KR100596288B1 - Manufacturing method of laminated ceramic electronic parts - Google Patents

Abstract

In the present invention, organic matters are uniformly removed from each ceramic laminate at the time of binder removal, thereby preventing variation in characteristics, and improving the handling of the ceramic laminate after the binder removal treatment, thereby increasing reliability. Obtain a ceramic electronic component.

When the unbaked ceramic laminate 3 is subjected to a binder removal treatment, organic matters in the ceramic laminate 3 after debinding are 0.5% by weight to 8.5% by weight, preferably 1.0% by weight to It remains 5.0 weight%. This debinding process is performed in an atmosphere gas using an inert gas. In this debinding step, the debinding start temperature of the internal electrodes 5 and 6 of the unfired ceramic laminate 3 is set higher than the debinding start temperature of the ceramic layer 7.

Description

Manufacturing method of multilayer ceramic electronic component {MANUFACTURING METHOD OF LAMINATED CERAMIC ELECTRONIC PARTS}             

1 is a perspective view showing a ceramic green sheet for making a multilayer ceramic electronic component according to the present invention;

2 is a perspective view conceptually showing a state in which an internal electrode pattern is printed on a part of the ceramic green sheet;

3 is an exploded perspective view conceptually illustrating a process of laminating the ceramic green sheet;

4 is a perspective view showing a laminate of ceramic green sheets obtained by the lamination step;

5 is a partially cutaway perspective view showing a ceramic laminate obtained by cutting the laminate of the ceramic green sheet;

6 is an exploded perspective view conceptually showing the layer structure of the ceramic laminate;

7 is a graph showing an example of a furnace internal pressure, a furnace temperature, and a time profile in a binder removal furnace when the ceramic laminate is subjected to a binder removal treatment;

8 is a partially cutaway perspective view illustrating an example of a completed laminated ceramic electronic component.

Explanation of symbols for the main parts of the drawings

3: ceramic laminate

5: internal electrode

6: internal electrode

7: ceramic layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer ceramic electronic component such as a multilayer ceramic capacitor, and more particularly, after de-bindering an unfired ceramic laminate, firing the unfired ceramic laminate to produce a multilayer ceramic electronic component. It relates to a method of manufacturing a part.

A multilayer ceramic electronic component such as a multilayer ceramic capacitor has an internal electrode formed of a conductor film by laminating in a thickness direction inside a ceramic laminate. In order to manufacture such a multilayer ceramic electronic component, generally, the binder solution which consists of an organic binder, a dispersing agent, and a solvent is mixed with a raw material powder, and a slurry is made, and the electrode pattern was printed on the ceramic green sheet obtained from this by screen printing etc. By stacking them.

The binder obtained by cutting and dividing the obtained ceramic laminate into desired dimensions to form a chip shape and removing the organic binder and the like before firing the chip-shaped ceramic laminate is performed.

By the way, when the chip-shaped ceramic laminate is de-bindered and the organic component therein is removed, the ceramic laminate is weakened and structural defects due to handling of the ceramic laminate are likely to occur. Thereby, defects, such as a crack, arise easily in a ceramic laminated body in a subsequent baking process etc., for example.

In addition, when the unbaked ceramic laminate is charged into the binder removal furnace and subjected to the binder removal treatment as described above, it is difficult to keep the atmosphere in the furnace constant, and the atmosphere is partially changed. Therefore, when the chip-shaped ceramic laminate is placed in the furnace, the removal amount of the organic binder is changed depending on the place, and as a result, a variation occurs in the content of the organic matter contained in the ceramic laminate after the binder removal, and after firing There existed a subject that the dispersion | variation in the electrical characteristic of the laminated ceramic electronic component obtained becomes large for every product.

Therefore, an object of the present invention is to uniformly remove organic matter from each ceramic laminate in the case of binder removal, thereby suppressing characteristic variations, and further improving the handling of the ceramic laminate after the binder removal treatment. It is to provide a manufacturing method capable of obtaining a multilayer ceramic electronic component having high reliability and no structural defect.

In order to achieve the above object, in the present invention, when the unbaked ceramic laminate 3 is subjected to a binder removal treatment, the organic matter in the ceramic laminate 3 after the binder removal is 0.5% by weight to 8.5% by weight, preferably 1.0 weight%-5.0 weight% remain | survive. In addition, in this binder removal process, the binder removal start temperature of the internal electrodes 5 and 6 of the unfired ceramic laminated body 3 is set higher than the binder removal start temperature of the ceramic layer 7.

 That is, in the manufacturing method of the multilayer ceramic electronic component in the present invention, an unfired ceramic in which internal electrodes 5 and 6 made of a ceramic layer 7 and a non-metal film are alternately laminated in layers. In the manufacturing method of the multilayer ceramic electronic component which has the process of carrying out the binder removal process of the laminated body 3, and the process of baking the unbaked ceramic laminated body 3 which carried out the binder removal process, the ceramic laminated body after debinder 3 ) 0.5 wt% to 8.5 wt%, preferably 1.0 wt% to 5.0 wt%.

In this way, by debinding, almost all organic binders in the ceramic laminate 3 can be decomposed and removed without burning, thereby eliminating the occurrence of delamination or cracking of the chip components. You can prevent it. On the other hand, by leaving some organic binder in the chip-shaped ceramic laminated body 3, the ceramic laminated body 3 does not become extremely weak and the structure by the handling of the ceramic laminated body 3 after a binder removal process is carried out. The defect can be eliminated and the conveyance of the ceramic laminated body 3 can be performed easily, and the crack in a subsequent baking process etc. becomes difficult to occur.

When the amount of the organic substance contained in the ceramic laminated body 3 after debinding is less than 0.5 weight%, the ceramic laminated body 3 after debinding process will be easy to break, the handling property will fall, and the ceramic laminated body 3 It is difficult to convey without damaging). On the other hand, if the amount of the organic matter contained in the ceramic layer 7 of the ceramic laminate 3 after the binder removal is more than 8.5% by weight, the organic substance decomposed in the baking furnace is liable to occur in the baking step after the binder removal treatment. The atmosphere in the baking furnace cannot be maintained stably. More preferably, 1.0% by weight to 5.0% by weight of organic matter is contained in the ceramic laminate 3 after debinding, so that the problem of atmospheric fluctuations in the firing furnace during firing and structural defects of the multilayer ceramic electronic component can be solved. I can certainly solve it.

In the multilayer ceramic electronic component according to the present invention, the unfired ceramic laminate 3 in which the internal electrodes 5 and 6 made of the ceramic layer 7 and the non-metal film are alternately laminated in a plurality of layers is removed from the inside. In the manufacturing method of the multilayer ceramic electronic component which has the process of binder process and the process of baking the unbaked ceramic laminated body 3 which carried out the binder removal process, the debinder start temperature of the internal electrodes 5 and 6 is a ceramic. It is set higher than the binder removal start temperature of the layer 7, It is characterized by the above-mentioned.

In this way, in the binder removal process, the binder removal of the internal electrodes 5 and 6 is started later than the binder removal of the ceramic layer 7. That is, in the binder removal processing, first, the binder is started from the ceramic layer 7 in the portion near the surface side of the ceramic laminate 3, and the interior of the ceramic laminate 3 is later than that. Debinding of the electrodes 5, 6 is disclosed. Thereby, an organic binder can be removed uniformly over the whole ceramic laminated body 3.

The debinding treatment step is performed in an atmosphere gas using an inert gas. In this way, the organic binder can be decomposed without burning, thereby preventing the occurrence of the lamination or cracking of the chip component after firing. In particular, when the internal electrodes 5 and 6 are formed using the nonmetallic paste, oxidation of the nonmetal in the binder removal process is suppressed, and as a result, a highly reliable multilayer ceramic electronic component can be obtained.

In the process of raising the temperature of the debinding furnace, the pressure in the furnace of the debinding furnace is made higher than atmospheric pressure. By doing in this way, an appropriate amount of organic substance can be remained in the binder removal-processed ceramic laminated body 3.

 The above and other objects, features, aspects, advantages, and the like of the present invention will become more apparent from the following detailed embodiments described with reference to the accompanying drawings.

(Example)

Next, embodiments of the present invention will be described in detail and with reference to the drawings.

A case of manufacturing a multilayer ceramic capacitor as a multilayer ceramic electronic component will be described as an example. The raw material of the dielectric for forming the ceramic layer of the multilayer ceramic capacitor is mainly BaTiO ₃ . In addition, in order to reduce the lowering of the sintering temperature, the addition of a glass component as a main component such as _{Si 2 O 3, B 2 O} 3, Li 2 O 3. In addition, rare earth elements such as Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, etc. It is preferable to add the oxide containing and the oxide containing transition metals, such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni.

From such raw material powder, a dielectric material is obtained by the following means, for example.

First, starting materials are weighed and blended in predetermined amounts, and wet-mixed, for example, by a ball mill or the like. Subsequently, it is dried by a spray dryer or the like and then plasticized to obtain a dielectric oxide. Moreover, plasticity is normally performed at 800-1300 degreeC for about 2 to 10 hours. Subsequently, it grind | pulverizes until it becomes a predetermined particle diameter by a jet mill, a ball mill, etc., and obtains a dielectric material.

Next, a slurry is prepared. A slurry mainly consists of said dielectric material, a binder, and a solvent, You may add a plasticizer, a dispersing agent, etc. as needed.

As a binder, abienic acid resin, polyvinyl butyral, ethyl cellulose, an acrylic resin, etc. are mentioned, for example. As a solvent, ethanol, terpineol, butyl carbitol, toluene, kerosene, etc. are mentioned, for example. As a plasticizer, abienic acid derivative, diethyl oxalic acid, polyethylene glycol, polyalkylene glycol, a phthalic ester, dibutyl phthalate etc. are mentioned, for example. Examples of the dispersant include glycerin, octadisilamine, trichloroacetic acid, oleic acid, octadiene, ethyl oleate, glycerin monooleate, glycerin trioleate, glycerin tristearate and mencedene oil.

When adjusting this slurry, the ratio with respect to the whole dielectric material is about 30 to 80 weight%, In addition, 2 to 5 weight% of a binder, 0.1 to 5 weight% of a plasticizer, 0.1 to 5 weight% of a dispersing agent, a solvent 20 to 70% by weight.

Next, the dielectric material and these are mixed. The mixing of the slurry is carried out using a basket mill, ball mill, beads mill or the like.

Next, this slurry is coated to obtain a ceramic green sheet. Coating is performed on a ceramic green sheet having a thickness of 1 µm to 20 µm using a doctor braid, a lip coater, a die coater, a reverse coater, or the like.

Further, by cutting the ceramic green sheet to an appropriate size, a ceramic green sheet 1 as shown in FIG. 1 is obtained.

Next, as shown in FIG. 2, internal electrode patterns 2a and 2b are formed on the surfaces of some of the ceramic green sheets 1a and 1b obtained above.

As a conductor material used when manufacturing an internal electrode paste, nonmetallic materials, such as Ni and Cu, their alloys, and also their mixture are used. There is no restriction | limiting in particular in such shapes, such as a spherical shape and a scaly shape, such a conductor material may be mixed with these shapes. As for the average particle diameter of a conductor material, 0.1-10 micrometers, Preferably what is about 0.1-1 micrometer may be used. An organic vehicle is one containing a binder and a solvent. As a binder, all well-known things, such as ethyl cellulose, an acrylic resin, butyral resin, can be used, for example. The binder content is about 1 to 10% by weight. As a solvent, all well-known things, such as terpineol, butyl carbitol, a kerosene, can be used, for example. Solvent content is made into about 20 to 55 weight%. In addition, in the range of about 10 weight% or less in total, dispersing agents, such as a sorbitan fatty acid ester and a glycerol fatty acid ester, plasticizers, such as a dioctyl phthalate, dibutyl phthalate, and butyl phthalyl glycolate, and di, as needed. Various ceramic powders, such as a dielectric material and an insulator, etc. can also be added for the purpose of prevention of dilation, suppression of sintering, etc. It is also effective to add an organometallic resin salt.

Using the internal electrode paste thus obtained, two types of internal electrode patterns 2a and 2b are printed by a printing method, a transfer method, a sheet method and the like as shown in FIG. The ceramic green sheets 1a and 1b on which these internal electrode patterns 2a and 2b are printed are denoted by the reference numerals in FIG. 2 so as to distinguish the internal electrode patterns 2a and 2b from the ceramic green sheet 1 which is not printed. "1a" and "1b" are shown.

The ceramic green sheets 1a and 1b on which these internal electrode patterns 2a and 2b are printed are alternately stacked as shown in FIG. 3, and the internal electrode patterns 2a and 2b are not printed on both sides thereof. Ceramic green sheets 1 and 1 and so-called dummy sheets are further laminated, and these are compressed to obtain a laminate as shown in FIG. 4.

In addition, as described above, the ceramic green sheets 1a and 1b on which the internal electrode patterns 2a and 2b are printed, and the ceramic green sheets 1 and 2 on which the internal electrode patterns 2a and 2b are not printed, are described. In addition to the method of laminating 1), the ceramic green sheet and the conductive paste can also be obtained by a so-called slurry built-in method in which the ceramic green sheet and the conductive paste are sequentially printed and laminated in a predetermined order.

The laminate is cut vertically and horizontally and divided into individual chip-shaped unfired ceramic laminates 3 as shown in FIG. 5. This ceramic laminated body 3 has a layer structure as shown in FIG. 6, for example. Ceramic layers 7, 7... Made of a dielectric having internal electrodes 5, 6 are laminated in the order shown in FIG. 6, and ceramic layers 7 in which internal electrodes 5, 6 are not formed on both sides thereof. , 7...) Are laminated in plural layers, respectively. The internal electrodes 5 and 6 are alternately exposed at the ends of the ceramic laminate 3 having such a layer structure.

Next, this ceramic laminate 3 is subjected to a binder removal treatment and then fired.

What is necessary is just to determine suitably the shape and size of the multilayer ceramic capacitor obtained in this way according to an objective and a use. For example, in the case of a rectangular parallelepiped shape, it is about 1.0-3.2 mm x 0.5-1.6 mm x 0.5-1.6 mm normally.

Here, the said binder removal process is demonstrated. In addition, the "de-binder" referred to in this specification heats the ceramic laminated body 3, removes the binder contained in the ceramic laminated body 3, and other organic substance, and replaces the one part with the ceramic laminated body 3 The process of remaining in the system.

As a binder removal process, the undivided ceramic laminated body 3 divided first is charged to a binder removal furnace. At that time, the ceramic laminate 3 adheres a fusion inhibitor to the surface by static electricity, fills the surface into a zirconia-coated alumina case, and loads it into the furnace. In addition, by using the mesh case smaller than the length of the ceramic laminated body 3 instead of the alumina quality case, it becomes easy to remove binder uniformly.

As the binder removal treatment conditions, in addition to the case where the pressure in the furnace is normally set in a constant pressure state and the temperature and time of the furnace are set, the pressure in the furnace may be changed. For example, as shown in FIG. 7, first, the internal pressure of a furnace is raised to 10 atmospheres at normal temperature, and it heats up at the rate of 20 degree-C / hr after that. When the furnace temperature becomes 200 degreeC, pressure reduction is started and it returns to atmospheric pressure. On the other hand, after maintaining furnace temperature for a fixed time at the peak temperature Tp set by the characteristic of the binder used, a binder removal is complete | finished.

Here, the temperature which starts high pressure and pressure reduction which are initially added is all selected by the binder, and is not limited to said 10 atmospheres and 200 degreeC.

In this way, in the binder removal process, by maintaining the furnace pressure at 10 atm in the process of raising the furnace temperature, the organic matter is 0.5 to the ceramic laminate 3 in the binder binder treated ceramic body 3. 8.5% by weight will be included. In this way, by adjusting the content of the organic matter of the ceramic laminate 3 after the binder removal, the structural defect due to the handling of the ceramic laminate 3 can be eliminated, and the conveyance can be easily carried out. Since generation | occurrence | production of an organic substance can be suppressed and the atmosphere in a baking furnace can be kept stable, baking unevenness can be suppressed.

Here, the organic substance contained in the ceramic laminated body 3 is not limited to the residue of a binder, but means the residue of a binder and other organic substance. In general, the solvent evaporates when the slurry is sheeted, but the organic substances contained in the ceramic laminate 3 herein refer to all of the organic substances remaining in the ceramic laminate 3, and the removal of the ceramic laminate 3 It can measure by the difference of the weight before and behind a binder process.

In this binder removal process, if the furnace is operated in an inert gas, for example, a nitrogen atmosphere, the organic binder can be decomposed without burning, thereby preventing the occurrence of the delamination or cracking of the chip components after firing. Can be. In particular, since the internal electrodes 5 and 6 are formed using a nonmetallic paste, the oxidation of the internal electrodes 5 and 6 can be suppressed.

Further, by appropriately selecting the binder contained in the internal electrodes 5, 6 and the binder contained in the ceramic layer 7, the debonder start temperature of the internal electrodes 5, 6 and the removal of the ceramic layer 7 are performed. The binder start temperature can be varied. Specifically, by setting the binder removal start temperature of the internal electrodes 5 and 6 higher than the binder removal start temperature of the ceramic layer 7, the internal electrode (after the binder removal processing of the ceramic layer 7 is finished) The debinding process of 5 and 6 can be advanced, and the uniform debinding process can be performed in and around a chip component.

The firing of the ceramic laminate 3 after the binder removal can use an atmosphere tunnel furnace or an atmosphere fixing furnace.

After firing the ceramic laminate 3 in this way, as illustrated in FIG. 8, external electrodes 2 and 2 are formed at the end of the ceramic laminate 3. In order to form the external electrodes 2 and 2, generally, Ni, a Ni alloy, Cu, a Cu alloy, etc. can be used for a conductor component. When the external electrodes 2 and 2 are formed using the conductive paste, the conductive paste is applied to the end of the ceramic laminate 3 by the dipping method or the like. Thereafter, the external electrodes 2 and 2 are formed by firing at 600 to 1000 ° C. in a neutral atmosphere or a reducing atmosphere. The conductive paste may be applied to the end of the unfired ceramic laminate 3 before firing, and the conductive paste may be fired at the same time as the firing of the ceramic laminate 3 to form the external electrodes 2 and 2. In addition, the external electrodes 2 and 2 may be formed using a dry method such as vapor deposition or sputtering.

For example, the multilayer ceramic capacitor produced as described above has little damage during handling of the ceramic laminate 3 after the binder removal, and its handling is easy. In addition, at the time of baking of the unfired ceramic laminated body 3, the dispersion | variation in electrical characteristics between products was suppressed without being influenced by the deviation of the binder removal in a binder removal process.

In the above description, the manufacturing method of the multilayer ceramic capacitor is described as an example of the multilayer ceramic electronic component. However, the present invention can be applied to a multilayer ceramic inductor or a multilayer ceramic composite only by changing the shape of the ceramic material, the internal electrode pattern, and the stacking order thereof. It goes without saying that the present invention can be similarly applied to the production of other multilayer ceramic electronic components such as components.

As mentioned above, according to the manufacturing method of the laminated ceramic electronic component of this invention, the handling property of the ceramic laminated body 3 after debinding is improved, and a laminated ceramic electronic component can be manufactured efficiently and with high yield. have. In the case of the binder removal, organic matters are uniformly removed from each unfired ceramic laminate, thereby suppressing the characteristic variation as a product and obtaining a highly reliable multilayer ceramic electronic component.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

Claims (6)

delete De-binder-processing the unbaked ceramic laminated body in which the internal electrode which consists of a ceramic layer and a nonmetallic film internally laminated by several layers alternately, and the unbaked process which carried out the binder removal process In the manufacturing method of the multilayer ceramic electronic component which has a process of baking the ceramic laminated body of A method for producing a multilayer ceramic electronic component, comprising 1.0% by weight to 5.0% by weight of an organic substance contained in the ceramic laminate after the binder removal. A multilayer ceramic having a step of de-bindering an unfired ceramic laminate in which internal electrodes composed of a ceramic layer and a non-metal film are alternately laminated in a plurality of layers, and firing the unfired ceramic laminate after the de-binder treatment In the manufacturing method of the electronic component, The binder removal start temperature of an internal electrode is set higher than the binder removal start temperature of a ceramic layer, The manufacturing method of the multilayer ceramic electronic component characterized by the above-mentioned. The method of claim 2 or 3, An atmosphere gas is used in the debinding treatment step, wherein the multilayer ceramic electronic component manufacturing method is used. The method of claim 4, wherein The atmosphere gas comprises an inert gas, the method of manufacturing a multilayer ceramic electronic component. The method of claim 2 or 3, A method of manufacturing a multilayer ceramic electronic component, wherein the pressure in the furnace of the binder removal furnace is higher than atmospheric pressure in the process of increasing the temperature of the binder binder furnace in the binder removal treatment step.

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