JP2002234775A - Method for producing sintered compact, apparatus therefor and method for measuring concentration of plasticizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for selectively and rapidly extracting and removing a plasticizer from a green multilayer body in the production of a multilayer ceramic capacitor. SOLUTION: Carbon dioxide is introduced into a pressure vessel 121 in which a green multilayer body 100 has been disposed and the temperature and pressure of the pressure vessel are regulated to 40 deg.C and 10 MPa to fill the pressure vessel 121 with supercritical carbon dioxide 124. A plasticizer is extracted and removed from the green multilayer body 100 by the supercritical carbon dioxide 124. Ordinary binder removing and firing steps are then carried out. Since the plasticizer is selectively removed before the binder removing step, the formation of a graphitic material can be suppressed even when heating is carried out at a high rate in the subsequent binder removing and firing steps, accordingly the lowering of production yield and the lowering of product performance are not caused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a sintered body obtained by sintering a laminate obtained by laminating a layer containing ceramic powder or metal powder and an organic layer such as a binder and a plasticizer. And related technologies.

[0002]

2. Description of the Related Art In recent years, miniaturization of laminated ceramic parts constituted by laminating ceramic layers and conductor layers in a mixed manner has been promoted.
High performance is being promoted. A multilayer ceramic component will be described using a multilayer ceramic capacitor as one example. Multilayer ceramic capacitors are used as main components of mobile stations (small portable terminals) in mobile communication systems represented by mobile phones, and contradictory improvements such as miniaturization and large capacity are required. Have been. For this reason, thinning and multilayering of the dielectric layer and increasing the dielectric constant of the dielectric layer have been promoted. However, since there is a limit in increasing the dielectric constant by reducing the thickness of the dielectric film and developing the material of the dielectric layer, the multilayer ceramic capacitor tends to have a larger area every year in order to increase the capacitance.

Here, a multilayer ceramic capacitor is generally formed by the following manufacturing method. First, a dielectric material powder, a binder, a plasticizer, a dispersant, a solvent and the like are mixed and stirred to prepare a dielectric slurry having an appropriate viscosity. At this time, barium titanate as a dielectric material, an acrylic resin as a binder, an ester plasticizer such as dibutyl phthalate as a plasticizer, an anionic surfactant such as a carboxylate as a dispersant, As the solvent, esters such as butyl acetate, alcohols, ethers, and hydrocarbons are often used. On the other hand, an internal electrode paste is prepared by mixing a metal powder such as nickel and an organic substance into a paste.

[0004] Next, using a printing laminating machine or the like, the dielectric slurry is directly screen-printed to form a dielectric film. Subsequently, the screen is changed, and the internal electrode paste is directly screen-printed similarly to form an internal electrode pattern. As described above, the screen printing of the dielectric film and the internal electrode pattern is repeatedly performed alternately a desired number of times.
A green sheet is formed by alternately laminating electrodes and dielectric films. After the completion of the laminating step, the green sheet is cut in accordance with the size of each printed chip to obtain a green laminate. Thereafter, pod packing is performed for firing, and the process proceeds to a degreasing step and a firing step. The degreasing step refers to a step of removing organic substances such as a binder, a plasticizer, and a solvent contained in the green laminate. The firing step refers to a step of performing sintering by reaction between ceramic particles. After the completion of the firing step, the external electrodes and the like are formed after polishing the side surfaces and the like as necessary in order to connect the internal electrodes and take out the terminals to the outside at the same time. Depending on the structure of the ceramic laminated component, a base electrode, an intermediate electrode, and the like may be formed.

[0005] Here, in the production of the multilayer ceramic capacitor, the degreasing step occupies a large proportion of time. As described above, in the degreasing step, organic substances such as binders and plasticizers used for maintaining the shape of the green sheet are decomposed and removed. Usually, the degreasing step is performed in air. In order to increase the production efficiency, it is preferable to perform degreasing by heating and cooling the furnace at a high speed.
Since organic substances such as a binder and a plasticizer are rapidly vaporized and decomposed, structural defects such as delamination and cracks may be induced. These defects have a great effect on the quality of the product. Therefore, at present, 150
The temperature is slowly raised and lowered over a period of 20 hours to several days in a temperature range of up to 300 ° C. to degrease the green laminate. In recent years, the time required for the degreasing process tends to be longer due to the increase in the size (particularly, the area) of the chip accompanying the increase in the capacity of the capacitor. In addition, as described above, degreasing is performed to remove organic matter in the green laminate, but the organic matter contained in the green laminate is a variety of mixtures such as a binder, a plasticizer, a dispersant, and a solvent. Yes,
Since these have different vaporization temperatures and decomposition temperatures, extremely accurate temperature control and process control are required.

[0006]

As described above, in the degreasing step, extremely high-precision temperature control and process control are required, and the time required for the degreasing step is further increased with the increase in the capacity and size of the capacitor. However, in the conventional thermal decomposition removal method in air, it was very difficult to shorten the process time by increasing the speed of the degreasing process. On the other hand, if the firing step is performed without sufficiently removing organic substances such as a binder, many problems occur. In particular, if the plasticizer remains without being sufficiently removed in the degreasing step, the benzene ring in the plasticizer reacts in the firing step to form a graphite-like substance,
This graphite-like substance causes various defects of the laminated ceramic component. First, since the graphite-like substance has a different expansion coefficient from that of ceramics, internal electrode materials and the like, structural defects such as delamination and cracks are easily induced. In addition, since the graphite-like substance has high conductivity because it has pi electrons, the graphite-like substance causes a leak current between the internal electrodes. As described above, if the plasticizer is not removed in the degreasing step, the yield of the product decreases, and the performance of the multilayer ceramic component also decreases. For this reason, a long-time degreasing step had to be performed.

[0007] Furthermore, in the conventional thermal decomposition removal method in air, there are cases where organic substances are mixed in the gas discharged in the binder removal step, and thus there is a problem in terms of environment. It is necessary to completely decompose and burn the organic matter or to remove the organic matter by adsorption or the like, and there has been a problem in terms of cost.

On the other hand, a method for degreasing ceramics using a supercritical fluid has been proposed for some time (Chemical Engineering, May 1986, pp. 46-49, Shozaburo Saito) Science and Technology of Supercritical Fluids Sankyo Business
etc). Generally, supercritical fluids have a high dissolving capacity. If the binder is removed using a supercritical fluid, degreasing of the ceramic molded body can be performed in a very short time. However, in this method, when the plasticizer and the binder are removed from the green laminate, the function of maintaining the shape of the green laminate deteriorates, and the shape accuracy of the product deteriorates.

An object of the present invention is to pay attention to the fact that if only a plasticizer can be rapidly removed from various organic substances used for forming a green sheet, the time required for the entire degreasing step can be shortened. An object of the present invention is to provide a method and an apparatus for manufacturing a laminated ceramic body that can improve the production efficiency while maintaining the shape of a green laminated body with high accuracy by utilizing the characteristics of a fluid.

[0010]

According to a first method for producing a sintered body of the present invention, an internal electrode layer containing at least a powder of a conductive material;
Forming a green laminate by laminating a ceramic material powder, a binder and a dielectric layer containing a plasticizer (a)
(B) contacting the green laminate with a fluid in a supercritical state or a subcritical state to extract and remove a plasticizer in the green laminate, and after the step (b), The method includes a step (c) of decomposing and removing the binder in the green laminate, and a step (d) of sintering the green laminate after the step (c).

In the conventional degreasing process, the plasticizer and the binder are removed from the green laminate by thermal decomposition.
Sudden heating causes structural defects in the green laminate, and gradual heating to prevent the occurrence of structural defects increases the processing time. In contrast, according to the method of the present invention,
Prior to the binder removal process, the plasticizer is selectively extracted and removed from the green laminate using a supercritical or subcritical fluid, so that graphite can be obtained even if the temperature is increased at a high speed in the subsequent binder removal process. Formation of the substance can be suppressed. Therefore, while suppressing the deterioration of quality due to the occurrence of structural defects in the green laminate and thus the sintered body,
Manufacturing efficiency can be increased.

In the step (a), at least one resin selected from butyral resins, acrylic resins, polypropylene and polyethylene can be used as the binder.

In the step (a), as the plasticizer,
At least one substance selected from esters, stearic acid, stearyl alcohol, and paraffin can be used. In particular, it is preferable to use a phthalic acid ester.

In the step (a), as the plasticizer,
It is preferable to use paraffin which becomes a solid state during the treatment in the step (b).

In the step (b), it is preferable to use at least one substance selected from carbon dioxide, hydrocarbon and polyhalogenated hydrocarbon as the fluid in the supercritical or subcritical state.

In the step (b), carbon dioxide is used as the fluid in the supercritical state or the subcritical state, and the temperature of the carbon dioxide is set in the range of room temperature to 50 ° C. or 140 ° C. or higher. It is preferable to carry out the reaction while maintaining the temperature in the range of (1) or lower.

In the step (b), at least one substance selected from alcohols, ketones and hydrocarbons is mixed as an entrainer (extraction aid) into the fluid in the supercritical or subcritical state. Can be used.

In the step (b), the pressure of the fluid containing the plasticizer extracted and removed from the green laminate is reduced to bring the fluid into a gaseous state, and the fluid and the plasticizer are mixed with each other. By separating and recovering the plasticizer, it is possible to save labor and cost of disposal treatment of the plasticizer.

In the step (a), at least one metal selected from Pt, Pd and Ni can be used as the powder of the conductor material.

In the step (b), the pressure of the fluid in the critical state or the subcritical state is fluctuated with time, whereby the extraction and removal efficiency of the plasticizer can be further increased.

In the step (b), the efficiency of extracting and removing the plasticizer can be further increased by applying ultrasonic vibration to the fluid.

Between the steps (a) and (b), the green laminate is heated at 250 ° C. in a vacuum or in a gas.
By further including a step of adding a heat treatment below,
The occurrence of structural defects in the green laminate and the sintered body can be more effectively suppressed.

In the step (b), the green laminate is pressurized by using a pressurized medium, and then the pressurized medium is replaced with the supercritical or subcritical fluid to obtain a green laminate. It is possible to more effectively suppress the occurrence of structural defects in the body, and eventually the sintered body.

It is preferable that an inert gas is used as the pressurized medium and at least one substance selected from carbon dioxide, hydrocarbon and polyhalogenated hydrocarbon is used as the supercritical or subcritical fluid. preferable.

In the step (b), the fluid is subjected to 1MP
By rapidly pressurizing at a rate of a / min or more to bring the supercritical state or the subcritical state, it is possible to more effectively suppress the occurrence of structural defects in the green laminate, and finally the sintered body.

At any point after the step (b) and before the step (d), the method includes a step of evaluating the plasticizer concentration distribution in the green laminate using microscopic laser Raman spectroscopy. Is preferred.

It is more preferable to obtain a relative concentration distribution by obtaining the relative intensity by normalizing the peak intensity of the absorption band caused by the plasticizer in the Raman spectrum with the peak intensity of the absorption band caused by the ceramic.

According to the second method for producing a sintered body of the present invention, there are provided a step (a) of forming a mixture of an inorganic substance and an organic substance to obtain a molded body, and a step of flowing the molded body in a supercritical state or a subcritical state. (B) extracting the organic matter from the molded body by contacting the molded body, and (c) sintering the molded body to obtain a sintered body after the step (b). Including
In this method, a material that is in a liquid state in the step (b) and a solid state in the step (c) is used as the organic substance.

According to this method, in the step (a), since the organic substance has fluidity, the molding is performed smoothly. On the other hand, in the step (b), since the organic substance is a solid, the volume expansion of the organic substance does not occur, so that the occurrence of structural defects in the molded body and the sintered body after the step (b) is suppressed. be able to.

According to a third method for producing a sintered body of the present invention, there are provided a step (a) of molding a mixture of an inorganic substance and an organic substance to obtain a molded body; (B) performing a heat treatment for partially removing the organic substance in a vacuum or in a gas, and after the step (b), contacting the compact with a fluid in a supercritical or subcritical state A step (c) of extracting and removing the organic matter in the molded body; and a step (d) of sintering the molded body to obtain a sintered body after the step (c). I have.

According to this method, the organic matter is partially removed in the step (b), so that voids are generated in the molded body. As a result, even if the fluid in the organic matter expands in the step (c). Since the expansion is alleviated by the voids, the occurrence of structural defects in the compact and the sintered body is suppressed.

According to a fourth method for producing a sintered body of the present invention, a step (a) of molding a mixture of an inorganic substance and an organic substance to obtain a molded article; After pressurizing the compact using, the pressurized medium is replaced with the fluid in the supercritical state or subcritical state, and the compact is brought into contact with the fluid in the supercritical state or subcritical state. ,
Step (b) of extracting and removing the organic substance in the molded body
And, after the step (b), a step (c) of sintering the molded body to obtain a sintered body.

In step (b), since the compact has already been pressurized, the volume expansion of the fluid in the organic matter of the compact does not occur, so that the occurrence of structural defects in the compact and thus the sintered compact is suppressed. Is done.

It is preferable that an inert gas is used as the pressurized medium and at least one substance selected from carbon dioxide, hydrocarbon and polyhalogenated hydrocarbon is used as the supercritical or subcritical fluid. preferable.

The fifth method for producing a sintered body according to the present invention comprises a step (a) of forming a mixture of an inorganic substance and an organic substance to obtain a molded body, and a step of forming the molded body in a supercritical state or a subcritical state. A step (b) of extracting and removing the organic matter in the molded body by contacting with a fluid, and a step (c) of sintering the molded body to obtain a sintered body after the step (b) And
In the step (b), the fluid is rapidly pressurized at a speed of 1 MPa / min or more to bring the fluid into a supercritical state or a subcritical state.

According to this method, since the fluid is maintained at a high pressure in a state where the fluid is not sufficiently dissolved in the organic substance, the volume expansion of the organic substance is small, so that the occurrence of structural defects in the molded article and the sintered body is reduced. Is suppressed.

The sixth method for producing a sintered body according to the present invention comprises a step (a) of obtaining a porous body by molding a mixture of at least a powder of a conductor material or a powder of a ceramic material and an organic substance; (B) contacting the porous body with a fluid in a supercritical state or a subcritical state to extract and remove organic substances in the porous body; and after the step (b), the porous body is heated to a high temperature. And (c) obtaining a porous sintered body.

According to this method, the deterioration of the quality due to the occurrence of structural defects in the formed body and thus the sintered body is suppressed,
Manufacturing efficiency can be increased.

In the step (a), as the organic substance,
It is preferable to use at least one substance selected from camphor, naphthalene, and paraffin.

The apparatus for producing a laminate according to the present invention includes a pressure vessel configured to maintain a fluid in a supercritical state or a subcritical state, a supply device for supplying the fluid, A temperature control device for controlling the temperature of the pressure vessel, a pressure control device for controlling the pressure of the pressure vessel, a pressure reducing device for reducing the pressure of the fluid discharged from the pressure vessel, A plasticizer recovery device for separating and recovering the plasticizer from the fluid as a liquid or a solid in the decompression device.

This makes it possible to reduce the labor and cost of disposal of the plasticizer while implementing the above-described method for producing a laminate.

The pressure reducing device is further provided with a pressurizing device for pressurizing the fluid, whose pressure has been reduced, to a supercritical state or a subcritical state. Labor and cost can be saved.

By further providing a spectrometer for spectroscopically measuring the fluid in the supercritical state or the subcritical state, the end point of the extraction and removal of the plasticizer can be accurately detected by in-situ observation. it can.

The method for measuring the concentration of a plasticizer of the present invention is a method for measuring the concentration of the above-mentioned plasticizer in a molded product obtained by molding a mixture of an inorganic substance and an organic substance containing a plasticizer and a binder. And a method of evaluating the concentration distribution of the plasticizer in the molded body by using a microscopic laser Raman spectroscopy.

According to this method, a benzene ring or an ester group, which is often not contained in a binder or an inorganic substance, can be detected with high sensitivity by utilizing the characteristics of laser Raman light.

The relative intensity distribution can be obtained by obtaining the relative intensity by normalizing the peak intensity of the absorption band caused by the plasticizer in the Raman spectrum with the peak intensity of the absorption band caused by the inorganic substance.

The evaluation method of the present invention is an evaluation method for evaluating the volume of a substance dissolved in a fluid in a supercritical or subcritical state in the fluid,
(A) mounting a transparent tube member in which the substance is introduced into a tube to a pressure vessel configured to maintain a fluid in a supercritical state or a subcritical state; Supplying the fluid and measuring the length of the region where the substance is present in the pipe member at a plurality of pressure values while changing the pressure in the pressure vessel at a certain temperature (b) ) And a step (c) of obtaining the pressure dependency of the volume of the substance in the fluid from the measurement result in the step (b).

According to this method, when a substance to be measured is contained in a molded article or a certain member, it is possible to determine conditions under which a structural defect occurs in the molded article or the member due to volume expansion of the substance. become. Therefore, it is possible to appropriately set the conditions for the process of manufacturing components such as multilayer ceramic components and capacitors.

The evaluation device of the present invention comprises a pressure vessel configured to maintain a fluid in a supercritical state or a subcritical state, a supply device for supplying the fluid,
A temperature control device for controlling the temperature of the pressure vessel,
A pressure control device for controlling the pressure of the pressure vessel,
A window member provided in a part of the pressure vessel and capable of transmitting light from inside the pressure vessel and emitting light to the outside.

Thus, the behavior of the object in the fluid in the supercritical state or subcritical state can be accurately grasped, so that an important guideline for setting the conditions of the manufacturing process can be obtained. . When this evaluation device is used for manufacturing, it is possible to perform a process using a fluid in a supercritical state or a subcritical state while observing the internal state in-situ.

The apparatus further comprises a transparent tube member disposed in the pressure vessel and capable of introducing the substance into the tube, and a means for measuring a region where the substance exists in the tube of the tube member. This makes it possible to measure the volume change of the organic substance.

[0052]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) In this embodiment, a supercritical fluid (in the embodiment of the present invention,
A method of manufacturing a ceramic laminate including a degreasing step of a green laminate using a fluid in a supercritical state) will be described with reference to FIG. FIG.
It is a flowchart figure which shows the manufacturing process of the ceramic laminated body (sintered body) in this embodiment and 2nd Embodiment mentioned later.

First, in step ST1, a dielectric material powder, a binder, a plasticizer, a dispersant, a solvent, and the like are mixed and stirred to form a dielectric slurry having an appropriate viscosity. At this time, barium titanate as a ceramic dielectric material, butyral resin such as polyvinyl butyral or an acrylic resin, polypropylene, polyethylene as a binder, esters such as dibutyl phthalate or butyl benzyl phthalate as a plasticizer, stearic acid, Stearyl alcohol, paraffin and the like, an anionic surfactant such as a carboxylate as a dispersant, and esters, alcohols, ethers and hydrocarbons such as butyl acetate as a solvent can be used. On the other hand, in step ST2,
An internal electrode paste is prepared by mixing a metal powder such as nickel (Ni) or palladium (Pd) with an organic substance to form a paste.

Next, in step ST3, a dielectric slurry is formed by directly screen-printing the dielectric slurry using a printing laminating machine or the like. Subsequently, the screen is changed, and the internal electrode paste is directly screen-printed similarly to form an internal electrode pattern. As described above, the screen printing of the dielectric film and the internal electrode pattern is repeated alternately a desired number of times to form a green sheet (green laminate) in which the internal electrodes and the dielectric film are alternately laminated. And
Pre-press.

After the completion of the pre-pressing step, step ST4
Then, the green sheet is cut in accordance with the size of each printed chip to obtain an individual green laminate 100.

FIGS. 1A and 1B are a vertical sectional view and a perspective view, respectively, of a green laminate 100 formed by the above-described steps. As shown in FIG. 1A, the green laminate 100 has a dielectric film 101 and a base end formed of a first layer.
The tip is exposed on the side A (one side) and the first side A
The first internal electrode 102 extends near the second side surface B (the other side surface) opposing the first internal electrode 102, and the base end portion is exposed on the second side surface B and the distal end portion extends near the first side surface A. The second internal electrodes 103 are stacked. However, in the present embodiment, the first internal electrode 102 and the second internal electrode 1
03 is made of the same material and has the same thickness and size on a plane. Then, the first internal electrode 10
The region between the front end of the second internal electrode 103 and the side surface B and the region between the front end of the second internal electrode 103 and the side surface B are filled with the dielectric film 101. So to speak, dielectric film 1
Numeral 01 exists as a matrix, in which the internal electrodes 102 and 103 alternately protrude from the side surfaces A and B, respectively, and extend substantially parallel to the upper surface E and the lower surface F. The upper surface E and the lower surface F are constituted by the surface of the dielectric layer 101. Also, two side surfaces C, orthogonal to the side surfaces A, B of the green laminate 100,
In D, the end faces of the internal electrodes 102 and 103 are exposed.

Next, in step ST5 shown in FIG. 10, the green laminate 100 is placed in the pressure vessel 1 through which the supercritical fluid flows.
21 and subjected to a deplasticizing treatment.

FIG. 2 is a view showing a state in which the green laminate 100 is installed in a pressure vessel 121 through which a supercritical fluid flows. The pressure vessel 121 is provided with an introduction port 123 for introducing a fluid for bringing into a supercritical state, and a discharge port 125 for discharging a supercritical fluid. Although not shown in FIG. 2, a gas cylinder, a liquid pump, a temperature control device, a pressurizing device, a pressure control device, and the like, which will be described later with reference to FIG. 9, are provided outside the pressure vessel 121. When a large number of green laminates 100 are installed in the pressure vessel 121, it is preferable to use the above-mentioned pods or the like so as to ensure a space between the green laminates 100. This is because the plasticizer is efficiently extracted by bringing the surface of the green laminate 100 into contact with the supercritical fluid as much as possible, as described later.

Next, after the temperature of the pressure vessel 121 is set at 40 ° C., gaseous carbon dioxide 122 is gradually introduced from the introduction port 123, and then carbon dioxide is pressurized in the pressure vessel 121 to 10 MPa. At this time, it is generally preferable to increase the pressure at a pressure change rate of 10 MPa / hour or less, instead of suddenly changing the pressure, in order to suppress the occurrence of structural defects in the green laminate 100. However, since the upper limit of the pressure change rate greatly differs depending on the size of the green laminate 100 and the above-described pre-pressing conditions, it is necessary to optimize the pressure change rate according to the size of the green laminate 100 and the above-described pre-pressing conditions. There is.

FIG. 4 is a phase diagram of carbon dioxide. In the figure, the horizontal axis represents temperature, and the vertical axis represents pressure.
The point where the temperature is the critical temperature Tc and the pressure is the critical pressure Pc (Tc,
Pc) is the critical point. A range in which the temperature is equal to or higher than the critical temperature Tc and the pressure is equal to or higher than the critical pressure Pc is a supercritical region Rcp. The subcritical region Rpcp is a range where the temperature is equal to or higher than the critical temperature Tc and the pressure is slightly lower than the critical pressure Pc, and a range where the pressure is equal to or higher than the critical pressure Pc and the temperature is slightly lower than the critical temperature Tc. In this supercritical region Rcp, carbon dioxide is in a supercritical state (supercritical fluid), which is a different phase from gas, liquid, and solid, and may exhibit different properties from gas, liquid, and solid. Are known.

The critical temperature Tc of carbon dioxide is 31.0 ° C., and the critical pressure Pc of carbon dioxide is 7.4 MPa. Therefore, the carbon dioxide 12 in the pressure vessel 121
By setting the temperature of 4 to 40 ° C. and the pressure to 10 MPa, the carbon dioxide 124 in the pressure vessel 121 is almost completely in a supercritical state.

Next, when the pressure in the pressure vessel 121 is 10MPa
After reaching a, the supercritical carbon dioxide 122 is introduced from the introduction port 123, and after the pressure in the pressure vessel 121 stably reaches 10 MPa, the state is maintained for about 100 minutes, whereby the supercritical state is obtained. Is performed to extract and remove the plasticizer from the green laminate 100 with the carbon dioxide 124, that is, to remove the plasticizer. At this time, the dielectric film 101 in the green laminate 100 and each internal electrode 102,
103 have very different thermal expansion coefficients, and at 40 ° C., very fine voids are formed at the interface between the dielectric film 101 and the internal electrodes 102 and 103. Then, carbon dioxide 124 in a supercritical state permeates into the inside of the green laminate 100 through the gap, and the plasticizer inside the green laminate 100 excluding the surface portion, particularly the plasticizer in the dielectric film 101, is mainly It is extracted and removed to the outside through the gap between the dielectric film and the internal electrode.

As described above, the permeation of the supercritical fluid into the green laminate 100 and the outflow of the supercritical fluid and the plasticizer from the inside of the green laminate 100 are mainly caused by the gap between the dielectric film and the internal electrode. Since the process is performed through the gap, stress is hardly generated inside the green laminate 100, and the plasticizer can be vaporized, decomposed, and removed at high speed without generating a structural defect in the dielectric film 101.

Thereafter, the supercritical carbon dioxide 124 containing the extracted plasticizer is discharged from the discharge port 125 to the outside of the pressure vessel 121. After the process of extracting and removing the plasticizer from the green laminate 100 (the deplasticizing step), first, the pressure in the pressure vessel 121 is reduced. Also at this time, it is generally preferable to reduce the pressure at a pressure change rate of 10 MPa / hour or less, instead of suddenly changing the pressure, in order to suppress the occurrence of structural defects in the green laminate 100.

Next, after the pressure in the pressure vessel 121 returns to normal pressure, the temperature is lowered, and after returning to room temperature, the green laminate 100 is taken out of the pressure vessel 121.

Thereafter, steps ST6, S6 shown in FIG.
At T7, the binder removing process and the firing process of the green laminate 100 are performed. At this time, since the plasticizer has already been removed, the formation of the graphite-like substance in the green laminate 100 can be suppressed even when the temperature is increased at a high speed in the subsequent binder removal step and firing step. That is,
Unlike the conventional case, it is not necessary to slowly raise and lower the temperature in the temperature range of 150 to 300 ° C. over 20 hours to several days.

Then, as shown in FIG. 3, when the firing step is completed, the dielectric films 101,
Each of the internal electrodes 102 and 103 has a strong structure due to a solid phase reaction or the like, and a structure 130 which is a main part of the capacitor is formed.
(Sintered body) is formed. Then, after polishing the surface of the required portion of the structure 130, the first base electrode 131 is formed on the first side A and the second base electrode 132 is formed on the second side B by applying and baking an Ag film. Form each. Next, the first external electrode 133 is formed on the first base electrode 131 by attaching solder (SnPb) by electrolytic plating or the like.
And a second external electrode 134 is formed on the second base electrode 132. That is, the plurality of first internal electrodes 102
Is connected to the first external electrode 133, and the plurality of second internal electrodes 103 are connected to the second external electrode 134. Thereby, a ceramic laminate is obtained.

According to the present embodiment, the plasticizer is selectively extracted and removed from the green laminate 100 using a supercritical fluid before the binder removal step, so that the plasticizer is rapidly removed in the subsequent binder removal step and firing step. Even if the temperature is raised, the formation of a graphite-like substance can be suppressed. Therefore, without causing a reduction in manufacturing yield or product performance,
Manufacturing efficiency can be increased. Further, other binder components are extracted and removed to the outside through the voids formed during the deplasticizing step, so that the internal stress does not increase. Therefore, no structural defect is induced by the binder removal process after the degreasing process.

Next, the optimum conditions for the deplasticizing agent will be described. FIG. 5 is a diagram showing the temperature dependence of the plasticizer extraction / removal speed when the pressure in the pressure vessel is 10 MPa. As shown in the figure, the extraction rate of the plasticizer is considerably high at 40 ° C. or lower, and the extraction and removal processing of the plasticizer with high efficiency is possible as described in the present embodiment. Meanwhile, 4
At 0 ° C. or higher, the rate of extraction of the plasticizer decreases as the temperature increases. In particular, if the temperature of carbon dioxide is 50
In the range of from 140 ° C to 140 ° C, the extraction / removal rate of the plasticizer is low, and is the lowest at 80 ° C to 100 ° C. However, when the temperature of the carbon dioxide exceeds 100 ° C., the extraction / removal rate of the plasticizer increases again. When the temperature of carbon dioxide reaches about 150 ° C., the plasticizer can be extracted and removed at high speed.

According to the present invention, it is necessary to efficiently extract and remove almost only a plasticizer from a green laminate having a structure in which a dielectric layer containing a ceramic powder, a binder, a plasticizer and the like and a metal electrode are laminated. As an empirical fact, FIG.
It was found that there was a region with poor removal efficiency as shown in FIG. Therefore, the extraction and removal of the plasticizer is performed at room temperature to 50 ° C.
Or in the range of 140 ° C. to the binder removal temperature. Further, in order to realize a higher extraction / removal efficiency of the plasticizer, a range of room temperature to 40 ° C or 150 ° C
It is preferable to perform the deplasticizing treatment under the conditions of the binder temperature. In addition, in order to save the heating time for raising the temperature, the range from room temperature to 40 ° C. is most preferable.

In this embodiment, only carbon dioxide in the supercritical state is used in the step of extracting and removing the plasticizer. However, in some cases, an appropriate amount of carbon dioxide in the supercritical state is used as an entrainer (extraction aid). If another substance is mixed, the plasticizer can be extracted and removed at higher speed and with higher efficiency. As the entrainer, alcohols such as methanol and ethanol, ketones such as acetone, and hydrocarbons such as methane and ethane are used.

FIG. 6 is a graph showing the pressure dependence of the rate of extraction and treatment of the plasticizer with supercritical carbon dioxide at a temperature of 40 ° C. FIG. 7 is a diagram showing the pressure dependence of the extraction and treatment speed of a plasticizer with carbon dioxide in a supercritical state at a temperature of 150 ° C. 6 and 7, the horizontal axis represents the pressure of carbon dioxide in the pressure vessel, and the vertical axis represents the amount of extraction and removal of the plasticizer due to the decrease in the weight of the green laminate. As shown in FIG. 6 and FIG.
The removal rate increases as the pressure of carbon dioxide increases, but when the pressure reaches 12 MPa, the amount of increase decreases. That is, considering that the higher the pressure, the stronger the structure of the pressure vessel needs to be, it can be said that the pressure of carbon dioxide is preferably in the range of 9 MPa to 12 MPa.

FIGS. 8 (a) and 8 (b) are diagrams showing the absorption spectrum of the extract and the standard absorption spectrum of DBP (dibutyl phthalate) when the temperature of carbon dioxide in the supercritical state is 50 ° C., respectively. 8 (a) and 8
Comparison with (b) shows that under these conditions, substances other than the plasticizer were hardly extracted and removed. That is, the plasticizer can be efficiently extracted from the green laminate while leaving the binder in the green laminate by the deplasticizing treatment of the present embodiment.

In this embodiment, the supercritical carbon dioxide 124 discharged to the outside of the pressure vessel 121 from the discharge port 125 shown in FIG. At this time, since the temperature is relatively low, the solubility of carbon dioxide in the plasticizer decreases,
The carbon dioxide in a gaseous state and the plasticizer in a liquid state can be easily separated. That is, since a relatively high-purity plasticizer is recovered in a liquid state, it can be reused. On the other hand, the carbon dioxide returned to the gaseous state can be reused for forming the green laminate 100 by pressurizing using a pressurizing device or the like, and the amount of carbon dioxide released into the atmosphere can be reduced. It can be extremely small.

As described above, in the conventional degreasing step by thermal decomposition in air, in the degreasing step of simultaneously removing the plasticizer and the binder, an organic substance may be mixed in the discharged high-temperature gas. Therefore, it is necessary to completely decompose and burn the organic matter or to remove the organic matter in the gas by adsorbing the organic matter in another substance, which increases the production cost. In addition, chemicals containing benzene rings adhered to equipment and piping, which increased maintenance costs.

On the other hand, when the present embodiment is used, the carbon dioxide in the supercritical state changes to the gaseous state with a decrease in pressure, and the remarkable decrease in the solubility in the plasticizer is used to make use of the carbon dioxide in the gaseous state. Since the agent can be easily separated from the agent, the plasticizer can be recovered and reused, and it is possible to avoid environmental problems and reduce costs.

In this embodiment, the green laminate 1
As materials constituting the internal electrodes 102 and 103 of No. 00,
Although Ni and Pd were used, depending on the combination of the metal material used for the internal electrode and the material constituting the plasticizer, the surface of the metal material may act as a catalyst to promote the extraction and removal of the plasticizer. is there. This phenomenon is particularly remarkable in a high-temperature region where the catalytic activity is high. At 150 ° C. or higher, the extraction and removal of the plasticizer may be performed at a very high speed. A particularly remarkable catalytic effect can be expected as a metal material.
t, Pd, Ni and the like.

In this embodiment, carbon dioxide 122
Was flowed at a constant flow rate and the pressure in the pressure vessel 121 was controlled to be constant. However, in order to efficiently extract and remove the plasticizer from the green laminate 100, the pressure vessel 1
In some cases, it is better to vibrate the pressure vessel 121 by slightly changing the pressure inside the pressure vessel 21. In order to finely change the pressure in the pressure vessel 121, a method of temporally changing the supply flow rate of the carbon dioxide 122 or a pressure control device 161 (such as a relief valve) controlling the pressure of the pressure vessel 121 is used.
For example, a method of temporally varying the pressure set value. Further, in order to locally vary the pressure, the pressure vessel 121
The ultrasonic wave may be applied to a part of the.

In this embodiment, carbon dioxide in the supercritical region where the temperature and the pressure are equal to or higher than the critical temperature Tc at the critical point and the critical pressure Pc, respectively, is used. If the temperature and pressure of carbon dioxide are restricted depending on the decomposition temperature or the like, a subcritical region in which only one of the temperature and the pressure exceeds the critical temperature or the critical pressure may be used. In this case, the extraction / removal efficiency may decrease, but since the plasticizer that decomposes in the supercritical region can be recovered without being decomposed, there is an advantage that the plasticizer can be recycled. Further, depending on the type of the plasticizer, a hydrocarbon such as ethane or a polyhalogenated hydrocarbon such as tetrafluoroethylene may be used as a main solvent in a supercritical state or a subcritical state.

(Second Embodiment) FIG. 9 is a diagram schematically showing a configuration of a manufacturing apparatus of a laminate according to a second embodiment using the method of the present invention. This manufacturing apparatus is for extracting and removing a plasticizer. In addition to a pressure vessel 121 shown in FIG. 2, a liquefied carbon dioxide cylinder 151 which is a supply source of carbon dioxide, and a carbon dioxide 122 in a liquid state are provided. A liquid pump 152 for pressurizing the pressure vessel, a temperature controller 153 for controlling the temperature of the carbon dioxide 122 supplied into the pressure vessel 121, and a heater, a cooler, and the like for directly controlling the temperature of the pressure vessel 121. Temperature controller 155
And a spectroscopic device 160 for detecting completion of the plasticizer extraction / removal process, and a pressure vessel 12 including a relief valve and the like.
1, a pressure reducing device 162 for discharging supercritical carbon dioxide 124 from the pressure vessel 121, and a plasticizer recovery device 163.
And a pressurizing device 164 for pressurizing gaseous carbon dioxide extracted from the decompressing device 162.

The procedure of the deplasticizer treatment in this manufacturing apparatus will be described. First, the green laminate 100 is placed in the pressure vessel 121, and the temperature controller 155
The temperature inside the pressure vessel 205 is maintained at 40 ° C. Next, liquid carbon dioxide is pumped up from the liquefied carbon dioxide cylinder 151 by the liquid pump 152, and the temperature of the liquid carbon dioxide 122 is raised to 40 ° C. by the temperature adjusting device 153. It is introduced into the pressure vessel 121. After that, the temperature and pressure in the pressure vessel 121 are adjusted by the temperature control device 155 and the pressure control device 16.
1. According to 1, conditions under which carbon dioxide becomes a supercritical state or a subcritical state (40 ° C., 10 MPa in the case of the present embodiment)
Is controlled. As a result, the inside of the pressure vessel 121 is filled with carbon dioxide 124 in a supercritical state.

Then, extraction from the green laminate 100
Supercritical carbon dioxide 124 with removed plasticizer
Is sent to the pressure control device 161 through the discharge port 125, and then is continuously sent to the decompression device 162 in appropriate amounts in order to maintain the pressure in the pressure vessel 121 as it is.
In the decompression device 162, the supercritical carbon dioxide 12
4 is changed to gaseous carbon dioxide by the decrease in the pressure. At this time, the solubility of carbon dioxide in the plasticizer rapidly decreases, and the temperature is as low as about 50 ° C., so that the plasticizer in the liquid state is separated from the carbon dioxide in the gaseous state and collected in the plasticizer recovery device 163. Is done. The carbon dioxide returned to the gaseous state is pressurized again by the pressurizing device 164, sent to the liquid pump 152, liquefied again, and reused. On the other hand, the plasticizer recovered in the plasticizer recovery device 163 can be reused for forming the green laminate 100.

When a fluid, which is normally in a liquid state, is used in a supercritical state or a subcritical state, when the plasticizer is a solid, the two can be easily separated. As in the present embodiment, when carbon dioxide, which is in a gaseous state, is used, when the plasticizer is a liquid or a solid, the two can be easily separated. However, even if the fluid is in a subcritical state,
In the range where the ability to dissolve the plasticizer has been lost, the fluid and the plasticizer can be easily separated, so it is not necessary to reduce the pressure of the fluid to a normal state in order to collect the plasticizer. There is nothing to be done.

As described above, in the conventional degreasing step by thermal decomposition in air, in the degreasing step of simultaneously removing the plasticizer and the binder, an organic substance may be mixed in the discharged high-temperature gas. Therefore, it is necessary to completely decompose and burn the organic matter or to remove the organic matter in the gas by adsorbing the organic matter in another substance, which increases the production cost. On the other hand, by using the present embodiment, when the supercritical carbon dioxide changes to a gas state with a decrease in pressure, the solubility in the plasticizer is remarkably reduced. Since the agent can be easily separated from the agent, the plasticizer can be recovered and reused, and it is possible to avoid environmental problems and reduce costs.

Here, esters such as dibutyl phthalate and butyl benzyl phthalate are often used as the plasticizer used for forming the green laminate, but these substances have an absorption band in the ultraviolet region. Therefore, as shown in FIG. 9, a spectroscopic device 160 is provided between the discharge port 125 and the pressure control device 161 to perform in-situ spectroscopic analysis in the ultraviolet region of the discharged supercritical fluid (carbon dioxide 124). In this case, the concentration of the plasticizer in the fluid can be known. That is, the absorption band in the specific ultraviolet region detected during the extraction and removal of the plasticizer is not detected after the extraction and removal of the plasticizer is almost completed. By utilizing this, it is possible to spectroscopically detect the end point of whether or not the extraction and removal processing of the plasticizer is completed. However, the spectroscopic device 160 does not necessarily need to be disposed between the discharge port 125 and the pressure control device 161. For example, the spectroscopic device 160 can perform the same function as described above even if it is directly attached to the pressure vessel 121. Can be.

In general, the internal electrode in the green laminate often contains dielectric powder, a binder, a plasticizer, and the like, but depending on the type of the laminated ceramic component, the internal electrode contains these. It does not have to be.

Here, it is preferable in the process to employ the low-temperature side region among the high-temperature side region and the low-temperature side region sandwiching the region of 80 ° C. to 100 ° C. shown in FIG. Has already been described. On the other hand, in the low-temperature side region, since the binder is not flexible, there is a possibility that cracks may occur in the green laminate when the plasticizer is extracted and removed. Therefore, when extracting and removing the plasticizer under the condition that the temperature range is in the low-temperature side region, the dielectric substance is added by adding a small amount of alcohol or the like which is soluble in carbon dioxide and has good affinity for the polymer. This is preferable in that the flexibility of the body layer can be maintained and the occurrence of cracks and the like in the green laminate can be prevented.

As the pressurizing medium, an inert gas such as argon and helium can be used in addition to nitrogen.

(Third Embodiment) —Experiment for Examining Appropriate Conditions— As described above, when the first embodiment is used, structural defects in the green laminate and thus the ceramic laminate (sintered body) The production efficiency can be improved while suppressing the deterioration of the quality due to the occurrence of the odor. This is because the deplasticizing step in the first embodiment is performed at a relatively low temperature, so that during the deplasticizing step, the plasticizer concentration of the dielectric layer in the green laminate and the plasticizer in the internal electrode The fact that the concentration is substantially uniform is also considered to be one factor. However, we need to examine a little more under any conditions to ensure that no failures occur. Therefore, the appropriate conditions were examined by the following procedure.

FIGS. 11 (a) and 11 (b) show, respectively,
FIG. 3 is a cross-sectional view of a green laminate for explaining measurement points for examining appropriate conditions, and a diagram showing a Raman spectrum from an untreated sample.

FIG. 11 (a) is a cross-sectional view of a large-capacity green laminate taken along a direction substantially perpendicular to the main surface of the internal electrode so as to be approximately two minutes. As shown in the figure, the plasticizer concentration at each of the points A1, A2, A3,... Located at the center of the dielectric layer of the green laminate was evaluated at every 100 μm from the sample end. Further, the plasticizer concentration at point B at a distance of 500 μm from the sample end in the internal electrode (nickel layer) was evaluated. In addition to the plasticizer, the green laminate
Various organic substances such as binders and inorganic substances such as ceramic powders are contained, and it is difficult to accurately evaluate the concentration of the plasticizer by the elemental analysis method due to the presence of various organic substances such as binders. In this type of green laminate, BBP containing a benzene ring or an ester group is used as a plasticizer, but the benzene ring or the ester group is not contained in other organic substances such as a binder. Therefore, if the concentration of a benzene ring or an ester group can be evaluated, the BBP concentration can be evaluated. Then, it was found that the concentration of a benzene ring or an ester group can be evaluated by using the microscopic laser Raman method.

The principle of the microscopic laser Raman method is as follows. When the surface of a substance is irradiated with laser light, Raman scattered light of λ0 ± λ is generated in addition to scattered light of the irradiation light wavelength λ0. The transition wavelength λ is a value specific to the substance or some of the functional groups therein, and by measuring the intensity of the transition wavelength λ, the amount (concentration) of the substance can be determined. Therefore, when the beam diameter of the laser beam is reduced to 1 μm or less and the object is irradiated, the Raman scattered light is condensed through an optical microscope and measured. Becomes possible. Here, A is used as the laser light.
Using light having a wavelength of 514.5 nm among the r ion lasers,
The measurement was performed using a 100 × objective lens. Laser power was used in the range of 30 to 150 mW. It has been confirmed at several points that the Raman spectrum obtained from the point A is substantially equal to the Raman spectrum in the dielectric layer near the point B.

FIG. 11B shows a Raman spectrum on the dielectric layer of the untreated green laminate. The Raman spectrum shows 1607c due to the benzene ring.
An absorption peak at m ^{-1 and} an absorption peak at 1735 cm ^-1 due to an ester group are observed. Since the peak intensity changes according to the sample cross-sectional shape, each peak intensity is normalized by the absorption peak intensity of 525 cm ⁻¹ caused by the ceramics, that is, the peak intensity of 1607 cm ⁻¹ caused by the benzene ring, The plasticizer concentration was evaluated by measuring the relative intensity ratio to the peak intensity of 525 cm ^-1 due to ceramics.

FIGS. 12 (a) and 12 (b) show data for examining the plasticizer removal effect of the conventional method and the method using the medium in the supercritical or subcritical state according to the present invention, respectively. It is. FIG. 12 (a), the (b), the peak intensity of the vertical axis 1607 cm ^-1 and 525 cm ^-1
And the horizontal axis represents the distance (μm) of each measurement point from the sample end.

As shown in FIG. 12A, in the unprocessed chip, points A1, A2, A
The difference in the concentration of the plasticizer is small, and the difference in the concentration of the plasticizer between the point B and the point A7 at the same distance from the sample end is small. Therefore, it can be said that the untreated chips have a relatively uniform concentration of the plasticizer. On the other hand, 200
In the chip that has been subjected to the heat treatment at ° C., the density at point B is lower than the density at point A. This is presumably because the heating caused the point B, that is, the rate of temperature rise in the internal electrode, to be higher than that of the other portions, so that the deplasticizer proceeded faster than the other portions.

On the other hand, as shown in FIG. 12B, in the case where the treatment with carbon dioxide in the supercritical state was performed, the difference in the concentration of the plasticizer between the points A and B was hardly observed. The reason is considered that since the treatment with carbon dioxide in the supercritical state is performed at a low temperature, the plasticizer in the dielectric film and the plasticizer in the internal electrode are extracted and removed at a substantially uniform rate. Can be The dielectric film and the internal electrode
Since the layers are stacked at a pitch of the order of m, a local variation in the concentration of the plasticizer may cause a structural defect to be formed in the green laminate. Therefore, it is very effective to make the concentration of the plasticizer uniform by treatment with carbon dioxide in a supercritical state.

In addition, the technique of evaluating the concentration of the plasticizer using the microlaser Raman method can be applied to various applications other than the treatment with carbon dioxide in a supercritical state. For example, if the concentration distribution of the plasticizer in the depth direction in the green laminate after the heat treatment of the green laminate is evaluated, in a subsequent process,
When a structural defect occurs in the green laminate, it becomes clear how the distribution of the plasticizer concentration in the depth direction in the green laminate occurs when the structural defect occurs. It is possible to estimate the critical gradient of plasticization and the concentration of the plasticizer. In addition, even when a defect occurs after the conditions for proceeding to the next step are established, it is possible to estimate whether or not the cause of the defect has occurred in the deplasticizing step by performing this evaluation.

Further, the method for measuring the concentration of a plasticizer in a molded product of a mixture of an inorganic substance other than ceramic, a plasticizer, and a binder can be applied. In that case, the relative intensity distribution can be obtained by normalizing the peak intensity of the absorption band caused by the plasticizer in the Raman spectrum with the peak intensity of the absorption band caused by the inorganic substance and obtaining the relative intensity.

In the present embodiment, the case where phthalic acid esters such as dibutyl phthalate and butyl benzyl phthalate are used as the plasticizer has been mainly described.
As mentioned earlier, phthalates are excellent plasticizers,
High solubility in supercritical carbon dioxide. However,
The mixing ratio of the plasticizer, the dielectric material, and the binder in the dielectric slurry used to form the green laminate, the particle size of the dielectric material, and the conditions of the pre-press performed after forming the green sheet are inappropriate. In such a case, a structural defect may occur in the green laminate. It is considered that the main cause is that carbon dioxide dissolves in the phthalate ester as a plasticizer at the time of pressurization, the volume of the phthalate ester increases, and structural defects occur due to volume expansion. Therefore,
If the limit value of the volume expansion of this phthalate ester is quantitatively determined, and materials and forming conditions other than the plasticizer of the green laminate are designed so that the volume expansion does not reach the limit value, Generation of structural defects in the green laminate can be suppressed. Alternatively, even if another plasticizer having a small volume expansion coefficient is used, the occurrence of structural defects in the green laminate can be suppressed. Which of the two methods should be adopted can be determined according to the type and size of the green laminate.

-Evaluation Method and Apparatus for Volume Expansion- Here, the behavior of a material such as a plasticizer in a supercritical or subcritical medium (fluid) is observed, and if possible, the volume expansion of the plasticizer or the like is determined. To evaluate
It is suitable to carry out the following procedure using the following apparatus.

FIG. 13 is a partial sectional view showing the configuration of an apparatus for quantitatively evaluating the volume expansion of a plasticizer or the like. As shown in the figure, the apparatus includes a pressure vessel 205 for bringing a medium (carbon dioxide in the present embodiment) used for a purpose into a supercritical state or a subcritical state, and a supercritical state or a subcritical state. A cylinder 201 for supplying a medium to be brought into a state, a cooler 200 for cooling a medium flowing out of the cylinder 201, and a forcing for sending a medium (a medium in a liquid state in this embodiment) to the pressure vessel 205. A fluid pump 202 (a liquid pump in the present embodiment) as a feeding unit, a temperature control device 203 for controlling the temperature of the medium in the pressure vessel 205, and a cooling medium for cooling the medium flowing out of the pressure vessel 205. A cooling coil 207, an ultraviolet spectrometer 208 for performing ultraviolet spectrometry of the medium flowing out of the pressure vessel 205, and a set value of the pressure of the medium flowing out of the pressure vessel 205. Relief valve 20 for control
9 and an extraction and collection vessel 210 for collecting the medium flowing out of the pressure vessel 205.

The pressure vessel 205 is provided with a heater 206 for heating the pressure vessel 205 and a thermocouple 204 for measuring the temperature of the pressure vessel 205. Then, the temperature of the pressure vessel 205 is controlled by controlling the amount of current supplied to the heater 206 according to the difference between the temperature indicated by the thermocouple 204 and the set temperature by the temperature control device 203.
The medium (carbon dioxide in a liquid state in this embodiment) is supplied from a cylinder 201, pushed out by a fluid pump 202 through a cooler 200, and introduced into a pressure vessel 205. The medium (carbon dioxide) flowing out of the pressure vessel 205 is cooled by the cooling coil 207, and reaches the relief valve 209 via the ultraviolet spectrometer 208. Pressure vessel 20
5 and the pressure of the piping system connected to the relief valve 2
The set pressure is 09. That is, the fluid pump 20
A high pressure is applied to the region from 2 through the pressure vessel 205 to the relief valve 209. The liquid component or the solid component in the medium discharged from the relief valve 209 is extracted and collected by the container 2.
Collected at 10.

Here, in the apparatus of the present embodiment, the following members are provided to quantitatively measure the volume expansion of the plasticizer and the like.

The sapphire window 2 is provided on the ceiling of the pressure vessel 205.
11 is provided, and the inside of the pressure vessel 205 can be observed from the outside. Above the ceiling of the pressure vessel 205, a light 213 for illuminating the inside of the pressure vessel 205, a CCD 215 for forming an image of the inside of the pressure vessel 205, and a CCD 215 for reflecting light reflected from the inside of the pressure vessel 205. Lens 214 for collecting light
And a video recording device 216 for continuously recording images that change every moment taken by the CCD 215.
And a monitor 217 for observing an image photographed by the CCD 215. Also, lens 2
A heat absorbing glass 212 for protection 14 is inserted between the sapphire window 211 and the lens 214. CCD
The image captured by the video recording device 215
6 and can also be observed by the monitor 217.

On the other hand, inside the pressure vessel 205, a critical diameter (in the present embodiment, about 1 mm) which causes a capillary phenomenon of a plasticizer or the like.
mm), a transparent glass tube 218 having an inner diameter of not more than mm) and a support member 220 for the glass tube 218 are arranged.
In implementing the method of the present invention for quantitatively measuring the concentration of a plasticizer or the like, a plasticizer 219 is introduced into a part of the inside of a transparent glass tube 218. Then, the medium (in the present embodiment, carbon dioxide) in the pressure vessel 205 is maintained in a range from the normal state to the supercritical state, and the volume change of the plasticizer 219 is evaluated under various temperature and pressure conditions. The volume expansion of a plasticizer or the like can be quantitatively evaluated. Some materials such as plasticizers cannot be detected by the ultraviolet spectrometer 208. By using the method of observing a change in volume of the plasticizer or the like, the material of the object to be measured such as the plasticizer is used. Regardless of the method, it is possible to evaluate the dissolution rate of the measured object in the medium.

However, the transparent glass tube 218 and the supporting member 220 need not always be provided. Also in this case, since the inside of the pressure vessel 205 can be observed, the behavior of the object to be processed in the fluid in the supercritical state or subcritical state can be accurately grasped, and the conditions of the manufacturing process can be set. You can get important guidance when doing this. When this evaluation device is used for manufacturing, in-s
It is possible to perform a process using a supercritical or subcritical fluid while observing the internal state with itu.

FIG. 14 is a diagram showing the results of evaluating the pressure dependence of the volume of various plasticizers. In the figure, the horizontal axis represents the additional pressure (MPa) that is applied to the atmospheric pressure,
The vertical axis represents the relative volumes of various objects to be measured, where 1 is set when the additional pressure is 0. In the evaluation, the pressure vessel 205
With the temperature in the inside kept constant (40 ° C.), the relative volume of the plasticizer was measured 10 minutes after the pressure reached the test pressure value. And the test pressure is 0MP
a to 4 MPa, 2 MPa in increments of 4 MPa to 10
The relative volume of the plasticizer at each test pressure is measured by increasing the pressure by 1 MPa up to the MPa.

The following can be seen from FIG. DBP
The volume of (dibutyl phthalate) increases with an increase in pressure, becomes about 1.5 times the volume at normal pressure near 7 MPa, and then decreases rapidly with an increase in pressure. It is considered that the reason why the volume of DBP continues to increase from normal pressure to around 7 MPa is that carbon dioxide is dissolved in DBP. Therefore, if a green laminate is manufactured under the same conditions as in this experiment, the volume of DBP is about 1.
It is necessary to take measures to prevent a structural defect from occurring even if it expands five times. Further, the reason why the relative volume of DBP rapidly decreases when the relative volume of DBP is 7 MPa or more is that DBP dissolves in carbon dioxide slightly after the carbon dioxide dissolves in DBP. The amount of DBP dissolved in carbon dioxide greatly depends on time. On the other hand, since carbon dioxide in a supercritical state or subcritical state dissolves very rapidly in DBP, it is considered that the amount of carbon dioxide dissolved in DBP does not depend much on time. The value on the vertical axis shown in FIG. 14 depends on the difference between the amount of dissolved carbon dioxide in DBP and the amount of dissolved DBP, and is therefore considered to vary slightly depending on the experimental conditions. However, by using this method of measuring volume expansion, the solubility of a medium in a substance such as a plasticizer can be easily evaluated. In the present embodiment, the description will be made with reference to the results shown in FIG.

When BBP (butyl benzyl phthalate) is used, although the volume expansion coefficient is slightly smaller than that when DBP is used, the pressure dependency of the relative volume is D.
It shows the same tendency as BP. That is, if the additional pressure is 8
Until the MPa is reached, the relative volume of BBP increases and then starts decreasing.

On the other hand, the relative volume of glycerin hardly changed. This indicates that neither dissolution of glycerin in carbon dioxide nor dissolution of carbon dioxide in glycerin has occurred, that is, it is difficult to dissolve glycerin using only carbon dioxide.

The pressure dependence of the relative volume of liquid paraffin shows the same tendency as the pressure dependence of the relative volume of phthalic esters such as DBP and BBP.

The relative volume of paraffin 52 having a molecular weight higher than that of liquid paraffin (paraffin that liquefies at 52 ° C. or higher) does not increase even if the pressure increases, but only decreases. The reason is that paraffin 52 is solid at the experimental temperature of 40 ° C.
It is considered that this is because it is difficult for carbon dioxide to dissolve therein, and only the dissolution of paraffin 52 in carbon dioxide proceeds.

The above evaluation method can be applied not only to a single plasticizer but also to a mixture of at least two or more plasticizers. In addition, the above evaluation method can be generally widely applied to a case where a mixture containing a substance other than a plasticizer is evaluated for a change in volume of the substance under high temperature and high pressure.

When the above experimental results are combined, the following preferred specific methods can be considered as a method for removing a specific substance such as a plasticizer from the mixture.

-First Specific Method- In the case of using paraffin 52 as a plasticizer and a medium in a supercritical or near supercritical state (for example, carbon dioxide), a green sheet forming step (step shown in FIG. 10) In ST3), since the plasticizer needs to have fluidity, it is heated to bring the paraffin 52 into a liquid state, and in the deplasticizer step (step ST5 shown in FIG. 10), the paraffin 52 By maintaining the temperature at which the solid exists, it is possible to suppress the occurrence of structural defects in the green laminate (compact) due to the volume expansion of the plasticizer and, consequently, the structural defects in the ceramic laminate (sinter). Can be.

-Second Specific Method- As described above, when the phthalic acid ester such as dibutyl phthalate or butyl benzyl phthalate is used as the plasticizer and the deplasticizing step of the first embodiment is performed, the green laminate Structural defects in the body may occur. In such a case, first, a heating deplasticizer at about 200 ° C. to 250 ° C. under normal pressure is performed after step ST4 shown in FIG. 10 and before step ST5, and then, as in the first embodiment. By performing the deplasticizing step, the deplasticizing agent can be realized almost completely without generating structural defects. For example, if the deplasticizer step of the first embodiment is performed after performing the heat deplasticizer at 220 ° C. for 3 hours in nitrogen, no structural defect occurs. , And there was further weight loss. From the mass calculation, all the plasticizers have been extracted and removed.

The reason that no structural defects are generated in the green laminate by this procedure is that many small voids (micro open pores) connected to the outside are generated in the green laminate during heating by the deplasticizer. Is considered to be a space for buffering the volume expansion of the plasticizer. After the deplasticizer by heating, if the deplasticizer step of the first embodiment is performed, there is a further mass reduction because carbon dioxide in a supercritical state has a low viscosity and a high ability to dissolve the plasticizer,
It is considered that the plasticizer remaining in the green laminate can be efficiently extracted. Therefore, the combination of the deplasticizing step by heating and the deplasticizing step of the first embodiment is an effective means when it is absolutely necessary to use a plasticizer that causes volume expansion under specific conditions.

-Third Specific Method- Another effective method is a fluid replacement method. For example, a case where the deplasticizing step (Step ST5 shown in FIG. 10) of the first embodiment is performed using BBP (butylbenzyl phthalate) will be described as an example. When performing the first embodiment, the temperature of the pressure vessel 121 is set to 40 ° C.
Then, after gradually introducing liquid carbon dioxide 122 from the introduction port 123, the carbon dioxide was pressurized to 10 MPa in the pressure vessel 121 of FIG. At this time, since carbon dioxide dissolves in the BBP during a period from normal pressure to about 8 MPa, a volume expansion of about 25% occurs in the BBP,
Eventually, structural defects may occur in the green laminate. Therefore, first, BB with substances other than carbon dioxide
The pressure vessel 121 is filled with a substance having no or very low ability to dissolve P, for example, nitrogen, and the pressure of nitrogen or the like in the pressure vessel 205 is reduced to, for example, 10M.
After pressurizing to Pa, nitrogen is gradually replaced with carbon dioxide while maintaining the pressure at 10 MPa. In that case, it is possible to extract and remove BBP from the green laminate without causing volume expansion of the BBP due to carbon dioxide. In this example, nitrogen was used, but any substance may be used as long as it has no ability to dissolve a plasticizer or has an extremely small ability.

—Fourth Specific Method— As another method, there is a method of rapidly pressurizing the inside of the pressure vessel 205. In the description of the first embodiment, generally, in the deplasticizing step, it is better to pressurize at a pressure change rate of 10 MPa / hour or less in the green laminate 100 (molded body), and further, in the ceramic laminate (fired body). Although it has been described that it is preferable in terms of suppressing the occurrence of structural defects in (consolidation), when a plasticizer whose volume expansion is remarkable is used, it may be better to pressurize rapidly instead. For example, BBP as a plasticizer
In the case where is used, a high-speed pressure increase of 1 MPa / min or more during the period from normal pressure to about 8 MPa resulted in less structural defects. The reason is that the carbon dioxide is maintained at a high pressure in a state where the carbon dioxide is not sufficiently dissolved in the BBP.
It is considered that the volume expansion of P is small.

In the process of manufacturing a sintered body having a step of sintering a mixture of an organic substance and an inorganic substance, not only a plasticizer, but only an organic substance is removed from the mixture,
The organic substance can be removed by the fluid in the supercritical state or the subcritical state in the third embodiment. In that case, when there are a plurality of types of organic substances, each specific method of the present embodiment may be used to remove only some of the types of organic substances, or to remove all of the plurality of organic substances. Alternatively, each specific method of the present embodiment may be used.

(Other Embodiments) The first, second, and third embodiments show that only a plasticizer can be extracted and removed from a green laminate, which is a mixture of a dielectric material, a binder, a plasticizer, and a metal powder. However, the present invention can be applied to other embodiments. Hereinafter, a tantalum solid electrolytic capacitor will be described as an example.

FIG. 15 is a process diagram showing an outline of a manufacturing process of a tantalum solid electrolytic capacitor. FIG. 16 is a cross-sectional view showing the structure of the tantalum solid electrolytic capacitor completed by the process shown in FIG. 15 (from “Latest Capacitor Technology and Materials '86 Edition (General Technology Publishing), published October 1985”).

As shown in FIGS. 15 and 16, highly purified fine tantalum metal powder and an organic binder such as camphor or naphthalene dissolved in an organic solvent are mixed, and the lead is mixed in this mixture. The wire is buried and pressed into a predetermined shape to obtain a porous body. Thereafter, the binder is removed in a vacuum or the like, and the organic binder such as camphor or naphthalene is removed. Then, in a high vacuum of about 10 ⁻³ to 10 ⁻⁴ Pa, at a high temperature of 1500 to 2000 ° C., a sintering process is performed. The bonding between the tantalum particles and the bonding between the tantalum particles and the lead wire are performed to obtain the porous sintered body 251. Next, a dielectric oxide film 252 (T) is formed on the porous sintered body by electrochemical anodic oxidation in an electrolytic solution such as phosphoric acid.
a oxide). Next, after performing a first inspection, the dielectric oxide film 25 is thermally decomposed by manganese nitrate.
2, a manganese dioxide layer 253 is formed, and then a colloidal carbon layer 254 for reducing contact resistance is formed on the manganese dioxide layer 253. Next, after forming a conductive paint layer 255 which is a cathode metal layer such as a silver paint layer on the colloidal carbon layer 254, a second inspection is performed. Thereafter, external terminals 257 and 258 are connected to the leads and a part of the conductive paint layer 255, respectively. Finally, a resin exterior is applied to the surface of the capacitor, and the capacitor is completed through an aging process and a finishing process.

In the above manufacturing process, if the binder removal is incomplete, the dielectric oxide film 252 (Ta oxide) cannot be formed with a uniform thickness, leading to a product failure. Therefore, in such a tantalum solid electrolytic capacitor as well, complete removal of the organic binder is important. For this purpose, as shown in FIG.
After the formation, a first inspection is performed.

Therefore, by applying the method of the first or second embodiment or each specific method of the third embodiment to the binder removal step in the manufacturing process of the tantalum solid electrolytic capacitor, almost all of the organic binder is removed. Complete removal is possible. In this case, unlike the above-described method of selectively extracting and removing only the plasticizer from the green laminate, which is a mixture of the dielectric material, the binder, the plasticizer, and the metal powder, the tantalum metal powder and the organic binder are used. This is a step of selectively extracting and removing only the organic binder from the mixture of the above. Therefore, a mixture of tantalum metal powder and an organic binder such as camphor or naphthalene is placed in a pressure vessel, and the supercritical state or subcritical state (supercritical state) is obtained by the method of each of the above-described embodiments (including each specific method). By contacting carbon dioxide in a state close to the critical state), only the organic binder can be selectively extracted and removed in a short time. Further, the organic binder such as camphor and naphthalene extracted and removed can be collected and reused, so that the production efficiency and product quality can be improved.

[0126]

According to the present invention, in the process of manufacturing a sintered body such as a multilayer ceramic part, before removing the binder from the green laminate, a supercritical or subcritical fluid is used. By selectively and quickly extracting and removing the plasticizer from the green laminate, even if the temperature is raised at a high speed in the subsequent binder removal step and firing step, and the formation of a graphite-like substance can be suppressed, the manufacturing process The cost can be reduced without deteriorating the product and the product performance.

[Brief description of the drawings]

FIGS. 1A and 1B are a vertical sectional view and a perspective view, respectively, of a green laminate formed during a manufacturing process according to a first embodiment.

FIG. 2 is a diagram showing a state in which a green laminate is set in a pressure vessel through which a supercritical fluid flows, in a manufacturing process of the first embodiment.

FIG. 3 is a cross-sectional view of the structure formed after the firing step of the green laminate is completed in the manufacturing process of the first embodiment.

FIG. 4 shows the temperature of carbon dioxide used as a supercritical or subcritical fluid in each embodiment of the present invention.
It is a figure showing a state about pressure.

FIG. 5 is a diagram showing the temperature dependence of the extraction / removal rate of the plasticizer in the pressure vessel in the first embodiment.

FIG. 6 is a diagram showing the pressure dependence of a plasticizer extraction / treatment rate with supercritical carbon dioxide at a temperature of 40 ° C. in the first embodiment.

FIG. 7 is a diagram showing pressure dependency of a plasticizer extraction / treatment speed by supercritical carbon dioxide at a temperature of 150 ° C. in the first embodiment.

FIGS. 8A and 8B are diagrams respectively showing an absorption spectrum of a carbon dioxide extract in a supercritical state and a standard absorption spectrum of DBP (dibutyl phthalate).

FIG. 9 is a view schematically showing a configuration of a manufacturing apparatus of a laminate according to a second embodiment of the present invention.

FIG. 10 is a flowchart showing a process of manufacturing a ceramic laminate according to the first and second embodiments of the present invention.

FIGS. 11 (a) and 11 (b) are a cross-sectional view of a green laminate for explaining measurement points for examining appropriate conditions of the present invention and a Raman spectrum from an untreated sample, respectively. FIG.

FIGS. 12 (a) and 12 (b) are diagrams showing data for examining the plasticizer removal effect of the conventional method and the method using the medium in the supercritical state or subcritical state of the present invention, respectively. is there.

FIG. 13 is a partial sectional view showing the configuration of an apparatus for quantitatively evaluating volume expansion of a plasticizer or the like.

FIG. 14 is a diagram showing the results of evaluating the pressure dependence of the volume of various plasticizers.

FIG. 15 is a process chart showing an outline of a tantalum solid electrolytic capacitor manufacturing process in another embodiment.

16 is a sectional view showing a structure of a tantalum solid electrolytic capacitor completed by the step shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 green laminate 101 dielectric film 102 first internal electrode 103 second internal electrode 121 pressure vessel 122 carbon dioxide 123 introduction port 124 carbon dioxide 125 discharge port 130 structure 131 first base electrode 132 second base electrode 133 first outside Electrode 134 second external electrode 135 first internal electrode 136 second internal electrode 151 liquefied carbon dioxide cylinder 152 fluid pump 153 temperature regulator 154 introduction port 155 temperature controller 160 spectrometer 161 pressure controller 162 decompression device 163 plasticizer recovery device 164 pressure device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01G 4/12 364 C04B 35/00 E (72) Inventor Itakura-Hun 1006 Kazuma Kazuma, Kadoma City, Osaka Matsushita Electric F-term (reference) in Sangyo Co., Ltd. 4K018 CA08 KA39 5E001 AB03 AH01 AH09 AJ01 AJ02

Claims (33)

[Claims] A step of laminating at least an internal electrode layer containing a powder of a conductive material and a dielectric layer containing a powder of a ceramic material, a binder and a plasticizer to form a green laminate; (B) extracting the plasticizer from the green laminate by removing the plasticizer from the green laminate by bringing the laminate into contact with a fluid in a supercritical state or a subcritical state; (C) decomposing and removing the binder, and (d) sintering the green laminate after the step (c). 2. The method for producing a sintered body according to claim 1, wherein in the step (a), at least one resin selected from a butyral resin, an acrylic resin, polypropylene, and polyethylene is used as the binder. A method for producing a sintered body, comprising: 3. The method for producing a sintered body according to claim 1, wherein in the step (a), the plasticizer is at least one substance selected from ester, stearic acid, stearyl alcohol, and paraffin. A method for manufacturing an electronic component, comprising using: 4. The method for producing a sintered body according to claim 3, wherein in the step (a), a phthalate ester is used as the plasticizer. 5. The method for producing a sintered body according to claim 1, wherein, in the step (a), paraffin which is in a solid state during the treatment in the step (b) is used as the plasticizer. A method for producing a sintered body, characterized in that: 6. The method for producing a sintered body according to claim 1, wherein in the step (b), the fluid in the supercritical state or the subcritical state is carbon dioxide, A method for producing a sintered body, comprising using at least one substance selected from hydrocarbons and polyhalogenated hydrocarbons. 7. The method for producing a sintered body according to claim 6, wherein in the step (b), carbon dioxide is used as the fluid in the supercritical state or the subcritical state, and the temperature of the carbon dioxide is equal to or higher than room temperature. And maintaining the temperature in the range of not higher than 50 ° C. or in the range of not lower than 140 ° C. and the temperature in step (c). 8. The method for producing a sintered body according to any one of claims 1 to 7, wherein in the step (b), an entrainer ( A method for producing a sintered body, wherein at least one substance selected from alcohols, ketones and hydrocarbons is mixed and used as an extraction aid). 9. The method for producing a sintered body according to claim 1, wherein in the step (b), the plasticizer extracted and removed from the green laminate is included. A method for producing a sintered body, comprising reducing the pressure of a fluid to make the fluid into a gaseous state, separating the fluid from the plasticizer, and collecting the plasticizer. 10. The method for producing a sintered body according to claim 1, wherein in the step (a), the powder of the conductive material is P
A method for producing a sintered body, comprising using at least one metal selected from t, Pd and Ni. 11. The method for producing a sintered body according to any one of claims 1 to 10, wherein in the step (b), the pressure of the fluid in the critical state or the subcritical state is temporally changed. A method for producing a sintered body, wherein the method is varied. 12. The method for producing a sintered body according to claim 1, wherein in the step (b), ultrasonic vibration is applied to the fluid. The method of manufacturing the aggregate. 13. The method for manufacturing a sintered body according to claim 1, wherein the green laminate is placed in a vacuum or between the steps (a) and (b). A method for producing a sintered body, further comprising a step of performing a heat treatment at 250 ° C. or lower in a gas. 14. The method for producing a sintered body according to any one of claims 1 to 13, wherein in the step (b), the green laminate is pressed using a pressing medium, A method for producing a sintered body, wherein the pressurized medium is replaced with the fluid in a supercritical state or a subcritical state. 15. The method for producing a sintered body according to claim 14, wherein an inert gas is used as the pressurized medium, and carbon dioxide, hydrocarbon and polyhalogenated are used as the supercritical or subcritical fluid. A method for producing a sintered body, comprising using at least one substance selected from hydrocarbons. 16. The method for producing a sintered body according to any one of claims 1 to 13, wherein in the step (b), the fluid is rapidly pressurized at a speed of 1 MPa / min or more. A method for producing a sintered body, which is in a supercritical state or a subcritical state. 17. The method for producing a sintered body according to claim 1, wherein at any time after the step (b) and before the step (d), The plasticizer concentration distribution in the green laminate,
A method for producing a sintered body, comprising a step of evaluating using microscopic laser Raman spectroscopy. 18. The method of manufacturing a sintered body according to claim 17, wherein the relative intensity is obtained by normalizing the plasticizer-induced absorption band peak intensity of the Raman spectrum with the ceramic-induced absorption band peak intensity. A method for producing a sintered body, characterized by obtaining a concentration distribution. 19. A step (a) of forming a mixture of an inorganic substance and an organic substance to obtain a molded body, and contacting the molded body with a fluid in a supercritical state or a subcritical state to form a mixture in the molded body. A step (b) of extracting and removing the organic substance; and a step (c) of sintering the molded body to obtain a sintered body after the step (b). ), Wherein a material that is in a liquid state while in step (c) is in a solid state is used. 20. A step (a) of forming a mixture of an inorganic substance and an organic substance to obtain a molded article; and, after the step (a), partially decomposing the organic substance in a vacuum or in a gas. Step (b) of performing a heat treatment for removal, and after the step (b), contacting the compact with a fluid in a supercritical state or a subcritical state to extract the organic matter in the compact A method for producing a sintered body, comprising: a removing step (c); and, after the step (c), a step (d) of sintering the molded body to obtain a sintered body. 21. A step (a) of molding a mixture of an inorganic substance and an organic substance to obtain a molded article; and after the step (a), the molded article is pressurized using a pressurized medium, The pressurized medium is replaced with a supercritical or subcritical fluid, and the compact is brought into contact with a supercritical or subcritical fluid to extract and remove the organic matter in the compact. A method for producing a sintered body, comprising: a step (b); and, after the step (b), a step (c) of sintering the molded body to obtain a sintered body. 22. The method for producing a sintered body according to claim 21, wherein an inert gas is used as the pressurized medium, and carbon dioxide, hydrocarbon and polyhalogenated are used as the supercritical or subcritical fluid. A method for producing a sintered body, comprising using at least one substance selected from hydrocarbons. 23. A step (a) of molding a mixture of an inorganic substance and an organic substance to obtain a molded body, and bringing the molded body into contact with a fluid in a supercritical state or a subcritical state to form a mixture in the molded body. The method includes a step (b) of extracting and removing the organic substance, and a step (c) of sintering the molded body to obtain a sintered body after the step (b). A method for producing a sintered body, characterized in that a fluid is rapidly pressurized at a rate of 1 MPa / min or more to a supercritical state or a subcritical state. 24. A step (a) of forming a mixture of at least a powder of a conductor material or a powder of a ceramic material and an organic substance to obtain a porous body, and flowing the porous body in a supercritical state or a subcritical state. (B) extracting and removing organic matter in the porous body by contacting the porous body, and after the step (b), sintering the porous body at a high temperature;
And (c) obtaining a porous sintered body. 25. The method for producing a sintered body according to claim 24, wherein in the step (a), camphor,
A method for producing a sintered body, comprising using at least one substance selected from naphthalene and paraffin. 26. A pressure vessel configured to maintain a fluid in a supercritical state or a subcritical state, a supply device for supplying the fluid, and for controlling a temperature of the pressure vessel. A temperature control device, a pressure control device for controlling the pressure of the pressure vessel, a pressure reducing device for reducing the pressure of the fluid discharged from the pressure container, and the plasticizer in the pressure reducing device. And a plasticizer recovering device for separating and recovering from the fluid as a liquid or a solid. 27. The apparatus for producing a sintered body according to claim 26, further comprising: a pressurizing device for pressurizing the fluid, the pressure of which has been reduced in the depressurizing device, to a supercritical state or a subcritical state. An apparatus for manufacturing a sintered body, comprising: 28. The apparatus for producing a sintered body according to claim 26, further comprising a spectrometer for performing spectroscopic measurement of the fluid in the supercritical state or the subcritical state. Equipment for manufacturing sintered bodies. 29. A method for measuring the concentration of the plasticizer in a molded article obtained by molding a mixture of an inorganic substance and an organic substance containing a plasticizer and a binder, the method comprising: A method for measuring the concentration of a plasticizer, characterized in that the distribution is evaluated using microscopic laser Raman spectroscopy. 30. The method for measuring the concentration of a plasticizer according to claim 29, wherein a relative intensity is obtained by normalizing a plasticizer-induced absorption band peak intensity of the Raman spectrum with an inorganic-based absorption band peak intensity. A method for measuring the concentration of a plasticizer, characterized by obtaining a concentration distribution. 31. An evaluation method for evaluating a volume of a substance dissolved in a fluid in a supercritical state or a subcritical state in the fluid, wherein the fluid is maintained in a supercritical state or a subcritical state. (A) mounting a transparent tube member in which the substance is introduced into a pressure vessel, which is configured to be capable of supplying the fluid to the pressure vessel under a certain temperature. (B) measuring the length of a region where the substance is present in the pipe member at a plurality of pressure values while changing the pressure in the pressure vessel, and from the measurement results in the step (b). Determining a pressure dependency of the volume of the substance in the fluid. (C). 32. A pressure vessel configured to maintain a fluid in a supercritical state or a subcritical state, a supply device for supplying the fluid, and controlling a temperature of the pressure vessel. Temperature control device, a pressure control device for controlling the pressure of the pressure vessel, provided in a part of the pressure vessel, capable of transmitting light from inside the pressure vessel and emitting light to the outside An evaluation device comprising a window member. 33. The evaluation device according to claim 32, wherein the transparent tube member is disposed in the pressure vessel and is capable of introducing the substance into a tube, and the presence of the substance in the tube of the tube member. A volume estimating device further comprising means for measuring an area.