JP2000203928A - Production of ceramic green paste for laminated ceramic electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required to produce a ceramic green paste, to sufficiently crush or disperse powdery ceramic materials and to produce laminated ceramic electronic parts which reduce the rate of occurrence of defective short circuits and ensure high reliability. SOLUTION: Powdery ceramic materials, a resin binder, a plasticizer and a solvent for the resin binder and for the plasticizer are used as constituent materials. In one embodiment of this invention, the constituent materials except at least the resin binder are previously mixed and then mixed with the resin binder in the solid state together with a solvent incompatible with the previously mixed constituent materials. In another embodiment, the powdery ceramic materials, the plasticizer, the solvent for the resin binder and for the plasticizer and 0.1-20% of the resin binder in the solid state are previously mixed and then further mixed with the remaining resin binder in the solid state, optionally together with a solvent incompatible with the previously mixed constituent materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a ceramic green paste used for producing a multilayer ceramic electronic component.

[0002]

2. Description of the Related Art A multilayer ceramic electronic component is formed by forming a ceramic green sheet from a ceramic green paste obtained by kneading and mixing a ceramic powder raw material, a resin binder, a plasticizer, and a solvent, and drying the ceramic green sheet. An internal electrode is printed from one side of the ceramic sheet on one side of the ceramic sheet, a plurality of the internal electrodes and the ceramic sheet are alternately laminated and heated and pressed to obtain a ceramic laminate, and the ceramic laminate is manufactured as a base. I have.

Conventionally, a ceramic green paste for a multilayer ceramic electronic component has been manufactured by charging a ceramic powder raw material, a resin binder, a plasticizer, and a solvent all at once into a ball mill and mixing and dispersing for several hours. Also, since the resin binder is a solid,
It is mixed by previously dissolving it in a lacquer with a compatible solvent. However, since it takes a number of days to dissolve the resin binder with the solvent, the total production time is long.

[0004] The resin binder can be dissolved with a solvent even if mixed as a solid. However, since the resin binder has a functional group, it promotes the wettability between the ceramic powder raw material and the solvent.However, when the amount exceeds a certain amount, the resin binder is easily aggregated. Cannot be sufficiently crushed or dispersed.

When a thin ceramic layer having a thickness of 10 μm or less is formed by using the ceramic green paste,
As a multilayer ceramic electronic component, the reliability is significantly deteriorated with time, which causes a large number of defective products such as short-circuit defects.

[0006]

SUMMARY OF THE INVENTION The present invention shortens the production time of a ceramic green paste by mixing a resin binder in a solid state with another composition material, and sufficiently disintegrates a ceramic powder raw material. It is another object of the present invention to provide a method for producing a ceramic green paste for a multilayer ceramic electronic component, which can be dispersed and reduces the incidence of short circuit failure and the like, and can produce a highly reliable multilayer ceramic electronic component.

[0007]

According to a first aspect of the present invention, there is provided a method for producing a ceramic green paste for a multilayer ceramic electronic component, comprising: a ceramic powder raw material, a resin binder, a plasticizer, a solvent for the resin binder, and a solvent for the plasticizer. When producing a ceramic green paste for a multilayer ceramic electronic component as a composition material, at least other composition materials except for the resin binder are mixed first, and finally, a solvent incompatible with the previously mixed composition material. Along with
The resin binder is mixed in a solid state.

According to a second aspect of the present invention, there is provided a method for producing a ceramic green paste for a multilayer ceramic electronic component, wherein a ceramic powder raw material, a resin binder, a plasticizer,
When preparing a ceramic green paste for laminated ceramic electronic components using a solvent for resin binder and a solvent for plasticizer as a composition material, the ceramic powder raw material, plasticizer, solvent for resin binder and solvent for plasticizer are finally required. 0.1-20% of the added amount of the resin binder is first mixed in a solid state, and then the remaining amount of the resin binder is further mixed in the solid state.

According to a third aspect of the present invention, there is provided a method for producing a ceramic green paste for a multilayer ceramic electronic component, wherein a ceramic powder raw material, a resin binder, a plasticizer,
When preparing a ceramic green paste for laminated ceramic electronic components using a solvent for resin binder and a solvent for plasticizer as a composition material, the ceramic powder raw material, plasticizer, solvent for resin binder and solvent for plasticizer are finally required. 0.1-20% of the added amount of the resin binder is first mixed in a solid state, and then the remaining resin binder is solidified together with the incompatible solvent with the previously mixed composition material. To further mix.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for producing a ceramic green paste for a multilayer ceramic chip capacitor will be described below as an embodiment. The ceramic green paste is mainly made of a dielectric ceramic powder of BaTiO ₃ .
MgO, Cr ₂ O ₃ , Y ₂ O ₃ , V ₂ O ₅ , BaO, S
Ceramic powder raw materials containing metal oxides or porcelain additives of iO ₂ and CaO, resin binders such as acrylics, plasticizers such as phthalic acid esters, ketone-based organic solvents as compatible solvents for resin binders and plasticizers It is manufactured by using a solvent as a composition material.

As a first manufacturing method, as shown in FIG. 1, among the above-mentioned composition materials, at least other composition materials except for the resin binder are first dispersed and mixed, and finally, the previously mixed composition materials are mixed. A resin green binder is dispersed and mixed together with a solvent that is incompatible with the above, and the dispersion is mixed and filtered to obtain a ceramic green paste.

The dispersion of the composition material is 2.0 mm in diameter.
It can be performed by applying a ball mill with a certain amount of zirconia balls. With this ball mill, the above-mentioned dispersion mixing may be performed as primary mixing for about 1 to 10 hours, and the final dispersion mixing may be performed as secondary mixing for about 10 hours.

The ceramic powder raw material containing the dielectric porcelain powder, metal oxide or porcelain additive is preliminarily dispersed and mixed with water to be pulverized before mixing with other composition materials, or to remove the resin binder. It may be directly mixed with other composition materials. As the incompatible solvent, dealuminal spirit naphtha or the like can be used.

From the step of first dispersing and mixing other composition materials excluding the resin binder, and finally dispersing and mixing the resin binder in a solid state together with the previously mixed composition material and an incompatible solvent, As a resin binder, it can be sufficiently dissolved even when used as a solid, and can be prevented from being aggregated by an incompatible solvent. In addition, since the ceramic powder raw material can be sufficiently pulverized or dispersed without agglomeration, a material suitable as a ceramic green paste for a multilayer ceramic chip capacitor can be obtained in a short time only by a mixing process.

Using the ceramic green paste, first, a ceramic green sheet is formed by transferring the sheet to a sheet surface of a carrier sheet such as a polyethylene terephthalate film by a doctor blade method. The ceramic green sheet is subjected to a drying process, cut into ceramic sheets having an area for taking a plurality of components, and then internal electrodes having a predetermined pattern are screen-printed on one side with a conductive paste such as nickel.

Next, using the ceramic sheet, a plurality of internal electrodes and ceramic sheets are alternately laminated, and a ceramic sheet having no internal electrode is laminated on the outermost layer to form a ceramic laminate. .
This ceramic laminate is subjected to a thermocompression bonding process, and the manufacturing process of the ceramic laminate is completed.

The ceramic laminate is cut into parts, and after degreasing, 1% is placed in an N ₂ + H ₂ (5% hydrogen) atmosphere furnace in which the oxygen concentration is controlled so that the internal electrodes are not oxidized.
The firing treatment is performed at a temperature of about 300 ° C. In addition, the external electrode 4
And paste and paste the Cu paste on both ends.
A multilayer ceramic chip capacitor can be manufactured by applying a plating process to a Cu film in the order of i-plating and Sn plating.

In order to confirm the characteristics of the multilayer ceramic chip capacitor, a ceramic green paste was prepared from the above-mentioned composition material. At this time, since the influence of the primary mixing time is confirmed, the primary mixing is performed in 1 hour, 5 hours, 10 hours, and 15 hours, and the secondary mixing is performed for 10 hours each to produce a ceramic green paste. (Samples 1 to 4).

At the same time, even if the same composition material was used, the effect of mixing all of them at once was confirmed.
(Comparative Example 1). In addition, using a resin binder dissolved in a lacquer shape with a solvent, a primary binder was mixed for 5 hours by the above-described process, and a secondary binder was also prepared for 10 hours.
(Comparative Example 2).

Using each of the ceramic green pastes, a recovery rate by filtration and a viscosity (cps) were measured, and then a ceramic sheet having a thickness of 6 μm was prepared. This ceramic sheet was used to form internal electrodes having a thickness of 2 μm using Ni paste, and to laminate 200 layers on each of the layers and heat-press to obtain a ceramic laminate. The ceramic laminated body is cut into a chip body having a length of 3.2 mm, a width of 1.6 mm and a height of 1.6 mm, and external electrodes are formed through the above-described steps, thereby forming 1000 laminated ceramic chip capacitors. Manufactured.

Forty of each of the multilayer ceramic chip capacitors were arbitrarily selected and inspected based on short-circuit failure and reliability tests. The viscosity was measured with a Brook Heald viscometer at a measured value of 50 rpm, and the short-circuit failure was measured using an impedance analyzer (Puret Packard, H
P4284A), continuous measurement was made with 10 MΩ · μF or less as defective. The reliability was determined to be 2000 hours or more in a high-temperature load test (85 ° C.-20 V), and passed 1000 hours or more. In addition, the number of deterioration was judged up to 1000 hours. The results are as shown in Table 1 below.

[0022]

[Table 1]

As can be seen from the data, it was found that a resin binder dissolved in a lacquer form with a compatible solvent
In Comparative Example 2 in which primary mixing was performed for 10 hours and secondary mixing was performed for 10 hours, and Samples 1 to 3, almost the same preferable results were obtained in all inspection items.

Sample 4 was good in terms of product, but the primary mixing was too long, 15 hours, so that the grinding of the ceramic powder material proceeded too much and the paste viscosity increased too much.
It is not suitable for industrial production because the paste recovery is extremely poor. Further, even if the same composition material is used, the ceramic powder raw material cannot be sufficiently pulverized or dispersed simply by mixing all at once without applying the primary mixing as in Comparative Example 1, so that a good result is obtained as a product. It turns out that it cannot be done.

The mixing time including the resin binder is 1
There is no difference in the characteristics when the operation is performed for 0 hours or more.
If the time is less than 10 hours, the thickness of the ceramic sheet tends to vary, so it is preferable to apply the heat treatment for 10 hours or more.

According to the above-described process, the ceramic powder raw material including the dielectric ceramic powder, the plasticizer, and the compatible solvent for the resin binder and the plasticizer are dispersed and mixed together for 5 hours, and the resin binder and the incompatible solvent are mixed. Was added and mixed for 24 hours (sample 5). Based on this sample, the characteristics were examined in the same manner as shown in Table 1, and the results shown in Table 2 were obtained.

[0027]

[Table 2]

Next, as a second production method, as shown in FIG. 2, a ceramic powder raw material, a plasticizer, a solvent for a resin binder and a solvent for a plasticizer, and a final addition amount of 0.1. A ceramic green paste is obtained by first mixing 1 to 20% of the resin binder in a solid state and then further mixing the remaining amount of the resin binder in a solid state.

In the second manufacturing method, the same composition material as that in the first manufacturing method is used. Also, as the mixing means, similarly to the first manufacturing method, a diameter of 2.0 m was used.
A ball mill with about m m of zirconia balls is applied. However, the ceramic powder raw material containing the dielectric porcelain powder, the metal oxide or the porcelain additive may be preliminarily dispersed and mixed with water to be pulverized before being mixed with another composition material.

Under the above conditions, a ceramic powder raw material, a plasticizer, a solvent for the resin binder and a solvent for the plasticizer, and a resin binder in an amount of 0.1 to 20% of the final required amount are added to a solid. As a primary mixture, the mixture is dispersed and mixed in a ball mill for 1 to 10 hours in advance, and the remaining amount of the resin binder is added as it is as a solid mixture, and the mixture is dispersed and mixed in a ball mill for 10 hours as a secondary mixture. To obtain a ceramic green paste.

The resin binder is divided as a primary mixture and added in an amount of 0.1 to 20% of the finally required addition amount, so that even if the resin binder has a functional group, the initial addition amount is small. Agglomeration can be prevented from occurring.
At the same time, even if the remaining amount of the resin binder is added in a solid state, it can be sufficiently dissolved in a solvent, and the ceramic powder raw material can be sufficiently pulverized or dispersed by primary mixing without agglomeration. By mixing and dispersing the mixture, the pulverization treatment is performed before mixing with another composition material, so that a suitable ceramic green paste for a multilayer ceramic chip capacitor can be obtained in a short time by a simple mixing means.

In order to confirm the effectiveness, a ceramic powder raw material, a plasticizer, a solvent for a resin binder, a solvent for a plasticizer, and a 1% resin binder were firstly mixed in a solid state, and the mixing time was 1 hour, 5 hours. Time, 10 hours, and 20 hours.
A ceramic green paste was obtained by adding the remaining amount of the resin binder in a solid state and dispersing and mixing the resulting mixture as a secondary mixture by ball mill mixing for 10 hours (samples 6 to 9).

At the same time, even if the same composition material was used, the effect of mixing all of them at once was confirmed, and all the components were dispersed and mixed for 10 hours.
(Comparative Example 3). Using these ceramic green pastes, multilayer ceramic chip capacitors were manufactured under the same conditions as in the first manufacturing method, and inspections were performed based on surface roughness, breakdown voltage failure, short circuit failure, and reliability tests.

The short-circuit failure and the reliability test were performed under the same conditions as in the first manufacturing method, and the surface roughness was the average value obtained by measuring the difference between five peaks and five valleys five times using a Taristep (manufactured by Taylor Bobson). According to The withstand voltage failure was determined based on whether or not 10% or more of the voltage breakdown occurred by applying a 200 V DC current. The results are as shown in Table 3 below.

[0035]

[Table 3]

As is apparent from the data, the raw material of the ceramic powder, the plasticizer, the solvent for the resin binder and the solvent for the plasticizer and 1% of the resin binder were primarily mixed in a solid state, and the mixing time was 1 to 10 hours. Sample 6 set to
8 shows that any of the inspection items can obtain almost the same preferable results as those obtained by the first manufacturing method.

Sample 9 was completely unsuitable because the primary mixing was too long, 20 hours, and the grinding of the ceramic powder raw material proceeded too much to increase the paste viscosity. Also,
Even if the same composition material is used, the ceramic powder raw material cannot be sufficiently pulverized or dispersed simply by mixing all at once without applying the primary mixing as in Comparative Example 3, so that a good result as a product is obtained. Is not obtained.

Next, the influence of the amount of the resin binder added at the time of the primary mixing was examined. The primary mixing time was set to one hour, the amount of the resin binder added was set to 0.01%,
0.1%, 1.0%, 10.0%, 20.0%, 30.
Each ceramic green paste was prepared by setting it to 0% and dispersing and mixing for 10 hours including the remaining amount of the resin binder (samples 10 to 15).

Using each of these ceramic green pastes, a multilayer ceramic chip capacitor was manufactured in the same manner as described above, and inspections were performed based on surface roughness, withstand voltage failure, short circuit failure, and reliability tests. The results are as shown in Table 4 below.

[0040]

[Table 4]

As is clear from the data, Sample 1 in which the amount of the resin binder added was set to 0.1 to 20.0%.
It can be seen that Nos. 1 to 14 provide favorable results with any of the test items.

On the other hand, in Sample 10 in which the addition amount of the resin binder was set to 0.01%, since the addition amount of the resin binder was small, the wettability between the ceramic powder raw material and the solvent by the resin binder could not be sufficiently achieved, and Due to large roughness, withstand voltage failure and short circuit failure often occurred. On the other hand, in Sample 15 in which the addition amount of the resin binder was set to 30.0%, since the addition amount of the resin binder was large, the dispersibility of the resin binder and the ceramic powder raw material was poor, and the surface roughness was large and the resistance was low. Many voltage failures and short-circuit failures occurred.

Further, as a third manufacturing method, as shown in FIG. 3, a ceramic powder raw material, a plasticizer, a solvent for a resin binder and a solvent for a plasticizer, and a final required amount of 0.1% are added. 〜20% of the resin binder is first mixed in a solid state, and then the remaining amount of the resin binder is mixed in a solid state with a solvent such as dealuminal spirit naphtha incompatible with the previously mixed composition material. Thus, a ceramic green paste is obtained.

Also in this third manufacturing method, the same composition material as in the first manufacturing method is used. Also, as the mixing means, similarly to the first manufacturing method, a diameter of 2.0 m was used.
A ball mill with about m m of zirconia balls is applied. However, also in this case, the ceramic powder raw material containing the dielectric porcelain powder, the metal oxide or the porcelain additive may be preliminarily dispersed and mixed with water to be pulverized before being mixed with other composition materials.

Under the above conditions, a ceramic powder raw material, a plasticizer, a solvent for a resin binder and a solvent for a plasticizer, and a resin binder in an amount of 0.1 to 20% of the finally required addition amount are solidified. Disperse and mix 1 to 10 hours earlier by ball mill mixing as primary mixing as it is, and further add the remaining amount of resin binder as a solid with solvent such as incompatible dealuminal spirit naphtha, and mix as ball mill as secondary mixing For 10 hours, and a filtration process is performed after the dispersion and mixing to obtain a ceramic green paste.

The resin binder can be prevented from agglomerating by adding 0.1 to 20% of the finally required addition amount as a primary mixture, and the solvent binder can be added even if the remaining amount of the resin binder is added as a solid. Can be sufficiently dissolved, and
By adding an incompatible solvent, the ceramic powder raw material can be sufficiently pulverized or dispersed by primary mixing without agglomeration. Therefore, a material suitable as a ceramic green paste for a multilayer ceramic chip capacitor can be obtained by a simple mixing means in a short time. Can be obtained.

In order to confirm its effectiveness, a ceramic powder raw material, a plasticizer, a solvent for a resin binder and a solvent for a plasticizer and 1% of a resin binder were added in a solid state to form a primary mixture, followed by dispersion mixing for 5 mixing hours. Further, a ceramic green paste was prepared by adding the remaining amount of the resin binder in a solid state together with the incompatible solvent and dispersing and mixing the resulting mixture as a secondary mixture by ball mill mixing for 10 hours (Sample 16).

Further, a ceramic green paste was prepared by using the same lacquer-like resin binder dissolved in a compatible solvent as the resin binder in the same process as that of Sample 16 (Comparative Example 4).

Using each of these ceramic green pastes, a multilayer ceramic chip capacitor was manufactured in the same manner as described above, and inspections based on surface roughness, withstand voltage failure, short circuit failure, and reliability tests were performed. The results are as shown in Table 5 below.

[0050]

[Table 5]

As is clear from the data, the sample 16
However, preferable results substantially equivalent to those of Comparative Example 4 using a resin binder dissolved in a lacquer state with a compatible solvent were obtained.

[0052]

As described above, according to the method for producing a ceramic green paste for a multilayer ceramic electronic component according to the first aspect of the present invention, a ceramic powder raw material, a resin binder, a plasticizer, a resin binder and a plasticizer are provided. When preparing a ceramic green paste for a multilayer ceramic electronic component using the above solvent as a composition material, at least other composition materials except for a resin binder are mixed first, and finally, the composition material is incompatible with the previously mixed composition material. Along with the solvent, the resin binder is mixed as it is, so that the production time of the ceramic green paste can be reduced,
The ceramic powder raw material can be sufficiently disintegrated or dispersed to reduce the occurrence rate of short circuit failure and the like, and a highly reliable multilayer ceramic electronic component can be manufactured.

According to the method for producing a ceramic green paste for a multilayer ceramic electronic component according to the second aspect of the present invention, a ceramic powder raw material, a resin binder, a plasticizer, a solvent for the resin binder, and a solvent for the plasticizer are used as composition materials. In preparing ceramic green paste for multilayer ceramic electronic components, ceramic powder raw materials, plasticizers,
The solvent for the resin binder and the plasticizer and the resin binder of 0.1 to 20% of the finally required addition amount are mixed in a solid state first, and the remaining amount of the resin binder is solidified. By further mixing as it is, the production time of the ceramic green paste can be shortened, and the ceramic powder raw material can be sufficiently disintegrated or dispersed to reduce the incidence of short-circuit defects and the like, and the highly reliable multilayer ceramic electronic component Can be manufactured.

According to the method for producing a ceramic green paste for a multilayer ceramic electronic component according to a third aspect of the present invention, a ceramic powder raw material, a resin binder, a plasticizer, a solvent binder and a solvent for the plasticizer are used as composition materials. In preparing ceramic green paste for multilayer ceramic electronic components, ceramic powder raw materials, plasticizers,
The solvent for the resin binder and the plasticizer and the resin binder of 0.1 to 20% of the final required amount are first mixed in a solid state, and then mixed with the previously mixed composition material. By further mixing the remaining amount of the resin binder in a solid state with the compatible solvent, the production time of the ceramic green paste can be shortened, and the ceramic powder raw material can be sufficiently crushed or dispersed to prevent short-circuit failure and the like. The incidence rate is reduced, and a highly reliable multilayer ceramic electronic component can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a mixing step of a ceramic green paste for a multilayer ceramic electronic component according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a mixing step of a ceramic green paste for a multilayer ceramic electronic component according to a second embodiment of the present invention.

FIG. 3 is an explanatory view showing a mixing step of a ceramic green paste for a multilayer ceramic electronic component according to a third embodiment of the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Sato 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Risunori Sasaki 1-13-1-1, Nihonbashi, Chuo-ku, Tokyo F-term in DK Corporation (reference) 4G030 AA07 AA08 AA10 AA12 AA16 AA19 AA22 AA37 BA12 GA04 GA14 GA15 GA17 4J038 EA011 HA206 HA216 HA456 HA566 KA06 KA10 LA06 PB09 PC03 5E001 AB03 AC09 AE00 A04 A00 A03 A00

Claims (3)

[Claims] 1. A ceramic powder raw material, a resin binder,
When producing a ceramic green paste for a multilayer ceramic electronic component using a plasticizer, a resin binder and a solvent for the plasticizer as a composition material, at least other composition materials except for the resin binder are mixed first, and finally, A method for producing a ceramic green paste for a multilayer ceramic electronic component, wherein a resin binder is mixed as it is with a solvent incompatible with a composition material previously mixed. 2. A ceramic powder raw material, a resin binder,
When preparing a ceramic green paste for a multilayer ceramic electronic component using a plasticizer, a resin binder and a solvent for the plasticizer as a composition material, a ceramic powder raw material, a plasticizer, a solvent for the resin binder and a solvent for the plasticizer, Characterized in that the resin binder of 0.1 to 20% of the required addition amount is first mixed in a solid state, and then the remaining amount of the resin binder is further mixed in the solid state. Of producing ceramic green paste for laminated ceramic electronic components. 3. A ceramic powder raw material, a resin binder,
When preparing a ceramic green paste for a multilayer ceramic electronic component using a plasticizer, a resin binder and a solvent for the plasticizer as a composition material, a ceramic powder raw material, a plasticizer, a solvent for the resin binder and a solvent for the plasticizer, 0.1 to 20% of the required amount of the resin binder is first mixed in a solid state, and then the remaining amount of the resin binder is mixed with the previously mixed composition material and the incompatible solvent. A method for producing a ceramic green paste for a multilayer ceramic electronic component, wherein the ceramic green paste is further mixed as it is.