JP2006013246A - Method for manufacturing multilayer electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer electronic component, such as a multilayer ceramic capacitor having low costs, that has high stacking properties (adhesion properties in lamination), can form an electrode layer appropriately and precisely, and can reduce nonadhesion defects (nonlamination) and short-circuiting fraction defective. <P>SOLUTION: The method for manufacturing the multilayer electronic component contains a process for forming a separation layer containing low-viscosity resin on a support sheet before forming the electrode layer on the support sheet; and a process for forming an adhesive layer on a surface at the side of an opposite electrode layer of a green sheet for laminating the green sheet having the electrode layer via the adhesive layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a multilayer electronic component such as a multilayer ceramic capacitor. More specifically, even when the green sheet is extremely thin, the stackability (adhesiveness at the time of lamination) is high, and the solvent in the paint is less Effectively prevent the cause of sheet attack, the electrode layer can be formed with good and high accuracy, non-adhesion defects (non-lamination) and short defect rate can be reduced, and the cost is low The present invention relates to a method for manufacturing a mold electronic component.

  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 increase the capacity of this multilayer ceramic capacitor, there has been a strong demand for a thinner dielectric layer. Recently, the thickness of the dielectric green sheet that forms the dielectric layer after firing is increased. Is also thinned to several μm or less.

  In order to produce a dielectric green sheet, first, a green sheet paint comprising a dielectric powder, a binder, a plasticizer and an organic solvent (toluene, alcohol, MEK, etc.) is first prepared. Next, this green sheet paint is applied on a carrier film such as PET by the doctor blade method or the like and dried.

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

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

  However, when the internal electrode paste is directly printed on the green sheet, the solvent in the internal electrode paste soaks into the green sheet, and a so-called sheet attack occurs. The sheet attack due to the penetration of the solvent often causes a pinhole in the green sheet and often causes a short circuit failure. In particular, when the dielectric green sheet is formed very thin, the effect of this sheet attack becomes significant, and it is difficult to reduce the interlayer thickness of the sheet.

  On the other hand, in the following Patent Documents 1 to 4, 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 onto the surface of each dielectric green sheet or the surface of a laminate of dielectric green sheets.

  However, with the techniques shown in Patent Documents 1 to 4, it is extremely difficult to adhere the electrode pattern layer to the surface of the green sheet and transfer it with high accuracy, especially when the thickness of the green sheet is thin. In the transfer process, there is a problem that the dielectric green sheet is partially damaged and a short circuit occurs. Furthermore, as in the above Patent Documents 1 to 4, when the green sheet on which the electrode pattern layer is formed is directly laminated, the adhesive force between the internal electrode forming surface and the green sheet surface becomes insufficient, resulting in poor adhesion. There was also a problem that it occurred.

  Alternatively, in order to solve the above-described sheet attack problem, an electrode layer is directly formed on a support sheet such as a PET film by a printing method using an internal electrode paste, and a green sheet is formed on the surface of the electrode layer. A method to do this has also been proposed. However, in this case, since the internal electrode paste is directly printed on the support sheet, there has been a problem that a defect of the electrode layer due to the repelling of the paste occurs or a peeling failure occurs.

  In order to solve the problem of adhesion failure and short circuit failure, for example, in Patent Documents 5 to 7, a green sheet having a structure in which upper and lower surfaces are sandwiched between green sheet layers is formed as a green sheet having an internal electrode pattern. And the method of laminating | stacking this green sheet is disclosed. In the methods described in these documents, for example, green sheet layers that are about half the desired thickness are bonded to each other to obtain a desired thickness (a thickness corresponding to one layer). According to this method, since the green sheet layers are bonded to each other when they are stacked, it is possible to improve the adhesion between the sheets and reduce short-circuit defects caused by pinholes. . However, in this method, since the green sheet layer needs to be about half the desired thickness, that is, extremely thin, it is difficult to cope with further thinning of the green sheet.

  Further, Patent Documents 8 to 13 disclose a method of laminating using a green sheet formed by stacking two or more green sheet layers as a green sheet having an internal electrode pattern. According to these documents, it is described that the occurrence of short circuit defects and delamination can be suppressed. However, in the methods described in these documents, it is necessary to make each green sheet layer thinner in order to make the green sheet itself thinner, so it is difficult to cope with further thinning of the green sheet. Met.

  In particular, these documents use a green sheet in which two or more green sheet layers having a thickness of about several μm are stacked. That is, in Patent Documents 5 and 6, there are 2-3 green sheet layers of about 2 to 3 μm, in Patent Documents 7 and 8, two green sheet layers of about 6 to 7 μm are used, and in Patent Documents 9 and 10, 3 to 3. A green sheet layer of about 4 μm and a green sheet layer of about 0.6 to 1 μm are overlaid. Therefore, in these documents, it is difficult to cope with thinning.

JP-A-63-51616 Japanese Patent Laid-Open No. 3-250612 JP-A-5-159966 Japanese Patent Laid-Open No. 7-31326 JP 7-297073 A JP 2004-103983 A Japanese Patent Laid-Open No. 2004-119802 Japanese Patent Laid-Open No. 10-50552 Japanese Patent Laid-Open No. 11-144992 JP-A-8-37128 JP-A-5-101970 JP 2003-264120 A JP 2003-272947 A

  The present invention has been made in view of such a situation, and even when the green sheet is extremely thin, the stackability (adhesiveness at the time of lamination) is high, and the sheet attack due to the solvent contained in the paint is effectively prevented. Production of multilayer electronic components such as multilayer ceramic capacitors that can form electrode layers well and with high precision, reduce non-adhesion defects (non-lamination) and short-circuit defect rate, and are inexpensive. It aims to provide a method.

  As a result of intensive studies to achieve the above object, the present inventor, before forming the electrode layer on the support sheet, a step of forming a release layer containing a resin having low adhesive force on the support sheet; The object of the present invention is achieved by forming an adhesive layer on the surface opposite to the electrode layer of the green sheet having the electrode layer and laminating the green sheet having the electrode layer via the adhesive layer. As a result, the present invention has been completed.

That is, the manufacturing method of the multilayer electronic component of the present invention includes:
Forming an electrode layer on the first support sheet;
Forming a green sheet on the surface of the electrode layer to obtain a green sheet having an electrode layer;
Laminating a green sheet having the electrode layer to form a green chip;
A step of firing the green chip, comprising the steps of:
Forming the electrode layer on the first support sheet through a release layer containing a resin having low adhesive strength; and
Before laminating the green sheet having the electrode layer, an adhesive layer is formed on the surface of the green sheet having the electrode layer on the counter electrode layer side,
A green sheet having the electrode layer is laminated through the adhesive layer.

  In the production method of the present invention, an adhesive layer is formed on the surface of the green sheet having the electrode layer on the side opposite to the electrode layer, and the green sheet having the electrode layer is laminated through the adhesive layer to form a green chip. Therefore, stackability (adhesiveness at the time of lamination) can be improved, and non-adhesion defects (non-lamination) and poor adhesion can be prevented. Furthermore, when laminating, high pressure and heat are not required, and adhesion at a lower pressure and lower temperature is possible. Even when the green sheet is extremely thin, the green sheet is not destroyed and can be laminated well. it can.

  Moreover, in the present invention, first, an electrode layer is formed on the first support sheet, and then a green sheet is formed on the surface of the electrode layer, thereby manufacturing a green sheet having the electrode layer. Therefore, when directly printing the internal electrode paste on the green sheet, it is possible to effectively prevent solvent penetration (sheet attack) into the green sheet, which has been particularly problematic, and to reduce the short-circuit defect rate. It becomes possible. Further, since the penetration of the solvent can be prevented, there is no possibility of adversely affecting the composition of the electrode layer or the green sheet.

  Furthermore, in this invention, formation on the 1st support sheet of an electrode layer is performed through the peeling layer containing resin with low adhesive force. Therefore, electrode repelling can be effectively prevented, and the electrode layer can be formed satisfactorily and with high accuracy. Further, by forming the release layer, the peel strength between the electrode layer and the first support sheet can be lowered, and the first support sheet can be peeled favorably from the electrode layer. The electrode layer is not damaged during peeling. In the present invention, “electrode repellency” means that when an electrode layer is formed on a support sheet by, for example, a printing method using an electrode paste, the electrode paste is repelled from the support sheet. Cannot be formed satisfactorily or with high accuracy.

  In the present invention, the green sheet can be formed on the surface of the electrode layer without using an adhesive layer. Examples of the green sheet forming method include a thick film forming method such as a coating method using a dielectric paste, or a thin film method such as vapor deposition and sputtering. In particular, the green sheet is formed by a die coating method using a die coater. It is preferable to do. When the green sheet is formed on the surface of the electrode layer without using an adhesive layer, the manufacturing process can be simplified and the manufacturing cost can be reduced. Moreover, in the present invention, even in that case, since the green sheets having the electrode layers are stacked via the adhesive layer, the stackability (adhesiveness at the time of stacking) can be kept high.

Preferably, the adhesive layer has a thickness of 0.02 to 0.3 μm, more preferably 0.05 to 0.2 μm.
In the present invention, it is preferable that the thickness of the adhesive layer is in the above range from the viewpoint of preventing delamination and cracking. When the thickness of the adhesive layer is too thin, the thickness of the adhesive layer becomes smaller than the unevenness of the green sheet surface, and the adhesiveness tends to be remarkably lowered. In addition, 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 starting point of crack generation or the electrostatic capacity corresponding to the volume It tends to decrease significantly. Further, when an adhesive layer thicker than the average particle diameter of the dielectric particles contained in the green sheet is formed, a gap is easily formed inside the element body after sintering depending on the thickness of the adhesive layer, There is a tendency for the capacitance to decrease significantly.

  Preferably, the thickness of the green sheet is 1.5 μm or less, and the thickness of the adhesive layer is 1/10 or less of the thickness of the green sheet. Preferably, the electrode layer has a thickness of 1.5 μm or less. According to the present invention, even when the green sheet and the electrode layer are thinned to the above thickness, the stackability is high, and the non-adhesion defect and the short-circuit defect rate can be reduced.

  Furthermore, in this invention, it is preferable that the total thickness of the said green sheet and the said electrode layer shall be 3.0 micrometers or less. The present invention is particularly effective when the thickness of the green sheet and the electrode layer is within the above range.

  In the present invention, the thickness of the adhesive layer, the green sheet, and the electrode layer means the thickness when dried.

  Preferably, the green sheet includes dielectric particles mainly composed of barium titanate, and the average particle size of the dielectric particles is 0.3 μm or less. If the average particle size of the dielectric particles is too large, it tends to be difficult to form a thin green sheet.

  Preferably, the green sheet includes an acrylic resin and / or a butyral resin as a binder. In the case of forming a thin green sheet, by using such a binder, a green sheet having sufficient strength can be formed even if it is thin.

  Preferably, the adhesive layer includes an organic polymer material substantially the same as the binder included in the green sheet. This is because the binder is removed from the chip by a binder removal process under the same conditions when the green chip is removed.

  Preferably, the adhesive layer includes a plasticizer, and the plasticizer is at least one of phthalate ester, glycol, adipic acid, and phosphate ester. By including this kind of plasticizer in a predetermined amount, good adhesiveness can be exhibited.

  Preferably, the adhesive layer includes an antistatic agent, and the antistatic agent includes one of imidazoline-based surfactants, and the weight-based addition amount of the antistatic agent is the amount of the organic polymer material. It is below the weight basis addition amount. By including a predetermined amount of this type of antistatic agent, an effect of preventing static electricity can be obtained.

  The adhesive layer may include dielectric particles, and the dielectric particles have an average particle diameter equal to or smaller than an average particle diameter of the dielectric particles included in the green sheet, and the dielectric included in the green sheet. It may include a dielectric composition of substantially the same type as the composition. Since the adhesive layer becomes a part of the element body after firing, it is preferable that substantially the same type of dielectric particles as the dielectric particles included in the green sheet are included. In addition, since it is necessary to control the thickness of the adhesive layer, it is preferable that the average particle diameter of the dielectric particles is equal or small.

  Preferably, the weight-based addition ratio of the dielectric particles included in the adhesive layer is less than the weight-based addition ratio of the dielectric particles included in the green sheet. This is for maintaining good adhesion of the adhesive layer.

  The adhesive layer, the electrode layer, and the green sheet may contain a plasticizer together with the binder resin. The plasticizer is preferably contained in an amount of 25 to 100 parts by mass with respect to 100 parts by mass of the binder resin.

  The resin having a low adhesive strength contained in the release layer is not particularly limited. For example, acrylic resin, butyral resin, acetal resin, epoxy resin, polyolefin, polyurethane, polystyrene, urea resin, polyimide, or a combination thereof. A polymer etc. are mentioned. Especially, it is preferable to use 1 type, or 2 or more types chosen from an acrylic resin, a butyral resin, an acetal resin, and an epoxy resin from a viewpoint of low adhesive force and affinity with a support sheet. By using these resins, even when the release layer is thinned, the effect of forming the release layer is sufficiently exhibited.

  Preferably, the thickness of the release layer is 0.02 to 0.2 μm, more preferably 0.02 to 0.1 μm, and still more preferably 0.05 to 0.1 μm. If the thickness of the release layer is too thin, the effect of forming the release layer tends not to be obtained. On the other hand, if the release layer is too thick, the remaining amount of the release layer on the electrode layer side at the time of peeling tends to increase, and the rate of occurrence of cracks at the time of binder removal tends to deteriorate.

  In the present invention, the release layer is preferably peeled off from the electrode layer together with the first support sheet when the first support sheet is peeled from the electrode layer. It doesn't matter. Even in this case, the remaining peeling layer is sufficiently thin as compared with the green sheet or the electrode layer, so that there is no problem.

  In the present invention, for example, by making the adhesive force of the adhesive layer stronger than the adhesive force of the release layer, the first support sheet can be selectively and easily peeled off.

  Preferably, the electrode layer is formed in a predetermined pattern on the surface of the release layer, and a blank pattern layer having substantially the same thickness as the electrode layer is formed on the surface of the release layer where the electrode layer is not formed. The blank pattern layer formed is made of substantially the same material as the green sheet. That is, in the present invention, by forming an electrode layer and a blank pattern layer on the release layer in advance, a predetermined pattern electrode layer and a blank pattern layer having a complementary pattern on the surface of the green sheet are provided. Preferably, it is formed.

  By forming the blank pattern layer in the portion where the electrode layer is not formed, the step on the surface due to the electrode layer having a predetermined pattern is eliminated. Therefore, even if a large number of green sheets are laminated and pressed, the outer surface of the laminate is kept flat, the electrode layer is not displaced in the plane direction, and the electrode layer breaks through the green sheet. Can also be prevented. In the present invention, the blank pattern layer means a dielectric layer formed in a pattern complementary to the electrode layer.

Preferably, before laminating the green sheet having the electrode layer, the first support sheet is peeled from the green sheet having the electrode layer,
With the first support sheet peeled off, the electrode layer side surface of the green sheet having the electrode layer is laminated on another green sheet.

Alternatively, in the state having the first support sheet, the surface of the green sheet having the electrode layer is laminated on another green sheet,
After laminating the green sheet having the electrode layer, it is preferable to peel the first support sheet from the green sheet having the electrode layer.

  In the present invention, the adhesive layer is preferably formed by a transfer method or a coating method.

When forming the adhesive layer by a transfer method,
The adhesive layer is preferably formed on the surface of the second support sheet so as to be peelable first, and is pressed and transferred to the surface of the green sheet having the electrode layer on the side opposite to the electrode layer.

  By forming the adhesive layer by a transfer method, it is possible to effectively prevent the components of the adhesive layer from penetrating into the electrode layer and / or the green sheet. Therefore, there is no possibility of adversely affecting the composition of the electrode layer and / or the green sheet. Furthermore, even when the adhesive layer is formed thin, the adhesiveness can be kept high because the components of the adhesive layer do not penetrate into the electrode layer and / or the green sheet.

Alternatively, when the adhesive layer is formed by a coating method,
The adhesive layer is preferably formed by direct application on the surface of the green sheet having the electrode layer on the side opposite to the electrode layer by a die coating method.

  By forming the adhesive layer by a die coating method using a die coater, it is possible to reduce the amount of PET film used and to form an adhesive layer as compared to the case of forming an adhesive layer by a transfer method. The time required for the process can be shortened, and the lead time and tact time of the process can be improved.

  The multilayer electronic component manufactured by 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 sheets having the electrode layers are laminated through the adhesive layer, even when the green sheets are extremely thin, the stackability (adhesiveness at the time of lamination) is high and non-adhesion defects (non-adhesive defects) It is possible to provide a method for manufacturing a multilayer electronic component such as a multilayer ceramic capacitor that can reduce lamination) and is inexpensive. In addition, in the present invention, since the electrode layer is formed on the first support sheet through a release layer containing a resin having low adhesive strength, electrode repelling can be effectively prevented, and the electrode layer is formed. Can be carried out satisfactorily and with high accuracy.

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.
2 (A) to 2 (C) are main part cross-sectional views showing a method for forming an electrode layer and a green sheet according to an embodiment of the present invention,
3 (A) to 3 (C) are main part cross-sectional views showing a method for forming an adhesive layer according to an embodiment of the present invention,
4 (A) to 4 (C), FIG. 5 (A), FIG. 5 (B), FIG. 6 (A), and FIG. 6 (B) are green sheets having electrode layers according to an embodiment of the present invention. Cross-sectional view of the main part showing the lamination method of
7 (A) to 7 (C) and FIGS. 8 (A) to 8 (C) are principal part cross-sectional views showing a method for laminating green sheets having electrode layers according to another embodiment of the present invention. .

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

  In this embodiment, as will be described in detail later, the internal electrode layer 12 is formed by forming the electrode layer 12a in a predetermined pattern on the carrier sheet 20 via the release layer 22, as shown in FIG. Manufactured.

  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 the present embodiment, the thickness is preferably 3 μm or less, more preferably 1.5 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.
In the present embodiment, first, the peeling layer 22, the electrode layer 12 a, the blank pattern layer 24, and the green sheet 10 a are formed on the carrier sheet 20 by the method shown in FIGS.

First, as shown in FIG. 2A, a release layer 22 is formed on a carrier sheet 20.
As the carrier sheet 20, for example, a PET film or the like is used, and a film coated with a silicon resin or the like is preferable in order to improve peelability. The thickness of the carrier sheet 20 is not particularly limited, but is preferably 5 to 100 μm.

  The release layer 22 contains at least a resin having low adhesive strength as a binder. The release layer 22 may include a plasticizer, a release agent, and a release agent in addition to the binder.

  In the present embodiment, the thickness of the release layer 22 is preferably 0.02 to 0.2 μm, more preferably 0.02 to 0.1 μm, and still more preferably 0.05 to 0.1 μm. If the thickness of the release layer 22 is too thin, the effect of forming the release layer 22 tends not to be obtained. On the other hand, if the release layer 22 is too thick, the amount of the release layer 22 remaining on the electrode layer 12a side at the time of peeling tends to increase, and the crack generation rate at the time of binder removal tends to deteriorate.

  The method for forming the release layer 22 is not particularly limited, but an application method using, for example, a wire bar coater or a die coater is preferable because it needs to be formed very thin. The release layer 22 is preferably dried after coating under conditions of a drying temperature of 50 to 100 ° C. and a drying time of 1 to 10 minutes.

  The resin having a low adhesive strength contained in the binder of the release layer 22 is not particularly limited as long as it has a low adhesive strength and can be satisfactorily formed on the carrier film 20. For example, acrylic resin, butyral resin, acetal Examples thereof include resins, epoxy resins, polyolefins, polyurethanes, polystyrenes, urea resins, polyimides, and copolymers thereof. Especially, it is preferable to use 1 type, or 2 or more types chosen from an acrylic resin, a butyral resin, an acetal resin, and an epoxy resin from a viewpoint of low adhesive force and affinity with a support sheet. By using these resins, even when the release layer is thinned, the effect of forming the release layer is sufficiently exhibited. Moreover, in this embodiment, it is preferable that the glass transition temperature Tg of resin with low adhesive force is high, and it is especially preferable that Tg is room temperature or more. By using a resin having a Tg of room temperature or higher, the peel strength of the release layer 20 can be further reduced. The release layer 20 may contain various binders other than the above-described resin having low adhesive strength.

  Examples of the acrylic resin include homopolymers of acrylic acid esters (for example, methyl acrylate, ethyl acrylate, etc.) and methacrylic acid esters (for example, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate), and their co-polymers. Coalescence etc. can be used.

  Examples of the butyral resin include polyvinyl butyral. The degree of polymerization and the degree of butyralization of polyvinyl butyral are not particularly limited, but usually the degree of polymerization is about 1000 to 3600 and the degree of butyral is about 63 to 77%.

  Examples of the acetal resin include polyvinyl acetal. The degree of polymerization and the degree of acetalization of polyvinyl acetal are not particularly limited, but usually the degree of polymerization is about 1000 to 3600, and the degree of acetalization is about 62 to 74%. Since the acetal resin has a relatively high Tg, it can be suitably used.

  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.

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

  The content of the plasticizer is 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 resin having low adhesive strength in the release layer 22. However, when the release layer 22 contains a butyral resin, it is better not to include a plasticizer.

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

  After the release layer 22 is formed on the surface of the carrier sheet 20, as shown in FIG. 2 (B), the 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 1.5 μm or less. 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. In the present embodiment, since the electrode layer 12a is formed on the release layer 22, electrode repelling can be effectively prevented, and the electrode layer 12a can be formed satisfactorily and with high accuracy.

  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 conductor material, such as a spherical shape or a flake shape, and a mixture of these shapes may also 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 resins, butyral resins such as polyvinyl butyral, acetal resins such as polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, and copolymers thereof, among others. Butyral resins such as ethyl cellulose and polyvinyl butyral are preferred.

  The binder is preferably contained in the electrode paste in an amount of 4 to 10 parts by mass with respect to 100 parts by mass of the conductive material (metal powder). Any known solvent such as terpineol, butyl carbitol, kerosene, acetone, isobornyl acetate 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 the adhesion to the green sheet, the electrode paste preferably contains a plasticizer or a pressure-sensitive adhesive. Examples of the plasticizer include phthalate esters such as dioctyl phthalate and benzylbutyl phthalate, adipic acid, phosphate esters, glycols, and the like. The addition amount of 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 before baking to fall remarkably. Moreover, it is preferable to add the plasticizer and the adhesive to the electrode paste to improve the adhesiveness and 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 that of the green sheet 10a described in detail later. The blank pattern layer 24 can be formed by the same method as the electrode layer 12a or the green sheet 10a described in detail later. The electrode layer 12a and the blank pattern layer 24 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.

  Next, as illustrated in FIG. 2C, the green sheet 10 a is formed on the surfaces of the electrode layer 12 a and the blank pattern layer 24 formed on the release layer 22. The green sheet 10a constitutes the dielectric layer 10 shown in FIG. 1 after firing. In the present embodiment, the green sheet 10a can be formed on the surfaces of the electrode layer 12a and the blank pattern layer 24 without using an adhesive layer. By forming the green sheet 10a on the electrode layer 12a and the blank pattern layer 24 without using an adhesive layer, the manufacturing process can be simplified and the manufacturing cost can be reduced while keeping the adhesive strength at the time of lamination high. Can be planned.

  The green sheet 10a is formed on the surface of the electrode layer 12a and the blank pattern layer 24 by a die coating method or the like using a dielectric paste containing a dielectric material. The green sheet 10a is preferably formed with a thickness of about 0.5 to 30 μm, more preferably about 0.5 to 10 μm, and is formed on the electrode layer 12a and the blank pattern layer 24 and then dried. 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 1.5 μm or less, and the green sheet 10a is preferably formed so that the total thickness of the green sheet 10a and the electrode layer 12a is 3.0 μm or less.

  The dielectric paste for producing the green sheet 10a is usually composed of an organic solvent-based paste or an aqueous paste obtained by kneading a dielectric material 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 0.3 μm or less, preferably 0.2 μm or less. 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, butyral resin such as acrylic resin or polyvinyl butyral is used.

  The organic solvent used in the organic vehicle is not particularly limited, and organic solvents such as terpineol, alcohol, butyl carbitol, acetone, methyl ethyl ketone (MEK), toluene, xylene, ethyl acetate, butyl stearate, isobornyl acetate are used. It is done. 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, charging aids, and the like as necessary. However, the total content of these is preferably 10% by mass or less. Examples of the plasticizer include phthalate esters such as dioctyl phthalate and benzylbutyl phthalate, adipic acid, phosphate esters, glycols, and the like. When using a butyral resin 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.

  Next, separately from the carrier sheet 20, as shown in FIG. 3A, an adhesive layer transfer sheet in which an adhesive layer 28 is formed on the surface of a carrier sheet 26 as a second support sheet is prepared. The carrier sheet 26 is composed of the same sheet as the carrier sheet 20. The thickness of the carrier sheet 26 may be the same as that of the carrier sheet 20 or may be different.

  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, when forming an adhesive layer having a thickness smaller than the particle diameter of the dielectric particles, the dielectric particles It is better not to include. In addition, when dielectric particles are included in the adhesive layer 28, the particle size of the dielectric particles is preferably smaller than the particle size of the dielectric particles included in the green sheet.

  As the binder for the adhesive layer 28, for example, an acrylic resin, a butyral resin such as polyvinyl butyral, an acetal resin such as polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, or an organic material made of a copolymer thereof, or Consists of an emulsion. In the present embodiment, it is particularly preferable to use an acrylic resin or a butyral resin such as polyvinyl butyral as the binder. 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.

  Although it does not specifically limit as a plasticizer for the contact bonding layer 28, For example, phthalic acid esters, such as dioctyl phthalate and bis (2-ethylhexyl) phthalate, adipic acid, phosphoric acid ester, glycols, etc. are illustrated. The plasticizer contained in the adhesive layer 28 may be the same as or different from the plasticizer contained in the green sheet 10a.

  The plasticizer is preferably 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 30 to 70 parts by weight with respect to 100 parts by weight of the binder.

  The adhesive layer 28 preferably further contains an antistatic agent, and the antistatic agent contains one of the imidazoline-based surfactants, and the weight-based addition amount of the antistatic agent is a binder (organic polymer material). It is preferable that the amount is less than or equal to the weight-based addition amount. The content of the antistatic agent is preferably included in the adhesive layer 28 in an amount of 0 to 200 parts by weight, preferably 20 to 200 parts by weight, and more preferably 50 to 100 parts by weight with respect to 100 parts by weight of the binder. .

  The thickness of the adhesive layer 28 is preferably 0.02 to 0.3 μm, more preferably 0.05 to 0.1 μm, and is preferably thinner than the average particle diameter of the dielectric particles contained in the green sheet. Moreover, it is preferable that the thickness of the contact bonding layer 28 is 1/10 or less of the thickness of the green sheet 10a.

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

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

  Next, an adhesive layer 28 is formed on the surface of the green sheet 10a formed on the electrode layer 12a and the blank pattern layer 24 shown in FIG. 2 (C) to obtain a laminate unit U1a shown in FIG. 3 (C). In the present embodiment, a transfer method is employed as a method for forming the adhesive layer 28. That is, as shown in FIG. 3A and FIG. 3B, the adhesive layer 28 of the carrier sheet 26 is pressed against the surface of the green sheet 10a, heated and pressurized, and then the carrier sheet 26 is peeled off. As shown in FIG. 3C, the adhesive layer 28 is transferred to the surface of the green sheet 10a to obtain a multilayer unit U1a.

  By forming the adhesive layer 28 by a transfer method, it is possible to effectively prevent the components of the adhesive layer from penetrating into the green sheet 10a, the electrode layer 12a, or the blank pattern layer 24. Therefore, there is no possibility of adversely affecting the composition of the green sheet 10a, the electrode layer 12a, or the blank pattern layer 24. Furthermore, even when the adhesive layer 28 is formed thin, the adhesive layer components do not soak into the green sheet 10a, the electrode layer 12a, or the blank pattern layer 24, so that the adhesiveness can be kept high.

  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.

  Next, a green chip is formed by laminating a plurality of laminate units in which the electrode layer 12a, the blank pattern layer 24, the green sheet 10a, and the adhesive layer 28 are laminated in this order. Lamination of the laminate units is performed by adhering the laminate units to each other via an adhesive layer 28 as shown in FIGS. 4 to 6. Hereinafter, the lamination method will be described.

  First, as shown to FIG. 4 (A) and FIG. 4 (B), the 1st support sheet 20 is peeled from the laminated body unit U1a produced above. Next, as shown in FIG. 4 (C), the laminated body unit U1a is made up of a green sheet 30 for an outer layer (a thickness of 100 to 30 μm in which an electrode layer is not formed and a plurality of laminated green sheets 30 to 100 μm thick). A 200 μm laminate).

  In this embodiment, since the laminated body unit U1a is formed on the carrier sheet 20 via the peeling layer 22, the carrier sheet 20 can be peeled favorably. Further, the electrode layer 12a and the blank pattern layer 24 of the multilayer unit U1a are not damaged at the time of peeling. In addition, although it is preferable that the peeling layer 22 is peeled from the laminated body unit U1a with the carrier sheet 20, as long as it is about a small amount, it may remain on the laminated body unit U1a side. Even in this case, the remaining peeling layer 22 is sufficiently thin as compared with the green sheet 10a and the electrode layer 12a constituting the multilayer body unit U1a, so that there is no problem.

  Next, as shown to FIG. 5 (A), another laminated body unit U1b produced by the method similar to the laminated body unit U1a is prepared. The first support sheet 20 is peeled off from the prepared laminate unit U1b, and as shown in FIG. 5B, the laminate unit U1b from which the carrier sheet 20 is peeled off and the laminate unit U1a are combined with each other. Are adhered and laminated through the adhesive layer 28.

  Next, as shown in FIG. 6 (A) and FIG. 6 (B), in the same manner, another laminate unit U1c is placed on the laminate unit U1b via the adhesive layer 28 of the laminate unit U1b. Glue and laminate. Then, by repeating the steps shown in FIGS. 6A and 6B, a plurality of laminate units are laminated. Next, an outer layer green sheet 30 is laminated on the upper surface of the laminated body, final pressing is performed, and then the laminated body is cut into a predetermined size to form a green chip. The pressure at the final pressurization is preferably 10 to 200 MPa, and the heating temperature is preferably 40 to 100 ° C.

  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 preferably performed under the following conditions.

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

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

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

The heat treatment after such firing is preferably carried out at a holding temperature or maximum temperature of preferably 1000 ° C. or higher, more preferably 1000 to 1100 ° C. If the holding temperature or maximum temperature during heat treatment is less than the above range, the dielectric material is insufficiently oxidized and the insulation resistance life tends to be shortened. In addition to a decrease, it tends to react with the dielectric substrate and shorten its lifetime. The oxygen partial pressure during the heat treatment is higher than the reducing atmosphere during firing, and is preferably 10 ⁻³ Pa to 1 Pa, more preferably 10 ⁻² Pa to 1 Pa. If it is less than the above range, it is difficult to reoxidize the dielectric layer 2, and if it exceeds the above range, the internal electrode layer 12 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 and mixed gas, etc., through a gas, for example, water heated, may be used to bubbling to device. 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 this embodiment, lamination is performed without using an adhesive layer in a process where non-adhesion defects (non-lamination) are not a problem. Moreover, in a process where non-adhesion defects (non-lamination) are likely to occur, lamination is performed via an adhesive layer. That is, since the adhesive layer is not used when forming the green sheet 10a on the electrode layer 12a, the manufacturing process can be simplified and the manufacturing cost can be reduced. Furthermore, since the green sheets 10a having the electrode layers 12a are stacked through the adhesive layer 28, adhesion can be improved and non-adhesion defects (non-lamination) can be reduced. Therefore, according to the manufacturing method of the present embodiment, even when the green sheet is extremely thin, it is possible to reduce non-adhesion defects (non-lamination) while maintaining high adhesiveness, and simplify the manufacturing process. Manufacturing cost can be reduced.

  Furthermore, in this embodiment, first, the release layer 28 containing a resin having low adhesive strength is formed on the carrier sheet 20, and the electrode layer 12a, the blank pattern layer 24, and the green sheet 10a are formed thereon. Therefore, it is possible to effectively prevent electrode repelling during the formation of the electrode layer, and it is possible to form the electrode layer satisfactorily and with high accuracy. Further, by forming the release layer 28, the peel strength between the electrode layer 12a and the carrier sheet 20 can be lowered, and the first support sheet can be peeled from the electrode layer 12a satisfactorily. Moreover, the electrode layer 12a is not damaged at the time of peeling.

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 adhesive layer 28 is formed by a transfer method. However, the adhesive layer 28 may be formed by coating directly on the green sheet 10a by, for example, a die coating method.

  Further, in the above-described embodiment, before laminating each laminate unit, the carrier sheet 20 is peeled from the laminate unit to laminate the laminate unit. For example, as shown in FIGS. A step of peeling the carrier sheet 20 after laminating the laminate unit may be employed.

  That is, as shown in FIGS. 7A and 7B, first, the laminate unit U1a from which the carrier sheet 20 is not peeled is placed on the green sheet 30 for the outer layer via the adhesive layer 28. Glue and laminate. Next, as shown in FIG. 7C, the carrier sheet 20 is peeled from the multilayer unit U1a.

  Next, as shown in FIGS. 8A to 8C, in the same manner, another laminate unit U1b is bonded onto the laminate unit U1a via the adhesive layer 28 of the laminate unit U1b. And stacking. Next, by repeating the steps shown in FIGS. 8A to 8C, a plurality of laminated body units are laminated. And the green sheet for outer layers is laminated | stacked on the upper surface of this laminated body, a final pressurization is performed, and a laminated body is cut | disconnected to predetermined size after that, and a green chip can be formed.

  In the case where the steps shown in FIGS. 7 and 8 are employed, the carrier sheet 20 can be selectively and easily peeled off by making the adhesive strength of the adhesive layer 28 stronger than the adhesive strength of the release layer 22. Is particularly effective.

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

Example 1
First, the following pastes were prepared.
Green Sheet Paste First, as additive (subcomponent) raw materials, (Ba, Ca) SiO ₃ : 1.48 parts by weight, Y ₂ O ₃ : 1.01 parts by weight, MgCO ₃ : 0.72 parts by weight, MnO : 0.13 parts by weight and V ₂ O ₅ : 0.045 parts by weight were prepared. Next, these additive (subcomponent) raw materials prepared were mixed to obtain an additive (subcomponent) raw material mixture.

Subsequently, the additive raw material mixture obtained above: 4.3 parts by weight, ethanol: 3.11 parts by weight, propanol: 3.11 parts by weight, xylene: 1.11 parts by weight and dispersant: 0.04 parts by weight The parts were mixed and ground using a ball mill to obtain an additive slurry. The mixing and pulverization were carried out using a 250 cc polyethylene resin container, charged with 450 g of ₂ mmφ ZrO ₂ media under conditions of a peripheral speed of 45 m / min and 16 hours. The particle diameter of the additive raw material after pulverization was 0.1 μm in median diameter.

Subsequently, the additive slurry obtained above: 11.65 parts by weight, BaTiO ₃ powder (BT-02 / Sakai Chemical Industry Co., Ltd.): 100 parts by weight, ethanol: 35.32 parts by weight, propanol: 35. 32 parts by weight, xylene: 16.32 parts by weight, dioctyl phthalate (plasticizer): 2.61 parts by weight, mineral spirit: 7.3 parts by weight, dispersant: 2.36 parts by weight, charging aid: 0.8. 42 parts by weight, organic vehicle: 33.74 parts by weight, MEK: 43.81 parts by weight and 2-butoxyethanol: 43.81 parts by weight were mixed using a ball mill to obtain a paste for a green sheet. The mixing by the ball mill was carried out using a 500 cc polyethylene resin container, charging 900 g of ₂ mmφ ZrO ₂ media, and at a peripheral speed of 45 m / min and 20 hours. In addition, the above organic vehicle has 15 parts by weight of polyvinyl butyral resin having a polymerization degree of 1450 and a butyralization degree of 69% (manufactured by Sekisui Chemical Co., Ltd.): 42.5 parts by weight of ethanol and 42.5 parts by weight of propanol. This was prepared by stirring and dissolving in a part at a temperature of 50 ° C. That is, the resin content (amount of polyvinyl butyral resin) in the organic vehicle was 15% by weight.

Internal Electrode Paste First, an additive material mixture was prepared in the same manner as the above green sheet paste.
Next, the additive raw material mixture obtained above: 100 parts by weight, acetone: 150 parts by weight, terpineol: 104.3 parts by weight, polyethylene glycol dispersant: 1.5 parts by weight are mixed to make a slurry, The obtained slurry was pulverized by a pulverizer (Ashizawa Finetech Co., Ltd., model LMZ0.6) to obtain an additive slurry.

Note that the additives in the slurry were pulverized by rotating the rotor at a peripheral speed of 14 m / min and circulating the slurry between the vessel and the slurry tank. The vessel is filled with ZrO ₂ beads having a diameter of 0.1 mm so as to be 80% of the vessel volume, and the pulverization requires 5 minutes of residence time of the entire slurry in the vessel. Went so. The median diameter of the crushed additive was 0.1 μm.

  Next, the crushed additive slurry was removed by evaporating acetone from the slurry using an evaporator to prepare an additive slurry in which the additive raw material was dispersed in terpineol. The additive raw material concentration in the additive slurry after removing acetone was 49.3% by weight.

Next, nickel powder (particle size 0.2 μm / Kawatetsu Kogyo Co., Ltd.): 100 parts by weight, additive slurry: 1.77 parts by weight, BaTiO ₃ powder (particle size 0.05 μm / Sakai Chemical Industry Co., Ltd.): 19.14 parts by weight, organic vehicle: 56.25 parts by weight, polyethylene glycol dispersant: 1.19 parts by weight, dioctyl phthalate (plasticizer): 2.25 parts by weight, isobornyl acetate: 32.19 parts by weight And 56 parts by weight of acetone were mixed using a ball mill to form a paste. Next, the obtained paste was removed by evaporating acetone by using an agitator equipped with an evaporator and a heating mechanism to obtain an internal electrode paste.

The mixing with the ball mill was carried out under the conditions of a peripheral speed of 45 m / min and 16 hours, with the ball mill filled with 30% by volume of ₂ mmφ ZrO ₂ media and 60% by volume of the mixture of the above raw materials. The organic vehicle is prepared by stirring and dissolving ethyl cellulose resin having a molecular weight of 130,000: 4 parts by weight and ethyl cellulose resin having a molecular weight of 230,000: 4 parts by weight in isobornyl acetate: 92 parts by weight at a temperature of 70 ° C. It was produced by. That is, the resin content (the amount of ethyl cellulose resin) in the organic vehicle was 8% by weight.

Then, the viscosity of the internal electrode paste obtained by using conical viscometer (HAAKE Co.), 25 ° C., the viscosity _{V 8} at a shear rate of 8 sec ^-1, and a viscosity _{V 50} at 50 sec ^-1, respectively It was measured. As a result of the measurement, V ₈ = 15.5 cps, V ₅₀ = 8.5 cps, V ₈ / V ₅₀ = 1.73, and it was confirmed that the viscosity could be used favorably in the printing method.

Blank Pattern Paste First, an additive slurry in which an additive raw material was dispersed in terpineol was prepared in the same manner as the internal electrode paste.
Next, additive slurry: 8.87 parts by weight, BaTiO ₃ powder (BT-02 / Sakai Chemical Industry Co., Ltd.): 95.70 parts by weight, organic vehicle: 104.36 parts by weight, polyethylene glycol-based dispersant: 1 0.0 parts by weight, dioctyl phthalate (plasticizer): 2.61 parts by weight, isobornyl acetate: 19.60 parts by weight, acetone 57.20 parts by weight, and imidazoline surfactant (charging aid): 4 parts by weight were mixed using a ball mill to form a paste. Next, the obtained paste was removed by evaporating acetone by using an agitator equipped with an evaporator and a heating mechanism to obtain a blank pattern paste. As the organic vehicle, the same organic vehicle as the internal electrode paste was used. That is, an 8% by weight isobornyl acetate solution of ethyl cellulose resin was used.

Subsequently, the viscosity of the obtained blank pattern paste was measured in the same manner as the internal electrode paste. As a result of the measurement, V ₈ = 19.9 cps, V ₅₀ = 10.6 cps, and V ₈ / V ₅₀ = 1.88, confirming that the viscosity can be used favorably in the printing method.

Adhesive layer paste polyvinyl butyral resin (polymerization degree 800, butyralization degree 83%, Sekisui Chemical Co., Ltd. BM-SH): 1.5 parts by weight, MEK: 98.5 parts by weight and DOP (dioctyl phthalate and phthalate) Adhesive layer paste was prepared by stirring and dissolving 50 parts by weight of a mixed solvent of acid bis (2-ethylhexyl).

Peeling layer paste Polymerization degree 2400, acetalization degree 63% polyvinyl acetal resin (Sekisui Chemical KS-5): 1.5 parts by weight of MEK: 98.5 parts by weight of MEK: 98.5 parts by weight. Produced.

Formation of Release Layer, Internal Electrode Layer, Blank Pattern, and Green Sheet The electrode layer 12a formed on the first support sheet 20 via the release layer 22 as shown in FIG. And the green sheet 10a which has the blank pattern 24 was manufactured.
First, a release layer was formed on a PET film (first support sheet) whose surface was subjected to a release treatment with a silicone resin. The release layer was formed by applying the above release layer paste with a die coater at a coating speed of 70 m / min. Then, the coating was carried out by drying using a drying furnace having an oven temperature of 80 ° C. The release layer was formed so that the film thickness upon drying was 0.1 μm.

  Next, on the surface of the release layer formed on the PET film, the internal electrode paste is printed by a screen printing machine and dried at 90 ° C. for 5 minutes to form an internal electrode layer having a predetermined pattern. did. The internal electrode layer was formed so that the film thickness when dried was 1 μm. In this example, it was possible to effectively prevent electrode repelling during the formation of the internal electrode, and it was possible to form the internal electrode layer satisfactorily and with high accuracy.

  Next, the blank pattern paste was formed on the surface of the release layer where the internal electrode layer was not formed by printing the blank pattern paste with a screen printer and drying at 90 ° C. for 5 minutes. . For the printing of the blank pattern, a screen plate making which is a complementary pattern to the pattern used when printing the internal electrode paste was used. The blank pattern was formed so that the film thickness at the time of drying was the same as that of the internal electrode layer.

  Next, the green sheet paste was formed on the internal electrode layer and the blank pattern formed above by applying the green sheet paste with a die coater and then drying. The coating speed is 50 m / min. And drying was performed using the drying furnace which made the furnace temperature 80 degreeC. The green sheet was formed so that the film thickness when dried was 1 μm.

Formation of adhesive layer, transfer of adhesive layer First, prepare another PET film (second support sheet), apply the above adhesive layer paste on the PET film with a die coater, and then dry it. Thus, an adhesive layer was formed. The coating speed is 70 m / min. And drying was performed using the drying furnace which made the furnace temperature 80 degreeC. The adhesive layer was formed so that the film thickness upon drying was 0.1 μm. In addition, the said 2nd support sheet used the PET film which performed the peeling process by the silicone type resin on the surface similarly to the 1st support sheet.

  Next, the adhesive layer 28 was transferred onto the green sheet 10a having the electrode layer 12a and the blank pattern 24 produced as described above by the method shown in FIG. 3 to form a multilayer unit U1a. At the time of transfer, a pair of rolls was used, the pressure was 5 MPa, the temperature was 100 ° C., and it was confirmed that the transfer could be performed satisfactorily.

Production of Green Chip First, a plurality of outer layer green sheets molded to a thickness of 10 μm are laminated so that the thickness at the time of lamination is about 50 μm, and the outer layer that becomes the lid portion (cover layer) of the multilayer capacitor after firing is formed. Formed. Lamination was performed under conditions of a press pressure of 200 MPa and a press temperature of 50 ° C. The green sheet for the outer layer is a green sheet formed using the green sheet paint produced above so that the thickness after drying is 10 μm.

  Next, 100 laminate units produced as described above were laminated thereon by the method shown in FIGS. Further, a plurality of outer layer green sheets molded to a thickness of 10 μm are laminated thereon so that the thickness at the time of lamination is about 50 μm, and the outer layer that becomes the lid portion (cover layer) of the multilayer capacitor after firing. Formed. And the obtained laminated body was press-molded on the conditions of 100 MPa and 70 ° C., and then cut with a dicing machine to obtain a green chip before firing. In this example, the green chip before firing was measured for the non-adhesion defect (non-lamination) ratio by a method described later.

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.

Binder removal
Temperature rising rate: 50 ° C / hour,
Holding temperature: 240 ° C.
Retention time: 8 hours,
Atmospheric gas: In air,
I went there.

Firing is
Temperature increase rate: 300 ° C / hour,
Holding temperature: 1200 ° C,
Retention time: 2 hours
Cooling rate: 300 ° C./hour,
Atmospheric gas: A mixed gas of N ₂ gas and H ₂ (5%) controlled at a dew point of 20 ° C.
I went there.

Annealing (reoxidation)
Retention time: 3 hours
Cooling rate: 300 ° C./hour,
Gas for atmosphere: N ₂ gas controlled at a dew point of 20 ° C.,
I went there. The atmosphere gas was humidified using a wetter at a water temperature of 0 to 75 ° C.

  Next, after polishing the end face of the chip-shaped sintered body by sand blasting, an external electrode is formed by applying an In—Ga alloy paste to the end, and a sample of the multilayer ceramic capacitor having the configuration shown in FIG. 1 is obtained. It was.

Measurement of peel strength For example, in the state shown in FIG. 3B, one end of the carrier sheet 20 is 8 mm / min. In the direction of 90 degrees with respect to the plane of the laminate. The force (mN / cm) acting on the carrier sheet 20 at that time was measured as the peel strength. By lowering the peel strength, the first support sheet can be peeled from the electrode layer satisfactorily, and damage to the electrode layer at the time of peeling can be effectively prevented. The lower one is preferable. Further, the lower limit of the peel strength of the release layer is preferably larger than the peel strength of the adhesive layer (about 4 mN / cm). The results are shown in Table 1.

Measurement of Non-Adhesion Defect (Non-Lamination) Ratio The degree of occurrence of non-adhesion defects (non-lamination) was measured for the green chip sample before firing obtained above. In the measurement, first, 50 green chip samples were embedded in a two-part curable epoxy resin so that the side surfaces of the dielectric layer and the internal electrode layer were exposed, and then the two-part curable epoxy resin was cured. . Next, the green chip sample embedded in the epoxy resin was polished to a depth of 1.6 mm using sandpaper. The sandpaper was polished by using # 400 sandpaper, # 800 sandpaper, # 1000 sandpaper, and # 2000 sandpaper in this order. Next, the sandpaper polished surface was subjected to mirror polishing using diamond paste. Then, using an optical microscope, this polished surface was observed at an enlargement magnification of 400 times to examine the presence or absence of non-adhesion defects. As a result of observation with an optical microscope, the ratio of the samples in which non-adhesion defects were generated relative to all measurement samples was defined as the non-adhesion defect ratio. The results are shown in Table 1.

Measurement of short circuit defect ratio The short circuit defect ratio was measured by preparing 50 capacitor samples and examining the number of short circuit defects.
Specifically, the resistance value was measured using an insulation resistance meter (E2377A multimeter manufactured by HEWLETT PACKARD), and the sample having a resistance value of 100 kΩ or less was defined as a short defect sample. The ratio of samples was defined as the short defect rate. The results are shown in Table 1.

Example 2
Except that the adhesive layer was formed by a coating method instead of a transfer method, a green chip and a multilayer ceramic capacitor sample before firing were prepared in the same manner as in Example 1, and in the same manner as in Example 1, The peel strength, non-adhesion defect ratio, and short defect rate were measured.
That is, in Example 2, the adhesive layer paste was formed by directly applying the adhesive layer paste onto the green sheet using a die coater and then drying. The adhesive layer paste has a coating speed of 70 / min. The coating was performed under the conditions described above, and the drying was performed in a drying furnace at an oven temperature of 80 ° C. The adhesive layer was formed so that the film thickness when dried was 1 μm.

Comparative Example 1
A green chip and a multilayer ceramic capacitor sample before firing were prepared in the same manner as in Example 1 except that the release layer was not formed. In the same manner as in Example 1, the peel strength, the non-adhesion defect ratio, and the short-circuit failure were produced. The rate was measured.
That is, in Comparative Example 1, the electrode layer was formed directly on the first support sheet without going through the release layer.

Evaluation 1
Table 1 shows the presence / absence of electrode repellency, peel strength, non-adhesion defect ratio, and short-circuit defect ratio in Examples 1 and 2 and Comparative Example 1, respectively.
From Table 1, in Example 1 and Example 2 in which the electrode layer was formed on the first support sheet via the release layer, both electrode repelling can be effectively prevented and the internal electrode layer is good. In addition, it can be formed with high accuracy. On the other hand, in Comparative Example 1 in which the electrode layer was formed directly on the first support sheet without using a release layer, the electrode repelling occurred when the internal electrode was formed, and high accuracy was achieved. It was difficult to form an internal electrode layer.

  In Example 1 and Example 2, the peel strength was as low as 42 mN / cm, and the carrier sheet could be peeled off satisfactorily. On the other hand, in Comparative Example 1, the peel strength is as high as 102 mN / cm, and when the carrier sheet is peeled off, it is necessary to peel off with a stronger force. At the time of peeling, the electrode layer and the blank pattern layer are damaged. It has happened.

  Furthermore, in Example 1 and Example 2, since the green sheets having the electrode layer are laminated through the adhesive layer, the non-adhesion defect ratio is 0%, and the non-adhesion defect defect is effectively prevented. I was able to confirm that it was possible. In Example 1, the short-circuit defect rate was 6%, which was a better result than Example 2. However, in Example 1, since the adhesive layer was formed by the transfer method, the component of the adhesive layer was This is considered to be because it was possible to effectively prevent the penetration of the electrode layer or the green sheet.

  From this result, it is possible to effectively prevent electrode repelling by forming the electrode layer on the first support sheet via the release layer, and to perform the formation of the electrode layer with good accuracy. It was confirmed that it was possible. In addition, by stacking green sheets with electrode layers through the adhesive layer, it is possible to improve stackability (adhesiveness during lamination) and effectively prevent non-adhesion defects and poor adhesion. there were. Further, it was confirmed that the short-circuit defect rate can be further reduced by forming the adhesive layer preferably by a transfer method.

Example 3
Samples of green chip and multilayer ceramic capacitor before firing were prepared in the same manner as in Example 1 except that an acrylic resin was used instead of polyvinyl butyral resin as the binder for the green sheet. In the same manner as in Example 1, the peel strength, the non-adhesion defect ratio, and the short-circuit defect rate were measured.

  That is, in Example 3, an acrylic resin green sheet paste manufactured by the following method was used as the green sheet paste.

Acrylic Resin Green Sheet Paste First, an additive material mixture was prepared in the same manner as the green sheet paste of Example 1.
Next, the additive raw material mixture obtained above: 4.3 parts by weight, ethyl acetate: 6.85 parts by weight, and dispersant: 0.04 parts by weight were mixed and ground using a ball mill, and the additive A slurry was obtained. The mixing and pulverization were carried out using a 250 cc polyethylene resin container, charged with 450 g of ₂ mmφ ZrO ₂ media under conditions of a peripheral speed of 45 m / min and 16 hours. The particle diameter of the additive raw material after pulverization was 0.1 μm in median diameter.

Subsequently, the additive slurry obtained above: 11.2 parts by weight, BaTiO ₃ powder (BT-02 / Sakai Chemical Industry Co., Ltd.): 100 parts by weight, ethyl acetate: 163.76 parts by weight, toluene: 21 48 parts by weight, dispersing agent: 1.04 parts by weight, PEG 400 (charging aid): 0.83 parts by weight, diacetone alcohol: 1.04 parts by weight, benzylbutyl phthalate (plasticizer): 2.61 parts by weight Parts, butyl stearate: 0.52 parts by weight, mineral spirit: 6.78 parts by weight and organic vehicle: 34.77 parts by weight were mixed using a ball mill to obtain a paste for a green sheet. The mixing by the ball mill was carried out using a 500 cc polyethylene resin container, charging 900 g of ₂ mmφ ZrO ₂ media, and at a peripheral speed of 45 m / min and 20 hours. The above organic vehicle was prepared by stirring and dissolving 15 parts by weight of acrylic resin in 85 parts by weight of ethyl acetate at a temperature of 50 ° C. That is, the resin content (amount of acrylic resin) in the organic vehicle was 15% by weight. As the acrylic resin, a copolymer of methyl methacrylate (MMA) and butyl acrylate (BA) having a molecular weight of 450,000, an acid value of 5 mgKOH / g, and Tg = 70 ° C. (MMA / BA = 82/18: weight ratio) It was used.

Evaluation 2
Example 3 using an acrylic resin instead of polyvinyl butyral resin as a binder for a green sheet can effectively prevent electrode repelling during the formation of the internal electrode layer, as in Example 1. The internal electrode layer could be formed satisfactorily and with high accuracy.

  Further, regarding the peel strength, the non-adhesion defect ratio, and the short-circuit defect rate, the peel strength was 48 mN / cm, the non-adhesion defect ratio was 0%, and the short-circuit defect rate was 9%. From this result, it was confirmed that even when an acrylic resin was used as the binder for the green sheet, the effects of the present invention were sufficiently exhibited.

FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 2A to FIG. 2C are cross-sectional views showing the main parts of the electrode layer and green sheet forming method according to one embodiment of the present invention. FIG. 3A to FIG. 3C are cross-sectional views of relevant parts showing a method for forming an adhesive layer according to an embodiment of the present invention. 4 (A) to 4 (C) are cross-sectional views showing a main part of a method for laminating green sheets having electrode layers according to an embodiment of the present invention. 5 (A) and 5 (B) are cross-sectional views of relevant parts showing a step subsequent to FIG. 6 (A) and 6 (B) are cross-sectional views of relevant parts showing a step subsequent to FIG. FIG. 7A to FIG. 7C are cross-sectional views showing the main part of a method for laminating green sheets having electrode layers according to other embodiments of the present invention. FIG. 8A to FIG. 8C are cross-sectional views of relevant parts showing a step subsequent to FIG.

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 (second support sheet)
28 ... Adhesive layer 30 ... Green sheet for outer layer U1a to U1c ... Laminate unit

Claims (14)

Forming an electrode layer on the first support sheet;
Forming a green sheet on the surface of the electrode layer to obtain a green sheet having an electrode layer;
Laminating a green sheet having the electrode layer to form a green chip;
A step of firing the green chip, comprising the steps of:
Forming the electrode layer on the first support sheet through a release layer containing a resin having low adhesive strength; and
Before laminating the green sheet having the electrode layer, an adhesive layer is formed on the surface of the green sheet having the electrode layer on the counter electrode layer side,
A method for producing a multilayer electronic component, comprising: laminating a green sheet having the electrode layer through the adhesive layer.   The method for manufacturing a multilayer electronic component according to claim 1, wherein the green sheet is formed on a surface of the electrode layer without using an adhesive layer.   The method for producing a multilayer electronic component according to claim 1, wherein the adhesive layer has a thickness of 0.02 to 0.3 μm.   The laminated electron according to any one of claims 1 to 3, wherein the resin having a low adhesive strength contained in the release layer is one or more selected from an acrylic resin, a butyral resin, an acetal resin and an epoxy resin. A manufacturing method for parts.   The method for producing a multilayer electronic component according to claim 1, wherein the release layer has a thickness of 0.02 to 0.2 μm.   The method for manufacturing a multilayer electronic component according to claim 1, wherein the green sheet has a thickness of 1.5 μm or less.   The thickness of the said electrode layer is 1.5 micrometers or less, The manufacturing method of the multilayer electronic component in any one of Claims 1-6.   The method for manufacturing a multilayer electronic component according to claim 1, wherein a total thickness of the green sheet and the electrode layer is 3.0 μm or less.   The electrode layer is formed in a predetermined pattern on the surface of the release layer, and a blank pattern layer having substantially the same thickness as the electrode layer is formed on the surface of the release layer where the electrode layer is not formed, The method of manufacturing a multilayer electronic component according to claim 1, wherein the blank pattern layer is made of substantially the same material as the green sheet. Before laminating the green sheet having the electrode layer, the first support sheet is peeled from the green sheet having the electrode layer,
The multilayer electronic component according to any one of claims 1 to 9, wherein the electrode layer side surface of the green sheet having the electrode layer is laminated on another green sheet in a state where the first support sheet is peeled off. Method. In the state having the first support sheet, the surface opposite to the electrode layer of the green sheet having the electrode layer is laminated on another green sheet,
The method for manufacturing a multilayer electronic component according to claim 1, wherein the first support sheet is peeled from the green sheet having the electrode layer after the green sheet having the electrode layer is laminated.   The method for manufacturing a multilayer electronic component according to claim 1, wherein the adhesive layer is formed by a transfer method.   The stacked electron according to claim 12, wherein the adhesive layer is formed on the surface of the second support sheet so as to be peelable first, and is pressed and transferred to the surface of the green sheet having the electrode layer on the side opposite to the electrode layer. A manufacturing method for parts. The method for manufacturing a multilayer electronic component according to claim 1, wherein the adhesive layer is formed by a coating method.

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