JP6890822B2 - Manufacturing method of ceramic molded product - Google Patents

Description

The present invention relates to a method for producing a ceramic molded product.

Conventionally, with the miniaturization of electronic devices, electronic components used in electronic devices are required to have small size, light weight, and high reliability. Ceramics can be mentioned as a material that meets such required physical characteristics. Ceramics are used as materials for forming various electronic components because they have high insulating properties and are not easily deformed by heat. Therefore, in recent years, in order to meet the above market demand, a method for producing a small ceramic molded product has been studied (see, for example, Patent Document 1).

JP-A-2007-260926

However, the method of Patent Document 1 does not describe the formation of a fine molded product having a size of less than 10 μm. With the miniaturization of electronic devices, the demand for such fine ceramic molded products is expected, and therefore, a method for manufacturing the fine ceramic molded products has been required.

In the present invention, a ceramic molded product having a size that fits in a cube of 200 μm square is referred to as a “micro ceramic molded product”.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for producing a ceramic molded product, which enables efficient production of the ceramic molded product.

In order to solve the above problems, one aspect of the present invention includes a step of filling a mold having a desired shape with a slurry containing ceramic fine particles, a step of removing a dispersion medium from the slurry to obtain a temporary molded body, and the above steps. The mold comprises a step of taking out the temporary molded body from the mold and a step of firing the temporary molded body, and the mold has a recess having a shape corresponding to the desired shape and a flat portion continuous with the recess. In the step of filling the slurry, the slurry is arranged across the recess and the flat portion, and in the step of obtaining the temporary molded body, the dryness obtained by removing the dispersion medium from the slurry is obtained. Provided is a method for producing a ceramic molded body in which a solid material is cut off at a boundary between a first portion included in the recess and a second portion overlapping the flat portion, and the first portion is used as the temporary molded body.

In one aspect of the present invention, the mold may be made of a resin material as a forming material, and the taking-out step may be performed after the mold is swollen with a solvent and the recesses are enlarged.

In one aspect of the present invention, in the taking-out step, a curable resin is filled in a gap between the enlarged recess and the temporary molded body and cured, and then the temporary molding is performed together with the curable resin from the recess. It may be a manufacturing method for taking out the body.

In one aspect of the present invention, the mold may be made of a resin material as a forming material, and the taking-out step may be a manufacturing method in which the mold is melted down.

In one aspect of the present invention, the mold may be made of a resin material as a forming material, and the taking-out step may be a manufacturing method in which the mold is burnt down.

According to the present invention, a ceramic molded product can be efficiently produced.

The process drawing which shows the manufacturing method of the ceramic compact which concerns on this embodiment. The process drawing which shows the manufacturing method of the ceramic compact which concerns on this embodiment. The process drawing which shows the manufacturing method of the ceramic compact which concerns on this embodiment. The process drawing which shows the manufacturing method of the ceramic compact which concerns on this embodiment. An enlarged photograph showing the state when the mold in which the temporary molded body remains in the concave portion is inflated. The process drawing which shows the manufacturing method of the ceramic compact which concerns on this embodiment. The process drawing which shows the manufacturing method of the ceramic compact which concerns on this embodiment. An SEM photograph of the temporarily molded product taken out. The process drawing which shows the manufacturing method of the ceramic compact which concerns on this embodiment.

[First Embodiment]
Hereinafter, a method for manufacturing a ceramic molded product according to the present embodiment will be described with reference to FIGS. 1 to 9. In all the drawings below, the dimensions and ratios of the components are appropriately different in order to make the drawings easier to see.

1 to 9 are explanatory views showing a method of manufacturing a ceramic molded product according to the present embodiment. FIGS. 1 to 4, 6, 7 and 9 are process charts showing a manufacturing method of a ceramic molded product, and FIGS. 5 and 8 are confirmation photographs confirming the manufacturing method of the ceramic molded product.

In the method for producing a ceramic molded product of the present embodiment, a ceramic molded product to which the desired shape is transferred is produced using a mold having a desired shape. The size of the target ceramic molded body can be variously selected, but a method for producing a ceramic molded body having a size on the submillimeter order, particularly a micro ceramic molded body having a size that fits in a cube of 200 μm square. Is suitable as.

In the following description, as the ceramic molded body, a prismatic microceramic molded body that fits in a 100 μm square will be manufactured.

(Step of filling slurry)
First, as shown in FIG. 1, the mold 100 is filled with the slurry 15.

The mold 100 has a recess 100a having a shape corresponding to the shape (desired shape) of the ceramic molded body which is the target object, and a flat portion 100b continuous with the recess 100a. Here, the fact that the recess 100a has "a shape corresponding to the shape of the ceramic molded body which is the target object" means that the prototype shape of the ceramic molded body, which will be described later, is transferred to the inner wall of the recess 100a, and the inner wall of the recess 100a. It means that and the shape of the prototype are in a complementary relationship.

Further, the mold 100 uses a resin material as a forming material. As the material for forming the mold 100, various materials can be used as long as they have strength and elasticity sufficient to retain the transferred shape in the operation described later and are swelled in a solvent in the operation described later. Further, in the operation described later, in order to facilitate the release of the temporarily molded body molded by the mold 100, a material having a low surface energy and difficult to adhere to the material filled in the recess 100a is preferable.

For example, as a material for forming the mold 100, a silicone resin such as PDMS (polydimethylsiloxane), a thermoplastic elastomer, a thermosetting elastomer, or the like can be used. Examples of the thermosetting elastomer include an epoxy resin, a urethane resin, a fluororubber, and the like, in addition to the silicone resin. Among these, in the present embodiment, the material for forming the mold 100 is preferably a silicone resin, and more preferably PDMS.

The mold 100 can be produced by a known method. For example, after producing a prototype of a desired shape by a known method such as stereolithography or shaving, the obtained prototype is molded with the above-mentioned forming material to prepare a mold 100 to which the shape of the prototype is transferred. be able to.

The slurry 15 is assumed to contain ceramic fine particles and substantially no polymer material. "Substantially free of polymer material" means that a small amount of polymer material is allowed to be contained within the range in which the effect of the present invention is exhibited.

The ceramic fine particles used in the slurry 15 are not particularly limited, and various ceramic fine particles can be used as long as a molded product can be obtained by sintering described later. Examples of the material for forming the ceramic fine particles include metal oxides and composite metal oxides. Examples of the metal oxide include alumina, zirconia, silica, titania and the like. Examples of the composite metal oxide include barium titanate.

The average particle size of the ceramic fine particles to be used may be set according to the size of the recess 100a of the mold 100 used in the range of several nm to several μm, that is, the size of the ceramic molded product to be produced. Further, when the ceramic molded body is manufactured by sintering the ceramic fine particles, it is preferable that the predicted value of the size of the crystal grains constituting the ceramic molded body is not too large with respect to the ceramic molded body.

For example, when the volume of the recess 100a of the mold 100 is about 1 mm ³ (≈10 μm square), the average particle size of the ceramic fine particles is preferably about 100 nm. Further, when the volume of the recess 100a of the mold 100 is about 1000 mm ³ (≈100 μm square), the ceramic fine particles can be used even if the average particle size is about several μm.

The smaller the average particle size of the ceramic fine particles, the easier it is for the ceramic fine particles to aggregate depending on the dispersion system used. In such a case, a dispersant may be used to stabilize the dispersion system as long as the effect of the present invention is not impaired.

The dispersion medium of the slurry 15 preferably contains water as a main component. The dispersion medium may contain an organic solvent.

The slurry 15 preferably has a ceramic fine particle content of 50% by mass or more, more preferably 60% by mass or more, further preferably 65% by mass or more, still more preferably 70% by mass or more, and 80% by mass or more. Mass% or more is particularly preferable.

As long as the fluidity of the slurry 15 can be ensured, the content of the ceramic fine particles in the slurry 15 can be increased. On the other hand, the content of the ceramic fine particles in the slurry 15 can be reduced as long as the shape of the dry matter can be maintained when the dispersion medium is removed from the slurry 15.

When filling the mold 100 with such a slurry 15, the mold 110 for the base may be used by superimposing the mold 100 on the mold 100 in order to suppress the outflow of the slurry 15. The mold 110 has a through hole 110a. The mold 110 is used so as to be overlapped with the flat portion 100b of the mold 100 so that the recess 100a of the mold 100 is exposed in the through hole 110a.
In this step, the slurry 15 is arranged so as to straddle the recess 100a and the flat portion 100b.

(Step to obtain a temporary molded product)
Next, as shown in FIG. 2, the dispersion medium is removed from the slurry 15 to obtain a temporary molded product.

First, the dispersion medium is removed from the slurry 15 placed on the mold 100. Removal of the dispersion medium may be accelerated by heating, blowing, depressurizing or a combination thereof.
As a result, a dry solid product 10X, which is an aggregate of ceramic fine particles, is obtained.

The obtained dry solid product 10X is brittle and easily damaged. In the present embodiment, utilizing such properties of the dry matter 10X, the first portion 10A included in the recess 100a and the second portion 10B overlapping the flat portion 100b are broken off at the boundary 10C. Thereby, the first portion 10A to which the desired shape is transferred and the second portion 10B which is an unnecessary portion can be easily separated.

Here, conventionally, the operation of "folding" has been considered to have problems such as poor dimensional accuracy and easy damage to necessary parts.

However, the dry matter 10X, which is the target of the operation of "breaking", has the above-mentioned properties, and is not particularly devised to improve the strength such as containing a binder.
Further, in the dry matter 10X, the boundary 10C is formed in a notch shape with respect to the dry matter X, and stress tends to concentrate.

From these, it was found that in the method for producing the ceramic molded product of the present embodiment, it is possible to cut off with high accuracy at the boundary 10C.

The first portion 10A remains inside the recess 100a. The obtained first portion 10A is hereinafter referred to as "temporary molded product 10A".

(Step to take out the temporary molded product)
Next, as shown in FIGS. 3 to 7, the temporarily molded product 10A is taken out from the mold 100.
First, the mold 100 in which the temporary molded body 10A remains in the recess 100a is swollen with the solvent S. For example, as shown in FIG. 3, it is preferable to store the solvent S in the storage tank 120 and immerse the mold 100 in the solvent S.

As shown in FIG. 4, as the mold 100 swells, the recesses of the mold 100 expand. In FIG. 4, the mold 100 swollen with the solvent S is indicated by reference numeral 105, and the concave portion of the mold 105 is indicated by reference numeral 105a. On the other hand, the temporary molded product 10A, which is a dry solid product of ceramic fine particles, does not change in volume even when immersed in the solvent S. Therefore, a gap 105X is generated between the temporarily molded body 10A and the recess 105a.

As the solvent S, various solvents can be used as long as the mold 100 can be swollen. Further, the solvent S may be appropriately selected according to the resin material used as the material for forming the mold 100 and the target value of the volume expansion coefficient of the mold 100 due to swelling. For example, examples of the solvent S that can be used include hydrocarbons, alcohols, ethers, ketones, phenols, water and the like. Only one of these solvents may be used, or two or more of these solvents may be used in combination.

As an example, Table 1 summarizes the volume expansion coefficient of silicone rubber after being immersed in various solvents for 168 hours.

The "volume expansion coefficient" refers to a value obtained by the following formula (A), where _{V 0 is the volume before swelling and V 1} is the volume after swelling.
Volume expansion rate (%) = (V ₁ −V ₀ ) / V ₀ × 100… (A)

When the coefficient of thermal expansion of PDMS was determined according to the above definition, the coefficient of thermal expansion after being immersed in ethanol for 170 hours was 26%, and the coefficient of thermal expansion after being immersed in isopropyl alcohol (IPA) for 170 hours was 81%. It was. When a mold using a silicone resin such as silicone rubber or PDMS as a forming material is used, the solvent to be used can be appropriately selected according to the required swelling rate by referring to the tendency shown in the results in Table 1 above. it can.

FIG. 5 is an enlarged photograph showing a state when the mold 100 in which the temporary molded body 10A remains in the recess is swollen with a solvent. More specifically, it is a photograph of the vicinity of the recess 105a of the mold 100 after the mold 100 has expanded (mold 105) when viewed in a plan view.

Here, a dry solid product of barium titanate fine particles was used as the temporary molded product 10A, and PDMS was used as the material for forming the mold 100. In addition, IPA was used as a solvent for swelling the mold 100.

As shown in the figure, the recess 105a is enlarged due to the swelling of the solvent, and it can be seen that a gap 105X is formed between the temporarily molded body 10A and the recess 105a.

Next, as shown in FIG. 6, the gap between the recess 105a and the temporary molded body 10A is filled with a curable resin and cured.

As the curable resin, either a thermosetting resin or a photocurable resin can be used, but it is preferable to use a photocurable resin. For example, as the curable resin, TSR-883 (epoxy resin, manufactured by Seamet Co., Ltd.), TSR-820 (epoxy resin, manufactured by Seamet Co., Ltd.), SCR-701 (epoxy resin, manufactured by JSR Corporation) are used. be able to. Further, a resin obtained by mixing SR499 (acrylic resin, manufactured by Sartmer Co., Ltd.) with a photopolymerization initiator may be used.

Further, as the thermosetting resin and the photocurable resin, generally known ones can be used, but those having a small amount of ash when fired are preferable.

Here, it will be described that TSR-883, which is an ultraviolet curable resin, is used as the curable resin.

For example, by applying a photocurable resin, filling the gap between the recess 105a and the temporary molded body 10A with the photocurable resin, stacking the substrates P, and further irradiating the ultraviolet L with ultraviolet rays L, the photocurable resin is obtained. The resin support layer 130 is formed.

As the substrate P, plate materials of various materials such as metal, glass, and ceramics can be used. When the mold 105 has light transmission, the substrate P may be one having light transmission or one having no light transmission. When the mold 105 does not have light transmission, a substrate P having light transmission is used.

Next, as shown in FIG. 7, the temporary molded body 10A is taken out from the recess 105a shown in FIG. 6 together with the support layer 130 using the curable resin as a forming material.

When the support layer 130 is not used, the temporary molded body 10A may adhere to the bottom surface of the recess, making it difficult to take out the temporary molded body 10A without damaging it. However, as in the manufacturing method of the present embodiment, by taking out the temporary molded body 10A together with the support layer 130 after forming the support layer 130, the temporary molded body 10A can be easily and surely taken out.

Since the mold becomes soft due to swelling, the temporary molded body 10A may be taken out while bending the mold 105.

FIG. 8 is an SEM photograph of the temporarily molded product 10A taken out. As shown in the figure, it can be seen that the temporarily molded body 10A can be taken out without being damaged.

Next, as shown in FIG. 9, the temporary molded body 10A is fired together with the support layer 130. The firing temperature is set to a temperature higher than the sintering temperature of the ceramic fine particles constituting the temporary molded body 10A.

By firing, the support layer 130 is burned down. Further, in the temporary molded body 10A, the ceramic fine particles constituting the temporary molded body 10A are sintered together to become the target molded body 10.

According to the method for manufacturing a ceramic molded product having the above configuration, it is possible to efficiently manufacture the ceramic molded product.

In the present embodiment, for the sake of convenience of explanation, the mold 100 has only one recess 100a, but the present invention is not limited to this. By using the mold 100 having a plurality of recesses 100a, a plurality of ceramic molded bodies can be produced at the same time.

Further, in the present embodiment, as the recess 100a of the mold 100, a tapered shape in which the opening diameter gradually decreases in the depth direction has been described with reference to the drawings, but the present invention is not limited to this. For example, when the recess 100a has a reverse-tapered shape in which the opening diameter gradually increases in the depth direction, the obtained temporary molded body is transferred to the recessed shape to become a reverse-tapered molded body. In this case, the temporarily molded product cannot normally be taken out from the recess 100a.

On the other hand, when the present embodiment is used, since the recess 100a expands to the recess 105a due to swelling, even a temporary molded product having a reverse taper shape can be taken out from the recess 105a.

Further, in the present embodiment, when the temporary molded body 10A is taken out from the mold 105, the support layer 130 is formed by using a curable resin, but the temporary molded body 10A is taken out without using the support layer 130. It may be that. For example, when the adhesive force between the temporary molded body 10A and the mold 105 is weak, the temporary molded body 10A can be taken out without using the support layer 130.

Further, in the present embodiment, when the temporary molded product is taken out from the mold, the mold is swollen with a solvent, but the present invention is not limited to this.

For example, a resin material soluble in an organic solvent may be used as the material for forming the mold 100, and the mold 100 may be dissolved in the organic solvent to take out the temporary molded product 10A.

Alternatively, the mold 100 may be thermally decomposed and burned to take out the temporary molded product 10A.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. The various shapes and combinations of the constituent members shown in the above-mentioned examples are examples, and can be variously changed based on design requirements and the like within a range that does not deviate from the gist of the present invention.

10 ... Molded product, 10A ... Temporary molded product, 10A ... 1st part, 10B ... 2nd part, 10C ... Boundary, 10X ... Dry matter, 15 ... Slurry, 100, 105, 110 ... Mold, 100a, 105a ... Recess , 100b ... Flat portion, 105X ... Gap, S ... Solvent

Claims (5)

A method for manufacturing a ceramic molded product, which manufactures a micro ceramic molded product.
A step of filling a slurry having a desired shape with a slurry containing fine ceramic particles,
A step of removing the dispersion medium from the slurry to obtain a temporary molded product, and
The step of taking out the temporary molded product from the mold and
It has a step of firing the temporary molded product.
The slurry is substantially free of polymeric materials
The dispersion medium contains water as a main component.
The mold has a recess having a shape corresponding to the desired shape and a flat portion continuous with the recess.
In the step of filling the slurry, the slurry is arranged across the recess and the flat portion.
In the step of obtaining the temporary molded product, the dry matter obtained by removing the dispersion medium from the slurry is cut off at the boundary between the first portion contained in the recess and the second portion overlapping the flat portion. A method for producing a ceramic molded product having the first portion as the temporary molded product. The mold uses a resin material as a forming material.
The method for producing a ceramic molded product according to claim 1, wherein the taking-out step is performed after the mold is swollen with a solvent and the recesses are enlarged. The second aspect of claim 2, wherein in the taking-out step, a curable resin is filled in a gap between the enlarged concave portion and the temporary molded product and cured, and then the temporary molded product is taken out together with the curable resin from the concave portion. Method for manufacturing ceramic molded products. The mold uses a resin material as a forming material.
The method for producing a ceramic molded product according to claim 1, wherein the taking-out step is performed by melting the mold. The mold uses a resin material as a forming material.
The method for producing a ceramic molded product according to claim 1, wherein the taking-out step is performed by burning the mold.

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