JP5003422B2 - SUPPORT SHEET AND METHOD FOR PRODUCING MULTILAYER CERAMIC ELECTRONIC COMPONENT - Google Patents

Description

  The present invention relates to a support sheet and a method for manufacturing a multilayer ceramic electronic component. More specifically, the present invention has a mold release function and an antistatic function, and the front and back surfaces are smooth and the back surface is slippery. The present invention relates to a support sheet and a method for manufacturing a multilayer ceramic electronic component in which an electronic component is manufactured using the support sheet.

  When manufacturing a multilayer ceramic electronic component such as a multilayer ceramic capacitor, a green sheet is formed on the surface of the support sheet by a doctor blade method or the like, and an electrode pattern layer is formed on the surface of the green sheet. In recent years, as the thickness of multilayer ceramic electronic components has been reduced, green sheets have been made thinner.

  The support sheet on which the green sheet is formed is made of, for example, polyethylene terephthalate (PET), and is usually mixed with a filler (filler) in order to improve its mechanical strength. Since the mixed filler is also present in the vicinity of the front and back surfaces of the support sheet, there are irregularities due to the protrusions of the filler on the front and back surfaces of the support sheet.

  When the thickness of the green sheet was relatively thick, there was no problem, but when the thickness of the green sheet became thinner, the surface of the support sheet became uneven due to minute irregularities present on the surface of the support sheet. There is a possibility that dents and pinholes may occur in the formed green sheet.

  If the green sheet has dents or pinholes, problems such as short-circuiting between internal electrodes and a decrease in reliability occur in the finally obtained multilayer ceramic capacitor.

  However, if the back surface of the support sheet is made smooth without simply mixing the filler, the support sheet is easily charged, the support sheet is in close contact with the guide roll, and the running property (slidability) of the support sheet is deteriorated. As a result, there are problems such as damage to the support sheet and the green sheet.

  Thus, for example, Patent Document 1 discloses that the number of protrusions present on the release layer side is smaller than the number of protrusions present on the opposite surface side. However, since Patent Document 1 does not prescribe the maximum peak height (Rp) on the film, there is a problem that it cannot cope with the thinning of the green sheet (for example, 2 μm or less).

  In Patent Documents 2 and 3, the maximum height Rmax of the ceramic slurry application surface is set to 0.2 μm or less, a release layer is formed on the ceramic slurry application surface, and an antistatic layer is formed on the opposite surface. It is disclosed.

  However, in Patent Documents 2 and 3, the maximum height Rmax of the support sheet surface is specified, but the maximum peak height (Rp) is not specified, and the green due to the protrusions formed on the surface of the support sheet is not specified. It was not possible to effectively prevent pinholes and local thin portions of the sheet.

  Further, the support sheets described in Patent Documents 2 and 3 are configured as shown in FIG. 6, and depending on the size of the filler, the protrusion on the surface on the antistatic layer side (the back surface of the support sheet) becomes large. End up. As a result, especially when the thickness of the green sheet is reduced and the thickness of the green sheet is 2 μm or less, when the support sheet is wound up after the green sheet is formed, the protrusions present on the surface on the antistatic layer side However, there is a problem that a dent or a pinhole is generated in the green sheet.

Patent Document 4 discloses a method for producing a laminated film in which an antistatic layer is formed by a so-called in-line process.
Japanese Patent No. 3948333 Japanese Patent No. 3870785 JP 2003-203821 A JP 2004-58648 A

  The present invention has been made in view of such a situation, and an object thereof is to have a mold release function and an antistatic function, and to have a smooth surface and back surface and a back surface that is easy to slid. It is to provide a support sheet suitable for use in the production of electronic components. Another object of the present invention is a method for producing a multilayer ceramic electronic component performed using the support sheet, and produces an electronic component having a short-circuit defect while having a thin dielectric layer. Is to provide a method.

  As a result of intensive studies to achieve the above object, the present inventors have an influence not on the maximum height Rmax that defines the size of the protrusions and recesses on the surface of the support sheet, but on the recesses and pinholes in the green sheet. Focusing on the maximum peak height (Rp) that defines only the size of the convex portion that gives the surface, by making the Rp on the front and back surfaces of the support sheet a specific range, the front and back surfaces are smooth, and the back surface is easy to slip. The present inventors have found that a supporting sheet can be obtained and have completed the present invention.

That is, the support sheet of the present invention is
A core layer having a synthetic resin;
A release layer formed on the surface of the core layer;
An antistatic layer formed on the back surface of the core layer, and a maximum peak height (Rp) of the front and back surfaces of the support sheet is 300 nm or less.

  In the present invention, by setting the maximum peak height (Rp) within the above specific range, a support sheet having a smooth front surface and a back surface and easy slipping on the back surface can be obtained. Therefore, according to the support sheet according to the present invention, it is possible to effectively prevent dents and pinholes in the green sheet while preventing good peeling of the green sheet and charging of the support sheet. Can cope with this.

  Preferably, the maximum peak height (Rp) of the surface of the support sheet is equal to or less than the maximum peak height (Rp) of the back surface, and more preferably less than the maximum peak height (Rp) of the back surface.

  By setting the Rp on the front surface to be equal to or less than the Rp on the back surface, more preferably less than Rp on the back surface, it is possible to achieve both smoothness and easy slipping of the back surface while smoothing the surface of the support sheet. As a result, the green sheet can be thinned, the adhesion between the green sheet and the support sheet can be prevented, and the travelability (slidability) of the support sheet can be ensured.

  Preferably, at least the front and back surfaces of the core layer are composed of a fillerless resin layer having a synthetic resin substantially containing no filler. By configuring the front and back surfaces of the core layer with fillerless resin layers, it becomes easy to set the maximum peak height (Rp) of the front and back surfaces of the support sheet within the above range, and good smoothness can be realized.

  Preferably, the antistatic layer further has an easy slip function. In the present invention, it is easy to achieve both smoothness and slidability on the back surface of the support sheet by imparting slidability to the antistatic layer opposite to the release layer on which the green sheet is to be formed. Therefore, it is possible to ensure air escape during winding of the support sheet and to prevent damage to the sheet.

  Preferably, the antistatic layer contains silica particles, and the silica particles have an average particle diameter of 150 to 450 nm.

  Preferably, the silica particles are contained in an amount of 0.3 to 5 parts by mass with respect to 100 parts by mass of the resin component contained in the antistatic layer.

  In the present invention, silica particles are contained in the antistatic layer with a specific average particle diameter and content as a means for exerting an easy slip function. By doing in this way, a moderate protrusion can be formed in the back surface of a support sheet, making maximum peak height (Rp) into said range. As a result, the surface of the support sheet can be made extremely smooth, and both smoothness and easy slipping can be achieved on the back surface.

  Preferably, the release layer is a conductive release layer containing a condensation reaction type peelable binder and a conductive polymer. By imparting conductivity to the release layer, it is possible to prevent foreign matters such as dust from adhering to the support sheet.

A method for producing a multilayer ceramic electronic component according to the present invention includes:
The step of pulling out the support sheet from the roll around which the support sheet according to any of the above is wound,
Forming a green sheet on the surface of the support sheet;
Removing the green sheet from the surface of the support sheet and stacking to obtain a laminate;
Firing the laminate.

  According to the method for manufacturing a multilayer ceramic electronic component according to the present invention, even when the green sheet formed on the surface of the support sheet is very thin, for example, 2 μm or less, preferably about 1 μm or less, Thin portions can be effectively prevented. Therefore, it is possible to manufacture an electronic component with few short-circuit defects while having a thin dielectric layer.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

FIG. 1 is a schematic sectional view of a support sheet according to an embodiment of the present invention,
FIG. 2 is an enlarged cross-sectional view in which the back surface vicinity portion II of the support sheet shown in FIG. 1 is enlarged,
FIG. 3 is a schematic diagram showing a process of forming a green sheet using the support sheet shown in FIG.
FIG. 4 is a schematic diagram showing a continuation process of FIG.
FIG. 5 is a schematic sectional view of a multilayer ceramic capacitor.
FIG. 6 is an enlarged cross-sectional view in which the vicinity of the back surface of the support sheet according to the conventional example is enlarged.

Support Sheet As shown in FIG. 1, a support sheet 20 according to an embodiment of the present invention has a configuration in which a release layer 27 is formed on the surface of the core layer 22 and an antistatic layer 28 is formed on the back surface. have. Furthermore, the core layer 22 is configured such that relatively thin fillerless resin layers 24 a and 24 b are formed on the front and back surfaces of the relatively thick filler resin layer 23.

  The filler resin layer 23 is made of a synthetic resin containing a filler (filler) that does not deteriorate transparency. As the synthetic resin, various resins conventionally used for a support sheet (carrier sheet) for producing a green sheet can be used without particular limitation, but a thermoplastic resin that is easily stretched is preferable. .

  Specifically, for example, polyester resin, polyolefin resin such as polypropylene resin and polyethylene resin, polylactic acid resin, polycarbonate resin, acrylic resin such as polymethyl methacrylate resin and polystyrene resin, polyamide resin such as nylon, polyvinyl chloride resin , Polyurethane resin, fluorine resin, polyphenylene sulfide resin, and the like can be used. Polyester resin is more preferable, and polyethylene terephthalate (PET) is particularly preferable in consideration of mechanical properties, transparency, cost, and the like. In addition, when used for applications in which heat, shrinkage stress or the like acts on the support sheet, polyethylene-2,6-naphthalate having excellent heat resistance and rigidity is particularly preferable.

  The filler 26 contained in the filler resin layer 23 is not particularly limited, and examples thereof include calcium carbonate, calcium phosphate, silica, kaolin, talc, titanium oxide, fumed silica, alumina, and organic particles, preferably calcium carbonate. , Silica and kaolin.

  The particle size of the filler 26 contained in the filler resin layer 23 is preferably 0.01 to 1.3 μm, more preferably 0.02 to 1 μm. If the particle size of the filler is too small relative to the coating thickness of the antistatic layer, the friction tends to increase and the strength of the support sheet 20 tends to decrease, and if the particle size is too large, the transparency tends to decrease. is there.

  The content of the filler 26 contained in the filler resin layer 23 is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass with respect to 100 parts by mass of the total mass of the filler resin layer 23. . If the content of the filler 26 contained in the filler resin layer 23 is too small, the friction tends to increase and the strength of the support sheet 20 tends to decrease. If the content is too large, the filler falls off from the edge. It tends to be easier.

  As described above, the filler resin layer 23 contains a filler, whereby the mechanical strength of the support sheet 20 itself can be improved. Further, filler protrusions are formed on the front and back surfaces of the support sheet, so that it is possible to ensure air escape during winding of the support sheet and to ensure easy slipping between the green sheet and the support sheet.

  However, if the protrusions of such fillers become too large, the smoothness of the support sheet surface may be impaired. As a result, pinholes and locally thin portions may occur in the green sheet formed on the surface of the support sheet 20, and the thickness of the green sheet may vary. This effect becomes more prominent as the green sheet becomes thinner (for example, 2 μm or less), and the possibility of short circuit defects after firing increases. Further, even when the back surface of the support sheet 20 is not smoothed, the back surface and the green sheet are in contact with each other in the state in which the support sheet on which the green sheet is formed is wound, and the above-described pinhole or local thin portion May occur.

  Here, in order to reduce the protrusion of the filler, by reducing the amount of filler blended in the filler resin layer 23 or by reducing the particle size of the filler, the unevenness of the surface of the support sheet is suppressed as low as possible. It is conceivable to reduce the influence. However, as described above, in this case, the mechanical strength of the seat is reduced, and the seat is easily damaged during traveling of the seat.

  Therefore, in this embodiment, in order to improve the smoothness of the support sheet 20 without reducing the amount of filler contained in the filler resin layer 23, the filler is formed on the surface of the filler resin layer 23 containing the filler. A filler-less resin layer 24b is formed on the back surface of the resin-less resin layer 24a. The fillerless resin layer 24 is substantially free of the filler as described above.

  Here, “substantially no filler” means that a filler having a particle size larger than 100 nm is not included. In other words, the filler having a particle size of 100 nm or less may be contained in an amount of 0.5 parts by mass or less with respect to the fillerless resin layers 24a and 24b.

  The synthetic resin constituting the fillerless resin layer 24 may be the same as or different from the synthetic resin constituting the filler resin layer 23.

  By forming such a fillerless resin layer 24, the surface of the support sheet can be smoothed, and even if the green sheet formed on this film is thinned, its thickness is Short circuit defects can be effectively prevented without variation.

  Such smoothness is specifically defined by the value of the maximum peak height (Rp) on the front and back surfaces of the support sheet 20, and in the present invention, the maximum peak height (Rp) of the front and back surfaces is 300 nm or less. Preferably, the maximum peak height (Rp) on the front surface is 200 nm or less, the maximum peak height (Rp) on the back surface is 300 nm or less, more preferably the maximum peak height (Rp) on the front surface is 100 nm or less, and the maximum peak height (Rp) on the back surface. ) Is 250 nm or less, more preferably the maximum peak height (Rp) of the front surface is 80 nm or less, and the maximum peak height (Rp) of the back surface is 200 nm or less.

  In order to ensure easy slipping, the lower limit of the maximum peak height (Rp) on the back surface is preferably 50 nm.

  The inventors found for the first time that pinholes and local thin portions of the green sheet formed on the surface of the support sheet can be effectively prevented by setting the maximum peak height (Rp) in a specific range. It was. Further, by making the maximum peak height (Rp) of the front surface smaller than the maximum peak height (Rp) of the back surface, it is possible to achieve both smoothness and easy slipping of the back surface while making the surface extremely smooth. It was also found for the first time by the present inventors that this can be done.

  Note that the maximum peak height (Rp) is different from the maximum height Rmax and evaluates only the convex portion on the surface of the support sheet 20 and is defined by JIS B0601. In this embodiment, the maximum peak height (Rp) was measured using a Micromap System (an optical interference type three-dimensional non-contact surface shape measuring system) manufactured by Ryoka System Co., Ltd., which will be described later.

  The thickness of the core layer 22 is not particularly limited, but is preferably 1 to 500 μm, more preferably 5 to 300 μm, and still more preferably 9 to 210 μm. Moreover, it is preferable that the thickness t0 of the filler resin layer 23 is 0-200 micrometers. The core layer 22 may not be provided with the filler resin layer 23 and may be composed only of the filler-less resin layer 24. However, as described above, in order to ensure the strength of the support sheet 20, the cost is also reduced. Therefore, the filler resin layer 23 is preferably present.

  The thickness t1 (t2) of the fillerless resin layer 24a (24b) is 1.2 to 5 times the maximum particle size of the filler 26 contained in the filler resin layer 23. The thicknesses t1 and t2 may be the same or different and are, for example, 2 to 3 μm. Further, by making the thickness t1 of the fillerless resin layer 24a (the front surface side of the support sheet) thicker than the thickness t2 of the fillerless resin layer 24b (the back surface side of the support sheet), the influence of the protrusion of the filler is reduced, The maximum peak height (Rp) of the front surface of the support sheet can be made smaller than the maximum peak height (Rp) of the back surface.

  If the thickness of each of the fillerless resin layers 24a and 24b is too thin, the maximum peak height (Rp) on the surface of the support sheet 20 is set to a predetermined value or less due to the influence of protrusions (convex portions) due to the filler contained in the filler resin layer 23. It becomes difficult to do. Moreover, when the thickness of the fillerless resin layer 24 is too thick, as described above, the manufacturing cost increases and the mechanical strength of the support sheet tends to be insufficient.

  In the core layer 22, various additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an ultraviolet absorber, an organic lubricant, a pigment, a dye, an organic or inorganic fine particle, an antistatic agent, A nucleating agent or the like may be added to such an extent that the characteristics are not deteriorated.

  With the core layer 22 having such a configuration, the filler resin layer 23 containing the filler sufficiently maintains the mechanical strength of the entire support sheet 20 and the filler-less resin layers 24a and 24b. The front and back surfaces of the core layer 22 can be rich in smoothness.

  The release layer 27 formed on the surface of the core layer 22 is not particularly limited, but in the present embodiment, the release layer 27 is a conductive release layer containing a condensation reaction type release binder and a conductive polymer. As the condensation reaction type release binder, an alkyd resin release agent is preferable, and a silicone-modified alkyd resin is particularly preferable. Examples of the conductive polymer include polyacetylene, polythiophene, polypyrrole, polyaniline, polyvinylenephenylene, and polyacene. From the viewpoint of conductivity and versatility, polythiophene, polypyrrole, and polyaniline. A system is preferable, and a polypyrrole system is particularly preferable. The mass ratio of the conductive polymer to the condensation reaction type release binder (conductive polymer / condensation reaction type release binder) in the conductive release layer is preferably 1/4 to 1/1, and more preferably. Is 1/3 to 1/1.

  In the case where the release layer 27 is formed using a known release agent, for example, a silicone polymer, a polyolefin polymer, a long-chain alkyl polymer, a fluorine polymer, and the like can be given.

  As will be described later, a ceramic green sheet is formed on the surface of the release layer 27. Since the release layer 27 is composed of the above components, the green sheet can be easily peeled, and In addition, it is possible to prevent problems such as contamination of the green sheet due to adhesion of dust and dirt due to charging of the support sheet.

  The thickness of the release layer 27 is preferably 0.03 to 0.5 μm, more preferably 0.05 to 0.2 μm. If the release layer 27 is too thin, sufficient peeling performance tends not to be obtained, and if it is too thick, the curability of the coating film becomes insufficient and the release property tends to change over time.

  The antistatic layer 28 formed on the back surface of the core layer 22 is not particularly limited, and may be formed using a known antistatic agent. For example, systems using conductive polymers such as polythiophene, polypyrrole, polyaniline, systems in which conductive fine particles such as ATO, PTO, ITO, pentoxide, etc. are mixed with resin, siloxane type, surfactant type, etc. Is mentioned. By providing such an antistatic layer, it is possible to prevent problems due to adhesion of dust, dust, etc. due to charging of the support sheet.

  In the present embodiment, the antistatic layer 28 further has slipperiness. As described above, since the front and back surfaces of the core layer 22 are composed of the fillerless resin layer 24, they are smoothed. As a result, the surface of the antistatic layer 28 formed on the back surface of the core layer 22 (the back surface of the support sheet 20) is also smoothed. Therefore, although the formation of pinholes and local thin portions of the green sheet can be prevented, the running property (easiness of sliding) of the support sheet is not sufficient, and when the green sheet is formed and wound on the support sheet, There is a possibility that the smoothed antistatic layer 28 and the green sheet adhere to each other. In this case, problems such as poor air escape during winding or damage to the green sheet may occur. In order to eliminate such a problem, preferably, the antistatic layer 28 is provided with an easy-slip function so that both smoothness and easy-slidability (runnability) on the back surface of the support sheet can be easily achieved. it can.

  A method for imparting an easy slip function is not particularly limited, but in order to eliminate the above-described problems, for example, it is conceivable to include inorganic particles or organic particles that exhibit an easy slip function. In the present embodiment, a method in which the antistatic layer 28 contains silica particles 29 is employed.

  As shown in FIG. 2, by containing silica particles 29 in the antistatic layer 28, protrusions can be generated in the antistatic layer 28 to such an extent that the smoothness of the back surface of the support sheet is not impaired. Due to this protrusion, even when the green sheet is wound together with the support sheet, the antistatic layer 28 and the green sheet are not in close contact with each other, and sufficient slipperiness is ensured. Further, since the silica particles 29 are hard, the protrusions are maintained and the slipperiness is not lowered.

  The thickness of the antistatic layer 28 is preferably 0.03 to 0.3 μm, more preferably 0.05 to 0.2 μm.

  Although it does not restrict | limit especially as the silica particle 29, Preferably colloidal silica is used. By using colloidal silica, it is uniformly dispersed in the antistatic layer 28, and sufficient slipperiness can be ensured, and variation in the thickness of the green sheet can be reduced.

  The average particle diameter of the silica particles 29 is preferably 150 to 450 μm, more preferably 150 to 400 μm. If the average particle size is too small, the thickness may be smaller than the thickness of the antistatic layer 28, and the protrusions tend not to be formed. On the other hand, if the average particle diameter is too large, the protrusions are too large and the maximum peak height (Rp) tends to be 300 nm or more.

  The silica particles 29 are preferably contained in an amount of 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the resin contained in the antistatic layer 28. If the content is too small, sufficient slipperiness tends not to be exhibited. If the content is too large, there is a possibility that particles fall off.

Further, the lower the electrical resistance of the antistatic layer 28, the greater the antistatic effect, but if the electrical resistance is too low, it is not preferable that electricity flows too rapidly. Therefore, the electrical resistance of the antistatic layer 28 is preferably 10 ⁵ Ω / □ to 10 ¹¹ Ω / □.

The manufacturing method of the support sheet which concerns on this embodiment below is demonstrated.

  The core layer 22 is formed by a coextrusion method. A pellet-shaped synthetic resin (PET or the like) containing a filler is kneaded by a main extruder to extrude the filler resin layer 23, and a pellet-shaped synthetic resin (PET or the like) containing no filler is kneaded by a sub-extruder. Then, the fillerless resin layer 24 is extruded, and the core layer 22 having a structure in which the filler resin layer 23 is sandwiched between the fillerless resin layers 24a and 24b is formed by a multi-manifold die.

  Next, a release layer 27 is formed on the surface of the obtained core layer 22, and an antistatic layer 28 is formed on the back surface to obtain a support sheet 20. A method for forming the release layer 27 and the antistatic layer 28 is not particularly limited, and an in-line coating method or an off-line coating method may be used.

  In the case of in-line coating, simultaneously with the formation of the core layer 22, the support sheet 20 is formed by coating the release layer 27 including the silica particles 29 and / or the antistatic layer 28. In the case of off-line coating, a release layer forming coating solution containing silica particles 29 and an antistatic layer forming coating solution are prepared and applied to the front and back surfaces of the core layer 22 by a known coating method. The support sheet 20 is formed by drying and heat treatment.

Manufacturing Method for Multilayer Ceramic Capacitor Hereinafter, a manufacturing method for a multilayer ceramic capacitor using the support sheet of the present embodiment will be described.

  First, the multilayer ceramic capacitor 2 shown in FIG. 5 will be described.

  As shown in FIG. 5, the multilayer ceramic capacitor 2 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.

  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, and particularly preferably 1.0 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. First, a dielectric paste (green sheet paste) is prepared in order to manufacture a ceramic green sheet that will form the dielectric layer 10 shown in FIG. 5 after firing.
The dielectric paste is composed of an organic solvent-based paste 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 polymerization degree of the polyvinyl butyral resin is 1000 or more and 1700 or less, preferably 1400 to 1700. The degree of butyralization of the resin is greater than 64% and less than 78%, preferably greater than 64% and 70% or less, and the residual acetyl group content is less than 6%, preferably 3% or less.

  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, paste 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 paste tends to be deteriorated by an ordinary method. In the method of the present embodiment, the paste dispersibility can be improved in order to add the ceramic powder and other components to the solution after dissolving the binder resin having a high degree of polymerization in the above-mentioned good solvent, 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 paste may contain additives selected from various dispersants, plasticizers, antistatic agents, dielectrics, glass frit, insulators, and the like as necessary.

  By using this dielectric paste, for example, as shown in FIG. 3, the surface of the support sheet 20 unwound from the first supply roll 20a around which the support sheet 20 shown in FIG. The green sheet 10a is formed. The green sheet 10 a formed on the surface of the support sheet 20 is dried by the drying device 32 and then wound up as the second supply roll 20 b together with the support sheet 20.

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 contracts by 5 to 25% as compared with that before drying. The thickness of the green sheet after drying is preferably 1 μm or less.

  Next, as shown in FIG. 4, in the support sheet 20 with the green sheet 10a unwound from the second supply roll 20b, the electrode paste layer 12a is formed in a predetermined pattern by the screen printing device 34, and then dried. After being dried by the device 36, it is taken up as the third supply roll 20 c together with the support sheet 20.

  The electrode paste for forming the electrode paste layer 12a is made of a conductive material made of various conductive metals or alloys, or various oxides, organometallic compounds, resinates, or the like that become the conductive material described above after firing, and an organic vehicle. And kneading.

  As a conductive material used when manufacturing the electrode paste, 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 paste 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 paste.

  In order to improve adhesion, the electrode paste 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, more preferably 10 to 200 parts by mass with respect to 100 parts by mass of the binder in the electrode paste. 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 paste to improve the adhesion and / or the pressure-sensitive adhesiveness of the electrode paste.

  The third supply roll 20c is then sent to the laminating apparatus. Therefore, although not shown, the unwound green sheet 10a with electrode paste layer 12a is peeled off from the support sheet 20, cut into a predetermined size, and stacked alternately.

  The green sheet 10a is formed by forming an electrode paste layer 12a on the surface of a support sheet different from the support sheet 20 on which the green sheet 10a is formed, and transferring the electrode paste layer 12a to the surface of the green sheet 10a. The electrode pattern layer 12a may be formed on the surface.

  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,
Holding temperature: 200-400 ° C.
Retention time: 0.5-20 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,
Holding temperature: 1100-1300 ° C.
Retention time: 0.5-8 hours,
Cooling rate: 50 to 500 ° 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 ⁻² Pa to 1 Pa, more preferably 10 ⁻² Pa to 1 Pa. Below the range, it is difficult to re-oxidize the dielectric layer 10, and when the range is exceeded, the internal electrode layer 12 tends to oxidize.

The sintered body (element body 4) thus obtained is subjected to end face polishing by, for example, barrel polishing, sand blasting, etc., and terminal electrode paste is baked to form terminal electrodes 6 and 8. The firing conditions for the terminal electrode paste are preferably, for example, 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 paste for terminal electrodes like the above-mentioned electrode paste.

  The multilayer ceramic capacitor 2 shown in FIG. 5 manufactured in this way is mounted on a printed circuit board by soldering or the like, and is used for various electronic devices.

  In the support sheet 20 according to the present embodiment, the surface of the release layer 27 on which the green sheet is formed (the surface of the support sheet) is extremely smooth, and comes into contact with the green sheet during winding of the sheet. The antistatic layer 28 (the back surface of the support sheet) has an antistatic function and an easy slip function. Therefore, the support sheet according to the present embodiment can be suitably used for manufacturing electronic components such as a multilayer ceramic capacitor in which the internal electrode and the dielectric green sheet are thinned.

  Further, according to the method for manufacturing the multilayer ceramic capacitor 2 according to the present embodiment, even when the green sheet 10a formed on the surface of the support sheet 20 is very thin, for example, about 2 μm or less, preferably about 1 μm or less, the green sheet 10a Pinholes and local thin portions can be effectively prevented. Therefore, it is possible to manufacture a multilayer ceramic capacitor having a shorted dielectric layer while having a thin dielectric layer.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

Examples 1-7, Comparative Examples 1 and 2
Pellets of polyethylene terephthalate (PET) containing calcium carbonate as filler (extreme viscosity 0.63 dl / g), pellets of polyethylene terephthalate (PET) substantially free of filler (extreme viscosity 0.63 dl / g), Was sufficiently dried under vacuum, and then fed to an extruder and melted at 285 ° C. And the PET sheet (core layer) laminated | stacked so that the PET sheet which does not contain a filler substantially may be pinched | interposed by the co-extrusion method. Next, it was wound around a mirror casting drum having a surface temperature of 25 ° C. by using an electrostatic application casting method, and was cooled and solidified. This unstretched sheet was heated to 92 ° C. and stretched 3.3 times in the longitudinal direction to obtain a uniaxially stretched sheet. This uniaxially stretched film is guided to the preheating zone while being gripped with a clip, continuously stretched 3.8 times in the width direction in the heating zone at 90 ° C., and further subjected to heat treatment in the heating zone at 225 ° C. (Core layer) was created.

  At this time, the thickness of the core layer was 38 μm, of which the thickness of the filler resin layer was 34 μm, and the thicknesses of the fillerless resin layers 24a and 24b were both 2 μm.

  Next, a release layer forming coating solution and an antistatic layer forming coating solution were prepared. The release layer forming coating solution was a silicone resin (KS-847H, manufactured by Shin-Etsu Chemical Co., Ltd., solid content 30% by mass): 300 parts by mass, a platinum catalyst (CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.). : 3 parts by mass, toluene: 2700 parts by mass to prepare.

  The coating solution for forming the antistatic layer is polyester polyurethane (UR1400, manufactured by Toyobo Co., Ltd., solid content: 30% by mass): 100 parts by mass, curing agent (Coronate 2030, manufactured by Nippon Polyurethane Co., Ltd., solid content: 50% by mass): 9 A mass part, a polypyrrole dispersion (CDP-310M, manufactured by Nippon Carlit Co., Ltd., solid content: 10% by mass): 173 parts by mass, methyl ethyl ketone: 720 parts by mass, and toluene: 720 parts by mass were prepared. Furthermore, colloidal silica is contained in the above-mentioned coating solution for forming an antistatic layer as the silica particles in the average particle size and addition amount shown in Table 1, and filtered using a 0.8 μm mesh filter to form a coating for forming an antistatic layer. Liquid. In addition, the addition amount of colloidal silica is the addition amount with respect to 100 mass parts of polyester urethane which is a resin component of an antistatic layer.

  The release layer forming coating solution is applied to one surface of the core layer, and the other is coated with the antistatic layer forming coating solution. The obtained support sheets (Examples 1 to 7, Comparative Examples 1 and 2) are as follows. The characteristics were evaluated.

  The release layer had a thickness of 100 nm, and the antistatic layer had the thickness shown in Table 1. Moreover, the sheet | seat after apply | coating the coating liquid for antistatic layer forming was evaluated after thermosetting at 60 degreeC for 24 hours.

Maximum mountain height Rp
According to JIS B0601, Rp on the front surface (release layer side) and back surface (antistatic layer side) of the support sheet was measured. For the measurement, Micromap System (an optical interference type three-dimensional non-contact surface shape measurement system) of Ryoka System Co., Ltd. was used, and the measurement was performed under the following conditions.

<Measurement conditions>
Optics Setup
Wavelength: W5600A
Objective: 50 ×
Body Tube: 1 x Body
Relay Lens: No Relay
Camera: Sony XC-ST30 1/3 "
Measurement Setup
Mode: Wave560M
Averages: 1
Format
Data Format: 640 × 480
Data Point: 307200
Sampling X: 1
Sampling Y: 1
The measurement location of the sample was changed, and 10 locations were measured. The measurement area is 94 μm × 71 μm in one measurement.

<Analysis>
After measurement with Micromap, the maximum peak height Rp was determined using analysis software SX-Viewer. The largest value among the 10 measured points was the maximum peak height. The maximum mountain height represents the height of the highest point (peak) in the Z-axis direction from the average plane. Rp was determined to be 300 nm or less. The results are shown in Table 1.

The coefficient of friction ease was evaluated by measuring the coefficient of friction on the back surface. That is, as the coefficient of friction increases, the slipperiness between the back surface and the green sheet or guide roll deteriorates, and the green sheet is damaged. The friction coefficient is a tape running tester SFT-700 type (manufactured by Yokohama System Laboratory Co., Ltd.) having a support sheet slit into a 1/2 inch wide tape, and has an atmosphere of 20 ° C.-60% RH. The initial friction coefficient (μk) was obtained from the following equation.

μk = (2 / π) · ln (T ₁ / T ₂ )
Here, _{T 1} enters the side tension, _{T 2} is the outlet side tension. The guide diameter is 6 mmφ, the guide material is SUS27 (surface roughness 0.2S), the winding angle is 90 degrees, and the running speed is 3.3 cm / second. The results obtained by this measurement are shown in Table 1.

Antistatic property The antistatic property was evaluated by measuring the electrical resistance of the antistatic layer using Hiresta (trade name, manufactured by Mitsubishi Chemical Corporation). The results are shown in Table 1.

  From Table 1, when the colloidal silica is not contained in the antistatic layer (Example 6) and when the average particle diameter of the colloidal silica is smaller than the preferred range of the present invention (Example 7), the surface of the support sheet Since no protrusion is formed on the substrate, the value of Rp can be reduced. However, since the surface of the support sheet is smooth, it can be seen that the support sheet tends to be in close contact with the guide roll, and the slip tends to be bad (coefficient of friction).

  Further, when the average particle size of colloidal silica is larger than the preferred range of the present invention, (Comparative Example 1), or when the amount added is large (Comparative Example 2), the value of Rp is out of the scope of the present invention. End up. As a result, when the antistatic layer was applied, a coating streak occurred, and a uniform coating film could not be obtained, or when the surface of the antistatic layer was rubbed with a bencot, silica particles were dropped off.

  In contrast, when the average particle size of the colloidal silica is within the preferred range of the present invention (Examples 1 to 5), the Rp of the antistatic layer is controlled to 300 nm or less. It can be seen that the coefficient of friction is reduced by the resulting protrusion, and that the antistatic property is maintained well.

  From the above, by making the average particle size and content of colloidal silica within the preferred range of the present invention, the properties such as releasability are improved, Rp is 300 nm or less, and the slipperiness is improved. It can be confirmed that

Example 8
100 parts by mass of a condensation reaction type peelable binder precursor (Tesfine TA31-209E, solid content concentration 45% by mass), 225 parts by mass of a conductive polymer (polypyrrole dispersion, CDP-310M), a condensation reaction catalyst p-toluenesulfone Acid: 3 parts by weight, 960 parts by weight of methyl ethyl ketone and 965 parts by weight of toluene are mixed and filtered using a 0.5 μm mesh filter to prepare a coating liquid for forming a conductive release layer. A support sheet was formed in the same manner as in Example 1 except that was formed.

  Dielectric slurry was applied to the surface of the obtained support sheet (Example 8) and the support sheet of Example 1, that is, the release layer surface, to form a green sheet having a coating thickness of 1.0 μm. At the time of forming the green sheet, the edge portion of the dielectric slurry application portion was visually observed to evaluate the meandering amount of the coating surface edge. When the slurry is uniformly applied, the edge portion of the application surface is linear, and the amount of meandering approaches zero.

  In the evaluation of the meandering amount, “◯” indicates that the moving average value between peaks is less than 0.5 mm, “Δ” indicates that the meandering amount is greater than 0.5 mm and less than 1 mm, × ”. The meandering amount is not less than 0.5 mm and less than 1 mm, that is, if it is evaluated as “Δ”, there is no practical problem, but if it exceeds 1 mm, the lamination accuracy may be deteriorated. The results are shown in Table 2.

Next, an electrode paste was printed on the green sheet formed above to form a green sheet with an electrode layer. After laminating the green sheet with the electrode layer, the charge amount of the support sheet after the laminate was peeled from the support sheet was measured and evaluated. When the charge amount of the support sheet is increased, dust and the like are easily adsorbed, and when foreign matter such as dust is mixed in the laminate, a short circuit failure or the like is caused. Therefore, the charge amount is preferably small. The results are shown in Table 2.

  From Table 2, the amount of meandering of the coating surface edge of the slurry formed on the support sheet of Example 8 in which the release layer is composed of a conductive release layer is very small, and the support sheet of Example 1 It can be confirmed that it is better than the case. Moreover, also about the charge amount after peeling, it can be confirmed that the support sheet of Example 8 has a charge amount of 0, which is better than the support sheet of Example 1.

  Therefore, by using the release layer as the conductive release layer of Example 8, in addition to the effect of Example 1, the support sheet has excellent moldability and can effectively reduce defects due to mixing of foreign matters and the like. Is obtained.

FIG. 1 is a schematic cross-sectional view of a support sheet according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view in which a rear surface vicinity portion II of the support sheet shown in FIG. FIG. 3 is a schematic view showing a step of forming a green sheet using the support sheet shown in FIG. FIG. 4 is a schematic view showing a step subsequent to FIG. FIG. 5 is a schematic cross-sectional view of a multilayer ceramic capacitor. FIG. 6 is an enlarged cross-sectional view in which the vicinity of the back surface of the support sheet according to the conventional example is enlarged.

Explanation of symbols

2 ... multilayer ceramic capacitor 4 ... capacitor body 6 ... first terminal electrode 8 ... second terminal electrode 10 ... dielectric layer 10a ... green sheet 12 ... internal electrode layer 12a ... electrode paste layer 20 ... support sheet 20a ... first supply Roll 20b ... Second supply roll 20c ... Third supply roll 22, 220 ... Core layer 23 ... Filler resin layer 24a, 24b ... Fillerless resin layer 26, 260 ... Filler 27 ... Release layer 28, 280 ... Antistatic layer 29 ... Silica particles 30 ... Doctor blade device 32 ... Drying device 34 ... Screen printing device 36 ... Drying device

Claims (8)

A core layer having a synthetic resin;
A release layer formed on the surface of the core layer;
Has, antistatic layer formed on the back surface of the core layer, front and back surfaces of the maximum peak height of the support sheet (Rp) is Ri der less 300 nm,
The antistatic layer has an easy-slip function,
A support sheet in which silica particles are contained in the antistatic layer, and the silica particles have an average particle diameter of 150 to 450 nm .   The support sheet according to claim 1, wherein the maximum peak height (Rp) of the front surface of the support sheet is equal to or less than the maximum peak height (Rp) of the back surface.   The support sheet according to claim 1 or 2, wherein at least the front and back surfaces of the core layer are composed of a fillerless resin layer having a synthetic resin substantially containing no filler. The support sheet according to any one of claims 1 to 3, wherein the silica particles are contained in an amount of 0.3 to 5 parts by mass with respect to 100 parts by mass of the resin component contained in the antistatic layer. The support sheet according to any one of claims 1 to 4 , wherein the release layer is a conductive release layer containing a condensation reaction type peelable binder and a conductive polymer. The support sheet according to any one of claims 1 to 5 , wherein the synthetic resin is polyethylene terephthalate. A step of withdrawing the support sheet from the roll that is rotating support sheet is wound according to any one of claims 1 to 6
Forming a green sheet on the surface of the support sheet;
Removing the green sheet from the surface of the support sheet and stacking to obtain a laminate;
And a step of firing the multilayer body. The method for producing a multilayer ceramic electronic component according to claim 7 , further comprising a step of forming an electrode pattern layer on a surface of the green sheet.

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