JP4357460B2 - Electrode step absorbing printing paste and method of manufacturing laminated electronic component - Google Patents

Description

  The present invention relates to an electrode level difference absorbing print paste used for manufacturing a laminated electronic component, and a method for manufacturing a laminated electronic component using the paste.

  In a multilayer ceramic capacitor as an example of a multilayer electronic component, a ceramic green sheet is usually formed on a carrier sheet using a dielectric paste by a doctor blade method or the like, and a conductive paste for forming an internal electrode is formed on the ceramic paste on a predetermined pattern. And printing and drying to form an internal electrode pattern. Thereafter, the ceramic green sheet is peeled off from the carrier sheet and laminated to a desired number of layers.

  Here, two types of lamination methods are known: a method of peeling the ceramic green sheet from the carrier sheet before lamination (sheet method) and a method of peeling the carrier sheet after lamination pressure bonding (printing method). There is no big difference. Finally, this laminate is cut into chips to produce green chips. After firing these green chips, external electrodes are formed to obtain a multilayer ceramic capacitor.

  By the way, in recent years, electronic devices are becoming lighter, thinner and shorter. Along with this, further downsizing and higher capacity are being promoted also in the multilayer ceramic capacitor used in the electronic device. The most effective way to reduce the size and increase the capacity of multilayer ceramic capacitors is to make both internal electrodes and dielectric layers as thin as possible (thinner layers) and stack them as much as possible ( Multi-layered).

  However, when the ceramic green sheets and the internal electrode patterns are alternately laminated like a multilayer ceramic capacitor, gaps (blank spaces) in which no electrodes are formed on the same row of the internal electrode patterns sandwiched between the ceramic green sheets. Pattern portion) is formed. Due to this blank pattern portion, a step is formed with the portion where the internal electrode pattern exists, which causes problems such as product chip deformation, cracks, and delamination between sheets. In particular, in order to increase the capacity of the capacitor, when the dielectric layer thickness per layer is further reduced to the thickness of the internal electrode, the dielectric layer is likely to be cut at the portion where the step is generated, and as a result, Short circuit defects due to short circuits between internal electrodes tend to occur, and the defect rate tends to increase.

  Therefore, in order to solve various problems caused by such steps in recent years, an electrode step absorbing printing paste is formed in a gap (blank pattern portion) where no internal electrode is formed following the formation of the internal electrode (internal electrode pattern). A technique is known in which a blank pattern layer is formed and laminated while the formation surface is flattened. The internal electrode pattern and the blank pattern layer have a negative and positive relationship with the photographic film.

  As the electrode level difference absorbing printing paste, a ceramic powder dispersed in an organic vehicle in which an organic binder is dissolved in a solvent is used as in the case of a dielectric paste for forming a ceramic green sheet.

  In the dielectric paste for forming the ceramic green sheet, for example, butyral resin is used as the organic binder in the organic vehicle, but in the electrode step absorbing printing paste, as the organic binder in the corresponding organic vehicle. Ethyl cellulose is used. The reason is that the printing suitability by screen printing or the like is taken into consideration. On the other hand, terpineol has been used as a solvent in organic vehicles.

  However, when printing paste for electrode step absorption using terpineol as a solvent is used in combination with a ceramic green sheet using butyral resin as the organic binder, the solvent in the paste swells or dissolves the organic binder in the ceramic green sheet. The so-called “sheet attack” phenomenon occurs.

  Such a sheet attack phenomenon is not a practical problem as long as the ceramic green sheet is relatively thick. However, when a sheet attack phenomenon occurs when the thickness of the ceramic green sheet is as thin as 5 μm or less, for example, when the ceramic green sheet is peeled off from a carrier sheet such as a PET film after printing the electrode level difference absorbing printing paste, the ceramic green sheet Is difficult to peel off. When the ceramic green sheet is difficult to peel off, wrinkles, holes, cracks, etc. occur in the ceramic green sheet due to this influence, and a normal laminate cannot be obtained in the lamination process. If a normal laminate is not obtained, short circuit failure, breakdown voltage failure (IR degradation), and delamination phenomenon (delamination) occur between the dielectric layer and the internal electrode layer in the final laminated electronic component. However, the yield was reduced.

  Therefore, in recent years, several measures for improving the seat attack phenomenon have been proposed. For example, Patent Document 1 proposes to use a solvent having a relatively low compatibility with butyral as a solvent for an electrode level difference absorbing print paste for forming a blank pattern layer. Specifically, this patent document 1 proposes a printing paste for absorbing an electrode step using dihydroterpineol.

  However, even when dihydroterpineol is used as a solvent, a sheet attack phenomenon occurs, and as a result, the thickness variation of the ceramic green sheet occurs. For this reason, when the thickness of the ceramic green sheet is further reduced to 3 μm or less, particularly 1 μm or less, the influence of the variation in the thickness of the green sheet becomes large. As a result, short circuit failure, breakdown voltage failure (IR degradation) However, there was a problem that delamination occurred. For this reason, such conventional electrode level difference absorbing printing paste has a limit in reducing the size and increasing the capacity of multilayer electronic components such as multilayer ceramic capacitors.

JP 2001-167971 A

  An object of the present invention is to provide a printing paste for absorbing an electrode step that is used for manufacturing a laminated electronic component, has good release properties, has an appropriate adhesion to a ceramic green sheet, and does not cause a sheet attack. The purpose is to provide. In addition, the present invention is manufactured using this electrode level difference absorbing printing paste, reducing the thickness variation of the green sheet, and effectively preventing the occurrence of short circuit failure, breakdown voltage failure (IR degradation), and delamination. In addition, an object of the present invention is to provide a method for manufacturing a laminated electronic component having excellent life characteristics.

  As a result of intensive studies to achieve the above object, the present inventors have included a specific dihydroterpineol derivative in the electrode level difference absorbing print paste used for producing the laminated electronic component, The inventors have found that the above object can be achieved and have completed the present invention.

That is, the electrode level difference absorbing printing paste of the present invention is
An electrode step absorption printing paste used for manufacturing a laminated electronic component,
A ceramic powder, an organic binder, and a solvent containing a dihydroterpineol derivative,
The dihydroterpineol derivative contained in the solvent is characterized in that a side chain containing one or more acyl groups is condensed with dihydroterpineol, and the total number of carbon atoms contained in the side chain is 3 or more. To do.

In the electrode level difference absorbing printing paste of the present invention, preferably, the dihydroterpineol derivative is one or more selected from the following formulas (1) to (4).
However, in the above formulas (1) and (2), k ≧ 2, and in the above formulas (3) and (4), m and n ≧ 1.

  In the electrode level difference absorbing printing paste of the present invention, preferably, the dihydroterpineol derivative is represented by the formula (1) or (2), and k in the formula is k = 2.

  In the electrode level difference absorbing print paste of the present invention, preferably, the organic binder is ethyl cellulose.

A method for manufacturing a laminated electronic component according to the present invention includes:
A green sheet containing butyral resin;
A method of manufacturing a laminated electronic component having a step of alternately stacking a plurality of pre-fired electrode layers of a predetermined pattern to obtain a green laminate,
Before forming the laminate, a blank pattern layer having substantially the same thickness as the pre-firing electrode layer is formed in a gap portion of the pre-firing electrode layer of a predetermined pattern,
Any one of the above electrode level difference absorbing print pastes is used as the electrode level difference absorbing print paste for forming the blank pattern layer.

  In the method for manufacturing a laminated electronic component of the present invention, preferably, the thickness of the green sheet is 3 μm or less.

In the method for producing a laminated electronic component of the present invention, preferably, as a conductive paste for forming the pre-firing electrode layer, a conductive powder, an organic binder, and a solvent containing a dihydroterpineol derivative,
The dihydroterpineol derivative contained in the solvent is a conductor paste in which a side chain containing one or more acyl groups is condensed to dihydroterpineol, and the total number of carbons contained in the side chain is 3 or more. use.

  Preferably, the dihydroterpineol derivative contained in the conductor paste has the same configuration as the dihydroterpineol derivative contained in the electrode level difference absorbing printing paste. The organic binder contained in the conductor paste is preferably ethyl cellulose.

  The multilayer electronic component according to the present invention is not particularly limited, and examples thereof include a multilayer ceramic capacitor, a piezoelectric element, a chip inductor, a chip varistor, a chip thermistor, a chip resistor, and other surface-mounted chip electronic components (SMD). .

  In the present invention, the dihydroterpineol derivative as described above is used as a solvent contained in the electrode level difference absorbing printing paste. Since the dihydroterpineol derivative as described above has low compatibility with the butyral resin as the binder of the green sheet, it does not dissolve or swell the butyral resin. Therefore, by using the electrode level difference absorbing printing paste of the present invention, it is possible to effectively prevent the occurrence of sheet attack when forming the blank pattern layer on the green sheet, the thickness variation of the resulting green sheet and The unevenness of the green sheet can be reduced.

  Further, in the method for manufacturing a laminated electronic component of the present invention, since the electrode level difference absorbing printing paste of the present invention is used, even when the thickness of the green sheet is reduced to 3 μm or less, particularly 1 μm or less, the electrode level difference When peeling the green sheet from a carrier sheet such as a PET film after printing the absorbent printing paste, the peelability of the green sheet is improved and the occurrence of wrinkles, holes, cracks, etc. in the green sheet can be effectively suppressed. At the same time, it is possible to effectively prevent problems caused by the thickness variation of the green sheet.

  That is, according to the method for manufacturing a laminated electronic component of the present invention, even when the thickness of the green sheet is as thin as 3 μm or less, particularly 1 μm or less, a normal laminate with little thickness variation can be obtained. Even when the size and capacity are increased, it is possible to suppress the occurrence of short-circuit failure, breakdown voltage failure (IR degradation), and delamination phenomenon (delamination) between the dielectric layer and the internal electrode layer. Can also improve the life characteristics. Furthermore, according to the method for manufacturing a laminated electronic component of the present invention, since the electrode level difference absorbing print paste of the present invention is used, the unevenness of the green sheet can be reduced and the contact area between the sheets can be increased. it can. Therefore, it is possible to effectively prevent the occurrence of structural defects and cracks in the obtained multilayer electronic component.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a 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 a part of the manufacturing process of the multilayer ceramic capacitor of FIG.
3A is an SEM photograph of the green sheet in the example of the present invention, and FIG. 3B is an SEM photograph of the green sheet in the comparative example.

  In the present embodiment, a multilayer ceramic capacitor will be described as an example of the multilayer electronic component.

Multilayer Ceramic Capacitor As shown in FIG. 1, a multilayer ceramic capacitor 1 according to an embodiment of the present invention includes a capacitor body 10 having a configuration in which dielectric layers 2 and internal electrode layers 3 are alternately stacked. A pair of external electrodes 4, 4 are formed at both ends of the capacitor body 10 and are electrically connected to the internal electrode layers 3 arranged alternately in the body 10. The internal electrode layers 3 are laminated so that the side end faces are alternately exposed on the surfaces of the two opposite ends of the capacitor body 10. The pair of external electrodes 4, 4 are formed at both ends of the capacitor body 10 and are connected to the exposed end surfaces of the alternately arranged internal electrode layers 3 to constitute a capacitor circuit.

  The outer shape and dimensions of the capacitor body 10 are not particularly limited and can be appropriately set depending on the application. Usually, the outer shape is substantially a rectangular parallelepiped shape, and the dimensions are usually vertical (0.4 to 5.6 mm) × It can be about horizontal (0.2 to 5.0 mm) × height (0.2 to 2.5 mm).

  The dielectric layer 2 is formed by firing a ceramic green sheet 30 shown in FIGS. 2A to 2C, which will be described later, and the material thereof is not particularly limited. For example, calcium titanate, strontium titanate and And / or a dielectric material such as barium titanate. In the present embodiment, the thickness of the dielectric layer 2 is preferably 3.0 μm or less, more preferably 0.5 to 2.0 μm.

  The internal electrode layer 3 is formed by firing a pre-fired electrode layer 40 composed of a conductor paste having a predetermined pattern shown in FIGS. 2B and 2C described later. The thickness of the internal electrode layer 3 is preferably reduced to 2 μm or less, more preferably 1 μm or less.

  As the material of the external electrode 4, copper, a copper alloy, nickel, a nickel alloy, or the like is usually used, but silver, a silver-palladium alloy, or the like can also be used. The thickness of the external electrode 4 is not particularly limited, but is usually about 10 to 50 μm.

Method for Manufacturing Multilayer Ceramic Capacitor Next, an example of a method for manufacturing the multilayer ceramic capacitor 1 according to this embodiment will be described.

Preparation of Dielectric Paste (1) First, a dielectric paste is prepared in order to manufacture a ceramic green sheet that will constitute the dielectric layer 2 shown in FIG. 1 after firing.
In the present embodiment, the dielectric paste is composed of an organic solvent-based paste obtained by kneading ceramic powder (dielectric material) and an organic vehicle.

  The ceramic powder can be appropriately selected from various compounds to be complex oxides and oxides, such as carbonates, nitrates, hydroxides, organometallic compounds, and the like, and can be used as a mixture. The ceramic powder is usually used as a powder having an average particle size of 0.4 μm or less, preferably about 0.1 to 0.3 μm. In order to form a very thin ceramic green sheet, it is desirable to use a powder finer than the thickness of the ceramic green sheet.

  In this embodiment, a butyral resin is used as the organic binder used in the organic vehicle. By using butyral resin as the organic binder, the coating strength of the obtained green sheet can be increased, and as a result, the green sheet can be made thinner. An example of such a butyral resin is polyvinyl butyral. The degree of polymerization of polyvinyl butyral is preferably 300 to 2400, more preferably 500 to 2000. The degree of butyralization of the resin is preferably 50 to 81.6%, more preferably 63 to 80%, and the amount of residual acetyl groups is preferably less than 6%, more preferably 3% or less.

  The organic solvent used in the organic vehicle is not particularly limited, and methyl ethyl ketone, butyl carbitol, acetone, toluene and the like are used.

  Content of each component in a dielectric paste is not specifically limited, For example, a dielectric paste can be prepared so that about 1 to about 50 weight% of solvent may be included.

  The dielectric paste may contain additives selected from various dispersants, plasticizers, dielectrics, subcomponent compounds, glass frit, insulators, and the like, if necessary. When these additives are added to the dielectric paste, the total content is desirably about 10% by weight or less.

  In this embodiment, since a butyral resin is used as the organic binder, the plasticizer content in this case is preferably about 25 to about 100 parts by weight with respect to 100 parts by weight of the binder.

Formation of Ceramic Green Sheet (2) Next, using this dielectric paste, a doctor blade method or the like is used, as shown in FIG. 2A, on the carrier sheet 20, preferably 3.0 μm or less, more preferably Forms a ceramic green sheet 30 with a thickness of 0.5 μm to 2.0 μm.

  As the carrier sheet 20, for example, a PET film or the like is used, and a film coated with silicone or the like is preferable in order to improve peelability. Although the thickness of the carrier sheet 20 is not specifically limited, Preferably it is 5-100 micrometers.

  The ceramic green sheet 30 is dried after being formed on the carrier sheet 20. The drying temperature of the ceramic green sheet 30 is preferably 50 to 100 ° C., and the drying time is preferably 1 to 20 minutes.

  The thickness of the ceramic green sheet 30 after drying shrinks to a thickness of 5 to 25% as compared with that before drying. In the present embodiment, the thickness of the dried ceramic green sheet 30 is 3 μm or less, preferably 2.0 μm or less, more preferably 1.0 μm or less, and even more preferably about 0.8 μm. This is in order to meet the demand for thinner layers in recent years. In addition, although the minimum of the thickness of a ceramic green sheet is not specifically limited, In this embodiment, it shall be about 0.5 micrometer.

Formation of Electrode Layer before Firing (3) Next, as shown in FIG. 2B, the surface of the ceramic green sheet 30 formed on the carrier sheet 20 becomes the internal electrode layer 3 shown in FIG. 1 after firing. A pre-firing electrode layer (internal electrode pattern) 40 having a predetermined pattern is formed.

  The thickness of the electrode layer 40 before baking is 2 micrometers or less, Preferably it is 0.5-1.5 micrometers. If the thickness of the pre-fired electrode layer 40 is too thick, the number of stacked layers must be reduced, and the acquired capacity is reduced, making it difficult to increase the capacity. On the other hand, if the thickness is too thin, it is difficult to form uniformly, and electrode breakage is likely to occur.

  The thickness of the pre-fired electrode layer 40 is in the above range in the current technology, but it is more desirable that the electrode layer 40 be thin in a range in which the electrode is not interrupted.

  The method for forming the pre-firing electrode layer 40 is not particularly limited as long as the layer can be formed uniformly, but in this embodiment, a screen printing method using a conductive paste is used.

  The conductor paste used in the present embodiment contains a conductor powder and an organic vehicle.

  Although it does not specifically limit as conductor powder, It is preferable to comprise at least 1 sort (s) chosen from Cu, Ni, and these alloys, More preferably, it comprises Ni or Ni alloy, and also these mixtures. .

  Ni or an Ni alloy is preferably an alloy of Ni and at least one element selected from Mn, Cr, Co, and Al, and the Ni content in the alloy is preferably 95% by weight or more. In addition, in Ni or Ni alloy, various trace components, such as P, Fe, and Mg, may be contained about 0.1 wt% or less.

  Such a conductor powder is not particularly limited in its shape, such as a spherical shape or a flake shape, and may be a mixture of these shapes. Moreover, the particle diameter of the conductor powder is generally 0.5 μm or less, preferably about 0.01 to 0.4 μm in the case of a spherical shape. This is to realize the thinning more surely.

  The conductor powder is preferably contained in the conductor paste in an amount of 30 to 60% by weight, more preferably 40 to 50% by weight.

  The organic vehicle contains an organic binder and a solvent as main components.

  Examples of the organic binder include ethyl cellulose, acrylic resin, polyvinyl butyral, polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, and copolymers thereof. In this embodiment, ethyl cellulose is the main component. It is preferable to do. When ethyl cellulose is the main component of the organic binder, the content of ethyl cellulose in the binder is preferably 95% by weight or more, and more preferably 100% by weight. A resin that can be used in combination with ethyl cellulose, although in a very small amount, includes an acrylic resin.

  The organic binder is preferably contained in the conductor paste in an amount of 1 to 10 parts by weight with respect to 100 parts by weight of the conductor powder. If the amount of the binder is too small, the film strength after printing tends to decrease. If the amount is too large, the metal filling density of the electrode layer before firing decreases, and the smoothness of the internal electrode formed after firing can be maintained. Can not.

  As the solvent, any known solvent such as terpineol, butyl carbitol, and kerosene can be used. However, in this embodiment, the main component is a dihydroterpineol derivative used in an electrode step absorption printing paste described later. Is preferred. This is because, by using a dihydroterpineol derivative as a main component, the same effects as those in the electrode level difference absorbing printing paste described later can be obtained.

  When the main component is a dihydroterpineol derivative as a solvent, the content of the dihydroterpineol derivative in the solvent is preferably 95% by weight or more, and more preferably 100% by weight. Examples of the solvent that can be used in combination with a dihydroterpineol derivative in a trace amount include terpinyl acetate, terpineol, and dihydroterpineol.

  The solvent is contained in the conductor paste in an amount of preferably 50 to 200 parts by weight, more preferably 80 to 100 parts by weight, with respect to 100 parts by weight of the conductor powder. If the amount of the solvent is too small, the paste viscosity becomes too high, and if it is too much, the paste viscosity becomes too low.

  The total content of the organic binder and the solvent in the organic vehicle is preferably 95% by weight or more, and more preferably 100% by weight. There are plasticizers, dispersants, leveling agents, and the like that can be contained in an organic vehicle together with an organic binder and a solvent, although in a very small amount.

  In the conductor paste, the same ceramic powder as the ceramic powder contained in the dielectric paste may be contained as a co-material. The common material has an effect of suppressing sintering of the conductor powder in the firing process. The ceramic powder (common material) is preferably contained in the conductive paste in an amount of 5 to 30 parts by weight with respect to 100 parts by weight of the conductive powder. If the amount of the co-material is too small, the sintering suppression effect of the conductor powder is lowered, the lineability (continuity) of the internal electrode is deteriorated, and the apparent dielectric constant is lowered. On the other hand, if the amount of the co-material is too large, the lineability of the internal electrode tends to deteriorate and the apparent dielectric constant tends to decrease.

  In order to improve adhesion, the conductor paste may contain a plasticizer. Examples of the plasticizer include phthalic acid esters such as benzylbutyl phthalate (BBP), adipic acid, phosphoric acid esters, glycols, and the like. In the present embodiment, preferably, dioctyl adipate (DOA), butyl butylene glycol phthalate (BPBG), didodecyl phthalate (DDP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), dioctyl phthalate ( DOP), dibutyl sebacate and the like are used. Of these, dioctyl phthalate (DOP) is particularly preferable. The plasticizer is contained in an amount of preferably 25 to 150 parts by weight, more preferably 25 to 100 parts by weight with respect to 100 parts by weight of the organic binder in the organic vehicle. By adding the plasticizer, the adhesive force of the pre-firing electrode layer 40 formed using the paste is increased, and the adhesive force between the pre-firing electrode layer 40 and the green sheet 30 is improved. In order to obtain such an effect, the amount of the plasticizer added is preferably 25 parts by weight or more. However, if the addition amount exceeds 150 parts by weight, it is not preferable because excess plasticizer oozes out from the pre-firing electrode layer 40 formed using the paste.

  The conductor paste can be obtained by kneading the above components with a ball mill or the like to form a slurry.

Formation of Blank Pattern Layer (4) In the present embodiment, after the pre-firing electrode layer 40 having a predetermined pattern is formed on the surface of the ceramic green sheet 30 by the printing method or before, the firing shown in FIG. As shown in FIG. 2C, a blank pattern layer 60 having substantially the same thickness as that of the pre-firing electrode layer 40 is formed in the surface gap (blank pattern portion 50) of the ceramic green sheet 30 on which the front electrode layer 40 is not formed. Form. The reason why the thickness of the blank pattern layer 60 is set to be substantially the same as that of the pre-firing electrode layer 40 is that a step is generated unless it is substantially the same.

  In this embodiment, the blank pattern layer 60 is formed by a screen printing method using an electrode level difference absorbing printing paste.

  The electrode level difference absorbing printing paste used in the present embodiment contains ceramic powder and an organic vehicle.

  It is preferable to use a ceramic powder having the same composition and the same average particle size as the ceramic powder contained in the ceramic green sheet 30.

  The ceramic powder is preferably contained in the electrode level difference absorbing printing paste in an amount of 25 to 70% by weight, more preferably 30 to 60% by weight. If the content of the ceramic powder is too small, the paste viscosity becomes small and printing is difficult. Moreover, when there is too much content rate of ceramic powder, it exists in the tendency for it to become difficult to make printing thickness thin.

  The organic vehicle contains an organic binder and a solvent as main components.

  As the organic binder, it is preferable that ethyl cellulose is a main component in the present embodiment. The content of ethyl cellulose in the organic binder is preferably 95% by weight or more, and more preferably 100% by weight. By using ethyl cellulose as the organic binder, it is possible to improve the printing characteristics of the electrode level difference absorbing print paste, and in particular, to improve the ability to separate the electrode level difference absorbing print paste from the printing screen during printing. Can do. Resins that can be used in combination with ethyl cellulose, although in very small amounts, include acrylic resins and polyvinyl butyral resins.

  The organic binder is contained in the electrode level difference absorbing printing paste in an amount of preferably 2.5 to 16 parts by weight with respect to 100 parts by weight of the ceramic powder. If the amount of the binder is too large or too small, the printing suitability and accuracy such as leveling and detachability are deteriorated.

  The solvent is mainly composed of a dihydroterpineol derivative. In the dihydroterpineol derivative used in this embodiment, a side chain containing one or more acyl groups is condensed to dihydroterpineol, and the total number of carbon atoms contained in the side chain containing these acyl groups is 3 or more. is there. By setting the total number of carbon atoms to 3 or more, the polarity of the solvent itself can be lowered, and the compatibility with the butyral resin as the organic binder contained in the green sheet can be lowered. As a result, sheet attack can be effectively prevented. The upper limit of the total number of carbon atoms contained in the side chain is not particularly limited, but is usually about 5.

The dihydroterpineol derivative is preferably one or more selected from the following formulas (1) to (4).
However, in the above formulas (1) and (2), k ≧ 2, and in the above formulas (3) and (4), m and n ≧ 1.

The dihydroterpineol derivatives represented by the above formulas (1) and (2) are derivatives having one side chain containing an acyl group. That is, it has a side chain represented by [—COC _k H _{2k + 1} ]. The dihydroterpineol derivatives represented by the above formulas (3) and (4) are derivatives having two side chains containing an acyl group. That is, it has a side chain represented by [—COC _m H _{2m + 1} ] and [—COC _n H _{2n + 1} ], respectively.

In the above formula (1), for example, when k = 2, the side chain containing an acyl group is represented by [—COC ₂ H ₅ ], and the total number of carbon atoms contained in the side chain is 3. . In the above formula (3), for example, when m = 1 and n = 1, the side chain including the acyl group is both represented by [—COCH ₃ ], and the number of carbons contained in the side chain Is 4 in total.

  In the present embodiment, dihydroterpinylpropionate represented by the above formula (1) or (2), in which k is k = 2, is particularly preferable. This is because the dispersibility of the ceramic powder and the organic binder in the electrode level difference absorbing print paste can be kept high while maintaining the compatibility with the butyral resin low.

  The content of the dihydroterpineol derivative in the solvent is preferably 90% by weight or more, and more preferably 100% by weight. Examples of the solvent that can be used in combination with a dihydroterpineol derivative in a trace amount include terpinyl acetate, terpineol, and dihydroterpineol.

  The solvent is contained in the electrode level difference absorbing printing paste in an amount of preferably 50 to 240 parts by weight, more preferably 80 to 200 parts by weight, based on 100 parts by weight of the ceramic powder. If the amount of the solvent is too small, the viscosity is high, the printing suitability and accuracy are deteriorated and the thickness is increased. If the amount is too large, the viscosity is low and the paste drips from the screen mesh, resulting in inconveniences that printability and accuracy deteriorate.

  In addition, the electrode level difference absorbing printing paste may contain various additives such as a dispersant, a plasticizer, an adhesive, and an antistatic agent.

  The dispersant is not particularly limited. For example, a polymer material such as an ester polymer or carboxylic acid is used, and the content thereof is preferably 0.25 to 1. with respect to 100 parts by weight of the ceramic powder. 5 parts by weight, more preferably 0.5 to 1.0 parts by weight is preferably contained.

  Although there is no limitation in particular as a plasticizer, For example, the thing similar to what is used for the above-mentioned conductor paste can be used. The content of the plasticizer is desirably 10 to 200 parts by weight, more preferably 50 to 100 parts by weight with respect to 100 parts by weight of the organic binder in the organic vehicle.

  The antistatic agent is not particularly limited. For example, an imidazoline-based antistatic agent is used, and the content thereof is 0.1 to 0.75 parts by weight, more preferably 100 parts by weight of the ceramic powder. It is preferable to contain by 0.25-0.5 weight part.

  This electrode level difference absorbing print paste is printed on the blank pattern portion 50 between the pre-firing electrode layers 40 shown in FIG. Thereafter, the pre-firing electrode layer 40 and the blank pattern layer 60 are dried as necessary. The drying temperature is not particularly limited, but is preferably 50 to 120 ° C., and the drying time is preferably 1 to 15 minutes.

Preparation of Green Chip, baking, etc. (5) Next, above that, the ceramic green sheet 30 before firing electrode layer 40 and the blank pattern layer 60 having a predetermined pattern is formed on the surface by laminating a plurality of green chips The external electrode paste is printed or transferred to the capacitor body 10 made of a sintered body, which is formed through a binder removal process, a firing process, and an annealing process performed as necessary, and fired. The external electrodes 4 and 4 are formed, and the multilayer ceramic capacitor 1 is manufactured.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the embodiment mentioned above at all, and can be variously modified within the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, the multilayer ceramic capacitor is exemplified as the electronic component according to the present invention. However, the electronic component according to the present invention is not limited to the multilayer ceramic capacitor and can be applied to a multilayer ceramic substrate or the like. It is.

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

Example 1
Preparation of each paste First, an electrode step absorption printing paste for forming a blank pattern layer and a dielectric paste for forming a ceramic green sheet were prepared by the following methods.

Preparation of Electrode Step Absorbing Printing Paste Ethyl cellulose and dihydroterpinyl propionate (mentanol propionate) represented by the following formula (1), where k is k = 2, were prepared. Then, 10 parts by weight of ethyl cellulose was dissolved in 100 parts by weight of dihydroterpinyl propionate to prepare an organic vehicle.
Next, a BaTiO ₃ ceramic powder having an average particle diameter of 0.5 μm was prepared, and 75 parts by weight of the organic vehicle was added to 100 parts by weight of the ceramic powder, kneaded by a ball mill, and slurried to absorb the electrode level difference. A printing paste was obtained.

Preparation of Dielectric Paste BaTiO ₃ -based ceramic powder, polyvinyl butyral (PVB), and methanol were prepared. Next, 10 parts by weight of organic binder and 150 parts by weight of solvent were weighed with respect to the ceramic powder, kneaded with a ball mill, and slurried to obtain a dielectric paste.

Preparation of Test Sample The dielectric paste prepared above was applied to a predetermined thickness on a PET film by a doctor blade method and dried to form a ceramic green sheet having a thickness of 1 μm after drying.

  Next, on the obtained ceramic green sheet, the electrode paste absorbing print paste prepared above is formed in a predetermined pattern by a screen printing method, and the blank of the predetermined pattern having a thickness after drying of about 1.0 μm A ceramic green sheet (test sample) having a pattern layer was obtained.

Evaluation of Test Sample Using the obtained test sample, “presence / absence of sheet attack” and “peelability of PET film from ceramic green sheet” were evaluated.

  “Presence / absence of sheet attack” means that the ceramic green sheet is observed with an electron microscope (SEM) from the side opposite to the blank pattern side (the surface in contact with the PET film), and the degree of dissolution of the ceramic green sheet is confirmed by the degree of deformation and hue It was done by doing. As a result, in this example using dihydroterpinylpropionate as a solvent, dissolution of the ceramic green sheet could not be observed. In addition, the obtained SEM photograph is shown in FIG.

  The “peelability of the PET film from the ceramic green sheet” was measured by measuring the peel strength when peeling the PET film from the test sample. The peel strength was measured by attaching a load cell to the end of a 9 cm × 20 cm green sheet with PET (a marginal part that creates a trigger for peeling) with an adhesive tape and measuring the load (load) while moving it upward. . As a result, the peel strength was an appropriate value of 5.0 gf or less. As a result, it was confirmed that the necessary holding force for the ceramic green sheet could be maintained and the efficiency of the peeling work was good.

Preparation of Multilayer Ceramic Chip Capacitor Sample First, a dielectric paste, an electrode step absorption printing paste, and a conductor paste were prepared.
The dielectric paste and the electrode level difference absorbing printing paste were prepared as described above. Moreover, the conductor paste was produced by the following method.

  That is, Ni particles having an average particle diameter of 0.3 μm as a conductor powder, ethyl cellulose as a binder, and dihydroterpinylpropionate as a solvent were prepared. Next, 8 parts by weight of a binder was dissolved with respect to 100 parts by weight of the solvent to prepare an organic vehicle. Then, 50 parts by weight of an organic vehicle was added to 100 parts by weight of the conductor powder, kneaded with a ball mill, and slurried to obtain a conductor paste.

  Next, the dielectric paste prepared above was applied to the PET film at a predetermined thickness by a doctor blade method and dried to prepare a green sheet for an outer layer having a thickness after drying of 20 μm. Similarly, an inner layer ceramic green sheet having a thickness of 1 μm after drying was formed. In this example, the inner layer green sheet was sandwiched between the five outer layer green sheets (100 μm). A plurality of ceramic green sheets for the inner layer were prepared as first green sheets.

  Next, an electrode layer (internal electrode pattern) 40 having a thickness of about 1 μm after drying is formed on the obtained first green sheet by a screen printing method using a conductive paste (see FIG. 2B). ) Was formed. After forming the pre-firing electrode layer 40, screen printing using an electrode step absorption printing paste on a blank pattern portion 50 (see FIG. 2B) where the electrode layer 40 is not formed on the first green sheet. A blank pattern layer 60 (see FIG. 2C) having substantially the same thickness as the electrode layer 40 was formed by the method. Then, a ceramic green sheet 30 having an electrode layer 40 and a blank pattern layer 60 as shown in FIG. In this example, this ceramic green sheet 30 was used as a second green sheet, and a plurality of these were prepared.

Next, the green sheet group was formed by laminating the outer layer green sheets until the thickness reached 100 μm. On this green sheet group, 200 second green sheets are laminated, and further, an outer layer green sheet group is laminated and formed thereon, and heated under conditions of a temperature of 60 ° C. and a pressure of 1.0 ton / cm ^2. -Pressurized to obtain a green ceramic laminate.

  Next, after cutting the obtained laminated body into a predetermined size, binder removal treatment, firing and annealing were performed to obtain a sintered body.

  Next, after polishing the end face of the obtained sintered body by sand blasting, an In—Ga alloy was applied to form a test electrode to obtain a multilayer ceramic chip capacitor sample.

  The size of the capacitor sample is 1.6 mm long × 0.8 mm wide × 0.8 mm high. The thickness of the dielectric layer 2 sandwiched between the pair of internal electrode layers is about 1 μm, and the thickness of the internal electrode layer 3 is 1 μm. Met.

Evaluation of Capacitor Sample The obtained capacitor sample was evaluated for short-circuit failure characteristics, withstand voltage characteristics (IR characteristics), life characteristics, and presence / absence of delamination.

  The short defect characteristics were evaluated by measuring the short defect rate. Specifically, with respect to 100 capacitor samples, 1.5 V was applied by a tester, and a sample having a value of 1 MΩ or less was determined to be defective, and a defective rate of less than 10% was considered good.

The withstand voltage characteristics (IR characteristics) were evaluated by measuring the withstand voltage defect rate. Specifically, a DC voltage 12 times the rated voltage (6.3 V) was applied to 100 capacitor samples for 3 seconds, and a sample with a resistance of less than 10 ⁴ Ω was determined to have a poor withstand voltage. A defective rate of less than 10% was considered good.

  The life characteristics were evaluated by measuring the life time. Specifically, 100 capacitor samples are held in a state where a direct current voltage of 85 ° C. and 12.6 V is applied, and the time from the start of application until the insulation resistance drops by one digit is defined as the life time. 1000 hours or more was considered good.

  About the presence or absence of delamination, the baking base was grind | polished and the lamination state was observed visually. In this example, the presence or absence of delamination was evaluated for 100 capacitor samples, and 0 out of 100 delaminations was considered good.

  Table 1 shows the results of the capacitor sample evaluation.

Comparative Examples 1-3
Except that the solvent used when preparing the electrode level difference absorbing printing paste was changed to terpineol (Comparative Example 1), dihydroterpineol (Comparative Example 2), dihydroterpinyl acetate (Comparative Example 3), respectively. In the same manner as in Example 1, capacitor samples were produced and evaluated in the same manner. The results are shown in Table 1.

In Table 1, delamination is expressed as “number of samples with delamination / number of measured samples”.

As shown in Evaluation Table 1 of Example 1 and Comparative Examples 1 to 3, Example 1 using an electrode step absorption printing paste containing dihydroterpinylpropionate is an electrode step absorption containing terpineol or dihydroterpineol. Compared with Comparative Examples 1 and 2 using the printing paste for printing, it can be confirmed that any of the short-circuit defects, withstand voltage characteristics, life characteristics, and delamination is dramatically improved. Further, in comparison with Comparative Example 3 using the electrode level difference absorbing printing paste containing dihydroterpinyl acetate, short-circuit defects, withstand voltage characteristics, life characteristics, and delamination are improved. That is, in Example 1, which is within the scope of the present invention, it can be confirmed that the reliability is improved even when the thickness of the green sheet is reduced to 1 μm as compared with Comparative Examples 1 to 3.

  3A and 3B show SEM photographs of the ceramic green sheet taken from the surface opposite to the blank pattern side (the surface in contact with the PET film). 3A and 3B, FIG. 3A is an SEM photograph of Example 1, and FIG. 3B is Comparative Example 2 obtained by the same method as in Example 1. It is a SEM photograph of.

  From FIG. 3 (B), in Comparative Example 2, it can be confirmed that a sheet attack due to the solvent occurs. That is, in Comparative Example 2, it can be confirmed that the polyvinyl butyral resin in the ceramic green sheet is dissolved by the influence of the solvent, and the dissolved polyvinyl butyral resin is re-solidified in the vicinity of the PET film surface ( (Black part in the figure). On the other hand, from FIG. 3A, in Example 1, the dissolution and re-solidification of the polyvinyl butyral resin as in Comparative Example 2 was not confirmed, and it was confirmed that the occurrence of sheet attack was effectively prevented.

FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. 2A to 2C are cross-sectional views illustrating a part of the manufacturing process of the multilayer ceramic capacitor of FIG. 3A is an SEM photograph of the green sheet in the example of the present invention, and FIG. 3B is an SEM photograph of the green sheet in the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Multilayer ceramic capacitor 10 ... Capacitor body 2 ... Dielectric layer 3 ... Internal electrode layer 4 ... External electrode 20 ... Carrier sheet 30 ... Ceramic green sheet 40 ... Electrode layer before firing (internal electrode pattern)
50 ... margin pattern portion 60 ... margin pattern layer

Claims (7)

An electrode step absorption printing paste used for manufacturing a laminated electronic component,
A ceramic powder, an organic binder, and a solvent containing a dihydroterpineol derivative,
The dihydroterpineol derivative contained in the solvent is characterized in that a side chain containing one or more acyl groups is condensed with dihydroterpineol, and the total number of carbon atoms contained in the side chain is 3 or more. Print paste for absorbing electrode level difference. The electrode step-absorbing printing paste according to claim 1, wherein the dihydroterpineol derivative is one or more selected from the following formulas (1) to (4).
However, in the above formulas (1) and (2), k ≧ 2, and in the above formulas (3) and (4), m and n ≧ 1.   The electrode level difference absorbing printing paste according to claim 2, wherein the dihydroterpineol derivative is represented by the formula (1) or (2), and k in the formula is k = 2.   The said organic binder is ethyl cellulose, The printing paste for electrode level | step difference absorption in any one of Claims 1-3. A green sheet containing butyral resin;
A method of manufacturing a laminated electronic component having a step of alternately stacking a plurality of pre-fired electrode layers of a predetermined pattern to obtain a green laminate,
Before forming the laminate, a blank pattern layer having substantially the same thickness as the pre-firing electrode layer is formed in a gap portion of the pre-firing electrode layer of a predetermined pattern,
A method for manufacturing a laminated electronic component, wherein the electrode level difference absorbing print paste according to claim 1 is used as the electrode level difference absorbing print paste for forming the blank pattern layer.   The method for manufacturing a laminated electronic component according to claim 5, wherein the thickness of the green sheet is 3 μm or less. The electrode level difference absorbing printing paste according to any one of claims 1 to 4, wherein the ceramic powder is contained in an amount of 25 to 70% by weight.