JP2003211422A - Method for producing three-dimensional ceramic structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a three-dimensional ceramic structure. <P>SOLUTION: A photosensitive sol-gel solution 5 containing a metal element is irradiated with electromagnetic waves such as laser beams from a laser 21 to be gelatinized. The gelatinized solution is repeatedly moved from the surface of the solution 5 to a prescribed depth, and the unirradiated portion of the solution 5 is dissolved/removed in a proper stage to make a layer-shaped, three-dimensional unsintered molding 4. Next, the molding 4 is burned to obtain the aimed three-dimensional ceramic structure. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a three-dimensional ceramic structure having a three-dimensional shape.

[0002]

2. Description of the Related Art A method for producing a three-dimensional ceramic structure having a three-dimensional shape is roughly divided into the following two typical methods.

The first method is a method of externally processing a fired ceramic sintered body to obtain a three-dimensional ceramic structure having a desired shape. In this method, in order to process the ceramic sintered body from the outside, for example, a method of mechanically cutting with a drill or the like, a method of chemically etching, a laser beam or an ion beam is applied. The method of forming the holes can be applied.

The second method is a method in which a green compact having a desired three-dimensional shape is molded in advance from a ceramic powder or a mixture of ceramic powder and resin, and then the raw compact is fired. . In the second method, in order to obtain a raw molded body having a desired three-dimensional shape, a method of using a mold and putting ceramic powder or a mixture of ceramic powder and resin in the mold and molding is applied. Alternatively, a method for producing a green molded body having a desired three-dimensional shape by punching or the like can be applied.

[0005]

However, both the first and second methods described above have problems to be solved.

First, when the method of mechanically cutting with a drill or the like is applied in the first method, chipping and cracks are likely to occur, and the material of the workable ceramic sintered body is Limited.

In order to cut mechanically, a sandblasting method may be applied. In this case,
After covering the ceramic sintered body to be processed with a resist and removing the resist only in the processed portion,
Holes and the like are provided by sandblasting. However, in this method, it is difficult to form a hole having a depth, and a relatively troublesome process such as coating with a resist and removing the resist is required.

When the method of chemically etching is applied in the first method, the steps of coating an etching resist, patterning an etching resist, and etching are generally carried out. However,
In this method, the selection range of the etching liquid and the etching resist is narrow, and the ceramic material that can be processed by etching is also limited. Also,
The depth that can be etched is limited by the size of the hole,
For example, there is a problem that it is difficult to form a deep hole or a high protrusion, and it is difficult to form a pot-shaped hole. Furthermore, a relatively complicated process such as application of etching resist and patterning is required.

In the first method, even if a method of processing using a laser beam or an ion beam is applied, it is relatively difficult to process with a depth or a large area.

On the other hand, in the second method, it is difficult to obtain a relatively complicated three-dimensional shape by the method using a mold, and when a green molded body is obtained by punching or the like,
It is more difficult to obtain a complicated three-dimensional shape.

Further, the second method generally requires firing at a relatively high temperature.

Furthermore, it is difficult to obtain a complicated three-dimensional structure having a space like a frame by either of the first and second methods.

As a special method, a high aspect ratio (depth / depth / depth) is obtained, for example, by exposure using X-rays with high brightness, high transparency and high directivity from synchrotron radiation.
A resist pattern of (hole diameter) is prepared, and (Pb,
There is a method in which a slurry of Zr) TiO ₃ is poured and cast, and then a step of removing an unnecessary resist is performed to obtain a three-dimensional ceramic structure. However, this method also has a problem that there is a limit to the production of a structure having a three-dimensional shape with a high aspect ratio and that a very complicated process is required.

On the other hand, as a method suitable for manufacturing a three-dimensional ceramic structure having a complicated three-dimensional shape, there is a layered molding method using optical molding. For example, JP 2000-3
Japanese Patent No. 41031 describes that a three-dimensional structure is produced from a mixture of a ceramic and a photocurable resin by using this method. However, the three-dimensional structure obtained by this method is composed of a composite of resin and ceramic, and it is difficult to exhibit the original characteristics of the ceramic.

Therefore, an object of the present invention is to provide a method for manufacturing a three-dimensional ceramic structure which can solve the above-mentioned various problems.

[0016]

In order to solve the above-mentioned technical problems, the method for manufacturing a three-dimensional ceramic structure according to the present invention irradiates a photosensitive sol-gel solution containing a metal element with an electromagnetic wave to form a gel. And a step of firing the three-dimensional green compact, and a step of firing the three-dimensional green compact.

The three-dimensional ceramic structure in the present invention refers to structures of any shape.
Specifically, for example, a structure having a relatively small surface irregularity such as a prismatic shape, a pyramidal shape, or a spherical shape, a shape with a space such as a skeleton, or a plurality of relatively high protrusions are arranged in close proximity to each other. It refers to both a structure having a complicated uneven surface such as a shape having a hole and a hole having a depth.

The photosensitive sol-gel solution preferably contains a solution of a metal organic compound and a photosensitive gelling reaction accelerator.

In producing a three-dimensional green compact, a step of gelling a liquid layer in the vicinity of the liquid surface of the sol-gel solution by irradiation of electromagnetic waves, and a gelled product obtained by the gelling step in the sol-gel solution It is preferable that the step of moving from the liquid surface to a position of a predetermined depth is repeatedly performed, whereby a three-dimensional green compact is formed in layers.

Preferably, after the gelling step and the moving step are carried out at least once, a step of dissolving and removing the unirradiated portion of the sol-gel solution is carried out.

In order to reinforce the three-dimensional ceramic structure obtained by the present invention, the space portion of the three-dimensional ceramic structure may be filled with a material different from that of the three-dimensional ceramic structure. For example, specifically, the space portion (recess) 32 of the photonic bandgap crystal 31 which is the three-dimensional ceramic structure shown in FIG. 3 is filled with resin.

[0022]

1 is a perspective view showing a piezoelectric transducer array 1 as an example of a three-dimensional ceramic structure manufactured by a manufacturing method according to the present invention.

The piezoelectric transducer array 1 shown in FIG. 1 is used in a medical ultrasonic diagnostic apparatus. The piezoelectric transducer array 1 is made of, for example, lead zirconate titanate (PZT).

The piezoelectric transducer array 1 has a large number of columnar transducers 2 and has a structure in which they are arranged. The resolution provided by the piezoelectric transducer array 1 depends on the size and array pitch of the individual transducers 2, therefore the transducers 2 are made as small as possible in order to increase the resolution, and
It is necessary to arrange them as densely as possible.

Such a piezoelectric transducer array 1
First, the piezoelectric transducer array 1 is manufactured.
A three-dimensional green compact having the same three-dimensional shape as the above is produced. In order to produce this three-dimensional green compact, a three-dimensional green compact manufacturing apparatus 3 as shown in FIG. 2 is used.

FIG. 2 schematically shows the three-dimensional green compact 4 manufactured by the three-dimensional green compact manufacturing apparatus 3.

The three-dimensional green compact manufacturing apparatus 3 contains a photosensitive sol-gel solution 5 containing a metal element, and a main tank 6 for manufacturing the three-dimensional green compact 4 therein.
Is equipped with. A stage 7 for manufacturing the three-dimensional green compact 4 is arranged in the main tank 6. The stage 7 is driven so as to be gradually lowered by a predetermined height, as indicated by an arrow 8.

A squeegee 9 is provided so as to move along the upper opening of the main tank 6. The squeegee 9 is for adjusting the liquid level of the sol-gel solution 5. As a result of the liquid level adjustment by the squeegee 9, the sol-gel solution 5 removed from the main tank 6 is stored in the excess solution storage tank 10 provided adjacent to the main tank 6.

A spare tank 11 is provided below the main tank 6. The preliminary tank 11 is connected to the main tank 6 via a conduit 13 with a pump 12 interposed therebetween, and the sol-gel solution 5 contained in the preliminary tank 11 is driven through the conduit 13 by driving the pump 12. It is supplied to the main tank 6.

Further, the preliminary tank 11 is connected to the main tank 6 via a conduit 15 in which a sol-gel solution recovery valve 14 is interposed. By opening the sol-gel solution recovery valve 14, the sol-gel solution 5 in the main tank 6 is recovered in the preliminary tank 11 through the conduit 15.

In addition, the above-mentioned excess solution storage tank 10 is provided with a conduit 15 via a conduit 16 and a sol-gel solution recovery valve 25.
Connected to. Therefore, the sol-gel solution 5 in the excess solution storage tank 10 can also be recovered in the preliminary tank 11 through the conduits 16 and 15 by opening the sol-gel solution recovery valves 14 and 25.

Further, the conduit 15 is connected to a conduit 18 with a developer disposal valve 17 interposed. This conduit 18 is developed in the main tank 6 (dissolving and removing unirradiated portion)
Is used for discarding the developer stored in the main tank 6.

The three-dimensional green compact manufacturing apparatus 3 also irradiates the sol-gel solution 5 in the main tank 6 with electromagnetic waves, more specifically, laser light as shown by arrows 19 and 20. A laser light generator 21 for gelling the sol-gel solution 5 is provided. Laser light generator 2
The laser light generated in 1 is reflected by the mirror 22 and focused by the lens 23, as shown by arrows 19 and 20, and then irradiated on the liquid surface of the sol-gel solution 5 in the main tank 6.

Further, the three-dimensional green compact manufacturing apparatus 3
Includes a lamp heater 24 for exerting a heating action on the three-dimensional green compact 4 on the stage 7.

Next, a method of manufacturing the three-dimensional green compact 4 using the three-dimensional green compact manufacturing apparatus 3 will be described.

First, a photosensitive sol-gel solution 5 is prepared. The sol-gel solution 5 preferably contains a solution of a metal organic compound and a photosensitive gelling reaction accelerator. As an example, lead acetate is dissolved in 2-methoxyethanol, heated and sufficiently dehydrated, zirconium-n-butoxide and titanium isopropoxide are added to this solution, and the mixture is further diluted with 2-methoxyethanol and further subjected to photosensitization. The o-nitrobenzyl alcohol is added to give a photosensitive sol-gel solution 5.

The sol-gel solution 5 described above is introduced into the main tank 6, and then the squeegee 9 adjusts the liquid level. At this time, the surplus amount of the sol-gel solution 5 is stored in the surplus solution storage tank 10.

Next, the laser light from the laser light generator 21 is irradiated toward the liquid surface of the sol-gel solution 5 in the main tank 6. The sol-gel solution 5 is gelated by irradiation with laser light.

The above-mentioned irradiation with laser light and the gelation of the sol-gel solution 5 by it are not performed all at once for the entire three-dimensional green compact 4 to be obtained, but to 3
This is sequentially carried out for each part obtained by dividing the three-dimensional green compact 4 into layers.

That is, at the stage of starting this process,
The stage 7 is located near the liquid surface of the sol-gel solution 5. For example, the stage 7 is positioned so as to form a liquid layer of the sol-gel solution 5 having a thickness of about 1 μm on the stage 7. In this state, laser light is irradiated to achieve gelation in the above-mentioned liquid layer portion, and then the stage 7 moves the gelled substance to a position of a predetermined depth from the liquid surface of the sol-gel solution 5. , For example, 1 μm is moved downward as indicated by an arrow 8, and laser light is irradiated again to gel a specific portion of the sol-gel solution 5.

The gelation of the sol-gel solution 5 by the irradiation of the laser beam as described above and the movement of the stage 7 in the direction of the arrow 8 are repeated, whereby the gelation is achieved in layers and the desired three-dimensional shape is achieved. The green compact 4 is produced in layers.

In addition, as a result of carrying out the above-mentioned steps, the non-gelled unirradiated portion remains in the three-dimensional green compact 4 obtained. This unirradiated part must be dissolved away.

As described above, when the unirradiated portion is dissolved and removed, the sol-gel solution recovery valve 14 is opened, and the sol-gel solution 5 in the main tank 6 passes through the conduit 15 and once.
It is collected in the preliminary tank 11. At this time, the excess solution storage tank 1
The sol-gel solution 5 stored in 0 also passes through the conduit 16,
It is collected in the preliminary tank 11.

Next, the developing solution is showered toward the stage 7, whereby the non-irradiated portion is removed. The developing solution from which the non-irradiated portion is thus removed is discharged from the main tank 6 through the conduits 15 and 18 by opening the developing solution disposal valve 17.

As described above, the gelled portion is removed by the lamp heater 24 after the removal of the unirradiated portion is completed.
For example, it is heated to 100 ° C. and cured.

Further, the sol-gel solution 5 stored in the preliminary tank 11 is driven by the pump 12 so that the conduit 13
And is again introduced into the main tank 6 to advance the reaction.

The removal of the non-irradiated portion as described above is carried out every time after the gelation of one layer by the irradiation of the laser beam is finished, or after the gelation of a plurality of layers is finished, or It may be performed after the desired three-dimensional green compact 4 is completed.

When a three-dimensional green compact such as a three-dimensional green compact 4 in which a plurality of relatively high protrusions are arranged in close proximity to each other is obtained, or a hole having a depth is formed. In the case of obtaining a three-dimensional unsintered compact having the above or a three-dimensional unsintered compact having a complicated three-dimensional shape, an unirradiated portion is formed in the process of producing such a three-dimensional unsintered compact. It is preferable to perform the dissolution and removal of the above, and repeat the gelation by the irradiation of the laser beam and the dissolution and removal of the non-irradiated portion.

In the case of a particularly complicated shape, it is desirable to develop each layer and prevent the shape from being deformed by proceeding with the reaction by the lamp heater 24 and hardening.

As an example, when the three-dimensional green compact 4 for obtaining the piezoelectric transducer array 1 shown in FIG. 1 is to be manufactured, the sol-gel solution 5 is gelated every 1 μm in the thickness of the liquid layer. , The thickness of the gel part is 10
Every time it reaches μm, the unirradiated part is dissolved and removed, and by repeating this, a height of 100 μm, for example, is achieved in the part of the three-dimensional green compact 4 that is to become the transducer 2.

As described above, after the three-dimensional unsintered compact 4 is formed in layers and the heat curing is finished, the three-dimensional unsintered compact 4 is taken out from the stage 7 and, for example, at 600 ° C. Sintered piezoelectric transducer array 1 is obtained by firing at temperature for 60 minutes.

The piezoelectric transducer array 1 is
Since it is fragile and brittle, in order to facilitate its handling, it is preferable to fix each transducer 2 with a resin 2a formed by impregnating and curing a resin solution as shown by an imaginary line in FIG.

FIG. 3 is a perspective view showing a photonic bandgap crystal 31 as another example of the three-dimensional ceramic structure manufactured by the manufacturing method according to the present invention.

Also when manufacturing the photonic bandgap crystal 31 shown in FIG. 3, the three-dimensional green compact manufacturing apparatus 3 shown in FIG. 2 is used.

More specifically, as the sol-gel solution 5,
Titanium isopropoxide was added to a solution of barium butoxide in 2-methoxyethanol, and the mixture was diluted with 2-methoxyethanol.
A photosensitive sol-gel solution with nitrobenzyl alcohol added is used. Then, the sol-gel solution 5 is gelled into a layer by using the three-dimensional green compact manufacturing apparatus 3 shown in FIG. 2 to produce barium titanate gel, and the obtained three-dimensional green compact 4 (its shape Corresponds to the photonic bandgap crystal 31 shown in FIG. 3), for example, 6
By firing at a temperature of 50 ° C. for 60 minutes, a photonic bandgap crystal 31 of barium titanate is obtained.

This photonic bandgap crystal 31
Has a diamond structure, can obtain a large difference in dielectric constant from air, and can provide a large photonic band gap.

This photonic bandgap crystal 31
In order to reinforce this, the photonic band gap crystal 3 made of resin or the like is provided in the space portion (recess) 32 in order to reinforce this.
You may make it fill with the material different from 1.

Although the present invention has been described above with reference to the illustrated embodiment, other various modifications are possible within the scope of the present invention.

For example, in the above-described embodiment, the piezoelectric transducer array 1 shown in FIG. 1 and the photonic bandgap crystal 31 shown in FIG. 3 are used as the three-dimensional ceramic structure manufactured by the manufacturing method according to the present invention. Although illustrated, the present invention can be applied to the manufacture of other three-dimensional ceramic structures having various three-dimensional shapes.

When a three-dimensional green compact is produced in layers, the thickness of each layer depends on the desired three-dimensional shape.
It can be changed as appropriate. The thinner the thickness of each layer, the more complicated the three-dimensional shape can be accommodated.

When the three-dimensional green compact is produced in layers, the thickness of each layer does not necessarily have to be the same. For example, for parts having the same cross-sectional shape, the thickness of the part to be gelled by one irradiation is increased, and the parts having the same cross-sectional shape are produced all at once, and more complicated cross-sectional shapes or various cross-sectional shapes different from each other With respect to the disordered portion, the thickness of the portion to be gelled by one irradiation may be reduced to obtain a three-dimensional green compact having a desired three-dimensional shape.

Further, in the above-described embodiment, the laser beam is used as the electromagnetic wave irradiated to gel the sol-gel solution, but other light beam, electron beam, ion beam or X-ray may be used.

[0063]

As described above, according to the present invention, a three-dimensional green compact that is fired to obtain a desired three-dimensional ceramic structure is produced. Since the sol-gel solution is irradiated with electromagnetic waves to cause gelation, a three-dimensional green compact having an arbitrary three-dimensional shape can be produced only by changing the irradiation mode of the electromagnetic waves. A three-dimensional ceramic structure having a shape can be easily manufactured.

In the present invention, in producing a three-dimensional green compact, a step of gelling the liquid layer in the vicinity of the liquid surface of the sol-gel solution by irradiation of electromagnetic waves, and a gelled product gelated by this gelling step Is repeatedly performed from the liquid surface of the sol-gel solution to a position of a predetermined depth, whereby a three-dimensional green compact having a layered structure is produced, and thus a complex three-dimensional shape is obtained.
3D green compacts can be produced and
It is possible to sufficiently cope with the further complicated three-dimensional shape of the three-dimensional ceramic structure.

When the step of dissolving and removing the unirradiated portion of the sol-gel solution is performed after the step of gelling and the step of moving the gel are performed at least once, a plurality of relatively high protrusions are formed on each other. When obtaining a three-dimensional unsintered compact that is arranged in close proximity, when obtaining a three-dimensional unsintered compact having a hole with a depth, or when a complex three-dimensional shape is used.
Even when a three-dimensional green compact is obtained, it can be developed and cured for each layer to ensure stability of the shape, and a three-dimensional green compact or a three-dimensional green compact having a desired three-dimensional shape can be obtained. The three-dimensional ceramic structure can be reliably manufactured.

In the present invention, if the space portion of the obtained three-dimensional ceramic structure is filled with a material different from the three-dimensional ceramic structure, such as a resin, the three-dimensional ceramic structure can be obtained. Strength can be increased.

[Brief description of drawings]

FIG. 1 is a view of a 3 manufactured by a manufacturing method according to the present invention.
It is a perspective view which shows the piezoelectric transducer array 1 as an example of a three-dimensional ceramic structure.

FIG. 2 schematically shows a configuration of a three-dimensional green compact manufacturing apparatus 3 used for manufacturing a three-dimensional green compact 4 having a three-dimensional shape corresponding to the piezoelectric transducer array 1 shown in FIG. It is a front view.

FIG. 3 is manufactured by the manufacturing method according to the present invention.
It is a perspective view which shows the photonic band gap crystal 31 as another example of a three-dimensional ceramic structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Piezoelectric transducer array (three-dimensional ceramic structure) 2 Transducer 2a Resin 3 Three-dimensional unsintered compact manufacturing device 4 Three-dimensional unsintered compact 5 Sol gel solution 6 Main tank 7 Stage 21 Laser light generator 31 Photonic bandgap crystal (3D ceramic structure) 32 space part

Continued front page    F-term (reference) 4G030 AA16 AA17 AA40 BA09 CA07                       GA10 GA17 GA19                 4G055 AA08 AB00 AC09 BA22

Claims (5)

[Claims] 1. A step of irradiating an electromagnetic wave to a photosensitive sol-gel solution containing a metal element to cause gelation to produce a three-dimensional green compact, and a step of firing the three-dimensional green compact. Prepare 3
Dimensional ceramic structure manufacturing method. 2. The method for producing a three-dimensional ceramic structure according to claim 1, wherein the photosensitive sol-gel solution contains a solution of a metal organic compound and a photosensitive gelling reaction accelerator. 3. The step of producing the three-dimensional green compact is a step of gelling a liquid layer near the liquid surface of the sol-gel solution by irradiation of the electromagnetic wave, and a step of gelling the liquid layer. A step of moving the gelled product from the liquid surface of the sol-gel solution to a position of a predetermined depth, the step of gelling and the step of moving are repeated,
The method for producing a three-dimensional ceramic structure according to claim 1 or 2, wherein the three-dimensional green compact is formed in layers. 4. The three-dimensional structure according to claim 3, wherein the step of gelling and the step of moving are performed at least once, and then a step of dissolving and removing an unirradiated portion of the sol-gel solution is performed. Method for manufacturing ceramic structure. 5. The three-dimensional ceramic structure according to claim 1, further comprising a step of filling a space portion of the three-dimensional ceramic structure with a material different from that of the three-dimensional ceramic structure. Body manufacturing method.