JP4626455B2 - Manufacturing method of multilayer electronic component - Google Patents

Description

  The present invention relates to a method for manufacturing a multilayer electronic component such as a multilayer ceramic capacitor.

  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. One of the electronic components is a multilayer ceramic capacitor, and the multilayer ceramic capacitor is also required to be small in size and high in performance.

  In order to reduce the size and performance of this multilayer ceramic capacitor, and in particular to increase the capacity, there is a strong demand for thinner dielectric layers. Recently, the thickness of dielectric green sheets has become several μm or less. I came.

  A ceramic green sheet is usually made of ceramic powder, a binder (acrylic resin, butyral resin, etc.), a plasticizer and an organic solvent (toluene, alcohol, MEK, etc.) using a doctor blade method. It is manufactured by applying on a carrier sheet such as a film and drying by heating.

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

  A method for manufacturing a multilayer ceramic capacitor using the ceramic green sheet will be described in detail. A conductive paste for internal electrodes including a metal powder and a binder is printed in a predetermined pattern on a ceramic green sheet and dried. To form an internal electrode pattern. Next, the carrier sheet is peeled from the ceramic green sheet, and a plurality of these laminated sheets are cut into chips to obtain green chips. Next, after firing the green chip, external electrodes are formed.

  In recent years, as the range of use of monolithic ceramic capacitors has increased, miniaturization and higher capacity have become a market demand. To that end, the interlayer thickness of the sheet on which the internal electrodes are formed has been increasingly reduced year by year. Yes.

  However, when the internal electrode paste is printed on the thinned ceramic green sheet, there is a problem that the solvent in the internal electrode paste dissolves or swells the binder component of the ceramic green sheet. There is also a problem that the internal electrode paste penetrates into the green sheet. These defects often cause short circuit defects.

  In order to eliminate such problems, in Patent Documents 1 to 3 below, an internal electrode pattern is formed on a support sheet and then dried, and a dry type electrode pattern is separately prepared. An internal electrode pattern transfer method has been proposed in which this dry type electrode pattern is transferred to the surface of each ceramic green sheet or the surface of a laminate of ceramic green sheets.

  However, in the technologies shown in these Patent Documents 1 to 3, it is extremely difficult to transfer the electrode pattern layer to the surface of the green sheet with high accuracy, particularly when the thickness of the green sheet is thin, In the transfer process, the ceramic green sheet may be partially destroyed.

  In addition, the transfer methods according to these conventional techniques require high pressure and heat in order to transfer the electrode pattern layer to the surface of the green sheet. Therefore, the green sheet, the electrode layer, and the support sheet are easily deformed. There is a possibility that it may not be practically used at the time of lamination, or a short circuit failure may occur due to the destruction of the green sheet.

  On the other hand, the present applicant has already proposed a method of transferring a dry type electrode layer via an adhesive layer containing a binder resin and a plasticizer (Patent Document 4). According to the technique of this document, even when the green sheet is thinned, it is possible to easily and accurately transfer the dry type electrode layer onto the surface of the green sheet. However, in order for such an adhesive layer to exhibit sufficient adhesiveness, if the thickness of the adhesive layer is relatively thick (for example, greater than 0.2 μm), it is contained in the adhesive layer in the binder removal step. There is a problem that the binder resin remains without being decomposed, voids are formed inside the sintered body, and delamination occurs due to the influence. On the other hand, when the thickness of the adhesive layer is reduced in order to solve the above problem, there is a problem that the adhesiveness becomes insufficient and delamination occurs similarly.

JP-A-63-51616 Japanese Patent Laid-Open No. 3-250612 Japanese Patent Laid-Open No. 7-31326 International Publication No. 2004/61880 Pamphlet

  The present invention has been made in view of such a situation, and even when the green sheet is thinned by laminating the green sheet and the electrode layer through the adhesive layer, the green sheet is broken or deformed. Therefore, the dry type electrode layer can be easily and accurately transferred to the surface of the green sheet, and in particular, the adhesive layer can be made thin while maintaining sufficient adhesiveness. It is an object of the present invention to provide a method for manufacturing a multilayer electronic component in which the delamination phenomenon caused by the formation of is effectively prevented.

  As a result of intensive studies to achieve the above object, the present inventor has achieved the object of the present invention by performing a drying treatment under predetermined conditions when forming an adhesive layer on the surface of an electrode layer or a green sheet. It has been found that this can be achieved, and the present invention has been completed.

That is, the manufacturing method of the multilayer electronic component according to the first aspect of the present invention includes:
Forming an adhesive layer containing a binder resin and a plasticizer on the surface of the electrode layer or the green sheet;
A step of laminating an electrode layer and a green sheet through the adhesive layer to form a green chip;
A step of firing the green chip, comprising the steps of:
The adhesive layer is formed by drying an adhesive layer paste film formed using an adhesive layer paste containing the binder resin, the plasticizer, and a solvent at a temperature of 80 ° C. or higher and 160 ° C. or lower. It is characterized by that.

A method for manufacturing a multilayer electronic component according to a second aspect of the present invention includes:
Forming an adhesive layer containing a binder resin and a plasticizer on the surface of the electrode layer or the green sheet;
A step of laminating an electrode layer and a green sheet through the adhesive layer to form a green chip;
A step of firing the green chip, comprising the steps of:
The adhesive layer is formed by drying an adhesive layer paste film formed using an adhesive layer paste containing the binder resin, the plasticizer, and a solvent,
The drying is performed so that the covering ratio, which is the ratio of the area actually covering the electrode layer or the green sheet on which the adhesive layer is formed on the surface, is 5% to 50%. It is characterized by performing.

  In the multilayer electronic component manufacturing method according to the first and second aspects of the present invention, an adhesive layer is formed on the surface of the electrode layer or the green sheet, and the electrode layer and the green sheet are interposed via the adhesive layer. And glue. By forming the adhesive layer, high pressure and heat are not required when the electrode layer and the green sheet are bonded, and bonding at a lower pressure and a lower temperature is possible. Therefore, even when the green sheet is extremely thin, the green sheet is not destroyed, and the electrode layer and the green sheet can be laminated satisfactorily, and occurrence of a short circuit failure or the like can be effectively prevented.

  And in the manufacturing method of the multilayer electronic component which concerns on the 1st viewpoint and 2nd viewpoint of this invention, when forming an contact bonding layer, a drying process is performed on the said conditions. In particular, by performing a drying treatment under the above conditions, the plasticizer in the adhesive layer oozes out to the surface of the adhesive layer, and the oozed plasticizer serves as a tackifier and improves the adhesiveness of the adhesive layer. be able to.

Preferably, the adhesive layer is thinned so that the average film thickness is in the range of 0.02 to 0.2 μm, more preferably in the range of 0.02 to 0.1 μm.
In the present invention, when the adhesive layer is formed, the drying treatment is performed under the above-described predetermined conditions. Therefore, even when the thickness of the adhesive layer is reduced as described above, sufficient adhesion (stack strength) is maintained. Can do. However, if the average film thickness of the adhesive layer is too thin, the adhesiveness is reduced, and when peeling the support sheet from a laminate composed of a plurality of electrode layers and a green sheet, the electrode layer and the green sheet The transfer interface between them breaks, and this breakage becomes a defect, causing a short circuit failure. Furthermore, the adhesion at the transfer interface between the electrode layer and the green sheet becomes insufficient, and a delamination phenomenon occurs after sintering. On the other hand, if the adhesive layer is too thick, the binder resin contained in the adhesive layer remains in the binder removal process without being decomposed, and voids are formed inside the sintered body. Will occur. Furthermore, if the thickness of the adhesive layer is too thick, a gap is likely to be 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 be significantly reduced.

  Preferably, the adhesive layer is first formed to be peelable on the surface of the support sheet, and is transferred by being pressed against the surface of the electrode layer or the surface of the green sheet. The adhesive layer is not formed directly on the surface of the electrode layer or green sheet by the application method, but by the transfer method, the components of the adhesive layer do not soak into the electrode layer or the green sheet, and the extremely thin adhesive layer Can be formed.

  Preferably, the adhesive layer has a covered portion that actually covers the electrode layer or the green sheet on which the adhesive layer is formed, and a non-covered portion that is not substantially covered. is doing. In the present invention, the uncoated portion is formed when the plasticizer contained in the adhesive layer oozes out as a result of setting the drying treatment conditions when forming the adhesive layer to the predetermined range. For this reason, the uncovered portion is usually observed as a circular repellant portion.

  Preferably, the diameter of the maximum non-covered portion (maximum repellant portion) having the maximum diameter among the uncovered portions (repellent portions) is 80 μm or less, more preferably 50 μm or less. When the diameter of the maximum repellency portion is too large, the adhesiveness tends to decrease.

Preferably, the thickness of the covering portion is in the range of 0.05 to 4 μm, more preferably in the range of 0.1 to 2 μm.
In the present invention, the non-covered portion (repellent portion) is substantially free of components (binder resin, plasticizer, etc.) constituting the adhesive layer, and the actual thickness is substantially zero. On the other hand, the component which comprises the contact bonding layer which existed in the said non-coating part (peeling part) before the drying process will be sprinkled out to the said coating | coated part side. For this reason, the thickness of the covering portion tends to be thicker than the average film thickness of the adhesive layer. In addition, the average film thickness of the said adhesive layer in this case averages the thickness of the said non-coating part (repelling part), and the thickness of a coating | coated part according to the abundance ratio.

  It does not specifically limit as said binder resin contained in a contact bonding layer, What is necessary is just to use the same kind as binder resin contained in the said green sheet. As such a resin, one or more selected from acrylic resins and butyral resins are preferably used.

Preferably, the content of the plasticizer in the adhesive layer is 10 to 100 parts by mass with respect to 100 parts by mass of the binder resin.
Preferably, the plasticizer contained in the adhesive layer is a phthalate ester. Examples of the phthalate ester include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, and benzyl butyl phthalate.

  Preferably, the green sheet has a thickness of 2 μm or less. The present invention is highly effective when the green sheet is thinned, particularly when the thickness of the green sheet is 2 μm or less.

  Preferably, the electrode layer is formed in a predetermined pattern on the surface of the support sheet via the release layer, and the surface of the release layer on which the electrode layer is not formed has substantially the same thickness as the electrode layer. A blank pattern layer is formed, and the blank pattern layer is made of substantially the same material as the green sheet.

  By forming the blank pattern layer, the step on the surface due to the electrode layer having a predetermined pattern is eliminated. Therefore, a large number of green sheets are laminated to form a green chip, and even if the green chip before firing is pressed, the outer surface of the laminate is kept flat, and the electrode layer is not displaced in the plane direction. It will not break through the green sheet and cause a short circuit.

  The multilayer electronic component manufactured according to the present invention is not particularly limited, and examples thereof include a multilayer ceramic capacitor and a multilayer inductor element.

  Moreover, in this invention, an electrode layer is used by the concept containing the electrode paste film | membrane used as an internal electrode layer after baking.

  According to the present invention, since the green sheet and the electrode layer are laminated through the adhesive layer, even when the green sheet is thinned, the green sheet is not destroyed or deformed, and the surface of the green sheet is not damaged. It is possible to provide a method for manufacturing a laminated electronic component that can transfer a dry-type electrode layer easily and with high accuracy and at a low cost. Moreover, in the present invention, when the adhesive layer is formed, the drying process is performed under predetermined conditions, so that the adhesive layer can be thinned while maintaining sufficient adhesiveness. The delamination phenomenon resulting from the formation can be effectively prevented.

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, and FIGS. 2A to 2C and FIGS. 3A to 3C show a method for transferring an electrode layer. 4A to FIG. 4C, FIG. 5A to FIG. 5C are main part cross-sectional views showing a method of stacking the laminated body unit, and FIG. 6A is the present invention. FIG. 6B and FIG. 6C are surface photographs of the adhesive layer according to the comparative example.

Multilayer Ceramic Capacitor First, the overall configuration of a multilayer ceramic capacitor will be described as an embodiment of an electronic component manufactured by the method according to the present invention.
As shown in FIG. 1, a multilayer ceramic capacitor 2 according to an embodiment of the present invention includes a capacitor element body 4 having a configuration in which dielectric layers 10 and internal electrode layers 12 are alternately stacked. A pair of external electrodes 6 and 8 are formed at both ends of the capacitor element body 4 so as to be electrically connected to the internal electrode layers 12 arranged alternately in the element element body 4. The internal electrode layers 12 are laminated such that the side end faces are alternately exposed on the surfaces of the two opposite ends of the capacitor body 4. The pair of external electrodes 6 and 8 are formed at both ends of the capacitor body 4 and are connected to the exposed end surfaces of the alternately arranged internal electrode layers 12 to constitute a capacitor circuit.

  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, and even more preferably 2 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).

Method for Manufacturing Multilayer Ceramic Capacitor Next, an example of a method for manufacturing the multilayer ceramic capacitor 2 according to this embodiment will be described.

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

  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 an extremely 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 in an organic solvent. The binder used in the organic vehicle is not particularly limited, and various ordinary binders such as ethyl cellulose, polyvinyl butyral, and acrylic resin are used. Preferably, acrylic resins and butyral resins such as polyvinyl butyral are used. .

  Further, the organic solvent used in the organic vehicle is not particularly limited, and organic solvents such as terpineol, alcohol, butyl carbitol, acetone, and toluene are used. Further, the vehicle in the aqueous paste is obtained by dissolving a water-soluble binder in water. The water-soluble binder is not particularly limited, and polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose, water-soluble acrylic resin, emulsion and the like are used. The content of each component in the dielectric paste is not particularly limited, and the normal content, for example, the binder may be about 1 to 5% by mass, and the solvent (or water) may be about 10 to 50% by mass.

  The dielectric paste may contain additives selected from various dispersants, plasticizers, dielectrics, glass frit, insulators and the like as required. However, the total content of these is preferably 10% by mass or less. When a butyral resin is used as the binder resin, the plasticizer preferably has a content of 25 to 100 parts by mass with respect to 100 parts by mass of the binder resin. If the amount of the plasticizer is too small, the green sheet tends to be brittle. If the amount is too large, the plasticizer oozes out and is difficult to handle.

  Then, by using this dielectric paste, it is preferably 0.5 to 30 μm, more preferably 0 on the carrier sheet 30 as the second support sheet, as shown in FIG. The green sheet 10a is formed with a thickness of about 5 to 10 μm. 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 2 μm or less.

  (2) Separately from the carrier sheet 30 described above, as shown in FIG. 2A, a carrier sheet 20 as a first support sheet is prepared, and a release layer 22 is formed thereon, on which An electrode layer 12a having a predetermined pattern is formed, 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 release layer 22 where the electrode layer 12a is not formed.

  As carrier sheets 20 and 30 (first and second support sheets), for example, a PET film or the like is used, and those coated with silicon or the like are preferable in order to improve 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. 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 of the release layer 22 is preferably less than or equal to 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, a coating method using a wire bar coater or a die coater is preferable. The thickness of the release layer 22 can be adjusted by selecting a wire bar coater having a different wire diameter. That is, in order to reduce the coating thickness of the release layer 22, 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 phthalic acid ester, adipic acid, phosphoric acid 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.

  Although it does not specifically limit as a mold release agent for the peeling layer 22, For example, a paraffin, a wax, silicone oil etc. are illustrated. 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. . However, the content ratio of the binder with respect to the dielectric particles contained in the release layer 22 is preferably about 10 to 50% less than the content ratio of the binder with respect to the dielectric particles contained in the green sheet 10a. This is to weaken the peel strength of the release layer 22.

  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. However, the content ratio of the plasticizer with respect to the binder contained in the release layer 22 is preferably about 10 to 100% higher than the content ratio of the plasticizer with respect to the binder contained in the green sheet 10a. This is to weaken the strength of the release layer 22.

  The release agent is contained in the release layer 22 in an amount of 0 to 100 parts by weight, preferably 2 to 50 parts by weight, particularly 5 to 20 parts by weight with respect to 100 parts by weight of the binder. However, the content ratio of the release agent with respect to the binder contained in the release layer 22 is preferably about 10 to 400% higher than the content ratio of the release agent with respect to the binder contained in the green sheet 10a. This is to weaken the strength of the release layer 22.

  After the release layer 22 is formed on the surface of the carrier sheet 30, as shown in FIG. 2A, an electrode layer 12a that will constitute the internal electrode layer 12 after firing is formed on the surface of the release layer 22 in a predetermined pattern. Form. 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 paste, 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 paste is prepared. The electrode paste 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 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 resin 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). Any known solvents such as terpineol, butyl carbitol, and kerosene can be used as the solvent. 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 content of 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 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.

  After or before the electrode paste 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 is 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, the adhesive layer transfer sheet in which the adhesive layer 28 is formed on the surface of the carrier sheet 26 as the third support sheet, as shown in FIG. prepare. The carrier sheet 26 is composed of a sheet similar to the carrier sheets 20 and 30.

  The adhesive layer 28 includes a binder and a plasticizer. The adhesive layer 28 may contain the same dielectric particles as the dielectric constituting the green sheet 10a. However, in the present embodiment, the release layer 28 is thinned, so that the dielectric particles are not included. Is good.

  The binder for the adhesive layer 28 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 adhesive layer 28 may be the same as or different from the binder contained in the green sheet 10a, but is preferably the same. In particular, acrylic resins and butyral resins are preferred.

  Although it does not specifically limit as a plasticizer for the contact bonding layer 28, For example, a phthalic acid ester, adipic acid, phosphoric acid ester, glycols etc. are illustrated. Of these, phthalic acid esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, and benzylbutyl phthalate are preferred.

  The content of the plasticizer in the adhesive layer 28 is preferably 10 to 100 parts by mass, more preferably 30 to 80 parts by mass with respect to 100 parts by mass of the binder.

  The adhesive layer 28 may further contain an antistatic agent. The antistatic agent includes one of imidazoline surfactants, and the weight-based addition amount of the anti-static agent is preferably equal to or less than the weight-based addition amount of the binder resin. 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.

  In the present embodiment, the adhesive layer 28 is thinned with an average film thickness of preferably 0.02 to 0.2 μm, more preferably 0.02 to 0.1 μm. In addition, this average thickness averages the thickness of the coating | coated part demonstrated later and the thickness of a non-coating part (repelling part) according to the abundance ratio.

  If the thickness of the adhesive layer 28 is too thin, the adhesive force is reduced, and the effect of forming the adhesive layer cannot be obtained. On the other hand, if it is too thick, depending on the thickness of the adhesive layer, gaps are likely to be formed inside the element body after sintering, causing delamination, and the capacitance of the volume tends to decrease significantly. is there.

  The adhesive layer 28 is formed on the surface of the carrier sheet 26 as the third support sheet by the following method. That is, first, using the adhesive layer paste, an adhesive layer paste film is formed on the surface of the carrier sheet 26 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. Next, the adhesive layer paste film is dried to form an adhesive layer 28. In addition, it does not specifically limit as a solvent contained in the paste for contact bonding layers, For example, the thing similar to the above-mentioned dielectric paste can be used.

  Next, the adhesive layer 28 formed on the surface of the carrier sheet 26 is transferred to the surfaces of the electrode layer 12a and the blank pattern layer 24 by a transfer method. 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 as shown in FIG. By peeling off the carrier sheet 26, the adhesive layer 28 is transferred to the surfaces of the electrode layer 12a and the blank pattern layer 24 as shown in FIG. The transfer of the adhesive layer 28 may be performed on the surface of the green sheet 10a shown in FIG. 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.

  In the present embodiment, the drying process conditions when drying the adhesive layer paste film formed on the carrier sheet 26 are set as predetermined conditions. That is, the drying temperature is over 80 ° C. and 160 ° C. or less, preferably 120 to 140 ° C., and the coverage of the adhesive layer on the carrier sheet 26 is 5% to 50%, preferably 10 to 30%. Assuming that there is no non-covered part (repellent part) where the component constituting the adhesive layer is not substantially present, the covering ratio is 100% as the ideal area where the adhesive layer covers the PET film, It is defined by the ratio of the area where the adhesive layer actually covers the carrier sheet 26. In addition, although drying time is not specifically limited, It is preferable to set it as 1 to 10 minutes.

  Further, the adhesive layer 28 is then transferred from the carrier sheet 26 to the surfaces of the electrode layer 12a and the blank pattern layer 24. In this embodiment, the adhesive layer 28 is transferred to the electrode layer 12a and the blank pattern layer. When transferring to 24, transfer conditions are set so that transfer is performed while maintaining the above-mentioned coverage. Therefore, the coverage of the adhesive layer 28 to the carrier sheet 26 is substantially equal to the coverage of the adhesive layer 28 to the electrode layer 12a and the blank pattern layer 24.

  When the adhesive layer 28 is formed, the plasticizer contained in the adhesive layer oozes out on the surface of the adhesive layer by performing a drying treatment under the above conditions, and the oozed plasticizer is a tackifier. The adhesiveness of the adhesive layer 28 can be improved. Therefore, according to this embodiment, even when the average film thickness of the adhesive layer 28 is reduced as described above, the adhesiveness of the adhesive layer 28 can be kept high. If the drying temperature is too low, such an effect cannot be obtained. On the other hand, if the drying temperature is too high, the carrier sheet 26 is thermally deformed and a transferable adhesive layer cannot be obtained. Further, if the coverage is too low or too high, the adhesiveness is lowered, and the transfer interface between the electrode layer 12a and the green sheet 10a is removed when the carrier sheet 20 is peeled after forming the laminated unit. It breaks. And this becomes a sheet defect and causes a short circuit defect, and many delaminations occur after sintering.

  Further, the adhesive layer 28 has a covered portion that actually covers the surfaces of the electrode layer 12a and the blank pattern layer 24 (or the carrier sheet 26) and an uncovered portion that is not substantially covered. is doing. In the uncovered portion, there are substantially no components (binder resin, plasticizer, etc.) constituting the adhesive layer, and the actual thickness is almost zero. The uncovered portion is a repellant portion formed by the plasticizer oozing out on the surface of the adhesive layer 28, and usually has a circular shape.

  In addition, the ratio of these coating | coated parts and a non-coating part (repellency part) is deeply related with the coverage mentioned above. That is, for example, when the coverage is 30%, in the adhesive layer 28, the area ratio of the covered portion is 30%, and the area ratio of the uncovered portion (repellent portion) is 70%.

  In the present embodiment, the diameter of the maximum non-covered portion (maximum repellant portion) having the maximum diameter among the non-covered portions (repellent portions) is preferably 80 μm or less, more preferably 50 μm or less. If the diameter of the maximum repellency portion is too large, the adhesiveness of the adhesive layer 28 tends to decrease.

  Further, the thickness of the covering portion is preferably in the range of 0.05 to 4 μm, more preferably in the range of 0.1 to 2 μm. The coated portion is a portion formed by repelling the components present in the non-coated portion (repellent portion) before the drying process toward the coated portion side. Therefore, the thickness of the covering portion tends to be thicker than the above average film thickness (preferably 0.02 to 0.2 μm, more preferably 0.02 to 0.1 μm).

  (4) Thereafter, the electrode layer 12a is bonded to the surface of the green sheet 10a formed on the surface of the carrier sheet 30 shown in FIG. For that purpose, as shown in FIG. 3B, the electrode layer 12a and the blank pattern layer 24 of the carrier sheet 20 are pressed together with the carrier sheet 20 onto the surface of the green sheet 10a via the adhesive layer 28, and heated and pressurized. 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.

  Next, 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, and the green sheet 10a, the electrode layer 12a, and the blank pattern layer are transferred. A laminate unit consisting of 24 is obtained. Thereafter, as shown in FIG. 5A, the laminate unit and the base material 40 are supported via the adhesive layer 28 formed on the surface of the green sheet 10a in a state where the base material 40 is supported by the suction holding base 50. Glue and laminate. In addition, lamination | stacking with a laminated body unit and the base material 40 is performed by press. Thereafter, as shown in FIG. 5 (B), the upper carrier sheet 20 is peeled off, and another laminate unit is laminated as shown in FIG. 5 (C). Then, the steps shown in FIGS. 5B and 5C are repeated to obtain a stacked body having a desired number of stacked layers. In addition, although it does not specifically limit as the base material 40, For example, the green sheet for outer layers (The thick laminated body which laminated | stacked the multilayered green sheet in which the electrode layer is not formed) etc. can be used.

  (5) Then, this laminated body is finally pressurized. The pressure at the time of final pressurization is preferably 10 to 200 MPa. Moreover, 40-100 degreeC is preferable for heating temperature. 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.

In the heat treatment after such firing is performed, the holding temperature or the maximum temperature is preferably 1000 ° C. or higher, more preferably 1000 to 1100 ° C. If the holding temperature or maximum temperature during the 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, reoxidation of the dielectric layer 2 is difficult, 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, in particular 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 baking to perform baking, and then cooled to reach the heat treatment holding temperature. Sometimes it is preferable to perform heat treatment by changing the atmosphere. 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 Preferably, 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, sand plast, etc., and terminal electrode paste 6 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 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 according to the present embodiment, the dry-type electrode layer 12a can be easily and accurately transferred to the surface of the green sheet 10a without breaking or deforming the green sheet 10a. Is possible.

  In particular, 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 stacked, and the occurrence of short-circuit defects and the like can be effectively prevented. it can.

  In addition, in the present embodiment, when the adhesive layer 28 is formed, the drying process is performed under the predetermined conditions described above. Therefore, by this drying treatment, the plasticizer contained in the adhesive layer oozes out to the surface of the adhesive layer, and the oozed plasticizer serves as a tackifier and improves the adhesiveness of the adhesive layer 28. be able to. As a result, according to the present embodiment, even when the average film thickness of the adhesive layer 28 is reduced as described above, sufficient adhesiveness can be ensured, and further, by reducing the adhesive layer 28. In the binder removal step, the binder resin contained in the adhesive layer 28 does not remain without being decomposed, so that the delamination phenomenon due to the formation of the adhesive layer 28 can be effectively prevented.

  In the past, the drying treatment temperature when forming the adhesive layer was set to a relatively low temperature, and an adhesive layer having high smoothness was formed. Therefore, when the adhesive layer is thinned, there is a problem that the adhesiveness is lowered. On the other hand, in the present embodiment, the drying treatment temperature when forming the adhesive layer 28 is set to a relatively high temperature, and the plasticizer contained in the adhesive layer 28 is oozed out. The conventional problem is solved by reducing the smoothness.

  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 formed by a transfer method, the components of the adhesive layer 28 do not soak into the electrode layer 12a or the green sheet 10a, and an extremely thin adhesive layer 28 can be formed. . Therefore, for example, the average film thickness of the adhesive layer 28 can be reduced to 0.02 to 0.2 μm. Even if the thickness of the adhesive layer 28 is thin, the components of the adhesive layer 28 do not soak into the electrode layer 12a or the green sheet 10a. Therefore, the adhesive force is sufficient, and the composition of the electrode layer 12a or the green sheet 10a is adversely affected. There is no risk of giving.

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.

  In the above-described embodiment, the method of forming the adhesive layer 28 by the transfer method is exemplified. However, a method of forming the adhesive layer 28 directly on the surface of the electrode layer 12a or the green sheet 10a by a coating method or the like is adopted. May be.

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

Example 1
In Example 1, sample numbers 1 to 9 shown in Table 1 (samples in which the drying conditions when forming the adhesive layer were changed) were prepared.
First, the following pastes were prepared.

Dielectric paste (green sheet and blank pattern paste)
BaTiO ₃ powder (BT-02 / Sakai Chemical Industry Co., Ltd.), MgCO ₃ , MnCO ₃ , (Ba _0.6 Ca _0.4 ) SiO ₃ and rare earths (Gd ₂ O ₃ , Tb ₄ O ₇ , Dy ₂ A powder selected from O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Tm ₂ O ₃ , Yb ₂ O ₃ , Lu ₂ O ₃ , Y ₂ O ₃ ) with a ball mill for 16 hours. A dielectric material was obtained by drying. These raw material powders had an average particle size of 0.1 to 1 μm.

(Ba _0.6 Ca _0.4 ) SiO ₃ was obtained by wet-mixing BaCO ₃ , CaCO ₃ and SiO ₂ with a ball mill for 16 hours, and firing in air at 1150 ° C. after drying using a ball mill. It was produced by wet milling for a period of time.

  Next, in order to paste the dielectric material, an organic vehicle was added to the dielectric material and mixed with a ball mill to obtain a dielectric green sheet paste. The organic vehicle is based on 100 parts by weight of the dielectric material, polyvinyl butyral: 6 parts by weight as a binder, bis (2-ethylhexyl) phthalate (DOP): 3 parts by weight, ethanol: 78 parts by weight, propanol: The mixing ratio is 78 parts by mass, xylene: 14 parts by mass, and paraffin as a release agent: 0.5 parts by mass.

Release Layer Paste A release layer paste was prepared by diluting the dielectric green sheet paste with ethanol / toluene (55/10) twice by weight.

Butylal resin as adhesive layer paste binder: 100 parts by weight, methyl ethyl ketone as solvent: 900 parts by weight, bis (2-ethylhexyl) phthalate as plasticizer: 50 parts by weight, stirring and dissolving paste for adhesive layer Was made.

Internal electrode paste (transferred electrode layer paste)
Next, it knead | mixed with three rolls with the compounding ratio shown below, and was made into the slurry, and was set as the paste for internal electrodes. That is, for 100 parts by mass of Ni particles having an average particle diameter of 0.4 μm, 40 parts by mass of organic vehicle (8 parts by mass of ethyl cellulose resin as a binder dissolved in 92 parts by mass of terpineol) and 10 parts by mass of terpineol were added. The mixture was kneaded with three rolls and slurried to obtain an internal electrode paste.

Formation of Adhesive Layer An adhesive layer 28 was formed on the PET film (third support sheet) by the following method. That is, first, using the above-mentioned adhesive layer paste, a wire bar coater is used to form an adhesive layer paste film. Thereafter, the adhesive layer paste film is dried at temperatures shown in Table 1 and drying time: 1 minute. It dried on the conditions of. In this example, the adhesive layers (sample numbers 1 to 9) were formed so that the average film thickness after drying was 0.05 μm. About the obtained adhesive layer 28, the coverage of the PET film surface, the diameter of the maximum uncoated portion (maximum repellency portion), and the thickness of the coated portion were measured by the method described later.

Production of Laminate Unit First, a green sheet having a thickness of 1.0 μm was formed on a PET film (second support sheet) using the above-described paste for green sheets, using a wire bar coater. Next, in order to form a release layer on another PET film (first support sheet), the above release layer paste is applied and dried with a wire bar coater to form a 0.2 μm release layer. did.

  Next, the electrode layer 12a and the blank pattern layer 24 were formed on the surface of the release layer. The electrode layer 12a was formed with a thickness of 1.2 μm by a printing method using the above internal electrode paste. The blank pattern layer 24 was formed with a thickness of 1.2 μm by a printing method using the above green sheet paste.

  Next, the adhesive layer 28 formed on the PET film (third support sheet) was transferred onto the surfaces of the electrode layer 12a and the blank pattern layer 24 by the method shown in FIG. At the time of transfer, a pair of rolls were used, the pressure was 1 MPa, and the temperature was 80 ° C.

  Next, the internal electrode layer 12a and the blank pattern layer 24 were adhered (transferred) to the surface of the green sheet 10a via the adhesive layer 28 by the method shown in FIGS. 3 (A) and 3 (B). At the time of transfer, a pair of rolls were used, the pressure was 1 MPa, and the temperature was 80 ° C.

  Next, the PET film (second support sheet) is peeled from the surface of the green sheet 10a by the method shown in FIG. 3 (C), and the surface of the green sheet 10a is removed by the method shown in FIGS. 4 (A) to 4 (C). The adhesive layer 28 was transferred to a laminate unit sample (sample numbers 1 to 9) as shown in FIG. About the obtained lamination | stacking unit, the presence or absence of the fracture | rupture at the time of peeling stack | stuck strength and PET film as a 1st support sheet from a lamination | stacking unit was confirmed with the method demonstrated later by the following method.

Production of Green Chip Next, a plurality of the laminated units produced above were prepared , and a plurality of laminated units were laminated so as to obtain desired characteristics. Then, on the top and bottom, a plurality of outer layer green sheets molded to a thickness of 10 μm are stacked so that the thickness when stacked is about 50 μm, and the outer layer that becomes the lid portion (cover layer) of the multilayer capacitor after firing Formed. The obtained laminate was press-molded under conditions of 100 MPa and 70 ° C., and then cut by a dicing machine to obtain a green chip before firing.

Production of sintered body Next, the final laminate was cut into a predetermined size and subjected to binder removal processing, firing and annealing (heat treatment) to produce a chip-shaped sintered body.

The binder removal was performed at a temperature rising rate: 50 ° C./hour, a holding temperature: 240 ° C., a holding time: 8 hours, and an atmospheric gas: in the air. Firing is carried out by heating at a heating rate of 300 ° C./hour, a holding temperature of 1200 ° C., a holding time of 2 hours, a cooling rate of 300 ° C./hour, and an atmosphere gas of N ₂ gas and H ₂ (5 %) And mixed gas. Annealing (reoxidation) was performed with a holding time: 3 hours, a cooling rate: 300 ° C./hour, and an atmosphere gas: N ₂ gas controlled to a dew point of 20 ° C. The atmosphere gas was humidified using a wetter at a water temperature of 0 to 75 ° C.

  Next, after polishing the end surface of the chip-shaped sintered body with sand blasting, an In-Ga alloy paste is applied to the end portion, and then firing is performed to form an external electrode. A sample of a multilayer ceramic capacitor was obtained. About the obtained capacitor | condenser sample (sample number 1-9), the short-circuit defect rate and the generation | occurrence | production number of delamination were measured by the method demonstrated later.

To determine the coverage of the adhesive layer, the diameter of the maximum uncovered portion (maximum repellency portion), the thickness of the coated portion, the coverage of the adhesive layer was first obtained by taking a metal micrograph on the surface of the adhesive layer 28 formed on the PET film. The coverage of the adhesive layer was measured using the obtained metal micrograph. Specifically, when it is assumed that the adhesive layer has no uncovered portion (repellent portion) where the component constituting the adhesive layer is not substantially present, the ideal area where the adhesive layer covers the PET film Was calculated by calculating the ratio of the area of the covering portion where the components constituting the adhesive layer substantially exist. For the coverage, 10 metal micrographs measured for a visual field of 30 μm × 30 μm were used, and the area ratio was determined by binarization of the coated portion and the uncoated portion of the adhesive layer using image processing. The results are shown in Table 1.

  The diameter of the maximum uncovered portion (maximum repellency portion) is the maximum uncovered portion having the largest diameter among the non-covered portions (repellent portions) existing in the adhesive layer using the metal micrograph obtained above. The diameter of the part was taken as the diameter of the largest uncovered part (maximum repellency part). The measurement was performed using 10 metal micrographs measured for a visual field of 30 μm × 30 μm.

  The thickness of the covering portion was determined by dividing the average thickness (0.05 μm) of the adhesive layer by the coverage of the adhesive layer determined above.

  In this example, for the adhesive layer 28 formed on the PET film, the coverage of the adhesive layer, the size of the maximum uncovered portion (maximum repellency portion), and the thickness of the covered portion were determined. The same result was obtained when the adhesive layer 28 formed on was transferred to the electrode layer 12a and the green sheet 10a.

  6A to 6C show metal micrographs of the adhesive layer taken as described above. Here, FIG. 6A is a metal micrograph of sample number 6 with a drying temperature of 120 ° C., and FIG. 6B is a metal micrograph of sample number 1 with a drying temperature of 40 ° C. FIG. 6C is a metallographic micrograph of Sample No. 3 with a drying temperature of 60 ° C.

Measurement of stack strength Stack strength (unit: N / cm ² ) was evaluated as follows. That is, a double-sided tape was affixed to the surface of the laminated unit sample having the configuration shown in FIG. 4C prepared above, and the sheet was pulled and peeled using the Instron 5543 tensile tester. The peel strength at the time was measured, and the peel strength at this time was defined as the stack strength. The higher the stack strength, the better the adhesion. The results are shown in Table 1.

Presence or absence of breakage at the time of peeling The presence or absence of breakage at the time of peeling was evaluated as follows. First, when the PET film 20 as the first support sheet was peeled from the laminated unit sample having the configuration shown in FIG. 4C prepared above, the surface of the peeled PET film 20 was observed, and the PET It was confirmed whether the electrode layer 12a or the blank pattern layer 24 remained on the surface of the film 20. When the fracture occurred at the interface between the electrode layer 12a and the green sheet 10a and the electrode layer 12a or the blank pattern layer 24 remained on the surface of the PET film 20, the fracture was considered. The results are shown in Table 1. In this example, the above peeling and observation were performed on 100 samples, and when there was even one sample in which the remaining electrode layer 12a or blank pattern layer 24 was confirmed, it was evaluated as impossible. Indicated by "x". On the other hand, when the remaining of the electrode layer 12a was not confirmed, it was judged to be good, and indicated by “◯” in Table 1.

Short defect rate The short defect rate was determined by applying a voltage of 1 Vrms to the capacitor sample and measuring the resistance value using an insulation resistance meter. Specifically, measurement was performed on 100 capacitor samples, a sample having a resistance value of 10Ω or less was defined as a short defect sample, and the ratio of the short defect sample to the total measurement sample was defined as a short defect rate. The results are shown in Table 1.

Number of delaminations First, the obtained capacitor sample was cut in a direction perpendicular to the internal electrode layer. Next, this cut surface was observed to confirm whether or not a delamination phenomenon occurred. In this example, 200 samples were inspected. The results are shown in Table 1.

Example 2
The content of butyral resin contained in the adhesive layer paste is 250 parts by mass and 400 parts by mass, respectively, and the average film thickness of the adhesive layer is 0.2 μm (sample number 10 in Table 1) and 0.3 μm (Table 1), respectively. Each sample was prepared in the same manner as in Example 1 except that the drying temperature of the adhesive layer was set to 85 ° C. and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Sample numbers 1 to 3 in which the average film thickness of the evaluation adhesive layer was 0.05 μm, and the drying temperatures when forming the adhesive layer were 40 ° C., 60 ° C., and 80 ° C., respectively, had a coating rate of the adhesive layer. Greater than 50%. And these sample numbers 1 to 3 have a stack strength of less than 40 N / cm ^2, and the fracture at the time of peeling was confirmed. As a result, the inferior short-circuit defect rate and the number of occurrences of delamination were increased. . Therefore, these sample numbers 1 to 3 were evaluated as “× (defect)”.

On the other hand, in Sample Nos. 4 to 8, in which the average film thickness of the adhesive layer was 0.05 μm and the drying temperature when forming the adhesive layer was in the range of 90 to 160 ° C., respectively, the coverage of the adhesive layer was 50 % Or less. And these sample numbers 4-8 became stack strength 40N / cm < ² > or more, the fracture | rupture at the time of peeling was not confirmed, as a result, the short-circuit defect rate was low, and also the generation | occurrence | production number of delamination was reduced. . In particular, among these sample numbers 4 to 8, sample numbers 6 and 7 were evaluated as “（(very good)” because the short-circuit defect rate was 0% and the number of delaminations was extremely small. About other than that, it evaluated as "(good)."

  In Sample No. 9 where the drying temperature when forming the adhesive layer was 170 ° C., the support sheet was deformed, and a transferable adhesive layer could not be obtained.

  In addition, from the results of Sample Nos. 10 and 11 in which the average thickness of the adhesive layer was increased to 0.2 μm and 0.3 μm, respectively, when the thickness of the adhesive layer is increased, the stack strength is increased while the short-circuit defect rate is deteriorated. It can be confirmed that the number of delaminations increases with the progress. Sample No. 10 having an average film thickness of 0.2 μm was evaluated as “◯” because the short-circuit defect rate was low and the number of delaminations was small. On the other hand, Sample No. 11 with an average film thickness of 0.3 μm was evaluated as “x” because the short-circuit defect rate was 100% and the number of delaminations was increased.

  Further, FIGS. 6A to 6C show metal micrographs of the adhesive layer. Here, FIG. 6A is a metal micrograph of sample number 6 with a drying temperature of 120 ° C., and FIG. 6B is a metal micrograph of sample number 1 with a drying temperature of 40 ° C. FIG. 6C is a metallographic micrograph of Sample No. 3 with a drying temperature of 60 ° C. From these photographs, it is possible to change the surface state of the adhesive layer by changing the conditions of the drying treatment. From the above results, the surface state of the adhesive layer is configured as shown in FIG. It can be confirmed that this is preferable. In FIGS. 6A to 6C, the white portion is the portion where the constituent component of the release layer is present (covered portion), while the black portion is substantially the constituent component of the release layer. This is a part that does not exist (uncoated part).

FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. 2 (A) to 2 (C) are cross-sectional views showing the main part of the electrode layer transfer method. FIG. 3A to FIG. 3C are cross-sectional views of relevant parts showing a step subsequent to FIG. 4 (A) to 4 (C) are cross-sectional views illustrating the main part of a method for laminating green sheets to which electrode layers are bonded. FIG. 5A to FIG. 5C are cross-sectional views of relevant parts showing a method for stacking stacked body units. FIG. 6A is a surface photograph of an adhesive layer according to an example of the present invention, and FIGS. 6B and 6C are surface photographs of an adhesive layer according to a comparative example.

Explanation of symbols

2 ... Multilayer ceramic capacitor 4 ... Capacitor body 6, 8 ... Terminal electrode 10 ... Dielectric layer 10a ... Green sheet 12 ... Internal electrode layer 12a ... Electrode layer 20 ... Carrier sheet (first support sheet)
22 ... Release layer 24 ... Blank pattern layer 26 ... Carrier sheet (third support sheet)
28 ... Adhesive layer 30 ... Carrier sheet (second support sheet)
40 ... Base material 50 ... Suction holding stand

Claims (8)

Forming an adhesive layer containing a binder resin and a plasticizer on the surface of the electrode layer or the green sheet;
A step of laminating an electrode layer and a green sheet through the adhesive layer to form a green chip;
A step of firing the green chip, comprising the steps of:
The adhesive layer, the binder resin, the plasticizer and paste film adhesive layer formed using the adhesive layer paste contains a solvent, is formed by drying at a temperature of eighty-five to one hundred sixty ° C.,
The drying is performed so that the covering ratio, which is the ratio of the area actually covering the electrode layer or the green sheet on which the adhesive layer is formed on the surface, is 5% to 50%. Done
A method for manufacturing a multilayer electronic component, wherein an average film thickness of the adhesive layer is in a range of 0.05 to 0.2 μm . 2. The method of manufacturing a multilayer electronic component according to claim 1, wherein the adhesive layer is first formed on the surface of the support sheet so as to be peelable, and is pressed and transferred to the surface of the electrode layer or the surface of the green sheet. The adhesive layer has a covering part that actually covers the electrode layer or the green sheet on which the adhesive layer is formed, and an uncovered part that is not substantially covered,
3. The method for manufacturing a multilayer electronic component according to claim 1, wherein a diameter of a maximum uncovered portion having a maximum diameter among the uncovered portions is 80 μm or less. The adhesive layer has a covering part that actually covers the electrode layer or the green sheet on which the adhesive layer is formed, and an uncovered part that is not substantially covered,
The thickness of the coating portion, the multilayer method for manufacturing the electronic component according to any of claims 1 to 3 in the range of 0.10～1.0Myuemu. Wherein the binder resin contained in the adhesive layer, the manufacturing method of the multilayer electronic component according to any one to claims 1-4 containing one or more selected from acrylic resin and butyral resin. The content of the plasticizer, relative to the binder resin 100 parts by weight, the multilayer method for manufacturing the electronic component according to any one of claims 1 to 5, 10 to 100 parts by weight of the adhesive layer. Method of manufacturing a multilayer electronic component according to any of claims 1-6 plasticizer is phthalate ester contained in the adhesive layer. The thickness of the green sheet is stacked method of manufacturing an electronic component according to any one of claims 1 to 7 at 2μm or less.