JP2006083060A - Coating for green sheet, its manufacturing method, green sheet, its manufacturing method and method for manufacturing electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating for a green sheet with which the green sheet having strength durable to exfoliation from a support and having superior adhesiveness and handleability can be manufactured even when the green sheet is very thin, the green sheet and their manufacturing methods and to provide a method for manufacturing an electronic component suitable for its thinning and multilayering. <P>SOLUTION: The coating for the green sheet has a ceramic powder, a binder resin, a plasticizer, a solvent and an electrification removing agent. The binder resin contains a polyvinyl butyral resin whose polymerization degree is 1,000 or more and 1,700 or less, whose nominal value of a butyralizing degree is 65% or more and 78% or less and where a residual acetyl radical is less than 6%. The electrification removing agent contains an imidazoline-based electrification removing agent by 0.1 pt. mass or more and 0.75 pt. mass or less to the ceramic powder of 100 pts. mass. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a green sheet coating, a green sheet, a method for manufacturing a green sheet coating, a method for manufacturing a green sheet, and a method for manufacturing an electronic component, and more particularly, handling and adhesion even for extremely thin sheets. The present invention relates to a coating material, a green sheet, and a method suitable for thinning and multilayering of electronic components.

  In recent years, with the miniaturization of various electronic devices, miniaturization and high performance of electronic components mounted inside the electronic devices have been advanced. As one of the electronic components, there are ceramic electronic components such as a CR-embedded substrate and a multilayer ceramic capacitor, and the ceramic electronic components are also required to be downsized and high performance.

  In order to reduce the size and increase the capacity of the ceramic electronic component, there is a strong demand for a thinner dielectric layer. Recently, the thickness of the dielectric green sheet constituting the dielectric layer has become several μm or less.

  In order to produce a ceramic green sheet, usually, ceramic powder, binder (acrylic resin, butyral resin, etc.), plasticizer (phthalates, glycols, adipic acid, phosphates) and organic solvent ( A ceramic paint made of toluene, MEK, acetone, etc.) is prepared. Next, this ceramic paint is applied onto a carrier sheet (PET, PP support) using a doctor blade method or the like, and dried by heating.

  In recent years, it has also been studied to prepare a ceramic suspension in which ceramic powder and binder are mixed in a solvent, and to produce a film-like molded body obtained by extrusion molding this suspension by biaxial stretching. ing.

  A method for manufacturing a multilayer ceramic capacitor using the above-described ceramic green sheet will be specifically described. On the ceramic green sheet, an internal electrode conductive paste containing metal powder and a binder is printed in a predetermined pattern and dried to form an internal electrode pattern. Thereafter, the green sheet is peeled off from the carrier sheet and laminated to a desired number of layers. Here, a method of peeling the green sheet from the carrier sheet before lamination and a method of peeling the carrier sheet after lamination pressure bonding have been devised, but there is no significant difference. Finally, this laminate is cut into chips to produce green chips. After firing these green chips, external electrodes are formed to manufacture electronic components such as multilayer ceramic capacitors.

  When manufacturing a multilayer ceramic capacitor, the interlayer thickness of the sheet on which the internal electrodes are formed is in the range of about 3 μm to 100 μm based on the desired capacitance required for the capacitor. In the multilayer ceramic capacitor, a portion where no internal electrode is formed is formed on the outer portion of the capacitor chip in the stacking direction.

  In such a multilayer ceramic capacitor, a polyvinyl butyral resin having a polymerization degree of 1000 or less (Mw = 50,000) is generally used as the binder used (Patent Document 1 below; 10-67567). The reason for this is to ensure sufficient adhesion of the ceramic green sheet during lamination, to reduce the surface roughness of the green sheet, to ensure the flexibility of the green sheet, and to lower the viscosity of the slurry. To do. As the plasticizer, phthalic acid, adipic acid, sebacic acid, and phosphoric acid esters are generally usable. However, for the purpose of imparting plasticity, the plasticizer has been selected from the viewpoints of boiling point and harmfulness.

  In recent years, with the miniaturization of electronic devices, the miniaturization of electronic components used therein has rapidly progressed. In a multilayer electronic component typified by a multilayer ceramic capacitor, an increase in the number of layers and a reduction in the thickness of an interlayer are rapidly progressing. In order to respond to such technical trends, the thickness of the green sheet that determines the interlayer thickness is becoming from 3 μm or less to 2 μm or less. For this reason, in the manufacturing process of the multilayer ceramic capacitor, it is necessary to handle an extremely thin green sheet, and it is necessary to design a very advanced green sheet physical property.

  Properties required as physical properties of such an extremely thin green sheet include sheet strength, flexibility, smoothness, adhesion at the time of lamination, handling properties (chargeability), etc., and high-dimensional balance. Required.

  In addition, as shown in Patent Document 2; JP-A-6-206756, a technique for using a polyvinyl butyral resin having a polymerization degree of 1000 or more as a binder in a slurry for a green sheet containing an aqueous solvent for the purpose of eliminating short-circuit defects is known. It has been.

  However, Patent Document 2 does not particularly reduce the thickness of the organic solvent-based green sheet, and does not limit the polymerization degree range of the polyvinyl butyral resin to a specific range. Moreover, no attention is paid to the degree of butyralization and the amount of residual acetyl groups of the resin.

  An object of the present invention is for a green sheet capable of producing a green sheet having a strength capable of withstanding peeling from a support, and having good adhesiveness and handling property, even if it is a very thin green sheet. It is providing the manufacturing method of a coating material, a green sheet, the coating material for green sheets, and the manufacturing method of a green sheet. Another object of the present invention is to provide an electronic component manufacturing method suitable for thinning and multilayering of electronic components.

  As a result of intensive studies to achieve the above object, the present inventor uses a polyvinyl acetal resin having a specific range of polymerization degree, a specific range of butyralization degree, and a residual acetyl group amount of a predetermined value or less as a binder. The present invention is completed by finding that even a thin green sheet can produce a green sheet having a strength that can withstand peeling from a support and having good adhesion and handling properties. It came to.

That is, the green sheet paint according to the first aspect of the present invention is a green sheet paint having ceramic powder, a binder resin, a plasticizer, and a solvent,
The binder resin contains a polyvinyl butyral resin, the degree of polymerization of the polybutyral resin is 1000 or more and 1700 or less, the nominal value of the degree of butyralization of the resin is 65% or more and less than 78%, and the residual acetyl group amount is 6 It is characterized by being less than%. Although it does not specifically limit as a solvent, Preferably an organic solvent is used. The nominal value of the degree of butyral varies in the range of ± 3%. That is, the nominal value of the degree of butyralization of 65% means 65 ± 3%. In the following description, the term “degree of butyralization” simply means “nominal value of the degree of butyralization”.

  In the first aspect of the present invention, when the degree of polymerization of the polybutyral resin is too small, sufficient mechanical strength tends to be hardly obtained when the layer is thinned to about 5 μm or less, preferably about 3 μm or less. On the other hand, when the degree of polymerization is too large, the surface roughness tends to deteriorate when the sheet is formed. If the degree of butyralization of the polybutyral resin is too low, the solubility in the paint tends to deteriorate, and if too high, the sheet surface roughness tends to deteriorate. Furthermore, if the amount of residual acetyl groups is too large, the sheet surface roughness tends to deteriorate.

  According to the green sheet paint according to the first aspect of the present invention, even a very thin green sheet has a strength capable of withstanding peeling from the support, and has good adhesion and handling properties. Sheets can be manufactured.

The green sheet paint according to the second aspect of the present invention,
A green sheet paint having ceramic powder, a binder resin, a plasticizer, and an organic solvent,
1 to 6 parts by mass of water is contained with respect to 100 parts by mass of the ceramic powder.

  Conventionally, in a green sheet paint using an organic solvent, it has been necessary to strictly manage so that moisture does not enter in order to absorb moisture and change characteristics. In the 2nd viewpoint of this invention, a water | moisture content is positively mixed with content of a predetermined range from the beginning of coating material preparation. For this reason, in the present invention, it is not necessary to strictly manage moisture absorption by moisture.

  If the water content is too small, the change with time in the paint properties due to moisture absorption is unfavorable, and the viscosity of the paint tends to increase, and the filtration characteristics of the paint tend to deteriorate. Moreover, when there is too much content of water, separation | separation and sedimentation of a coating material will arise, dispersibility will worsen, and it exists in the tendency for the surface roughness of a sheet to deteriorate.

The green sheet paint according to the third aspect of the present invention is:
A green sheet paint having a ceramic powder, a binder resin, a plasticizer, a solvent, and a dispersant,
The dispersant contains a polyethylene glycol-based nonionic dispersant, and has a hydrophilic / lipophilic balance (HLB (abbreviation of Hydrophilic Lipophilic Balance)) value of 5-6,
The dispersant is added in an amount of 0.5 to 1.5 parts by mass with respect to 100 parts by mass of the ceramic powder.
When the dispersant is a dispersant other than the polyethylene glycol-based nonionic dispersant, the coating viscosity increases, the sheet density decreases, the sheet surface roughness increases, or the sheet elongation decreases. There is a tendency. Further, when the HLB of the dispersant is outside the above range, the sheet density tends to decrease and the sheet surface roughness tends to increase.
According to the green sheet paint according to the third aspect of the present invention, even a very thin green sheet has a strength capable of withstanding peeling from the support, and has a good adhesion and handling property. Sheets can be manufactured.
In addition, in the third aspect of the present invention, when the amount of the dispersant added is too small, the viscosity of the paint increases, the sheet density decreases, and the sheet surface roughness tends to increase. Moreover, when there is too much addition amount, it exists in the tendency for adhesive strength to fall while the tensile strength of a sheet | seat falls.

The green sheet paint according to the fourth aspect of the present invention is:
A green sheet paint having a ceramic powder, a binder resin, a plasticizer, a solvent, and a charging aid,
The charge remover includes an imidazoline-based charge remover, and the charge assistant is contained in an amount of 0.1 parts by mass or more and 0.75 parts by mass or less with respect to 100 parts by mass of the ceramic powder.
In the fourth aspect of the present invention, when the charge remover is other than an imidazoline-based charge remover, the charge removal effect is small and the sheet strength, sheet elongation, or adhesiveness tends to deteriorate. According to the coating material for a green sheet according to the fourth aspect of the present invention, even if it is a very thin green sheet, it has a strength capable of withstanding peeling from the support, and static electricity generated at the time of peeling from the support. And a green sheet having good adhesion and handling properties can be produced.
In the fourth aspect of the present invention, if the addition amount of the antistatic agent is too small, the effect of removing the charge is reduced, and if it is too much, the surface roughness of the sheet deteriorates and the sheet strength tends to deteriorate. .
The green sheet paint according to the fifth aspect of the present invention is:
A green sheet paint having a ceramic powder, a binder resin, a solvent, and optionally a plasticizer and a dispersant,
The solvent includes an alcohol solvent and an aromatic solvent, and the total mass of the alcohol solvent and the aromatic solvent is 100 parts by mass, and the aromatic solvent is included in an amount of 10 parts by mass to 20 parts by mass. . When the content of the aromatic solvent is too small, the sheet surface roughness tends to increase. When the content is too large, the paint filtration characteristics deteriorate, and the sheet surface roughness also increases and deteriorates.

  Preferably, the binder resin is included in an amount of 5 parts by mass to 6.5 parts by mass with respect to 100 parts by mass of the ceramic powder. When the content of the binder resin is too small, the sheet strength tends to decrease and the stackability (adhesiveness at the time of lamination) tends to deteriorate. Moreover, when there is too much content of binder resin, segregation of binder resin will generate | occur | produce and there exists a tendency for a dispersibility to worsen, and it exists in the tendency for sheet surface roughness to deteriorate.

  Preferably, the plasticizer contains dioctyl phthalate (DOP) in an amount of 40 parts by weight to 70 parts by weight with respect to 100 parts by weight of the binder resin. Compared to other plasticizers, dioctyl phthalate is preferable in terms of both sheet strength and sheet elongation, and is particularly preferable because it has a small peel strength from the support and is easily peeled off. In addition, when there is too little content of this plasticizer, there exists a tendency for sheet | seat elongation to be small and for flexibility to become small. Moreover, when there is too much content, a plasticizer will bleed out from a sheet | seat, the segregation of the plasticizer with respect to a sheet | seat tends to generate | occur | produce, and it exists in the tendency for the dispersibility of a sheet | seat to fall.

  Preferably, when the total volume of the ceramic powder, the binder resin and the plasticizer is 100% by volume, the volume ratio occupied by the ceramic powder is 64.3% or more and 72% or less. If this volume ratio is too small, binder segregation tends to occur and the dispersibility tends to deteriorate, and the surface roughness tends to deteriorate. On the other hand, if the volume ratio is too large, the sheet strength tends to decrease and the stackability tends to deteriorate.

  Preferably, 3 parts by mass or more and 15 parts by mass or less of at least one of a hydrocarbon solvent, industrial gasoline, kerosene, and solvent naphtha is added to 100 parts by mass of the ceramic powder. By adding these additives, the sheet strength and the sheet surface roughness can be improved. If the addition amount of these additives is too small, the effect of the addition is small, and if the addition amount is too large, the sheet strength and the sheet surface roughness tend to be deteriorated.

The method for producing a coating material for a green sheet according to the present invention includes:
The binder resin is dissolved and filtered in advance in at least one alcohol solvent of methanol, ethanol, propanol, or butanol to obtain a solution, and the ceramic powder and other components are added to the solution. It is characterized by that.

  A binder resin having a high degree of polymerization is difficult to dissolve in a solvent, and the dispersibility of the paint tends to be deteriorated by an ordinary method. In the method of the present invention, since the binder resin having a high degree of polymerization is dissolved in the above-mentioned good solvent and the ceramic powder and other components are added to the solution, the paint dispersibility can be improved. Generation | occurence | production of melt | dissolving resin can be suppressed. In addition, in solvents other than the above-mentioned solvents, the solid content concentration cannot be increased, and the change in lacquer viscosity with time tends to increase.

The method for producing a green sheet according to the present invention includes:
Preparing the green sheet paint;
Forming a ceramic green sheet using the green sheet paint;
Have

A method for producing a ceramic electronic component according to the present invention includes:
Preparing the green sheet paint;
Forming a ceramic green sheet using the green sheet paint;
Drying the green sheet;
Laminating the green sheet after drying through an internal electrode layer to obtain a green chip;
Firing the green chip;
Have

  The green sheet which concerns on this invention is manufactured using the said coating material for green sheets.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.
2A to 2C are main part cross-sectional views showing a method for transferring an electrode layer,
3A to 3C are main part sectional views showing a continuation process of FIG.
4A to 4C are main part cross-sectional views showing a method for laminating green sheets to which electrode layers are bonded,
FIG. 5A to FIG. 5C are cross-sectional views of main parts showing a method for laminating green sheets to which electrode layers are bonded, showing the subsequent steps of FIG.
6A to 6C are main part cross-sectional views showing a continuation process of FIG.
FIG. 7 is a cross-sectional view of an essential part showing a step subsequent to FIG.
FIG. 8 is a fragmentary cross-sectional view showing a step continued from FIG. 7.
Best Mode for Carrying Out the Invention

  First, an overall configuration of a multilayer ceramic capacitor will be described as an embodiment of an electronic component manufactured using a green sheet paint (dielectric paste) and a green sheet according to the present invention.

  As shown in FIG. 1, the multilayer ceramic capacitor 2 according to this embodiment includes a capacitor body 4, a first terminal electrode 6, and a second terminal electrode 8. The capacitor body 4 includes dielectric layers 10 and internal electrode layers 12, and the internal electrode layers 12 are alternately stacked between the dielectric layers 10. One internal electrode layer 12 that is alternately stacked is electrically connected to the inside of the first terminal electrode 6 that is formed outside one end of the capacitor body 4. The other internal electrode layers 12 stacked alternately are electrically connected to the inside of the second terminal electrode 8 formed outside the other end of the capacitor body 4.

  In the present embodiment, as will be described in detail later, the internal electrode layer 12 is formed by transferring the electrode layer 12a to the ceramic green sheet 10a as shown in FIGS.

  The material of the dielectric layer 10 is not particularly limited, and is made of a dielectric material such as calcium titanate, strontium titanate and / or barium titanate. The thickness of each dielectric layer 10 is not particularly limited, but is generally several μm to several hundred μm. In particular, in this embodiment, the thickness is preferably 5 μm or less, more preferably 3 μm or less.

  Although the material of the terminal electrodes 6 and 8 is not particularly limited, copper, a copper alloy, nickel, a nickel alloy, or the like is usually used, but silver, an alloy of silver and palladium, or the like can also be used. The thickness of the terminal electrodes 6 and 8 is not particularly limited, but is usually about 10 to 50 μm.

  The shape and size of the multilayer ceramic capacitor 2 may be appropriately determined according to the purpose and application. When the multilayer ceramic capacitor 2 has a rectangular parallelepiped shape, it is usually vertical (0.6 to 5.6 mm, preferably 0.6 to 3.2 mm) × horizontal (0.3 to 5.0 mm, preferably 0.3 to 1.6 mm) × thickness (0.1 to 1.9 mm, preferably 0.3 to 1.6 mm).

  Next, an example of a method for manufacturing the multilayer ceramic capacitor 2 according to the present embodiment will be described.

(1) First, in order to manufacture a ceramic green sheet that will form the dielectric layer 10 shown in FIG. 1 after firing, a dielectric paint (green sheet paint) is prepared.
The dielectric paint is composed of an organic solvent-based paint obtained by kneading a dielectric material (ceramic powder) and an organic vehicle.

  As the dielectric material, various compounds to be complex oxides and oxides, for example, carbonates, nitrates, hydroxides, organometallic compounds, and the like are appropriately selected and used by mixing. The dielectric material is usually used as a powder having an average particle size of 0.4 μm or less, preferably about 0.1 to 3.0 μm. In order to form a very thin green sheet, it is desirable to use a powder finer than the thickness of the green sheet.

  An organic vehicle is obtained by dissolving a binder resin in an organic solvent. In this embodiment, polyvinyl butyral resin is used as the binder resin used in the organic vehicle. The degree of polymerization of the polybutyral resin is 1000 to 1700, preferably 1400 to 1700. The degree of butyralization of the resin is 65% or more and less than 78%, preferably 65% or more and 70% or less, and the amount of residual acetyl groups is less than 6%, preferably 3% or less.

  The degree of polymerization of the polybutyral resin can be measured by, for example, the degree of polymerization of a polyvinyl acetal resin that is a raw material. Further, the degree of butyralization can be measured in accordance with, for example, JISK6728. Furthermore, the amount of residual acetyl groups can be measured according to JISK6728.

  When the degree of polymerization of the polybutyral resin is too small, sufficient mechanical strength tends to be hardly obtained when the layer is thinned to, for example, 5 μm or less, preferably about 3 μm or less. On the other hand, when the degree of polymerization is too large, the surface roughness tends to deteriorate when the sheet is formed. If the degree of butyralization of the polybutyral resin is too low, the solubility in the paint tends to deteriorate, and if too high, the sheet surface roughness tends to deteriorate. Furthermore, if the amount of residual acetyl groups is too large, the sheet surface roughness tends to deteriorate.

  The organic solvent used for the organic vehicle is not particularly limited, and for example, organic solvents such as terpineol, alcohol, butyl carbitol, acetone, and toluene are used. In the present embodiment, the organic solvent preferably includes an alcohol solvent and an aromatic solvent, and the total mass of the alcohol solvent and the aromatic solvent is 100 parts by mass. More than 20 parts by mass. When the content of the aromatic solvent is too small, the sheet surface roughness tends to increase. When the content is too large, the paint filtration characteristics deteriorate, and the sheet surface roughness also increases and deteriorates.

  Examples of alcohol solvents include methanol, ethanol, propanol, butanol and the like. Examples of the aromatic solvent include toluene, xylene, benzyl acetate and the like.

  Binder resin should be dissolved and filtered in advance in at least one alcohol solvent of methanol, ethanol, propanol, or butanol, and a dielectric powder and other components should be added to the solution. Is preferred. A binder resin having a high degree of polymerization is difficult to dissolve in a solvent, and the dispersibility of the paint tends to be deteriorated by an ordinary method. In the method of the present embodiment, since the binder resin having a high degree of polymerization is dissolved in the above-described good solvent, and the ceramic powder and other components are added to the solution, the paint dispersibility can be improved. Generation | occurrence | production of undissolved resin can be suppressed. In addition, in solvents other than the above-mentioned solvents, the solid content concentration cannot be increased, and the change in lacquer viscosity with time tends to increase.

  The dielectric coating material may contain additives selected from various dispersants, plasticizers, antistatic agents, dielectrics, glass frit, insulators, and the like as necessary.

In the present embodiment, the dispersant is not particularly limited, but a polyethylene glycol nonionic dispersant is preferably used, and the hydrophilic / lipophilic balance (HLB) value thereof is 5 to 6. The dispersant is preferably added in an amount of 0.5 to 1.5 parts by mass, and more preferably 0.5 to 1.0 parts by mass with respect to 100 parts by mass of the ceramic powder.
When the HLB is out of the above range, the viscosity of the paint increases and the sheet surface roughness tends to increase. In addition, a dispersant that is not a polyethylene glycol-based nonionic dispersant is not preferable because the viscosity of the paint increases, the surface roughness of the sheet increases, and the sheet elongation decreases.
When the amount of the dispersant added is too small, the sheet surface roughness tends to increase, and when too large, the sheet tensile strength and stackability tend to decrease.
In the present embodiment, dioctyl phthalate is preferably used as the plasticizer, and is preferably contained in an amount of 40 to 70 parts by mass, more preferably 40 to 60 parts by mass with respect to 100 parts by mass of the binder resin. It is. Compared to other plasticizers, dioctyl phthalate is preferable in terms of both sheet strength and sheet elongation, and is particularly preferable because it has a small peel strength from the support and is easily peeled off. In addition, when there is too little content of this plasticizer, there exists a tendency for sheet | seat elongation to be small and for flexibility to become small. Moreover, when there is too much content, a plasticizer will bleed out from a sheet | seat, the segregation of the plasticizer with respect to a sheet | seat tends to generate | occur | produce, and it exists in the tendency for the dispersibility of a sheet | seat to fall.

  In this embodiment, the dielectric coating material contains water in an amount of 1 part by mass to 6 parts by mass, and preferably 1 to 3 parts by mass with respect to 100 parts by mass of the dielectric powder. If the water content is too small, the change with time in the paint characteristics due to moisture absorption becomes large and preferable, and the viscosity of the paint tends to increase, and the filtration characteristics of the paint tend to deteriorate. Moreover, when there is too much content of water, separation | separation and sedimentation of a coating material will arise, dispersibility will worsen, and it exists in the tendency for the surface roughness of a sheet to deteriorate.

  Furthermore, in this embodiment, at least one of a hydrocarbon solvent, industrial gasoline, kerosene, and solvent naphtha, preferably 3 parts by mass or more and 15 parts by mass with respect to 100 parts by mass of the dielectric powder. Hereinafter, more preferably 5 to 10 parts by mass are added. By adding these additives, the sheet strength and the sheet surface roughness can be improved. If the addition amount of these additives is too small, the effect of the addition is small, and if the addition amount is too large, the sheet strength and the sheet surface roughness tend to be deteriorated.

  The binder resin is preferably contained in an amount of 5 parts by mass to 6.5 parts by mass with respect to 100 parts by mass of the dielectric powder. When the content of the binder resin is too small, the sheet strength tends to decrease and the stackability (adhesiveness at the time of lamination) tends to deteriorate. Moreover, when there is too much content of binder resin, segregation of binder resin will generate | occur | produce and there exists a tendency for a dispersibility to worsen, and it exists in the tendency for sheet surface roughness to deteriorate.

Further, when the total volume of the ceramic powder, the binder resin, and the plasticizer is 100% by volume, the volume ratio occupied by the dielectric powder is preferably 62.42% or more and 72.69% or less, and more preferably Is 63.93% or more and 72.69% or less. If this volume ratio is too small, binder segregation tends to occur and the dispersibility tends to deteriorate, and the surface roughness tends to deteriorate. On the other hand, if the volume ratio is too large, the sheet strength tends to decrease and the stackability tends to deteriorate.
In particular, in the present embodiment, the dielectric paint preferably contains an antistatic agent, and the charging aid is preferably an imidazoline-based antistatic agent. When the charge remover is other than an imidazoline-based charge remover, the charge removal effect is small and the sheet strength, sheet elongation, or adhesiveness tends to deteriorate.
The charging aid is contained in an amount of 0.1 to 0.75 parts by mass, more preferably 0.25 to 0.5 parts by mass, with respect to 100 parts by mass of the ceramic powder. If the addition amount of the antistatic agent is too small, the effect of removing the charge becomes small, and if it is too large, the surface roughness of the sheet deteriorates and the sheet strength tends to deteriorate. If the effect of removing the charge is small, static electricity is likely to occur when the carrier sheet 30 as the support is peeled off from the ceramic green sheet 10a, and inconveniences such as wrinkling of the green sheet are likely to occur.

  Using this dielectric paint, by a doctor blade method or the like, for example, as shown in FIG. 3A, on the carrier sheet 30 as the second support sheet, preferably 0.5-30 μm, more preferably 0.5-10 μm. The green sheet 10a is formed with a certain thickness. The green sheet 10 a is dried after being formed on the carrier sheet 30. The drying temperature of the green sheet 10a is preferably 50 to 100 ° C., and the drying time is preferably 1 to 20 minutes. The thickness of the green sheet 10a after drying shrinks to a thickness of 5 to 25% as compared with that before drying. The thickness of the green sheet after drying is preferably 3 μm or less.

  (2) Apart from the carrier sheet 30, as shown in FIG. 2A, a carrier sheet 20 as a first support sheet is prepared, and a release layer 22 is formed thereon. Further, an electrode layer 12a having a predetermined pattern is formed thereon, and before and after that, a blank pattern layer 24 having substantially the same thickness as the electrode layer 12a is formed on the surface of the peeling layer 22 where the electrode layer 12a is not formed. Form.

  As the carrier sheets 20 and 30, for example, a PET film or the like is used, and those coated with silicon or the like are preferable in order to improve the peelability. Although the thickness of these carrier sheets 20 and 30 is not specifically limited, Preferably, it is 5-100 micrometers. The thicknesses of these carrier sheets 20 and 30 may be the same or different.

  The release layer 22 preferably includes the same dielectric particles as the dielectric that constitutes the green sheet 10a shown in FIG. 3A. In addition to the dielectric particles, the release layer 22 includes a binder, a plasticizer, and a release agent. The particle size of the dielectric particles may be the same as the particle size of the dielectric particles contained in the green sheet, but is preferably smaller.

  In the present embodiment, the thickness t2 of the release layer 22 is preferably equal to or less than the thickness of the electrode layer 12a, preferably 60% or less, and more preferably 30% or less.

  The method for applying the release layer 22 is not particularly limited. However, since it is necessary to form the release layer 22 very thinly, for example, an application method using a wire bar coater or a die coater is preferable. In addition, adjustment of the thickness of a peeling layer can be performed by selecting the wire bar coater of a different wire diameter. That is, in order to reduce the coating thickness of the release layer, a small wire diameter may be selected. Conversely, in order to form a thick film, a thick wire diameter may be selected. The release layer 22 is dried after application. The drying temperature is preferably 50 to 100 ° C., and the drying time is preferably 1 to 10 minutes.

  The binder for the release layer 22 is made of, for example, an organic material or an emulsion made of acrylic resin, polyvinyl butyral, polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, or a copolymer thereof. The binder contained in the release layer 22 may be the same as or different from the binder contained in the green sheet 10a, but is preferably the same.

  Although it does not specifically limit as a plasticizer for the peeling layer 22, For example, a phthalate ester, dioctyl phthalate, adipic acid, phosphate ester, glycols etc. are illustrated. The plasticizer contained in the release layer 22 may be the same as or different from the plasticizer contained in the green sheet 10a.

  The release agent for the release layer 22 is not particularly limited, and examples thereof include paraffin, wax, silicone oil, and the like. The release agent contained in the release layer 22 may be the same as or different from the release agent contained in the green sheet 10a.

  The binder is contained in the release layer 22 in an amount of preferably 2.5 to 200 parts by weight, more preferably 5 to 30 parts by weight, and particularly preferably about 8 to 30 parts by weight with respect to 100 parts by weight of the dielectric particles. .

  The plasticizer is preferably contained in the release layer 22 in an amount of 0 to 200 parts by mass, preferably 20 to 200 parts by mass, and more preferably 50 to 100 parts by mass with respect to 100 parts by mass of the binder.

  The release agent is preferably contained in the release layer 22 at 0 to 100 parts by mass, preferably 2 to 50 parts by mass, and more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the binder.

  After the release layer 22 is formed on the surface of the carrier sheet 30, as shown in FIG. 2A, an electrode layer 12 a that will form the internal electrode layer 12 after firing is formed in a predetermined pattern on the surface of the release layer 22. The thickness of the electrode layer 12a is preferably about 0.1 to 2 μm, more preferably about 0.1 to 1.0 μm. The electrode layer 12a may be composed of a single layer, or may be composed of a plurality of layers having two or more different compositions.

  The electrode layer 12a can be formed on the surface of the release layer 22 by a thick film forming method such as a printing method using an electrode paint or a thin film method such as vapor deposition or sputtering. When the electrode layer 12a is formed on the surface of the release layer 22 by a screen printing method or a gravure printing method which is a kind of thick film method, it is performed as follows.

  First, an electrode paint is prepared. The electrode paint is prepared by kneading a conductive material made of various conductive metals or alloys, or various oxides, organometallic compounds, resinates, or the like, which become the conductive material described above after firing, and an organic vehicle.

  As a conductive material used when manufacturing the electrode paint, Ni, Ni alloy, or a mixture thereof is used. There are no particular restrictions on the shape of such a conductive material, such as a spherical shape or a flake shape, or a mixture of these shapes may be used. The average particle diameter of the conductor material is usually 0.1 to 2 μm, preferably about 0.2 to 1 μm.

  The organic vehicle contains a binder and a solvent. Examples of the binder include ethyl cellulose, acrylic resin, polyvinyl butyral, polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, and copolymers thereof, but a butyral system such as polyvinyl butyral is particularly preferable.

  The binder is preferably included in the electrode paint in an amount of 8 to 20 parts by mass with respect to 100 parts by mass of the conductive material (metal powder). As the solvent, any known solvents such as terpineol, butyl carbitol, and kerosene can be used. The solvent content is preferably about 20 to 55% by mass with respect to the entire coating material.

  In order to improve adhesion, the electrode paint preferably contains a plasticizer. Examples of the plasticizer include phthalic acid esters such as benzylbutyl phthalate (BBP), adipic acid, phosphoric acid esters, glycols, and the like. The plasticizer is preferably 10 to 300 parts by mass, and more preferably 10 to 200 parts by mass with respect to 100 parts by mass of the binder in the electrode paint. In addition, when there is too much addition amount of a plasticizer or an adhesive, there exists a tendency for the intensity | strength of the electrode layer 12a to fall remarkably. In order to improve the transferability of the electrode layer 12a, it is preferable to add a plasticizer and / or a pressure-sensitive adhesive to the electrode paint to improve the adhesion and / or tackiness of the electrode paint.

  After or before the electrode coating layer having a predetermined pattern is formed on the surface of the release layer 22 by the printing method, the surface of the release layer 22 on which the electrode layer 12a is not formed has substantially the same thickness as the electrode layer 12a. The blank pattern layer 24 is formed. The blank pattern layer 24 is made of the same material as the green sheet 10a shown in FIG. 3A and is formed by the same method. The electrode layer 12a and the blank pattern layer 12a are dried as necessary. The drying temperature is not particularly limited, but is preferably 70 to 120 ° C, and the drying time is preferably 5 to 15 minutes.

  (3) Separately from the carrier sheets 20 and 30 described above, as shown in FIG. 2A, an adhesive layer transfer sheet in which an adhesive layer 28 is formed on the surface of a carrier sheet 26 as a third support sheet is prepared. The carrier sheet 26 is composed of a sheet similar to the carrier sheets 20 and 30.

  The composition of the adhesive layer 28 is the same as that of the release layer 22 except that it does not contain a release agent. That is, the adhesive layer 28 includes a binder, a plasticizer, and a release agent. The adhesive layer 28 may contain the same dielectric particles as the dielectric constituting the green sheet 10a. However, when forming an adhesive layer having a thickness smaller than the particle diameter of the dielectric particles, the dielectric particles It is better not to include. In addition, when dielectric particles are included in the adhesive layer 28, the particle size of the dielectric particles is preferably smaller than the particle size of the dielectric particles included in the green sheet.

  The plasticizer is preferably contained in the adhesive layer 28 in an amount of 0 to 200 parts by mass, preferably 20 to 200 parts by mass, and more preferably 50 to 100 parts by mass with respect to 100 parts by mass of the binder.

  The adhesive layer 28 further contains an antistatic agent, and the antistatic agent contains one of the imidazoline-based surfactants, and the weight-based addition amount of the antistatic agent is the weight of the binder (organic polymer material). It is preferable that it is below the reference addition amount. That is, it is preferable that the antistatic agent is contained in the adhesive layer 28 in an amount of 0 to 200 parts by weight, preferably 20 to 200 parts by weight, and more preferably 50 to 100 parts by weight with respect to 100 parts by weight of the binder.

  The thickness of the adhesive layer 28 is preferably about 0.02 to 0.3 μm, and is preferably thinner than the average particle size of the dielectric particles contained in the green sheet. Moreover, it is preferable that the thickness of the contact bonding layer 28 is 1/10 or less of the thickness of the green sheet 10a.

  If the thickness of the adhesive layer 28 is too thin, the adhesive strength is reduced, and if it is too thick, a gap is easily formed inside the element body after sintering depending on the thickness of the adhesive layer, and the electrostatic capacity corresponding to the volume. Tends to decrease significantly.

  The adhesive layer 28 is formed on the surface of the carrier sheet 26 as the third support sheet by a method such as a bar coater method, a die coater method, a reverse coater method, a dip coater method, or a kiss coater method, and is dried as necessary. . The drying temperature is not particularly limited, but is preferably room temperature to 80 ° C., and the drying time is preferably 1 to 5 minutes.

  (4) In order to form an adhesive layer on the surface of the electrode layer 12a and the blank pattern layer 24 shown in FIG. 2A, a transfer method is employed in this embodiment. That is, as shown in FIG. 2B, the adhesive layer 28 of the carrier sheet 26 is pressed against the surfaces of the electrode layer 12a and the blank pattern layer 24, heated and pressurized, and then the carrier sheet 26 is peeled off. As a result, as shown in FIG. 2C, the adhesive layer 28 is transferred to the surfaces of the electrode layer 12 a and the blank pattern layer 24. The transfer of the adhesive layer 28 may be performed on the surface of the green sheet 10a shown in FIG. 3A.

  The heating temperature during transfer is preferably 40 to 100 ° C., and the applied pressure is preferably 0.2 to 15 MPa. The pressurization may be a pressurization or a calender roll, but is preferably performed by a pair of rolls.

  Thereafter, the electrode layer 12a is adhered to the surface of the green sheet 10a formed on the surface of the carrier sheet 30 shown in FIG. 3A. For this purpose, as shown in FIG. 3B, the electrode layer 12a and the blank pattern layer 24 of the carrier sheet 20 are pressed against the surface of the green sheet 10a through the adhesive layer 28 together with the carrier sheet 20 and heated and pressurized. As a result, as shown in FIG. 3C, the electrode layer 12a and the blank pattern layer 24 are transferred to the surface of the green sheet 10a. However, since the carrier sheet 30 on the green sheet side is peeled off, when viewed from the green sheet 10 a side, the green sheet 10 a is transferred to the electrode layer 12 a and the blank pattern layer 24 via the adhesive layer 28.

  The heating and pressurization at the time of transfer may be pressurization / heating with a press or pressurization / heating with a calender roll, but is preferably performed with a pair of rolls. The heating temperature and pressure are the same as when the adhesive layer 28 is transferred.

  2A to 3C, a single layer of electrode layer 12a having a predetermined pattern is formed on a single green sheet 10a. In order to stack the green sheets 10a on which the electrode layers 12a are formed, for example, the steps shown in FIGS. 4A to 6C may be repeated. 4A to 6C, members that are the same as those shown in FIGS. 3A to 4C are denoted by the same reference numerals, and description thereof is partially omitted.

  First, as shown in FIGS. 4A to 4C, the adhesive layer 28 is transferred to the surface (back surface) on the counter electrode layer side of the green sheet 10a. Thereafter, as shown in FIGS. 5A to 5C, the electrode layer 12 a and the blank pattern layer 24 are transferred to the back surface of the green sheet 10 a through the adhesive layer 28.

  Next, as shown in FIGS. 6A to 6C, the green sheet 10 a is transferred to the surfaces of the electrode layer 12 a and the blank pattern layer 24 through the adhesive layer 28. Thereafter, by repeating these transfers, a laminated block in which a large number of electrode layers 12a and green sheets 10a are alternately laminated is obtained as shown in FIG.

  In addition, you may carry out as follows, without employ | adopting the process shown to FIG. 5C-FIG. 6C. That is, instead of peeling the lower carrier sheet 20 from the step shown in FIG. 5B, the upper carrier sheet may be peeled, and the laminate unit U1 shown in FIG. 4C may be laminated thereon. Thereafter, the upper carrier sheet 20 is peeled off again, and the laminate unit U1 shown in FIG. 4C is laminated thereon, and the operation of peeling the upper carrier sheet 20 again is repeated as shown in FIG. In addition, a laminated block in which a large number of electrode layers 12a and green sheets 10a are alternately laminated is obtained. The method of laminating the laminate unit U1 shown in FIG. 4C is superior in laminating work efficiency.

  When the number of green sheets to be stacked is small, the baking step in the next step is performed with this stacked block alone. Further, if necessary, a plurality of such laminated blocks may be laminated through an adhesive layer 28 formed by a transfer method in the same manner as described above to form a multilayer structure.

  (5) Thereafter, as shown in FIG. 8, an outer layer green sheet 40 (a thick laminate obtained by laminating a plurality of green sheets on which no electrode layer is formed) is laminated on the lower surface of this laminate, The entire body is supported by the suction holding stand 50. Thereafter, the upper carrier sheet 20 is peeled off, and the green sheet 40 for the outer layer is formed on the upper portion of the laminate in the same manner, and then final pressing is performed.

  The pressure at the time of final pressurization is preferably 10 to 200 MPa. The heating temperature is preferably 40 to 100 ° C. Thereafter, the laminate is cut into a predetermined size to form a green chip. This green chip is subjected to binder removal processing and firing processing, and heat treatment is performed to reoxidize the dielectric layer.

  The binder removal treatment may be performed under normal conditions, but when a base metal such as Ni or Ni alloy is used as the conductor material of the internal electrode layer, it is particularly preferable to perform under the following conditions.

Temperature increase rate: 5 to 300 ° C./hour, particularly 10 to 50 ° C./hour,
Holding temperature: 200-400 ° C, especially 250-350 ° C,
Retention time: 0.5 to 20 hours, especially 1 to 10 hours,
Atmosphere: A mixed gas of humidified N ₂ and H ₂ .

The firing conditions are preferably the following conditions.
Temperature increase rate: 50 to 500 ° C./hour, particularly 200 to 300 ° C./hour,
Holding temperature: 1100-1300 ° C., in particular 1150-1250 ° C.
Retention time: 0.5-8 hours, especially 1-3 hours,
Cooling rate: 50 to 500 ° C./hour, particularly 200 to 300 ° C./hour,
Atmospheric gas: A mixed gas of humidified N ₂ and H ₂ or the like.

However, the oxygen partial pressure in the air atmosphere during firing is preferably 10 ⁻² Pa or less, particularly 10 ⁻² to 10 ⁻⁸ Pa. If the above range is exceeded, the internal electrode layer tends to oxidize, and if the oxygen partial pressure is too low, the electrode material of the internal electrode layer tends to abnormally sinter and tend to break.

The heat treatment after such firing is preferably carried out at a holding temperature or maximum temperature of preferably 1000 ° C. or higher, more preferably 1000 to 1100 ° C. If the holding temperature or maximum temperature during heat treatment is less than the above range, the dielectric material is insufficiently oxidized and the insulation resistance life tends to be shortened. In addition to a decrease, it tends to react with the dielectric substrate and shorten its lifetime. The oxygen partial pressure during the heat treatment is higher than the reducing atmosphere during firing, and is preferably 10 ⁻³ Pa to 1 Pa, more preferably 10 ⁻² Pa to 1 Pa. If it is less than the above range, it is difficult to reoxidize the dielectric layer 2, and if it exceeds the above range, the internal electrode layer 3 tends to be oxidized. The other heat treatment conditions are preferably the following conditions.

Retention time: 0-6 hours, especially 2-5 hours,
Cooling rate: 50 to 500 ° C./hour, particularly 100 to 300 ° C./hour,
Atmospheric gas: humidified N ₂ gas or the like.

Note that to wet the N ₂ gas or mixed gas etc. may be used, for example a wetter etc.. In this case, the water temperature is preferably about 0 to 75 ° C. The binder removal treatment, firing and heat treatment may be performed continuously or independently. When performing these continuously, after removing the binder, the atmosphere is changed without cooling, and then the temperature is raised to the holding temperature at the time of firing and firing is performed. Next, it is preferable to cool and perform the heat treatment by changing the atmosphere when the heat treatment holding temperature is reached. On the other hand, when performing these independently, at the time of firing, after raising the temperature under N ₂ gas atmosphere with N ₂ gas or wet to the holding temperature of the binder removal processing, further continuing the heating to change the atmosphere Is preferred. Then, after cooling to the holding temperature at the time of heat treatment, it is preferable to change to N ₂ gas or a humidified N ₂ gas atmosphere and continue cooling. In the heat treatment, the temperature may be changed to a holding temperature in an N ₂ gas atmosphere, and the atmosphere may be changed, or the entire process of the heat treatment may be a humidified N ₂ gas atmosphere.

The sintered body (element body 4) thus obtained is subjected to end surface polishing by, for example, barrel polishing or sand plast, and terminal electrode paints are baked to form terminal electrodes 6 and 8. The terminal electrode coating condition is preferably set, for example, to about 10 minutes to 1 hour at 600 to 800 ° C. in a humidified mixed gas of N ₂ and H ₂ . Then, if necessary, a pad layer is formed on the terminal electrodes 6 and 8 by plating or the like. In addition, what is necessary is just to prepare the coating material for terminal electrodes like the above-mentioned electrode coating material.
The multilayer ceramic capacitor of the present invention thus manufactured is mounted on a printed circuit board by soldering or the like and used for various electronic devices.

In the method for manufacturing a multilayer ceramic capacitor using the dielectric paint (green sheet paint) and the green sheet 10a according to the present embodiment, the degree of polymerization in a specific range, the degree of butyralization in a specific range, and the amount of residual acetyl groups is a predetermined value or less. The polyvinyl acetal resin is used as a binder. Therefore, even if the green sheet 10a is extremely thin, for example, about 5 μm or less, it has a strength that can withstand peeling from the carrier sheet 30 and has good adhesion and handling properties. Further, the surface roughness of the sheet 10a is small and the stacking property is excellent. Therefore, it becomes easy to stack a large number of green sheets 10a via the electrode layer 12a, and it is also possible to omit the adhesive layer 28 and stack them as necessary.
Further, in the method for manufacturing a multilayer ceramic capacitor using the dielectric paint (green sheet paint) and the green sheet 10a according to this embodiment, the HLB is a specific type of dispersant and has a specific range of HLB. . Therefore, even if the green sheet 10a is extremely thin, for example, about 5 μm or less, it has a strength that can withstand peeling from the carrier sheet 30 and has good adhesion and handling properties. Further, the surface roughness of the sheet 10a is small and the stacking property is excellent. Therefore, it becomes easy to stack a large number of green sheets 10a via the electrode layer 12a, and it is also possible to omit the adhesive layer 28 and stack them as necessary.
Furthermore, in the method for manufacturing a multilayer ceramic capacitor using the dielectric paint (green sheet paint) and the green sheet 10a according to the present embodiment, the dielectric paint contains a charging aid, and the charging aid is an imidazoline-based charge remover. It is an agent. Therefore, even if the green sheet 10a is very thin, for example, about 5 μm or less, it has a strength that can withstand peeling from the carrier sheet 30 as a support, and suppresses static electricity generated when peeling from the carrier sheet 30. And the green sheet 10a which has favorable adhesiveness and handling property can be manufactured. Further, the surface roughness of the sheet 10a is small and the stacking property is excellent. Therefore, it becomes easy to stack a large number of green sheets 10a via the electrode layer 12a, and it is also possible to omit the adhesive layer 28 and stack them as necessary.

  Further, in the method for manufacturing a multilayer ceramic capacitor according to the present embodiment, the dry type electrode layer 12a is easily and accurately transferred to the surface of the green sheet 10a without breaking or deforming the green sheet 10a. It is possible.

  Further, in the manufacturing method of the present embodiment, the adhesive layer 28 is formed on the surface of the electrode layer or the green sheet by a transfer method, and the electrode layer 12a is adhered to the surface of the green sheet 10a via the adhesive layer 28. By forming the adhesive layer 28, when the electrode layer 12a is transferred to the surface of the green sheet 10a and transferred, high pressure and heat are not required, and bonding at a lower pressure and a lower temperature is possible. Therefore, even when the green sheet 10a is extremely thin, the green sheet 10a is not destroyed, the electrode layer 12a and the green sheet 10a can be satisfactorily laminated, and no short circuit failure occurs.

  Further, for example, by making the adhesive force of the adhesive layer 28 stronger than the adhesive force of the release layer 22 and making the adhesive force of the release layer 22 stronger than the adhesive force between the green sheet 10 a and the carrier sheet 30. The carrier sheet 30 on the green sheet 10a side can be selectively peeled easily.

  Furthermore, in this embodiment, since the adhesive layer 28 is not formed directly on the surface of the electrode layer 12a or the green sheet 10a by a coating method, but formed by a transfer method, the component of the adhesive layer 28 is the electrode layer 12a. Alternatively, the green sheet 10a is not soaked and an extremely thin adhesive layer 28 can be formed. For example, the thickness of the adhesive layer 28 can be reduced to about 0.02 to 0.3 μm. Even if the thickness of the adhesive layer 28 is thin, the adhesive force is sufficient because the components of the adhesive layer 28 do not penetrate into the electrode layer 12a or the green sheet 10a. In addition, there is no possibility of adversely affecting the composition of the electrode layer 12a or the green sheet 10a.

The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
For example, the method of the present invention can be applied not only to a method for manufacturing a multilayer ceramic capacitor but also to a method for manufacturing other multilayer electronic components.

  Hereinafter, the present invention will be described based on further detailed examples, but the present invention is not limited to these examples.

Example 1
Preparation of Green Sheet Paint BaTiO ₃ powder (BT-035 and BT-02 / Sakai Chemical Industry Co., Ltd.) was used as a starting material for ceramic powder. (Ba _0.6 Ca _0.4 ) SiO ₃ : 1.48 parts by mass, Y ₂ O ₃ : 1.01 parts by mass, MgCO ₃ : 0.72% by mass with respect to 100 parts by mass of this BaTiO ₃ powder. , Cr ₂ O ₃ : 0.13 mass%, and V ₂ O ₅ : 0.045 mass% were prepared ceramic powder subcomponent additives.

First, only the minor component additive was mixed with a ball mill to form a slurry. That is, auxiliary components (total amount 8.8 g) and ethanol / n-propanol 1: 1 solvent (16 g) were preliminarily pulverized with a ball mill for 20 hours. Next, with respect to BaTiO ₃ : 191.2 g, a preliminary pulverized slurry of additive additives, ethanol: 38 g, n-propanol: 38 g, xylene: 28 g, mineral spirit: 14 g, and a plasticizer component DOP (dioctyl phthalate): 6 g and polyethylene glycol-based nonionic dispersant (HLB = 5-6): 1.4 g as a dispersant were added and mixed by a ball mill for 4 hours. In addition, as the polyethylene glycol-based nonionic dispersant (HLB = 5 to 6) as a dispersant, a block polymer of polyethylene glycol and a fatty acid ester was used.

  Next, 15% lacquer of BH6 (polybutyral resin / PVB) manufactured by Sekisui Chemical Co., Ltd. (BH6 manufactured by Sekisui Chemical Co., dissolved in ethanol / n-propanol = 1: 1) is solidified as a binder resin in the dispersion paint. 6% by mass was added as a minute (80 g as lacquer addition amount). Then, a ceramic paint (green sheet paint) was obtained by ball milling for 16 hours.

  The degree of polymerization of the polybutyral resin as the binder resin was 1400, the degree of butyralization was 69 ± 3%, and the amount of residual acetyl groups was 3 ± 2%. This binder resin was contained in the ceramic coating at 6 parts by mass with respect to 100 parts by mass of ceramic powder (including ceramic powder subcomponent additives). Further, when the total volume of the ceramic powder, the binder resin and the plasticizer in the ceramic coating was 100% by volume, the volume ratio occupied by the ceramic powder was 67.31% by volume.

  Further, DOP as a plasticizer was contained in the ceramic coating at 50 parts by mass with respect to 100 parts by mass of the binder resin. The water was contained in an amount of 2 parts by mass with respect to 100 parts by mass of the ceramic powder. The polyethylene glycol-based nonionic dispersant as the dispersant was contained in an amount of 0.7 parts by mass with respect to 100 parts by mass of the ceramic powder.

  Further, in the coating material, 5 parts by mass of mineral spirit, which is at least one of hydrocarbon solvents, industrial gasoline, kerosene, and solvent naphtha, is added to 100 parts by mass of the ceramic powder. It was. Further, the paint contains an alcohol solvent and an aromatic solvent as a solvent, and the total mass of the alcohol solvent and the aromatic solvent is 100 parts by mass. Toluene as the aromatic solvent is 15 masses. Department was included.

  The viscosity of the paint was 180 mPa · S. The viscosity of the paint was measured using a B-type viscometer, using S21 as a rotor, at a measurement temperature of 25 ° C., and immediately after dropping the paint. The measurement rotation speed was 50 rpm.

Production of Green Sheet The paint obtained as described above was applied to a PET film as a support film with a thickness of 2 μm by a wire bar coater and dried to produce a green sheet. The coating speed was 50 m / min, and the drying conditions were a temperature in the drying furnace of 60 ° C. to 70 ° C. and a drying time of 2 minutes.

Evaluation of Green Sheet Thereafter, the sheet density, surface roughness, sheet tensile strength, sheet elongation, adhesion (stackability / peel strength) of the green sheet, and comprehensive evaluation were evaluated. The results are shown in Table 1.

  The sheet density was determined by measuring the thickness of the sheet after drying, measuring the weight of the sheet, and dividing the weight of the sheet by the volume. For the surface roughness, an average surface roughness Rz was measured using a surface roughness measuring instrument manufactured by Kosaka Laboratory. For the sheet tensile strength and sheet elongation, using a tensile tester of Instron 5543, five sheets punched into a dumbbell shape were prepared as samples, and each sample was pulled at a tensile rate of 8 mm / min. The strength and elongation were determined, and the average value was calculated.

  Adhesion was evaluated as follows. First, ten samples were prepared by cutting the dried sheets into 50 mm × 15 mm, and five sets of two sheets laminated (temporary stack) were prepared. Each set of sheets was preheated at 70 ° C. for 5 minutes and bonded together at 70 ° C. for 1 minute at about 2 MPa. Then, a double-sided tape was affixed to the surface of each set of sheets, the tensile tester of Instron 5543 was used to pull each set of sheets in the direction of peeling, and the peel strength when peeled was measured. The higher the peel strength, the better the adhesiveness.

In the comprehensive judgment, the sheet density is 3.3 g / cm ³ or more, the surface roughness is 0.6 μm or less, the sheet tensile strength is 6.0 MPa or more, the sheet elongation is 37% or more, and adhesive peeling is performed. Those having an intensity of 10 N / cm ² or more were judged to be good (◯), and one of them that did not satisfy the condition was judged to be bad (×). In addition, * before the number in a table | surface shows that it exceeds the preferable range. The same applies to the following tables.

Comparative Example 1
A green sheet was prepared in the same manner as in Example 1 except that polyvinyl acetal resin (PVAc) having a product number BX-1 manufactured by Sekisui Chemical Co., Ltd. was used as the binder resin, and the same evaluation was performed. The results are shown in Table 1.

Comparative Example 2
A green sheet was prepared in the same manner as in Example 1 except that an acrylic resin (MMA-BA) having a molecular weight of 450,000 and Tg = 70 ° C. was used as the binder resin, and the same evaluation was performed. The results are shown in Table 1.

Evaluation 1
As shown in Table 1, it was confirmed that polyvinyl butyral resin (PVB) is preferable as the binder resin.

Examples 2-3 and Comparative Examples 3-5
As shown in Table 2, as a polybutyral resin, a green sheet was prepared in the same manner as in Example 1 except that a product number (grade) manufactured by Sekisui Chemical Co., Ltd. was different and the polymerization degree was 300 to 2400. A similar evaluation was made. The results are shown in Table 2.

Evaluation 2
As shown in Table 2, it was confirmed that the polymerization degree of the polybutyral resin is preferably 1000 or more and 1700 or less. If the degree of polymerization is too low, the sheet tensile strength tends to decrease. If the degree of polymerization is too high, the sheet density decreases, the sheet surface roughness decreases, and the sheet elongation and adhesiveness also tend to decrease. I was able to confirm.

Example 3 and Comparative Example 6
As shown in Table 3, a green sheet was used in the same manner as in Example 1 except that the product number (grade) manufactured by Sekisui Chemical Co., Ltd. was different and the degree of butyralization was 65 to 78. The same evaluation was performed. The results are shown in Table 3.

Evaluation 3
As shown in Table 3, it was confirmed that the degree of butyralization of the polybutyral resin is preferably 65% or more and less than 78%. When the degree of butyralization is too low, the sheet elongation tends to decrease, and when it is too high, the sheet surface roughness tends to deteriorate.

Example 3 and Comparative Examples 7 and 8
As shown in Table 4, as polybutyral resin, the product number (grade) manufactured by Sekisui Chemical Co., Ltd. is different, and the amount of residual acetyl groups is 3 to 13. Sheets were prepared and evaluated in the same manner. The results are shown in Table 4.

Evaluation 4
As shown in Table 4, it was confirmed that the residual acetyl group content of the polybutyral resin is preferably less than 6%. It was confirmed that when the amount of residual acetyl groups was too large, the sheet density was lowered, the surface roughness was increased, and the adhesiveness was liable to be lowered.

Examples 4-7 and Reference Examples 1-7
As shown in Table 5, Example 1 except that the addition mass ratio (PHP) of the polybutyral resin as the binder resin was changed in the range of 2 to 7 parts by mass with respect to 100 parts by mass of the ceramic powder. A green sheet was prepared in the same manner as described above, and the same evaluation was performed. The results are shown in Table 5. Example 6 is the same as Example 1.

Evaluation 5
As shown in Table 5, it was confirmed that the addition mass ratio (PHP) of the polybutyral resin as the binder resin is preferably 5 parts by mass or more and 6.5 parts by mass or less with respect to 100 parts by mass of the ceramic powder. . It was confirmed that when the mass ratio is too low, the tensile strength, the sheet elongation and the adhesiveness are lowered, and when the mass ratio is too high, the sheet density tends to decrease and the surface roughness tends to increase.

  It can also be confirmed that when the total volume of the ceramic powder, the binder resin and the plasticizer is 100% by volume, the volume ratio of the ceramic powder is preferably 64.3% or more and 72% or less. It was. When the volume ratio was too low, it was confirmed that the sheet density decreased and the surface roughness increased, whereas when the volume ratio was too high, the tensile strength, sheet elongation, and adhesiveness tended to decrease.

Examples 8-11 and Reference Examples 8-18
As shown in Table 6, with the exception of changing the addition mass ratio (PHR) of dioctyl phthalate (DOP) as a plasticizer in the range of 30 to 100 parts by mass with respect to 100 parts by mass of the binder resin. Green sheets were produced in the same manner as in Example 1, and the same evaluation was performed.

  Moreover, as shown in Table 6, dibutyl phthalate (DBP) or benzyl butyl phthalate (BBP) is used as the plasticizer, and the added mass ratio (PHR) of the plasticizer to 30 parts by mass of the binder resin is 30 A green sheet was produced in the same manner as in Example 1 except that the amount was changed in the range of ˜100 parts by mass, and the same evaluation was performed. These results are shown in Table 6. Example 9 is the same as Example 1.

Evaluation 6
As shown in Table 6, it was confirmed that DOP is preferable as the plasticizer, and the addition mass ratio is preferably 40 parts by mass or more and 70 parts by mass or less. When the mass ratio is too low, the sheet elongation and adhesiveness are reduced, and when the mass ratio is too high, it is confirmed that the sheet density decreases and the surface roughness increases and the tensile strength tends to decrease. .

Examples 12-15 and Reference Examples 19-22
As shown in Table 7, the same procedure as in Example 1 was conducted except that the additive mass ratio of water (PHP) was changed in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the ceramic powder. A similar evaluation was performed except that a green sheet was prepared and a filtration test was added. These results are shown in Table 7. Note that Example 13 is the same as Example 1.

The evaluation of the filtration test was performed using a product number No. Using 5 C and a reserved particle diameter of 1 μm, 200 g of the green sheet coating material passed through a 28.26 cm ² filter paper area under a pressure of 0.2 MPa, and evaluated. The shorter the passage time, the better the filtration characteristics. An excellent filtration property means that there are few aggregates in the paint and the binder resin is well dissolved. A filter having a filtration time of 3.50 (minutes.seconds) or less was evaluated as good (◯) in the comprehensive judgment.

Evaluation 7
As shown in Table 7, it was confirmed that the added mass ratio of water is preferably 1 part by mass or more and 6 parts by mass or less. It was confirmed that when the mass ratio is too low, the filtration characteristics tend to deteriorate, and when the mass ratio is too high, the sheet density tends to decrease and the surface roughness tends to increase.

Examples 16-22 and Reference Examples 23-27
As shown in Table 8, green powder was obtained in the same manner as in Example 1 except that the additive mass ratio (PHP) of mineral spirit was changed in the range of 1 to 20 parts by mass with respect to 100 parts by mass of the ceramic powder. Sheets were prepared and evaluated in the same manner.

  Further, instead of mineral spirit, a green sheet was prepared in the same manner as in Example 1 except that the type of solvent was changed as shown in Table 8, or this type of solvent was not included. Evaluation was performed. These results are shown in Table 8. Example 20 is the same as Example 1. Moreover, MIBK in Table 8 is methyl isobutyl ketone.

Evaluation 8
As shown in Table 8, it was confirmed that it is preferable that at least one of hydrocarbon solvents, industrial gasoline, kerosene, and solvent naphtha is added in an amount of 3 parts by mass or more and 15 parts by mass or less. . It was confirmed that when the mass ratio is too low, the surface roughness increases and the adhesiveness tends to deteriorate, and when the mass ratio is too high, the sheet density tends to decrease and the surface roughness tends to increase.

Examples 23 to 25 and Reference Examples 28 to 31
As shown in Table 9, the total mass of the alcohol solvent (ethanol and propanol) and the aromatic solvent (toluene) is 100 parts by mass, and the addition mass ratio of the aromatic solvent (toluene) is 5 to 50 mass. A green sheet was produced in the same manner as in Example 1 except that the amount was changed in the range of the part, and the same evaluation as in Examples 12 to 15 was performed. These results are shown in Table 9. Example 24 is the same as Example 1.

Evaluation 9
As shown in Table 9, the solvent in the paint includes an alcohol solvent and an aromatic solvent, and the total mass of the alcohol solvent and the aromatic solvent is 100 parts by mass. It was confirmed that the content was preferably 20 parts by mass or more and 20 parts by mass or less. If the mass ratio is too low, the surface roughness tends to increase and the adhesiveness tends to deteriorate. If the mass ratio is too high, the filtration characteristics deteriorate, the sheet density decreases, the surface roughness increases, It was confirmed that the strength also tends to decrease.

Reference Example 32
As shown in Table 10, BH6 (polybutyral resin / PVB) manufactured by Sekisui Chemical Co., Ltd. as a binder resin was dissolved in an alcohol solvent of ethanol / n-propanol = 1: 1 in advance and filtered to obtain a solution. A green sheet was produced in the same manner as in Example 1 except that the binder resin powder was directly put in the paint, and the same evaluation as in Examples 12 to 15 was performed. These results are shown in Table 10.

Evaluation 10
As shown in Table 10, the binder resin was dissolved and filtered in advance in at least one alcohol solvent of methanol, ethanol, propanol, and butanol, and the solution was mixed with the ceramic powder and It was confirmed that it was preferable to add other components. Otherwise, it was confirmed that the filtration characteristics deteriorate and the surface roughness tends to increase.

Examples 1a-1g
As a dispersant, as shown in Table 11,
Sorbitan monostearate nonionic dispersant (HLB = 4 or more and less than 5),
Polyethylene glycol nonionic dispersant (HLB = 5-6),
Nonionic dispersant of polyethylene glycol-based polyoxylene stearin ether (HLB = 6 to 7),
An ammonium polycarboxylate dispersant,
Maleic acid dispersant,
Sodium dialkylsulfosuccinate, which is an oxalic acid dispersant,
A green sheet was prepared in the same manner as in Example 1 except that polyoxyethylene lauryl amino ether (HLB = 9.8) as an amine dispersant was used, and the same evaluation was performed. The results are shown in Table 11.
In addition, the evaluation of the filtration test was performed using a product number No. manufactured by Advantech as filter paper. Using 5 C and a reserved particle diameter of 1 μm, 200 g of the green sheet paint passed through a 28.26 cm ² filter paper area under a pressure of 0.2 MPa, and evaluated. The shorter the passage time, the better the filtration characteristics. An excellent filtration property means that there are few aggregates in the paint and the binder resin is well dissolved. Further, in the measurement of the filtration rate, those that could not be measured because clogging occurred were shown as-in Table 11. The same applies to Table 12 below.

Evaluation 11
As shown in Table 11, it was confirmed that a polyethylene glycol-based nonionic dispersant (HLB = 5 to 6) was most preferable as the dispersant.
In the comprehensive judgment in Table 11, the sheet density is 3.3 g / cm ³ or more, the surface roughness is 0.6 μm or less, the sheet tensile strength is 6.0 MPa or more, and the sheet elongation is 37% or more. An adhesive peel strength of 8.9 N / cm ² or more and a filtration rate (filtration time) of 4.50 (minutes.seconds) or less was judged to be good (◯). Any one that did not satisfy the condition was judged to be defective (x). The determination in Table 12 is the same.

Examples 1h-1m
A green sheet was prepared in the same manner as in Example 1b, except that the content of the dispersant was changed in the range of 0.2 to 2 parts by mass with respect to 100 parts by mass of the ceramic powder. went. The results are shown in Table 12.

Evaluation 12
As shown in Table 12, the content of the dispersant is preferably in the range of 0.5 to 1.5 parts by mass, more preferably 0.5 to 1.0 parts by mass with respect to 100 parts by mass of the ceramic powder. It was confirmed that it was in the range.

Examples 1n-1y
As shown in Table 13, a green sheet was prepared in the same manner as in Example 1 except that various antistatic agents were added to the green sheet paint at various parts by mass (PHP) with respect to 100 parts by mass of the ceramic powder. The same evaluation was performed. The results are shown in Table 13.
The static electricity (charging characteristics) was evaluated as follows. That is, using Nakako S55-1 Co., Ltd., immediately after the green sheet was peeled off, the distance between the green sheets was set to 1 cm. The measured value is a value measured 5 seconds after peeling. The less static electricity (kV) is generated, the better. When static electricity is generated, wrinkles are generated on the sheets, making it difficult to perform lamination accurately.

表１３において、アミン系界面活性剤としては、オクタデシルアミン酢酸塩を用い、イミダゾリン系界面活性剤としては、１−ヒドロキシエチル２−アルキルイミダゾリン４級塩を用い、ポリエチレングリコール系帯電除剤としては、ポリエチレングリコールドデシルエーテルを用い、ＰＥＧ４００としては日本油脂社製のものを用いた。

In Table 13, octadecylamine acetate is used as the amine-based surfactant, 1-hydroxyethyl 2-alkylimidazoline quaternary salt is used as the imidazoline-based surfactant, and as the polyethylene glycol-based antistatic agent, Polyethylene glycol dodecyl ether was used, and PEG400 manufactured by NOF Corporation was used.

Evaluation 13
As shown in Table 13, it was confirmed that an imidazoline surfactant is preferable as the antistatic agent. In addition, as shown in Table 13, if the amount of the charge remover added is too small, the effect of removing the charge is reduced, and if too much, the surface roughness of the sheet deteriorates and the sheet strength tends to deteriorate. It was confirmed.
In the comprehensive judgment shown in Table 13, the sheet density is 3.3 g / cm ³ or more, the surface roughness is 0.6 μm or less, the sheet tensile strength is 6.0 MPa or more, and the sheet elongation is 40% or more. , Those having an adhesive peel strength of 9 N / cm ² or more and static electricity of 36 or less are judged to be good (◯), and one of them that does not satisfy the condition is defective ( (X), and the case where only the evaluation item of static electricity did not satisfy the above criteria was judged as (Δ).

  As described above, according to the present invention, even a very thin green sheet has a strength capable of withstanding peeling from the support, and a green sheet having good adhesion and handling properties is manufactured. It is possible to provide a green sheet paint, a green sheet, a method for producing a green sheet paint, and a method for producing a green sheet. Therefore, it is possible to provide a method of manufacturing an electronic component suitable for thinning and multilayering of the electronic component.

FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. 2A to 2C are main part cross-sectional views showing a method for transferring an electrode layer. 3A to 3C are main-portion cross-sectional views showing the continuation process of FIG. 4A to 4C are cross-sectional views of a main part showing a method for laminating green sheets to which electrode layers are bonded. FIGS. 5A to 5C are cross-sectional views illustrating the main part of a green sheet laminating method to which an electrode layer is bonded, which is a continuation of FIG. 6A to 6C are cross-sectional views of relevant parts showing steps subsequent to FIG. FIG. 7 is a fragmentary cross-sectional view showing a step continued from FIG. 6. FIG. 8 is a fragmentary cross-sectional view showing a step continued from FIG. 7.

Claims (12)

A green sheet paint having ceramic powder, a binder resin, a plasticizer, and a solvent,
The binder resin includes a polyvinyl butyral resin, the degree of polymerization of the polybutyral resin is 1000 or more and 1700 or less, the nominal value of the degree of butyralization of the resin is 65% or more and less than 78%, and the residual acetyl group amount is 6%. Green sheet paint characterized by being less than. The paint for green sheets according to claim 1, wherein the binder resin is contained in an amount of 5 parts by mass to 6.5 parts by mass with respect to 100 parts by mass of the ceramic powder. The paint for green sheets according to claim 1 or 2, comprising dioctyl phthalate as the plasticizer in an amount of 40 parts by mass to 70 parts by mass with respect to 100 parts by mass of the binder resin. The volume ratio occupied by the ceramic powder is 64.3% or more and 72% or less when the total volume of the ceramic powder, binder resin and plasticizer is 100% by volume. The paint for green sheets in any one of 1-3. A green sheet paint having ceramic powder, a binder resin, a plasticizer, and an organic solvent,
A green sheet coating material comprising 1 to 6 parts by mass of water with respect to 100 parts by mass of the ceramic powder. A green sheet paint having a ceramic powder, a binder resin, a plasticizer, a solvent, and a dispersant,
The dispersant contains a polyethylene glycol-based nonionic dispersant and has a hydrophilic / lipophilic balance value of 5 to 6,
The green sheet coating material, wherein the dispersant is added in an amount of 0.5 to 1.5 parts by mass with respect to 100 parts by mass of the ceramic powder. A green sheet paint having a ceramic powder, a binder resin, a plasticizer, a solvent, and a charging aid,
The green characterized in that the antistatic agent includes an imidazoline-based antistatic agent, and the charging aid is contained in an amount of 0.1 parts by mass or more and 0.75 parts by mass or less with respect to 100 parts by mass of the ceramic powder. Sheet paint. A green sheet paint having ceramic powder, a binder resin, and a solvent,
The solvent includes an alcohol solvent and an aromatic solvent, and the total mass of the alcohol solvent and the aromatic solvent is 100 parts by mass, and the aromatic solvent is included in an amount of 10 parts by mass to 20 parts by mass. A green sheet paint characterized by that. In the method for producing the coating material for a green sheet according to any one of claims 1 to 8,
The binder resin is dissolved and filtered in advance in at least one alcohol solvent of methanol, ethanol, propanol, or butanol to obtain a solution, and the ceramic powder and other components are added to the solution. A method for producing a coating material for a green sheet. Preparing a coating material for a green sheet according to any one of claims 1 to 8,
Forming a ceramic green sheet using the green sheet paint;
The manufacturing method of the ceramic green sheet which has this. Preparing a coating material for a green sheet according to any one of claims 1 to 8,
Forming a ceramic green sheet using the green sheet paint;
Drying the green sheet;
Laminating the green sheet after drying through an internal electrode layer to obtain a green chip;
Firing the green chip;
A method of manufacturing a ceramic electronic component having The green sheet manufactured using the coating material for green sheets in any one of Claims 1-8.

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