WO2010109562A1 - Method of producing multilayer ceramic electronic component - Google Patents

Abstract

A method of producing a multilayer ceramic electronic component, which coats ceramic slurry over an internal electrode pattern and ceramic green sheet to suppress and prevent "sheet attacks" occurring when forming the ceramic green sheet. This method comprises: coating and drying a ceramic slurry on a substrate (1) to form a ceramic green sheet (2a); applying and drying an internal electrode paste on the sheet to form an internal electrode pattern (3a); coating and drying a resin paste on the sheet and the pattern to form an unhardened protective resin layer (4), said resin paste including a solvent and a resin, and said solvent having difficulty dissolving the organic binders contained in the ceramic green sheet and internal electrode pattern; then, in the same manner, forming a ceramic green sheet (2b) and forming an internal electrode pattern (3b) to form a composite multilayer structure (10). Then, the steps of stacking the composite multilayer structure (10) are repeated so as to form an unfired multilayer structure which will become the multilayer ceramic electronic component after firing.

Description

Manufacturing method of multilayer ceramic electronic component

The present invention relates to a method of manufacturing a multilayer ceramic electronic component manufactured by forming a ceramic green sheet by applying a ceramic slurry and forming an internal electrode pattern by applying an internal electrode paste in a predetermined pattern. About.

A multilayer ceramic electronic component having a structure in which ceramic layers and internal electrode layers are alternately stacked, such as a multilayer ceramic capacitor, forms a ceramic green sheet by coating a ceramic slurry on a carrier film, for example, An internal electrode paste is applied (printed) on a ceramic green sheet to form an internal electrode pattern, and then the sheets punched into a predetermined pattern are sequentially stacked to form a laminate, which is then fired. Is common.
However, as electronic components become thinner and have higher characteristics, the number of laminated ceramic green sheets increases, the time required for the lamination process becomes longer, and productivity is reduced.

Therefore, the internal electrode pattern is formed on the ceramic green sheet formed by printing the ceramic slurry formed on the carrier film, and the formation of the green sheet and the internal electrode pattern by further printing the ceramic slurry thereon. Proposing a method to improve production efficiency by shortening the time required for the lamination process by forming a minority unit laminate of ceramic green sheets and internal electrode patterns by stacking and stacking composite laminates punched from this (See Patent Document 1).

However, as described above, in the method of forming a ceramic green sheet by further printing a ceramic slurry on the internal electrode pattern, organic solvent in the lower internal electrode pattern or ceramic green sheet is formed by the solvent of the ceramic slurry printed as the upper layer. There is a problem that a so-called sheet attack occurs in which the system binder is dissolved, resulting in a decrease in accuracy of the internal electrode pattern and a short circuit failure due to a pinhole generated in the ceramic green sheet.

Also, the sheet attack occurs when the internal electrode paste is applied on the ceramic green sheet depending on the combination of the organic binder contained in the ceramic green sheet and the internal electrode paste. As a technique for preventing sheet attack in this case, a ceramic green sheet is formed using a ceramic slurry containing a curable resin, and the curable resin in the ceramic green sheet is cured before applying the internal electrode paste. Thus, there has been proposed a method for manufacturing a multilayer electronic component that suppresses or prevents the organic binder in the ceramic green sheet from dissolving in the internal electrode paste (see Patent Document 2).

In the case of this method, the cured ceramic green sheet is less susceptible to attack by the internal electrode paste, but when this method is applied to the method disclosed in Patent Document 1, the ceramic green sheet itself is cured. Therefore, there are problems such as insufficient adhesion between layers, causing delamination, and causing cracks in the lamination process.

JP-A-8-250370 JP 2006-66852 A

The present invention solves the above-mentioned problems, and suppresses and prevents attacks to the internal electrode pattern by the ceramic green sheet (ceramic slurry) formed as an upper layer of the internal electrode pattern without curing the ceramic green sheet. In addition, it is possible to reliably manufacture highly reliable multilayer ceramic electronic components with desired characteristics, and to construct materials such as ceramic green sheets and internal electrode paste (for example, types of solvents and organic binders) It is an object of the present invention to provide a method for manufacturing a multilayer ceramic electronic component having a high degree of freedom in selecting the above.

In order to solve the above problems, a method for manufacturing a multilayer ceramic electronic component of the present invention (Claim 1) includes:
A method for producing a multilayer ceramic electronic component having a structure in which a ceramic layer and an internal electrode are laminated, and the internal electrodes are disposed so as to face each other through the ceramic layer,
(a) A step of applying a ceramic slurry containing an organic binder, a solvent and a ceramic raw material on a substrate and drying to form a ceramic green sheet;
(b) On the ceramic green sheet, an internal electrode paste containing an organic binder and a conductive component is applied and dried to form an internal electrode pattern;
(c) On the ceramic green sheet and the internal electrode pattern, a resin paste containing a solvent and a resin that hardly dissolves the organic binder contained in the ceramic green sheet and the internal electrode pattern is applied and dried. Forming a cured protective resin layer; and
(d) applying the ceramic slurry on the uncured protective resin layer and drying to form a ceramic green sheet;
(e) providing the internal electrode paste on the ceramic green sheet and drying to form an internal electrode pattern;
The steps (c) to (e) are performed once or more.

In addition, the method for manufacturing the multilayer ceramic electronic component of the present invention includes:
A method of manufacturing a multilayer ceramic electronic component having a structure in which ceramic layers and internal electrodes are alternately stacked, and the internal electrodes are disposed so as to face each other through the ceramic layers,
(a) On the substrate, an internal electrode paste containing an organic binder and a conductive component is applied and dried to form an internal electrode pattern;
(b) A resin paste containing a solvent and a resin that hardly dissolve the organic binder contained in the internal electrode pattern is applied onto the internal electrode pattern and the base material around the internal electrode pattern, and then dried and uncured protection Forming a resin layer;
(c) applying a ceramic slurry containing an organic binder, a solvent and a ceramic raw material on the uncured protective resin layer, and drying to form a ceramic green sheet;
(d) applying the internal electrode paste on the ceramic green sheet and drying to form an internal electrode pattern;
(e) On the ceramic green sheet and the internal electrode pattern, a resin paste containing a solvent and a resin that hardly dissolve the organic binder contained in the ceramic green sheet and the internal electrode pattern is applied and dried. Forming an uncured protective resin layer;
(f) applying a ceramic slurry containing an organic binder, a solvent and a ceramic raw material on the uncured protective resin layer, and drying to form a ceramic green sheet;
The steps (d) to (f) are performed once or more.

The method for producing a multilayer ceramic electronic component of the present invention comprises the steps (a) to (e) of claim 1 or the steps (a) to (f) of claim 2 on the substrate. A step of stacking a composite laminate including a plurality of layers of ceramic green sheets and a plurality of layers of internal electrode patterns, and forming an unsintered laminate that becomes a multilayer ceramic electronic component element after firing. It is characterized by having.

Further, in the method for manufacturing a multilayer ceramic electronic component of the present invention, after the step of forming the internal electrode pattern, a step between the internal electrode pattern and the periphery thereof is formed in a region around the formed internal electrode pattern. A step-absorbing layer is formed by applying and drying a step-absorbing layer ceramic paste to eliminate the step-absorbing layer.

Further, before the step of forming the internal electrode pattern, the step absorption is performed around the region where the internal electrode pattern is to be formed, so as to eliminate the step between the internal electrode pattern formed thereafter and the surrounding area. Applying and drying a ceramic paste for layer to form a step absorption layer, and then applying the internal electrode paste to a region where the step absorption layer is not formed and drying to form the internal electrode pattern It is a feature.

In the method for manufacturing a multilayer ceramic electronic component of the present invention, it is desirable that the protective resin layer has a thickness of 0.03 to 0.20 μm.

In the method for manufacturing a multilayer ceramic electronic component of the present invention, it is desirable that the resin paste used for forming the protective resin layer is a resin paste containing an aqueous solvent and a water-soluble resin.

The aqueous solvent preferably contains water and an organic solvent, and the water content is 30% by weight or more.

The aqueous solvent preferably contains alcohol as the organic solvent.

In addition, it is desirable that the water-soluble resin contained in the protective resin layer is polyvinyl alcohol having a polymerization degree of 500 or more and a hydroxyl group content of 90% or more.

Further, as the resin paste used for forming the protective resin layer, the ratio of the ceramic powder in the protective resin layer formed by curing the resin paste is not more than the critical particle volume fraction. It is desirable to use a ceramic powder.

As described above, the method for producing a multilayer ceramic electronic component of the present invention (Claims 1 and 2) is a method in which a ceramic slurry is applied to an internal electrode pattern or an internal electrode pattern and a ceramic green sheet via a protective resin layer. Since it is applied, sheet attack due to the ceramic slurry can be reliably suppressed and prevented, and a highly reliable multilayer ceramic electronic component having desired characteristics can be reliably manufactured.
That is, the present invention applies an uncured by applying a resin paste containing a solvent and a resin that hardly dissolves the binder of the ceramic green sheet and the internal electrode pattern onto the internal electrode pattern or the internal electrode pattern and the ceramic green sheet. The protective resin layer is formed, and then the ceramic slurry is applied thereon and dried to form a ceramic green sheet. Therefore, the ceramic slurry is not directly brought into contact with the internal electrode pattern and the ceramic green sheet. Therefore, it is possible to reliably suppress and prevent seat attack.

In addition, it is possible to effectively prevent sheet attack due to ceramic slurry to the ceramic green sheet and internal electrode pattern without requiring curing of the ceramic green sheet, so that accuracy is not caused without causing delamination. It is possible to efficiently manufacture a monolithic ceramic electronic component having a high internal electrode.

In addition, the ceramic slurry is applied on the protective resin layer containing a resin and a solvent that hardly dissolves the organic binder of the ceramic green sheet and the internal electrode pattern, so that the solvent used for the ceramic slurry can be freely selected. The degree can be improved dramatically.

In addition, since the protective resin layer is interposed between the internal electrode paste and the ceramic slurry (the edge is cut by the protective resin layer), the internal electrode paste is related to the solvent and the organic binder contained in the ceramic slurry. The type of organic binder to be contained is not restricted. Therefore, also in this respect, the degree of freedom in material selection is improved.

In the present invention, the application of the ceramic slurry includes a case where the ceramic slurry is formed into a sheet by a coater method or a doctor blade method, or a case where the ceramic slurry is printed into a sheet by a gravure printing method. It is a broad concept.

Examples of the method of applying the internal electrode paste include a method of printing and attaching the internal electrode paste on the ceramic green sheet by a screen printing method or the like. The present invention is not limited to this, and various other methods can be used.

In the invention of claim 2, when the first protective resin layer is formed, the resin paste to be used may be one that satisfies the requirement that the organic binder contained in the internal electrode pattern is difficult to dissolve. However, when forming the second and subsequent protective resin layers, it is necessary to use a resin paste that hardly dissolves the organic binder contained in each of the previously formed internal electrode pattern and ceramic green sheet. . However, it is usually possible to use the same resin paste by appropriately selecting the type of solvent and the type of organic binder.

In addition, by repeating the process of stacking a composite laminate including a plurality of layers of ceramic green sheets and a plurality of layers of internal electrode patterns, and forming an unfired laminate that becomes a multilayer ceramic electronic component element after firing, It becomes possible to efficiently manufacture a multilayer ceramic electronic component by reducing the time required for the lamination process.

In addition, after forming the internal electrode pattern, the step absorption layer is formed by applying the ceramic paste for the step absorption layer to the region around the internal electrode pattern, thereby eliminating the step and preventing delamination. A highly reliable multilayer ceramic electronic component can be obtained. If a step absorption layer is provided, the number of materials used increases, so in the conventional technology, the solvent used in the ceramic slurry and the internal electrode paste and the organic system are used in order to avoid sheet attack. Although the selection range of the binder is narrowed, in the present invention, the protective resin layer is interposed at a predetermined position as described above and functions to prevent sheet attack, so that the degree of freedom in selecting the solvent is kept high. be able to.
The step-absorbing layer ceramic paste preferably has a component that hardly dissolves the organic binder contained in the internal electrode pattern, but only contacts the internal electrode pattern at its peripheral edge. It ’s not a very strict requirement.

Also, before forming the internal electrode pattern, apply the step absorbing layer ceramic paste around the area where the internal electrode pattern is to be formed and dry to form the step absorbing layer, and then form the internal electrode pattern Similar effects can be obtained even when the internal electrode pattern is formed by applying and drying the internal electrode paste to the region to be formed.
In this case, it is desirable that the internal electrode paste applied to the region where the step absorption layer is not formed is such that the component hardly dissolves the organic binder contained in the step absorption layer. Since the paste only touches the step absorption layer at the peripheral edge thereof, it is not a very strict requirement.

In addition, by setting the thickness of the protective resin layer to 0.03 to 0.20 μm, it is possible to efficiently suppress both electrical characteristic defects due to sheet attack and structural defects due to delamination. It is preferable.
When the thickness of the protective resin layer is less than 0.03 μm, the effect of preventing sheet attack is insufficient, and when it exceeds 0.20 μm, delamination tends to occur.

Further, in the method for manufacturing a multilayer ceramic electronic component of the present invention, by using a resin paste containing an aqueous solvent and a water-soluble resin as a resin paste used for forming a protective resin layer, an internal electrode pattern and a ceramic green sheet are used. It is possible to reliably form a protective resin layer that protects the internal electrode pattern and the ceramic green sheet from attack by the ceramic slurry (solvent therein) without dissolving the organic binder contained therein. It becomes possible.

Moreover, in this invention, the organic binder contained in a ceramic green sheet and an internal electrode pattern is used by using what contains an organic solvent in the range which satisfies the requirement that the content rate of water is 30 weight% or more as an aqueous solvent. It is possible to realize an evaporation rate of the aqueous solvent that can shorten the drying time while suppressing and preventing the dissolution, and productivity can be improved.

In addition, when the content of water is less than 30% by weight and the ratio of the organic solvent is increased to 70% or more, the organic binder contained in the internal electrode pattern and the ceramic green sheet is easily dissolved, which is preferable. Absent. Also, when the solvent is only water or when the water content is high, it is preferable in that it is difficult to dissolve the organic binder contained in the internal electrode pattern and the ceramic green sheet, but in the drying process after applying the resin paste This is not preferable because a long drying time is required and productivity is lowered.

In addition, by using an aqueous solvent containing an alcohol as an organic solvent, it is possible to suppress and prevent the organic binder contained in the ceramic green sheet and the internal electrode pattern from being dissolved, while increasing the evaporation rate of the solvent. It becomes possible to keep the level at which there is no problem in practical use, and the present invention can be made more effective.

Further, as the water-soluble resin contained in the protective resin layer, polyvinyl alcohol having a degree of polymerization of 500 or more and a hydroxyl group content of 90% or more is used to be applied on the ceramic green sheet and the internal electrode pattern via the protective resin layer. The sheet attack by the ceramic slurry can be efficiently suppressed and prevented, and the occurrence of short circuit failure due to the sheet attack can be effectively suppressed.

Further, as the resin paste, one containing ceramic powder at a ratio such that the ratio of ceramic powder in the protective resin layer is equal to or less than the critical particle volume fraction is used, that is, the protective resin layer contains ceramic powder. In such a case, in the firing step, it becomes possible to diffuse the ceramic powder in the protective resin layer to the lower and upper ceramic green sheets, and to firmly bond the lower and upper ceramic green sheets, such as delamination. The occurrence of structural defects can be prevented more reliably.

It is sectional drawing which shows an example of the multilayer ceramic capacitor manufactured by the manufacturing method of the multilayer ceramic electronic component of this invention. It is sectional drawing which shows the composite laminated body formed at 1 process of the manufacturing method of the laminated coil component of Example 1 of this invention. It is sectional drawing which shows the composite laminated body formed at 1 process of the manufacturing method of the laminated coil component of Example 4 of this invention. It is sectional drawing which shows the composite laminated body formed at 1 process of the manufacturing method of the laminated coil component of Example 5 of this invention. It is sectional drawing which shows the composite laminated body formed at 1 process of the manufacturing method of the laminated coil component of Example 6 of this invention.

Hereinafter, the features of the present invention will be described in more detail with reference to examples of the present invention.

In Example 1, a case where a multilayer ceramic capacitor, which is one of typical multilayer ceramic electronic components, is manufactured will be described as an example. FIG. 1 is a diagram showing a configuration of a multilayer ceramic capacitor manufactured by a method according to an embodiment of the present invention.
As shown in FIG. 1, the multilayer ceramic capacitor includes a multilayer ceramic element (multilayer ceramic electronic component element) 51 in which a plurality of internal electrodes 53 a and 53 b are stacked via a ceramic layer 52. The internal electrodes 53a and 53b facing each other are alternately drawn out to the end faces 54a and 54b on different sides of the multilayer ceramic element 51 and connected to the external electrodes 55a and 55b formed on the end faces. ing.

In Example 1, a first dielectric green sheet (ceramic green sheet), a first internal electrode pattern, a protective resin layer, and a second dielectric green sheet (ceramic green sheet) are formed on a base material (support film). A case will be described in which a multilayer ceramic capacitor is manufactured through a process of sequentially laminating the second internal electrode patterns to form a composite laminate, and laminating a predetermined number of this composite laminate.

(1) Production of monolithic ceramic capacitor according to Example 1 of the present invention Barium carbonate (BaCO ₃ ) and titanium oxide (TiO ₂ ) were weighed so as to have a molar ratio of 1: 1. Then, it was denatured with Dy, Mg, etc., wet-mixed using a ball mill, dehydrated, and dried. The dried powder was calcined at a temperature of 1000 ° C. for 2 hours, and then dry pulverized to obtain a ceramic raw material. 60 parts by volume of the obtained ceramic raw material, 30 parts by volume of a highly polymerized polyvinyl butyral as an organic binder, 10 parts by volume of dioctyl phthalate as a plasticizer, and 900 parts by volume of a toluene / ethanol (50/50) mixture as a solvent Together with 600 parts by volume of zirconia cobblestone having a diameter of 1 mm, the mixture was placed in a ball mill and wet mixed for 24 hours to prepare a ceramic slurry.
In each of the following Examples and Comparative Examples, the same ceramic slurry produced here was used as the ceramic slurry for producing the ceramic green sheet.

Further, as an internal electrode paste for forming an internal electrode pattern, a paste containing Ni powder as a conductive component, dihydroterpineol acetate as a solvent, and ethyl cellulose as an organic binder was used.
In each of the following examples and comparative examples, the same internal electrode paste as used here was used as the internal electrode paste for forming the internal electrode pattern.

Further, as a resin paste for forming a protective resin layer, a polyvinyl alcohol highly polymerized product (degree of polymerization: 1700, hydroxyl group content: 98%) (water-soluble resin) is dissolved in water, and the resin concentration is 10% by weight. An aqueous resin solution was prepared. That is, in this resin paste, water containing no organic solvent is used as the aqueous solvent.

The ceramic slurry prepared as described above was applied by a coater method, and a first dielectric green sheet (ceramic green sheet) having a thickness of 1.2 μm was formed on a substrate (support film) 1 as shown in FIG. 2a was molded. Then, drying was performed at 80 ° C. for 5 minutes.

Thereafter, the internal electrode paste (Ni electrode paste) prepared as described above is applied on the dried first dielectric green sheet 2a by the screen printing method, and is dried at 60 ° C. for 5 minutes. Thus, the first internal electrode pattern 3a having a thickness of 0.5 μm was formed.

Next, a resin paste, that is, water containing no organic solvent prepared as described above is used as an aqueous solvent so as to cover the first dielectric green sheet 2a and the first internal electrode pattern 3a formed thereon. A resin paste in which polyvinyl alcohol (PVA) is dissolved in a proportion of 10% by weight in this aqueous solvent is adjusted to a predetermined thickness (0.01 μm, 0.03 μm, 0.20 μm, 0.22 μm). The protective resin layer 4 was formed by applying and drying at 80 ° C. for 10 minutes.

In addition, as a preferable example of the water-soluble resin that can be used in the present invention, in addition to polyvinyl alcohol (PVA), polyvinyl acetal, urethane, acrylic, fluorine-based resin, vinylidene chloride, vinyl acetate, acrylic styrene, phenol, Examples include polyimide and polyamideimide.

Then, the ceramic slurry is applied onto the protective resin layer 4 by a coater method to form a second dielectric green sheet (ceramic green sheet) 2b having a thickness of 1.2 μm, and is heated at 80 ° C. for 5 minutes. Drying was performed under the conditions.

Next, a Ni electrode paste is applied on the second dielectric green sheet 2b by screen printing and dried at 60 ° C. for 5 minutes to form a second internal electrode pattern 3b having a thickness of 0.5 μm. did. Thus, a composite laminate 10 having two layers of dielectric green sheets 2a and 2b and two layers of internal electrode patterns 3a and 3b was obtained. The composite laminate 10 includes one protective resin layer 4.

The resulting composite laminate 10 is stacked with 300 sheets while being peeled from the substrate (support film) using a continuous peeling and laminating machine, and pressed for 1 minute under the conditions of 50 ° C. and 100 MPa. An unfired laminated body to be a multilayer ceramic electronic component element) was produced.

Then, the obtained laminate was cut into chips, degreased in a nitrogen atmosphere at 500 ° C., and then fired at 1200 ° C. in a reducing atmosphere to obtain a multilayer ceramic element 51 (FIG. 1). In addition, the above-mentioned protective resin layer 4 is decomposed | disassembled and combusted by this baking process, and lose | disappears.

Then, a multilayer ceramic capacitor according to the example of the present invention (sample 1 of the example) having a structure as shown in FIG. 1 is applied to the multilayer ceramic element by applying and baking a conductive paste for forming an external electrode. To 4).

(2) Production of Comparative Multilayer Ceramic Capacitor (Comparative Example 1) For comparison, a procedure for explaining the multilayer ceramic capacitor of Comparative Example 1 that does not include the protective resin layer, which is an essential component of the present invention, will be described below. It was made with.
First, a ceramic slurry having the same composition prepared by the same method as in Example 1 was prepared.

Then, this ceramic slurry was applied by a coater method to form a first dielectric green sheet having a thickness of 1.2 μm on the base material (support film), and dried at 80 ° C. for 5 minutes.

Thereafter, a Ni electrode paste (internal electrode paste), which is an internal electrode paste, is applied on the dried first dielectric green sheet by screen printing, and dried under conditions of 60 ° C. for 5 minutes. A first internal electrode pattern having a thickness of 0.5 μm was formed.

Next, the ceramic slurry is applied by a coater method to form a second dielectric green sheet having a thickness of 1.2 μm on the first internal electrode pattern formed on the first dielectric green sheet. Then, drying was performed for 5 minutes.

Then, a Ni electrode paste was applied by screen printing on the second dielectric green sheet and dried at 60 ° C. for 5 minutes to form a second internal electrode pattern having a thickness of 0.5 μm. Thus, a composite laminate having two layers of dielectric green sheets and two layers of internal electrode patterns was obtained. However, this composite laminate is not provided with a protective resin layer.

300 sheets are stacked while peeling the obtained composite laminate from the base material (support film) using a continuous peeling and laminating machine, and pressed for 1 minute under the conditions of 50 ° C. and 100 MPa to become a laminated ceramic element after firing. An unfired laminate was produced.

The obtained laminate was cut into chips, degreased in a nitrogen atmosphere at 500 ° C., and then fired at 1200 ° C. in a reducing atmosphere to obtain a multilayer ceramic element.
Then, a multilayer ceramic capacitor (Comparative Example 1) having a structure as shown in FIG. 1 was obtained by applying a conductive paste for forming external electrodes to this multilayer ceramic element and baking it.

(3) Evaluation of characteristics For the multilayer ceramic capacitor of Example 1 (samples 1 to 4) and the multilayer ceramic capacitor of Comparative Example 1 manufactured as described above, the electrical property defect rate and the structural defect occurrence rate were examined.

As for the electrical property defect rate, the short-circuit defect occurrence rate was examined for the samples 1 to 4 of Example 1 and the sample of Comparative Example 1 (n = 100), and this was defined as the electrical property defect rate.
As for the structural defect occurrence rate, the delamination occurrence rate was examined for the samples 1 to 4 of Example 1 and the sample of Comparative Example 1 (n = 100), and this was used as the structural defect occurrence rate.
The results are shown in Table 1.

As shown in Table 1, in the case of the multilayer ceramic capacitor of Comparative Example 1 in which the protective resin layer was not provided in the manufacturing process, it was confirmed that although the delamination occurrence rate is low, the short failure occurrence rate is high. This is because the delamination rate is low because the bonding force between the dielectric sheets is not impaired, but since the ceramic slurry directly contacts the internal electrode pattern and the ceramic green sheet in the manufacturing process, the solvent in the ceramic slurry It is probable that a short-circuit defect occurred due to the attack. In the case of Comparative Example 1, the incidence of short circuit failure was 100%.

On the other hand, it was confirmed that the characteristics of the multilayer ceramic capacitor of Example 1 (Samples 1 to 4 of the Example) can be significantly improved as compared with the multilayer ceramic capacitor of Comparative Example 1.

That is, in the case of sample 1 of the example, the protective resin layer thickness is as thin as 0.01 μm, so the incidence of short-circuit failure is a little as high as 7%. When the thickness of the resin layer is 0.03 to 0.22 μm, it has been confirmed that the occurrence rate of short circuit can be suppressed to 2% or less.

Further, the delamination occurrence rate was 0% in the samples 1 to 3 of the example, but it was confirmed that the delamination occurrence rate was somewhat higher as 5% in the sample 4. This is because, when the protective resin layer exceeds 0.20 μm, the pattern between the first dielectric green sheet and the second dielectric green sheet and the first internal electrode pattern after thermal decomposition of the water-soluble resin (polyvinyl alcohol) in the degreasing process This is probably because a void layer is generated between the second dielectric green sheet and the second dielectric green sheet.

From the above results, the second dielectric green sheet 2b is formed by applying the ceramic slurry on the first dielectric green sheet 2a and the first internal electrode pattern 3a via the protective resin layer 4, thereby forming the electric It was confirmed that a monolithic ceramic capacitor having a low characteristic defect rate and a low structural defect rate can be efficiently manufactured.
Further, it was confirmed that the thickness of the protective resin layer is particularly preferably in the range of 0.03 μm to 0.20 μm under the above conditions.

In the configuration of Sample 2 in Example 1, the relationship between the degree of polymerization of polyvinyl alcohol (PVA), which is a water-soluble resin, and the amount of hydroxyl groups is as shown in Table 2. Degree of polymerization: 300 to 1700, amount of hydroxyl groups: 88% Multilayer ceramic capacitors (multilayer ceramic capacitors of Samples 5 to 8 in Examples) were produced by changing the content in the range of ˜98%.

For the multilayer ceramic capacitors of Samples 5 to 8 manufactured as described above, the electrical property defect rate and the structural defect occurrence rate were examined by the same method as in Example 1 above.
The results are also shown in Table 2.

As shown in Table 2, in any of Samples 5 to 8, the structural defect occurrence rate is as low as 1 to 2%, and no significant difference is observed between the samples, but a water-soluble resin having a polymerization degree of less than 500 ( Sample 6 (polymerization degree 300) using PVA) and sample 8 (hydroxyl group content 88%) using water-soluble resin (PVA) having a hydroxyl group content of less than 90% were confirmed to have a high incidence of short circuit failure. It was.
This is presumably because the ceramic slurry applied when forming the second dielectric sheet attacked the already formed dielectric green sheet and internal electrode pattern when the degree of polymerization or the amount of hydroxyl group decreased.

Samples 6 and 8 also have a significantly improved short-circuit defect rate as compared with Comparative Example 1 produced in Example 1 above, and the significance of the present invention is clear. When using an alcohol, it is particularly desirable to use an alcohol having a degree of polymerization of 500 or more and a hydroxyl group content of 90% or more.

In the configuration of Sample 2 in Example 1, the following aqueous solvents (1) to (4) were used as aqueous solvents for dissolving polyvinyl alcohol (PVA), which is a water-soluble resin. Under the same conditions, monolithic ceramic capacitors of Samples 9 to 11 (see Table 3) of Examples were produced.
(1) Water that does not contain organic solvents,
(2) Mixed solvent A in which ethanol is mixed with water (water: ethanol = 70: 30)
(3) Mixed solvent B in which ethanol is mixed with water (water: ethanol = 50: 50)
(4) Mixed solvent C in which ethanol is mixed with water (water: ethanol = 30: 70)
However, the ratio of water: ethanol in the mixed solvent is a weight ratio.

Note that Sample 2 in Table 3 is the same as that prepared in Example 1, and in Sample 2, water that does not contain an organic solvent is used as the aqueous solvent.

For the multilayer ceramic capacitors of Samples 9 to 11 produced as described above, the electrical property defect rate and the structural defect occurrence rate were examined by the same method as in Example 1 above.
The results are also shown in Table 3.

As shown in Table 3, the structural defect occurrence rate of all the samples 9 to 11 was as low as 1% or less, and no large difference was observed between the samples.
Further, the short-circuit defect occurrence rate is as low as 2% in the samples 9 and 10, but in the case of the sample 11 using the mixed solvent C of water: ethanol = 30: 70, the short-circuit defect occurrence rate is somewhat high as 5%. It was confirmed. However, in the case of the sample of Comparative Example 1 manufactured without providing the protective resin layer, since the short-circuit defect occurrence rate is 100% (see Comparative Example 1 of Table 1), a mixed solvent of water: ethanol = 30: 70 It is clear that there is sufficient significance when C is used.
If the ratio of water and ethanol becomes ethanol richer than water: ethanol = 30: 70, the underlying internal electrode pattern and the like may receive a sheet attack that cannot be ignored.

From this result, it can be seen that it is desirable to use a water-based solvent having a water content of 30% by weight or more. In addition, by using an organic solvent that contains an organic solvent and a water content of 30% by weight or more, the drying time can be shortened and the manufacturing cost can be reduced while keeping the occurrence rate of short-circuit defects low. It becomes possible to plan.

In Example 4, a first internal electrode pattern is first formed on a substrate (support film), and a protective resin layer, a first dielectric green sheet (ceramic green sheet), and a second internal electrode are sequentially formed thereon. A case will be described in which a multilayer laminate is formed by laminating a pattern, a protective resin layer, and a second dielectric green sheet (ceramic green sheet), and a multilayer ceramic capacitor is manufactured through a step of laminating a predetermined number of the composite laminate. . In the case of Example 4 as well, as in the case of Example 1, a multilayer ceramic capacitor having a structure as shown in FIG. A description will be given below.

In this Example 4,
(a) a ceramic slurry for forming a ceramic green sheet;
As the internal electrode paste for forming the internal electrode pattern (b) and the resin paste for forming the protective resin layer (c), the same one as used in Example 1 was used.

(1) Production of Multilayer Ceramic Capacitor According to Example 4 of the Present Invention First, as shown in FIG. 3, an internal electrode paste is formed on a base material (support film) 1 by a screen printing method so as to form a predetermined pattern. (Ni electrode paste) was printed and dried at 60 ° C. for 5 minutes to form a first internal electrode pattern 3 a having a thickness of 0.5 μm.

Then, on the base material 1 and the first internal electrode pattern 3a, a resin paste in which water containing no organic solvent is used as a water-based solvent and polyvinyl alcohol is dissolved in the water-based solvent at a ratio of 10% by weight is used. It apply | coated so that it might become thickness (0.01 micrometer, 0.03 micrometer, 0.20 micrometer, 0.22 micrometer), and it dried at 80 degreeC for 10 minutes, and formed the 1st protective resin layer 4a.

Next, the ceramic slurry prepared as described above is applied onto the first protective resin layer 4a by a coater method, and a first dielectric having a thickness of 1.2 μm is formed on the entire surface of the first protective resin layer 4a. The green sheet 2a was molded and dried at 80 ° C. for 5 minutes.

Thereafter, a Ni electrode paste as an internal electrode paste is applied on the dried first dielectric green sheet 2a by a screen printing method and dried under conditions of 60 ° C. for 5 minutes to obtain a thickness of 0.5 μm. The second internal electrode pattern 3b was formed.

Next, the resin paste is coated with a predetermined thickness (0.01 μm, 0.03 μm, 0.20 μm, 0.22 μm) so as to cover the second internal electrode pattern 3b and the surrounding first dielectric green sheet 2a. Then, the second protective resin layer 4b was formed by drying at 80 ° C. for 10 minutes.

Then, the ceramic slurry is applied onto the second protective resin layer 4b by a coater method, and dried at 80 ° C. for 5 minutes to obtain a second dielectric green sheet 2b having a thickness of 1.2 μm. By molding, a composite laminate 10 having two layers of dielectric green sheets 2a and 2b and two layers of internal electrode patterns 3a and 3b was obtained. The composite laminate 10 includes two protective resin layers 4a and 4b.

300 layers of the composite laminate 10 thus obtained are stacked while being peeled from the substrate (support film) 1 using a continuous peeling and laminating machine, and pressed for 1 minute under the conditions of 50 ° C. and 100 MPa, so that a laminated ceramic element after firing. An unfired laminate was produced.

The obtained laminate was cut into chips, degreased in a nitrogen atmosphere at 500 ° C., and then fired at 1200 ° C. in a reducing atmosphere to obtain a multilayer ceramic element.
In addition, the above-mentioned protective resin layer is decomposed | disassembled and combusted by this baking process, and lose | disappears.

Then, a conductive paste for forming an external electrode was applied to this multilayer ceramic element and baked to obtain multilayer ceramic capacitors (Samples 21 to 24 of Examples) according to Example 4 of the present invention. The structure of this multilayer ceramic capacitor is the same as that of the first embodiment shown in FIG.

(2) Manufacture of Comparative Multilayer Ceramic Capacitor (Comparative Example 2) Comparison is made in the same manner as in Example 4 except that it does not include the step of providing the first and second protective resin layers. A multilayer ceramic capacitor (Comparative Example 2) was prepared.

(3) Evaluation of characteristics The electrical characteristics of the multilayer ceramic capacitor of Example 4 (samples 21 to 24) and the multilayer ceramic capacitor of Comparative Example 2 manufactured as described above were obtained in the same manner as in Example 1 above. The defect rate and the structural defect occurrence rate were examined.
The results are shown in Table 4.

In the case of the multilayer ceramic capacitor of Comparative Example 2 in which the protective resin layer was not provided, it was confirmed that although the delamination occurrence rate is low, the sheet attack cannot be prevented, so that the short defect occurrence rate is increased. In the case of Comparative Example 2, the incidence of short circuit failure was 100%.

On the other hand, it was confirmed that the characteristics of the multilayer ceramic capacitor of Example 4 (Samples 21 to 24 of Example) can be improved as compared with the multilayer ceramic capacitor of Comparative Example 2.

That is, in the case of the sample 21 of the example, since the thickness of the protective resin layer is as thin as 0.01 μm, the short-circuit defect occurrence rate is a little as high as 7%. When the thickness of the resin layer is 0.03 to 0.22 μm, it has been confirmed that the occurrence rate of short circuit can be suppressed to 2% or less.

Further, the delamination occurrence rate was 0% in the samples 21 to 23 of the example, but it was confirmed that it was somewhat higher in the sample 24, 5%. If the protective resin layer exceeds 0.20 μm, the first internal electrode pattern between the first dielectric green sheet and the second dielectric green sheet after thermal decomposition of the water-soluble resin (polyvinyl alcohol) in the degreasing step It is considered that a void layer is generated between the first dielectric green sheet and the second internal electrode pattern and the second dielectric green sheet.

From the above results, even in the case of the configuration of this Example 4, a dielectric green sheet is formed by applying a ceramic paste through a protective resin layer, whereby a low electrical property defect rate and a structural defect occurrence rate are low. It was confirmed that the ceramic capacitor can be manufactured efficiently.
Further, it was confirmed that the thickness of the protective resin layer is particularly preferably in the range of 0.03 μm to 0.20 μm under the above conditions.

In the fifth embodiment, as shown in FIG. 4, after forming the first internal electrode pattern 3a, a step absorbing layer dielectric paste is applied between the first internal electrode patterns 3a, and after forming the second internal electrode pattern 3b. A step absorbing layer dielectric paste was applied between the second internal electrode patterns 3b and dried at 60 ° C. for 5 minutes to form a step absorbing dielectric pattern (step absorbing layer) 20 as in Example 1. Similarly, multilayer ceramic capacitors of Samples 31 to 34 (Table 4) corresponding to Samples 1 to 4 of Example 1 were produced.
In FIG. 4, the parts denoted by the same reference numerals as those in FIG. 2 indicate the same or corresponding parts.

In addition, except that the step absorption layer dielectric paste was applied between the first internal electrode patterns and between the second internal electrode patterns and dried at 60 ° C. for 5 minutes to form the step absorption dielectric pattern. A multilayer ceramic capacitor of Comparative Example 3 was produced in the same manner as in Comparative Example 1 of Example 1.

The step absorbing layer dielectric paste includes the same ceramic material as the ceramic slurry used to form the first and second dielectric green sheets, dihydroterpineol acetate as the solvent, and polyvinyl butyral as the binder. A paste containing was used.
The characteristics of the samples 31 to 34 of the example produced in Example 5 and the sample of Comparative Example 3 were examined in the same manner as in Example 1. The results are shown in Table 5.

As shown in Table 5, it was confirmed that the same characteristics as those of Samples 1 to 4 of Example 1 were obtained for Samples 31 to 34 of Example 5. However, in the multilayer ceramic capacitor of Comparative Example 3, it was not possible to prevent the occurrence of a short circuit due to the influence of the sheet attack.

Further, in the samples 31 to 34 of Example 5, the step absorption layer 20 was provided, so that the shape accuracy of the product could be improved.

In Example 6, as shown in FIG. 5, after the first internal electrode pattern 3a is formed, a step absorbing layer dielectric paste is applied between the first internal electrode patterns 3a, and after the second internal electrode pattern 3b is formed. Example 4 except that the step absorbing layer dielectric paste was applied between the second internal electrode patterns 3b and dried at 60 ° C. for 5 minutes to form the step absorbing dielectric pattern (step absorbing layer) 20. Similarly, multilayer ceramic capacitors of Samples 41 to 44 (Table 6) corresponding to Samples 21 to 24 of Example 4 were produced.
In FIG. 5, the parts denoted by the same reference numerals as those in FIG. 3 indicate the same or corresponding parts.

Further, a comparative multilayer ceramic capacitor (Comparative Example 4) was produced in the same manner as in Example 6 except that the step of providing the first and second protective resin layers was not provided.
In addition, as the dielectric paste for the step absorption layer, the same one as used in Example 5 was used.

Then, the characteristics of the samples 41 to 44 of the example manufactured in Example 6 and the sample of Comparative Example 4 were examined by the same method as in Example 4 above. The results are shown in Table 6.

As shown in Table 6, it was confirmed that the same characteristics as those of Samples 21 to 24 of Example 4 were obtained for Samples 41 to 44 of Example 6. However, in the multilayer ceramic capacitor of Comparative Example 4, it was not possible to prevent the occurrence of a short circuit failure due to the influence of the sheet attack.

Also, in the samples 41 to 44 of Example 6, the step absorption layer 20 was provided, so that the shape accuracy of the product could be improved.
The step absorption layer may be disposed in the area where the internal electrode pattern is not formed after the internal electrode pattern is formed, or the step absorption layer is formed in advance and the step absorption layer is formed. The internal electrode pattern may be formed in a region that is not, and the same effect can be obtained in any case.

In Example 7, the resin paste containing the ceramic powder having the same composition as the ceramic powder constituting the ceramic green sheet is used as the resin paste for forming the protective resin layer in the configuration of the sample 2 of Example 1. A multilayer ceramic capacitor was produced.

That is, in Example 7, as a resin paste, a water-soluble resin (polyvinyl alcohol) is dissolved in water, and the ceramic powder is in the range shown in Table 7 (the volume fraction in the formed protective resin layer is A multilayer ceramic capacitor was manufactured using a resin paste contained in a range of 0.1 vol% to 60 vol%.

The value of the volume fraction of the ceramic powder in the protective resin layer in Table 7 indicates the volume ratio of the ceramic powder to the protective resin layer containing the ceramic powder.
In addition, on the conditions of this Example 7, the critical particle volume fraction (CPVC) of the ceramic powder in a protective resin layer will be about 50 vol%.

The characteristics of the samples 51 to 54 produced in Example 7 were examined by the same method as in Example 1 above. The results are also shown in Table 7. Table 7 also shows the characteristics of the sample 2 of Example 1.

As shown in Table 7, in the case of samples 51 to 53 in which a protective resin layer containing ceramic powder in a range of 0.1 vol% to 50 vol% (that is, a range of critical particle volume fraction (CPVC) or less) was formed, The short defect rate was as low as 1%, and the structural defect occurrence rate was 0%, confirming that a multilayer ceramic capacitor with good characteristics was obtained.
However, in the case of the sample 54 in which the protective resin layer containing the ceramic powder at a ratio of 60 vol% (that is, the ratio exceeding the critical particle volume fraction (CPVC)) was formed, the structural defect occurrence rate was 0%. It was confirmed that the short-circuit defect rate was 10%, which was somewhat higher than those of samples 51 to 53.

When the protective resin layer containing the ceramic powder is formed at a predetermined ratio using the resin paste containing the ceramic powder as in Example 7, the ceramic green sheets of the lower layer and the upper layer are formed in the firing step. Thus, the ceramic powder in the protective resin layer diffuses and the lower and upper ceramic green sheets are firmly bonded. As a result, it is possible to more reliably prevent the occurrence of structural defects such as delamination and manufacture a highly reliable multilayer ceramic electronic component.

It should be noted that if the content ratio of the ceramic powder in the protective resin layer exceeds the critical particle volume fraction (CPVC), a region where no resin exists between the ceramic particles is formed, which is not preferable. That is, when a region in which no resin is present is formed, the region becomes a void, and the solvent in the ceramic slurry applied on the protective resin layer attacks the underlying ceramic green sheet and internal electrode layer through this void. Will do. Therefore, in the present invention, the content ratio of the ceramic powder in the resin paste is preferably set such that the ratio of the ceramic powder in the formed protective resin layer is equal to or less than the critical particle volume fraction (CPVC).

In the above embodiment, the multilayer ceramic capacitor has been described as an example. However, the present invention is applicable to various multilayer ceramic electronic components having a structure in which a ceramic layer and an internal electrode are stacked, such as a multilayer inductor and a multilayer LC composite component. It is possible to apply.

The present invention is not limited to the above embodiment in other points as well, but relates to the number of laminated ceramic layers and internal electrodes, a specific pattern of internal electrodes, a constituent material of the ceramic layers and internal electrodes, and the like. Various applications and modifications can be made within the scope of the invention.

1 Base material (support film)
2a First dielectric green sheet (ceramic green sheet)
2b Second dielectric green sheet (ceramic green sheet)
3a 1st internal electrode pattern 3b 2nd internal electrode pattern 4 Protective resin layer 4a 1st protective resin layer 4b 2nd protective resin layer 10 Composite laminated body
20 Step absorption dielectric pattern (step absorption layer)
51 Multilayer Ceramic Element (Multilayer Ceramic Electronic Component Element)
52 Ceramic layers 53a, 53b Internal electrodes 54a, 54b End faces of the multilayer ceramic element 55a, 55b External electrodes

Claims (11)

1. A method for producing a multilayer ceramic electronic component having a structure in which a ceramic layer and an internal electrode are laminated, and the internal electrodes are disposed so as to face each other through the ceramic layer,
   (a) A step of applying a ceramic slurry containing an organic binder, a solvent and a ceramic raw material on a substrate and drying to form a ceramic green sheet;
   (b) On the ceramic green sheet, an internal electrode paste containing an organic binder and a conductive component is applied and dried to form an internal electrode pattern;
   (c) On the ceramic green sheet and the internal electrode pattern, a resin paste containing a solvent and a resin that hardly dissolves the organic binder contained in the ceramic green sheet and the internal electrode pattern is applied and dried. Forming a cured protective resin layer; and
   (d) applying the ceramic slurry on the uncured protective resin layer and drying to form a ceramic green sheet;
   (e) providing the internal electrode paste on the ceramic green sheet and drying to form an internal electrode pattern;
   A method for producing a multilayer ceramic electronic component, wherein the steps (c) to (e) are performed once or more.
2. A method of manufacturing a multilayer ceramic electronic component having a structure in which ceramic layers and internal electrodes are alternately stacked, and the internal electrodes are disposed so as to face each other through the ceramic layers,
   (a) On the substrate, an internal electrode paste containing an organic binder and a conductive component is applied and dried to form an internal electrode pattern;
   (b) A resin paste containing a solvent and a resin that hardly dissolve the organic binder contained in the internal electrode pattern is applied onto the internal electrode pattern and the base material around the internal electrode pattern, and then dried and uncured protection Forming a resin layer;
   (c) applying a ceramic slurry containing an organic binder, a solvent and a ceramic raw material on the uncured protective resin layer, and drying to form a ceramic green sheet;
   (d) applying the internal electrode paste on the ceramic green sheet and drying to form an internal electrode pattern;
   (e) On the ceramic green sheet and the internal electrode pattern, a resin paste containing a solvent and a resin that hardly dissolve the organic binder contained in the ceramic green sheet and the internal electrode pattern is applied and dried. Forming an uncured protective resin layer;
   (f) applying a ceramic slurry containing an organic binder, a solvent and a ceramic raw material on the uncured protective resin layer, and drying to form a ceramic green sheet;
   A method for producing a multilayer ceramic electronic component, wherein the steps (d) to (f) are performed once or more.
3. A plurality of ceramic green sheets and a plurality of layers formed on the substrate through the steps (a) to (e) of claim 1 or the steps (a) to (f) of claim 2. 3. A step of repeating a step of stacking a composite laminate including the internal electrode pattern and forming an unfired laminate that becomes a multilayer ceramic electronic component element after firing is provided. The manufacturing method of the multilayer ceramic electronic component of description.
4. After the step of forming the internal electrode pattern, a step-absorbing layer ceramic paste for eliminating the step between the internal electrode pattern and the surrounding area is applied to the area around the formed internal electrode pattern and dried. The method for producing a multilayer ceramic electronic component according to any one of claims 1 to 3, further comprising a step of forming a step absorption layer.
5. Before the step of forming the internal electrode pattern, for the step absorption layer for eliminating the step between the internal electrode pattern to be formed and the surrounding area around the region where the internal electrode pattern is to be formed Applying and drying a ceramic paste to form a step absorption layer, and then applying the internal electrode paste to a region where the step absorption layer is not formed and drying to form the internal electrode pattern. The method for producing a multilayer ceramic electronic component according to any one of claims 1 to 3.
6. 6. The method for producing a multilayer ceramic electronic component according to claim 1, wherein the protective resin layer has a thickness of 0.03 to 0.20 μm.
7. 7. The method for producing a multilayer ceramic electronic component according to claim 1, wherein the resin paste used for forming the protective resin layer is a resin paste containing an aqueous solvent and a water-soluble resin. .
8. The method for producing a multilayer ceramic electronic component according to claim 7, wherein the aqueous solvent contains water and an organic solvent, and the water content is 30% by weight or more.
9. The method for producing a multilayer ceramic electronic component according to claim 8, wherein the aqueous solvent contains alcohol as the organic solvent.
10. 10. The multilayer ceramic according to claim 7, wherein the water-soluble resin contained in the protective resin layer is polyvinyl alcohol, having a polymerization degree of 500 or more and a hydroxyl group content of 90% or more. Manufacturing method of electronic components.
11. The resin paste used for forming the protective resin layer is a ceramic powder in such a ratio that the ratio of the ceramic powder in the protective resin layer formed by curing the resin paste is equal to or less than the critical particle volume fraction. The method for producing a multilayer ceramic electronic component according to any one of claims 1 to 10, wherein the multilayer ceramic electronic component is contained.

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