions (1) and (2), the boundary between the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed The force exerted thereon can be reduced, and the occurrence of cracks can be prevented.

In the method for producing a laminated electronic component of the present invention, it is preferable that the thickness of the first elastic sheet and the second elastic sheet is 20% of the stepped surface (thickness of the inner electrode layer x number of laminated layers of the inner electrode layer) Or more.

If the thickness of the elastic sheet is made thinner, the pressure applied to the portion where the internal electrode layer is formed becomes relatively high, and the dielectric thickness tends to be thin. As a result, the insulation resistance defect ratio (short defect ratio) increases, but the insulating resistance defect ratio can be reduced by setting the thickness of the elastic sheet to the above range.

In the method for producing a laminated electronic component according to the present invention, it is preferable that the durometer A hardness of the first elastic sheet and the second elastic sheet are 40 or more and 80 or less, respectively.

If the hardness of the elastomeric sheet is 40 or more, a 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 compression is not excessively large. When the hardness of the elastomer sheet is 80 or less, the effect of improving the adhesion at the portion where the internal electrode layer is not formed is sufficiently exhibited, which is preferable.

In the method for manufacturing a laminated electronic component according to the present invention, it is preferable that the stepped section determined by (the thickness of the internal electrode layer x the number of laminated internal electrode layers) is 50 占 퐉 or more and 200 占 퐉 or less.

When the vehicle is 50 mu m or more, the effect of the present invention is more remarkably exhibited. Further, when the stepped vehicle exceeds 200 占 퐉, it may become difficult to secure the adhesion between the green sheets.

In the method for manufacturing a laminated electronic component of the present invention, it is preferable to further perform a rigid pressing step after the pressing step.

By further performing a rigid body press after the pressing process, it is possible to reduce a step between a portion where the internal electrode layer is formed and a portion where the internal electrode layer is not formed. If the step difference is large, the stability is not sufficient at the time of mounting the laminated electronic component on the substrate, and soldering failure may occur, so that it is preferable to reduce the step.

In the method for manufacturing a laminated electronic component of the present invention, it is preferable that the laminated electronic component is a multilayer ceramic capacitor.

The multilayer ceramic capacitor tends to have a large number of laminated layers, which tends to cause a step, so that the method for manufacturing a laminated electronic component of the present invention is particularly effective.

In the method for manufacturing a laminated electronic component of the present invention, it is preferable that the laminated electronic component is a laminated electronic component having two or more internal electrode lead-out portions on one side.

If the laminated electronic component is a laminated electronic component having two or more internal electrode lead-out portions on one side, cracks are likely to occur particularly when the conventional pressing process is performed. Further, by applying the pressing step in the method for manufacturing a laminated electronic component of the present invention, it is possible to prevent the occurrence of cracks.

That is, the effect of the present invention is particularly remarkable for laminated electronic parts having two or more internal electrode lead-out portions on one side.

In the method for producing a laminated electronic component of the present invention, the compression temperature in the compression step is preferably 60 占 폚 or more and 85 占 폚 or less.

When the compression temperature is 60 占 폚 or higher, the effect of improving the adhesion at the portion where the internal electrode layer is not formed is sufficiently exhibited, and the possibility of causing structural defects such as delamination is reduced. When the compression temperature is 85 DEG C or less, the deformation amount due to temperature deformation of the laminate subjected to the compression bonding process is hard to increase. Therefore, in the step of cutting the laminate later into chip pieces, the defective ratio of internal electrode exposure due to the lowering of the cutting position accuracy is lowered.

According to the method for manufacturing a laminated electronic component of the present invention, it is possible to prevent the occurrence of cracks in the laminated body in the pressing step, thereby producing a laminated electronic component.

1 is a perspective view schematically showing an example of a multilayer ceramic capacitor which can be manufactured by the method for manufacturing a multilayer electronic component of the present invention.
2 (a) and 2 (b) are top views schematically showing a green sheet having an internal electrode layer having an internal electrode pattern for manufacturing a laminated electronic component having three internal electrode lead-out portions on one side . Fig. 2 (c) is a plan view showing the internal electrode patterns shown in Fig. 2 (a) and Fig. 2 (b) superposed.
3 (a) and 3 (b) are top views schematically showing 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. 3 (c) is a plan view showing the internal electrode patterns shown in Fig. 3 (a) and Fig. 3 (b) superposed.
4A and 4B are top views schematically showing 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 . Fig. 4 (c) is a plan view showing the internal electrode patterns shown in Fig. 4 (a) and Fig. 4 (b) superposed.
Fig. 5 is a schematic view showing a multi-faced pattern of a laminate in which a green sheet shown in Fig. 2 (a) and a green sheet shown in Fig. 2 (b) are laminated.
Fig. 6 is a cross-sectional view schematically showing a state in which an elastic sheet is arranged above and below a laminate in a pressing process.

Hereinafter, a method of manufacturing a laminated electronic component of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following configuration, and can be appropriately modified and applied without departing from the gist of the present invention. It is also the present invention that two or more of the preferred constitutions of the present invention described below are combined.

Hereinafter, a method for manufacturing a laminated electronic component of the present invention will be described by taking the case of producing a multilayer ceramic capacitor as an example.

1 is a perspective view schematically showing an example of a multilayer ceramic capacitor which can be manufactured by the method for manufacturing a multilayer electronic component of the present invention.

The multilayer ceramic capacitor 1 shown in Fig. 1 has an external electrode 21a, an external electrode 22a and an external electrode 23a provided on a first side face 11 of the multilayer body 10, The external electrode 21b, the external electrode 22b and the external electrode 23b are provided on the second side surface 12 of the substrate 10. The portion where each external electrode is provided is a portion where the internal electrode is drawn out from the side surface of the laminate. FIG. 1 schematically shows an internal electrode in an external electrode by a dotted line. The multilayer ceramic capacitor 1 shown in Fig. 1 can be regarded as a laminated electronic component having three internal electrode lead-out portions on one side.

Hereinafter, a method of manufacturing a multilayer electronic component capable of manufacturing such a multilayer ceramic capacitor will be described.

First, a green sheet having an internal electrode layer is prepared.

A ceramic slurry in which ceramics to be a dielectric layer, an organic material and a solvent are mixed is applied in a sheet form onto a carrier film such as a PET film by spray coating, die coating, screen printing or the like to obtain a ceramic green sheet.

Subsequently, a conductive paste for forming an internal electrode layer made of a metal material such as Ni powder, a solvent, a dispersant, and a binder is prepared. An internal electrode pattern is formed by printing a conductive paste for forming an internal electrode layer on a ceramic green sheet by a method such as screen printing or gravure printing.

In this way, a green sheet having an internal electrode layer is prepared.

In which the dielectric ceramics include, for example, barium titanate (BaTiO _3), calcium titanate (CaTiO _3), a ceramic material mainly composed of strontium titanate (SrTiO _3), or zirconate, calcium (CaZrO ₃₎ and the like. Further, the ceramic material may contain Mn, Mg, Si, Co, Ni, rare earth or the like as a subcomponent having a content lower than that of the main component.

Examples of the organic material contained in the ceramic slurry include a polyvinyl butyral based binder and a phthalic acid ester based binder as a binder.

The thickness of the ceramic green sheet is preferably 0.6 占 퐉 or more and 1.2 占 퐉 or less.

It is preferable that the conductive paste for forming the internal electrode layer contains a metal material such as Ni, Cu, Ag, Pd, Ag-Pd alloy or Au. It is also preferable that the ceramic green sheet contains a dielectric material having the same composition as that of the ceramic material contained in the ceramic green sheet.

The thickness of the internal electrode layer formed on the green sheet is preferably 0.2 mu m or more and 1.5 mu m or less. When the thickness of the internal electrode layer is 0.2 탆 or more, the continuity of the internal electrode is improved, so that the acquisition capacity is not lowered. When the thickness of the internal electrode layer is 1.5 占 퐉 or less, the adhesion between the green sheets is not lowered, and the occurrence of structural defects such as delamination can be prevented.

The internal electrode pattern drawn on the ceramic green sheet differs depending on the specification of the laminated electronic component to be produced, and some examples thereof will be described.

It is preferable that the laminated electronic component manufactured by the method for manufacturing a laminated electronic component of the present invention is a laminated electronic component having two or more internal electrode lead-out portions on one side.

An internal electrode pattern for manufacturing such a laminated electronic component is shown in Figs. 2A, 2B and 2C, and Figs. 3A, 3B and 3C .

2 (a) and 2 (b) are top views schematically showing a green sheet having an internal electrode layer having an internal electrode pattern for manufacturing a laminated electronic component having three internal electrode lead-out portions on one side . Fig. 2 (c) is a plan view showing the internal electrode patterns shown in Fig. 2 (a) and Fig. 2 (b) superposed.

In the green sheet 110a shown in Fig. 2 (a), the first long side 111a, which becomes the first side when formed as a laminate, is provided with the internal electrode withdrawing portion 121a, The internal electrode lead portion 122b reaches the second long side 112a, which becomes the second side face. On the other hand, in the green sheet 110b shown in Fig. 2 (b), the inner electrode lead portion 122a reaches the first long side 111b serving as the first side when the laminate is formed, The inner electrode lead-out portion 121b and the inner electrode lead-out portion 123b reach the second long side 112b serving as the second side.

Fig. 2 (c) shows the internal electrode patterns superimposed when the two green sheets 110a and the green sheets 110b are stacked. The internal electrode lead-out portion 121a, the internal electrode lead-out portion 122a, and the internal electrode lead-out portion 122a are formed on the first side surface of the laminate obtained by the first long side 111 when the laminate is formed from the shape obtained by superimposing the two green sheets. It can be seen that the electrode withdrawing portion 123a is located. The inner electrode lead portion 121b, the internal electrode lead portion 122b, and the internal electrode lead portion 123b are located on the second side surface of the laminate obtained by the second long side 112 when the laminate is used .

Fig. 2 (c) schematically shows a portion where a crack is liable to occur when a laminate having this internal electrode pattern is pressed by a conventional method by a broken line (wave line). According to the method for manufacturing a laminated electronic component of the present invention, it is possible to prevent cracks from being generated in this portion.

3 (a) and 3 (b) are top views schematically showing 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. 3 (c) is a plan view showing the internal electrode patterns shown in Fig. 3 (a) and Fig. 3 (b) superposed.

In the green sheet 210a shown in Fig. 3 (a), the internal electrode lead-out portion 221a reaches the first long side 211a which becomes the first side when the laminate is used, The inner electrode lead-out portion 222b reaches the second long side 212a, which is the side surface of the inner electrode lead-out portion 222a. On the other hand, in the green sheet 210b shown in Fig. 3 (b), the internal electrode lead-out portion 222a reaches the first long side 211b which becomes the first side when the laminate is formed, And the internal electrode withdrawing portion 221b reaches the second long side 212b serving as the second side.

Fig. 3 (c) shows the internal electrode patterns when the two green sheets 210a and the green sheets 210b are superimposed. The internal electrode withdrawing portion 221a and the internal electrode withdrawing portion 222a are positioned on the first side surface of the laminate obtained by the first long side 211 when the laminate is formed from the shape obtained by superimposing the two green sheets . It can also be seen that the internal electrode withdrawing portion 221b and the internal electrode withdrawing portion 222b are located on the second side surface of the laminate obtained by the second long side 212 when the laminate is used.

3 (c), a broken line 230 schematically shows a portion where a crack is likely to occur when a laminate having this internal electrode pattern is pressed by a conventional method. According to the method for manufacturing a laminated electronic component of the present invention, it is possible to prevent cracks from being generated in this portion.

The laminated electronic component manufactured by the method for producing a laminated electronic component of the present invention may be a laminated electronic component having one internal electrode lead-out portion on one side.

4 (a), 4 (b) and 4 (c) show internal electrode patterns for manufacturing such a laminated electronic component.

4A and 4B are top views schematically showing 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 . Fig. 4 (c) is a plan view showing the internal electrode patterns shown in Fig. 4 (a) and Fig. 4 (b) superposed.

In the green sheet 310a shown in Fig. 4 (a), the internal electrode lead portion 321a reaches the first long side 311a which becomes the first side when the laminate is used, The internal electrode lead-out portion 322a reaches the second long side 312a, which is the side surface of the second electrode. On the other hand, in the green sheet 310b shown in Fig. 4 (b), the first long side 311b as the first side and the second long side 312b as the second side The inner electrode withdrawing portion does not reach the inner electrode. In the green sheet 310b shown in Fig. 4 (b), the cross section inner electrode lead portion 323b reaches the first short side 313b, which becomes the first end face (end face) And the end face internal electrode withdrawing portion 324b reaches the second short side 314b which becomes the second end face when the multilayer body is formed.

Fig. 4 (c) shows the internal electrode patterns superimposed when the two green sheets 310a and the green sheets 310b are superimposed. From the shape obtained by superimposing the two green sheets, it can be seen that the internal electrode withdrawing portion 321a is located on the first side surface of the laminate obtained by the first long side 311 when the laminate is formed. It can also be seen that the internal electrode lead portion 322a is located on the second side surface of the laminate obtained by the second long side 312 when the laminate is formed.

Also, it can be seen that the end face internal electrode lead portion 323b is located on the first end face of the laminate obtained by the first short side 313 when the laminate is used. Also, it can be seen that when the laminate is formed into a laminate, the end face internal electrode withdrawing portion 324b is located on the second end face of the laminate obtained by the second short side 314.

4 (c), a broken line 330 schematically shows a portion where a crack is likely to occur when a laminate having this internal electrode pattern is compressed by a conventional method. According to the method for manufacturing a laminated electronic component of the present invention, it is possible to prevent cracks from being generated in 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. The length of the short side is preferably 0.4 mm or more and 0.8 mm or less.

A green sheet having internal electrode layers as described above is laminated to produce a laminate. The number of laminated sheets is preferably 100 sheets or more and 300 sheets or less.

Then, the thickness obtained by (the thickness of the internal electrode layer x the number of laminated layers of the internal electrode layers) is called a stepped vehicle. This stepped vehicle 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 of the present invention, the thickness of the elastic sheet is determined in consideration of the stepped portion in the pressing step.

The stepped vehicle is preferably 50 占 퐉 or more and 200 占 퐉 or less.

When the laminate is manufactured, the two types of green sheets are laminated so as to be alternately overlapped with each other, so that the internal electrode pattern of the laminate is the internal electrode pattern as shown in Fig. 2 (c), Fig. 3 (c) .

Fig. 5 shows a schematic view of this multi-layer structure in which a green sheet is prepared if the internal electrode pattern is repetitively drawn, and the position of the internal electrode pattern is shifted and laminated.

5 schematically shows a multi-faced pattern of the laminate 100 in which the green sheet 110a shown in Fig. 2 (a) and the green sheet 110b shown in Fig. 2 (b) are laminated. Fig. 5 shows a pattern of four multilayer ceramic capacitors. In Fig. 5, each region divided by the one-dot chain line corresponds to a pattern of one multilayer ceramic capacitor.

Further, at the time of manufacturing the laminate, it is preferable to further laminate the outer layer green sheet for forming the outer layer on the outer side of the green sheet on which the internal electrode layers are formed.

The outer layer green sheet is a ceramic green sheet having no electrode layer. The thickness of the outer layer green sheet is preferably 1 占 퐉 or more and 10 占 퐉 or less.

Subsequently, a compression step of placing the first elastic sheet on the upper surface in the lamination direction of the laminate, disposing the second elastic sheet on the lower surface in the lamination direction of the laminate, and pressing the laminate in the lamination direction is carried out.

Fig. 6 is a cross-sectional view schematically showing a state in which an elastic sheet is arranged above and below a laminate in a pressing process. 5 schematically shows a state in which an elastic sheet is arranged above and below a cut surface cut at a position corresponding to line A-A 'in a multi-side worn pattern of the laminate.

In Fig. 6, a first elastic sheet 101 is disposed on the upper surface of the laminate 100, and a second elastic sheet 102 is disposed on the lower surface of the laminate 100. As shown in Fig.

In the stacked body 100, a portion in which the internal electrode layer is formed and a portion in which the internal electrode layer is not formed are alternately arranged in the left-right direction, and a portion where the internal electrode layer is not formed is (thickness of the internal electrode layer x The thickness is reduced by the amount of the stepped vehicle obtained by the number of steps. Since the elastic sheet has elasticity (flexibility), the elastic sheet 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 it is a material having elasticity such that pressure is applied to a portion where the internal electrode layer is not formed. Specific examples thereof include 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, And rubber materials such as rubber, hydrogenated rubber, hydrogenated rubber, polysulfide rubber, and chlorosulfonated polyethylene rubber.

Further, resin materials such as polyethylene, polystyrene, and polyurethane can be used.

Among these materials, silicone rubber is preferable.

The durometer A hardness of the first elastic sheet and the second elastic sheet is preferably not less than 40 and not more than 80, respectively. The durometer A hardness is the degree of hardness measured by a Type A indenter (circumference).

The thicknesses of the first elastic sheet and the second elastic sheet satisfy the following relational expressions (1) and (2).

(Thickness of the internal electrode layer x number of laminated internal electrode layers) / 2 > thickness of the first elastic sheet (1)

(The thickness of the internal electrode layer x the number of laminated internal electrode layers) / 2 > the thickness of the second elastic sheet (2)

(1) and (2) in which the first elastic sheet and the second elastic sheet are thinner than half the thickness of the vehicle, the thickness of the inner electrode layer x the number of lamination of the inner electrode layers) ).

If the thicknesses of the first and second elastic sheet satisfy the relational expressions (1) and (2), 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 is reduced So that the occurrence of cracks can be prevented.

It is preferable that the thicknesses of the first elastic sheet and the second elastic sheet are respectively not less than 20% of the thickness of the stepped portion determined by (the thickness of the inner electrode layer x the number of laminated layers of the inner electrode layer).

It is preferable that the first elastic sheet and the second elastic sheet have a thickness of 20 mu m or more, respectively.

Each of the first elastic sheet and the second elastic sheet may be used one by one or a plurality of sheets may be stacked. The thickness of the elastic sheet when a plurality of elastic sheet sheets are stacked and 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. The thickness of the first elastic sheet and the thickness of the second elastic sheet may be different as long as they satisfy the relational expressions (1) and (2), respectively.

The pressing conditions in the pressing step are not particularly limited, but it is preferable to set the pressing temperature (mold temperature) to 60 ° C or more and 85 ° C or less. The press pressure is preferably 20 MPa or more and 60 MPa or less. The press time is preferably 30 seconds or more and 180 seconds or less. The pressing can be carried out by using any press apparatus.

Adhesion can be ensured in a portion where the internal electrode layer is not formed by pressing using an elastic sheet.

After the pressing process, it is preferable to further perform the rigid pressing process.

In the rigid pressing step, pressing is performed without using an elastic sheet to reduce steps between a portion where the internal electrode layer is formed and a portion where the internal electrode layer is not formed.

It is preferable to dispose a PET film between the mold (rigid body) and the laminate. Further, a releasing agent may be applied to the surface of the mold, and a rigid pressing step may be performed without disposing the PET film.

The pressing conditions in the rigid pressing step are not particularly limited, but it is preferable to set the pressing temperature (mold temperature) to 60 DEG C or more and 85 DEG C or less. The press pressure is preferably 70 MPa or more and 150 MPa or less. The press time is preferably 30 seconds or more and 300 seconds or less. The rigid pressing process can be carried out using an arbitrary press apparatus.

Further, in the laminate subjected to the pressing process, when the step between the portion where the internal electrode layer is formed and the portion where the internal electrode layer is not formed is small, the rigid pressing process may not be performed.

Thereafter, firing of the laminate and formation of external electrodes can be carried out to obtain a multilayer ceramic capacitor. These steps can be carried out by a known method.

Although the method of manufacturing the multilayer electronic component of the present invention has been described above as an example of manufacturing a multilayer ceramic capacitor, the multilayer electronic component manufactured by the multilayer electronic component manufacturing method of the present invention is limited to a multilayer ceramic capacitor It is not.

In the case of electronic components other than multilayer ceramic capacitors, piezoelectric ceramics such as PZT ceramics, semiconductor ceramics such as spinel ceramics, and magnetic ceramics such as ferrite can be used as the ceramics constituting the dielectric layer.

When piezoelectric ceramics are used, they function as piezoelectric parts. When semiconductor ceramics are used, they function as thermistors. When magnetic ceramics are used, they function as inductors.

Example

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the electronic component of the present invention will be described in detail. The present invention is not limited to these examples.

(Example 1)

1) Fabrication of a green sheet having an internal electrode layer

A polyvinyl butyral-based binder, a plasticizer and ethanol as an organic solvent were added to BaTiO ₃ as a ceramic raw material, and these were wet mixed with a ball mill to prepare a ceramic slurry. Subsequently, this ceramic slurry was formed into a sheet by a lip method to obtain a rectangular ceramic green sheet.

The thickness of the ceramic green sheet was 1.0 mu m on average.

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-out portions on one side surface as shown in Figs. 2 (a) and 2 (b).

2) Measurement of internal electrode layer thickness

The thickness of the printed internal electrode layer was measured by a fluorescent X-ray film thickness meter. The measurement was carried out at 25 points per sheet (five rows × five rows at the center of the internal electrode pattern) for five green sheets (total of 125 points in the five sheets).

The average thickness was 0.5 mu m.

3) Laminating process

100 sheets of two types of green sheets having internal electrode layers formed thereon were alternately stacked to obtain a laminate. The number of stacked sheets is 200 sheets.

Further, upper and lower green sheets having the same composition as the ceramic green sheet and having an average thickness of 50 mu m were laminated on and under the laminate.

The stepped vehicle in the laminate had an internal electrode layer thickness of 0.5 mu m x 200 sheets = 100 mu m.

4) Compression 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 占 퐉 was used.

A first elastic sheet was disposed on the upper surface of the laminate and a second elastic sheet was disposed on the lower surface of the laminate. Compression was performed at a mold temperature of 70 占 폚, a press pressure of 40 MPa, and a press time of 60 seconds.

5) Rigid body press process

Subsequently, a PET film having a thickness of 50 占 퐉 was disposed on the upper and lower surfaces of the laminate in place of the elastomer sheet, and compression (rigid press process) was performed at a mold temperature of 70 占 폚, a press pressure of 100 MPa, and a press time of 60 seconds.

6) Cutting and firing process

The pressed laminate was divided by dicing to obtain chips. The resulting chip was heated in an N ₂ atmosphere to burn the binder, and then fired at 1250 ° C in a reducing atmosphere containing H ₂ , N _2, and H ₂ O gases to obtain a sintered laminate.

The size of the produced laminate was L x W x T = 1.0 mm x 0.5 mm x 0.4 mm.

(Observation of crack number after firing)

The surface of the laminate subjected to the firing process was observed to confirm the presence of cracks.

The presence or absence of cracks is determined by observing a surface (upper surface or lower surface) perpendicular to the stacking direction of the laminated body after firing with a microscope. Particularly, cracks are liable to occur at a portion contacting 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 占 퐉 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 resistance of less than 50 M? The number of measurements was 3000, and the defect rate was expressed in%.

Examples of the samples for measuring the insulation resistance failure rate include a sintering step (not shown) after the squeezing step and a sintering step without the rigid sintering step (indicated as "after squeezing step" in Table 1), a sintering step (Shown as " after pressing the rigid body " in Table 1) were prepared.

(Measurement of vehicle)

After the sintering step, the laminate before dicing was filled with the resin and polished on one side to prepare a sample for observation of the cut surface.

The difference in height between the lowest portion in the portion where the internal electrode layer was not formed and the highest portion in the portion where the internal electrode layer was formed was measured to obtain a stepped vehicle.

The measurement of the height was carried out with respect to four chips (positions indicated by B, C, D, and E in FIG. 6) for one chip, and five chips were randomly extracted from the stack.

As a sample for measurement of the stepped vehicle, a sample subjected to a sintering process without a rigid press process after the squeezing process (shown as "after the squeezing process" in Table 1) and a sintering process (Those shown as "after rigid body press" in Table 1) were prepared.

(Examples 2 to 4)

The laminate was produced and evaluated in the same manner as in Example 1 except that the thicknesses of the elastic sheet were changed as shown in Table 1, respectively.

(Comparative Example 1)

A laminate was produced and evaluated in the same manner as in Example 1 except that the pressing process was performed without using an elastic sheet.

(Comparative Examples 2 and 3)

The laminate was produced and evaluated in the same manner as in Example 1 except that the thicknesses of the elastic sheet were changed as shown in Table 1, respectively.

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

(1) and (2) are satisfied when the thickness of the elastic sheet is less than 50 占 퐉, because [(thickness of the internal electrode layer x number of laminated internal electrode layers) / 2] = 50 占 퐉 in each example shown in Table 1 .

In all of Examples 1 to 4, an elastic sheet was used, and since the thickness satisfies relational expressions (1) and (2), it was possible to prevent the occurrence of cracks.

In addition, the insulation resistance defect rate was also lowered, and in Examples 3, 4 and 1 in which the thickness of the elastic sheet was 20 m or more, the insulation resistance defect rate was particularly low.

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 were produced because the thickness was too thick and the relational expressions (1) and (2) were not satisfied.

It was found that all the vehicles were small after the rigid press, and that the rigid press was able to make the small vehicle.

(Example 5, Comparative Example 4)

The internal electrode pattern is an internal electrode pattern for producing a laminated electronic component having two internal electrode lead portions on one side surface as shown in Figs. 3 (a) and 3 (b) .

The laminate was produced and evaluated in the same manner as in Example 5 except that the thickness of the elastic sheet was 40 탆, and that of Comparative Example 4 was 100 탆. For evaluation, only the number of cracks after baking was observed.

(Example 6, Comparative Example 5)

The internal electrode pattern was formed as an internal electrode pattern for manufacturing a laminated electronic component having one internal electrode lead portion on one side surface as shown in Figs. 4 (a) and 4 (b) .

The laminate was manufactured and evaluated as Comparative Example 5 in which the thickness of the elastic sheet was 40 占 퐉, and that of Example 6 was 100 占 퐉. For evaluation, only the number of cracks after baking was observed.

Table 2 summarizes the results of Example 1 and Comparative Example 3 and shows the relationship between the number of side electrode internal lead portions and the number of cracks.

The size of each of the stacked layers produced was L x W x T = 1.0 mm x 0.5 mm x 0.4 mm.

As shown in Table 2, cracks did not occur in all of the examples in which the thicknesses of the elastic sheet satisfied the relational expressions (1) and (2), but the thicknesses of the elastic sheet were determined by the relational expressions (1) and In each of the comparative examples which are not satisfied, cracks are generated. Since the number of generated cracks is large enough to increase the number of side inner electrode lead-out portions, it can be seen that the method of the present invention is particularly effective when the number of side inner electrode lead-out portions is large.

1: Multilayer Ceramic Capacitor
10, 100: laminate
11: first side
12: Second side
21a, 21b, 22a, 22b, 23a, 23b:
101: a first elastic sheet
102: second elastic sheet
110a, 110b, 210a, 210b, 310a, 310b:
111, 111a, 111b, 211, 211a, 211b, 311, 311a, 311b:
112, 112a, 112b, 212, 212a, 212b, 312, 312a, 312b:
The internal electrode withdrawing portions 121a, 121b, 122a, 122b, 123a, 123b, 221a, 221b, 222a, 222b, 321a,
130, 230, 330: broken line (area where crack is likely to occur)
313, 313b: first short side
314, 314b: second short side
323b, 324b: a cross-sectional inner electrode lead-

Claims (8)

A lamination step of laminating a plurality of green sheets on which an internal electrode layer is formed to manufacture a laminate; and a step of disposing a first elastic sheet on the upper surface in the lamination direction of the laminate, And a pressing step of pressing the laminate in the laminating direction, the method comprising:
(1) and (2): " (1) "
(Thickness of the internal electrode layer x number of laminated internal electrode layers) / 2 > thickness of the first elastic sheet (1)
(The thickness of the internal electrode layer x the number of laminated internal electrode layers) / 2 > the thickness of the second elastic sheet (2) The method according to claim 1,
Wherein the thickness of the first elastic sheet and the thickness of the second elastic sheet are respectively not less than 20% of the thickness of the internal electrode layer and not more than 20% of the thickness of the internal electrode layer. 3. The method according to claim 1 or 2,
Wherein the durometer A hardness of the first elastic sheet and the second elastic sheet is 40 or more and 80 or less, respectively. 3. The method according to claim 1 or 2,
The thickness of the internal electrode layer x the number of steps of lamination of the internal electrode layers is 50 占 퐉 or more and 200 占 퐉 or less. 3. The method according to claim 1 or 2,
Further comprising the step of pressing a rigid body after the pressing step. 3. The method according to claim 1 or 2,
Wherein the laminated electronic component is a multilayer ceramic capacitor. 3. The method according to claim 1 or 2,
Wherein the laminated electronic component is a laminated electronic component having two or more internal electrode lead-out portions on one side surface thereof. 3. The method according to claim 1 or 2,
Wherein the compression bonding temperature in the compression bonding step is 60 占 폚 or more and 85 占 폚 or less.

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