JPH02168510A - Ceramic complex - Google Patents

Abstract

PURPOSE:To obtain a complex displaying conductivity only between the internal and external surfaces and allowing formation into a desired thickness by orienting a wire-like conductor in a ceramic cylinder toward the internal and external surfaces thereof, and exposing both ends of the conductor to both internal and external surfaces of the cylindrical body. CONSTITUTION:A radial fine wire pattern is formed on an insulation green sheet mainly composed of a ceramic material, using an organic material. A plurality of the green sheets are laminated, compressed and then formed into a cylindrical body. Furthermore, the cylindrical body is baked and the organic material is eliminated, thereby forming cavities. Then, a complex is formed, using a procedure such as filling a conductive material in the cavities. According to the aforesaid construction, it is possible to obtain a complex showing conductivity only between the internal and external surfaces thereof and allowing formation into a desired thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cylindrical ceramic composite that exhibits electrical conductivity only between the inner and outer surfaces of the cylindrical body.

(Prior art) As a composite of electrically insulating ceramics and conductive materials, "Ceramics 21 (1986) No.
7. Page 603” shows synthetic β-3i, N4 by CVD method.
/TiN composites have been described. This composite is made by compounding titanium nitride into amorphous silicon nitride using the CVD method, so the titanium nitride with a diameter of 5 μm is oriented in one direction, so it does not exhibit electrical conductivity in the plane direction of the composite. , it has anisotropic conductivity in that it exhibits conductivity only in the thickness direction of the conductor.

(Problems to be Solved by the Invention) However, since the ceramic composite disclosed in the above-mentioned document is created by the CVD method, the conductor may be cut in the middle of the composite, or may be intertwined with other conductors. They are in contact with each other and may show conductivity in the plane direction of the composite, and in the above CVD method, the maximum thickness is 2 m + o.
However, it was only possible to create a complex of a certain extent, and it was of little practical use.

The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to provide a cylindrical ceramic that exhibits conductivity only between the inner and outer surfaces and can be formed to a desired thickness. The purpose is to provide a complex.

(Means for Solving the Problems) The ceramic composite of the present invention has a cylindrical body made of electrically insulating ceramics, and a linear conductor made of a conductive material on the inner and outer surfaces of the cylindrical body. The conductor is characterized in that a large number of conductors are buried independently and oriented in the same direction, and both ends of the conductor are exposed on the inner and outer surfaces of the cylindrical body, thereby achieving the above object.

The ceramic composite of the present invention is composed of an electrically insulating ceramic as a matrix and a conductive material, and a cylinder is formed of the ceramic. This cylinder may be a cylinder or a rectangular cylinder, and
The thickness, size, shape, etc. of the cylindrical body may be arbitrarily determined, and the linear conductor made of the above-mentioned conductive material is oriented in the direction of the inner and outer surfaces of the cylindrical body. Many books are buried. The diameter and number of the conductors are set appropriately, and the conductors may be slightly bent and oriented from the inner surface to the outer surface of the cylinder, so that one end of the conductor is exposed to the outer surface of the cylinder, and the other conductor is exposed to the outside of the cylinder. The end is exposed to the inner surface of the cylindrical body, and the outer and inner surfaces of the cylindrical body are electrically connected through the conductor portion.

The above ceramics include, for example, alumina, zirconia, magnesia, sialon, spinel, mullite, crystallized glass, silicon carbide, silicon nitride, aluminum nitride, etc.
gO-8iO□-CaO system, 3320. -3in. system,
PbO-B2O3-5i02 system, CaO-Si02Ca
O-5i02-based, PbO-5tO□-9203-Ca
The main component is O-based glass frit, and these may be used alone or in combination of two or more.

The above conductive materials include gold, silver, copper, tin, zinc, lead,
Conductive pastes (!!! materials) containing metals such as platinum, aluminum, nickel, alloys thereof, powders and linear bodies of carbon, etc. are used.

In order to manufacture the cylindrical ceramic composite of the present invention, for example, a cylindrical ceramic green is applied with a laser, a needle,
A method in which a large number of holes running in the radial direction are made by etching, etc., followed by firing, and metal is press-fitted into the holes. Methods include press-fitting metal into holes, and forming a conductive material such as metal paste radially on the surface of a donut-shaped ceramic green sheet, stacking a plurality of ceramic green sheets, pressing them together, and firing them. Although it may be adopted, the following method is particularly desirable for embedding the conductive material in the ceramic cylinder.

(1) A radial thin line pattern made of organic material is formed on an insulating green sheet whose main component is a ceramic material, multiple layers of this insulating green sheet are laminated and pressure-bonded, and then fired to remove the organic material. A method of filling the formed pores with a conductive material.

(2) Form a radial thin line pattern of conductive material on an insulating green sheet whose main component is ceramic material, and after laminating and crimping multiple insulating green sheets,
How to bake.

Next, a method for manufacturing a ceramic composite by the method (1) above will be explained in detail.

The green sheet used in the present invention is a pre-fired molded body mainly composed of ceramic powder, and any method may be adopted for its production. It can be obtained by mixing the mixture with a solvent according to the conditions, and molding the resulting mixture by a molding method such as injection molding, extrusion molding, compression molding, or casting molding. In particular, it is preferable to use a so-called doctor blade method in which a slurry of the above mixture is applied onto a substrate such as a polyester film or a glass plate using a doctor blade and then dried. Examples of the organic binder include polyvinyl butyral, Examples include polymeric materials such as polyvinyl alcohol, poly(meth)acrylate, cellulose, dextrin, polyethylene wax, starch, and casein, and plasticizers such as dioctyl phthalate, dibutyl phthalate, and polyethylene glycol. Examples of solvents include methanol and ethanol. , butanol, propatool, methyl ethyl ketone, acetone, ethyl acetate, toluene, water, etc.

The amount of the organic binder and solvent to be added may be appropriately determined depending on the manufacturing conditions of the green sheet, etc., but preferably the amount of the bridge filler is 5 to 3 parts by weight per 100 parts by weight of the ceramic powder.
0 parts by weight, and the solvent is added in an amount of 20 to 100 parts by weight.

Any method may be used to form a thin line pattern made of an organic material on the surface of the green sheet. For example, a method of printing a paste of an organic material on the surface of the green sheet by screen printing, intaglio printing, etc., a method of printing a photosensitive resin composition, etc. Examples include methods of laminating, exposing, and developing objects, with the latter method being particularly preferred.

As the photosensitive resin composition, one coated as a dry film photoresist (DFR) is preferably used, but if the green sheet contains an organic binder soluble in an organic solvent, Since the green sheet may be destroyed during solvent development, an alkaline development type DFR is preferred.

In order to form a radial fine line pattern on a green sheet using DFR, a conventionally known method may be used, such as press-bonding or heat-sealing the DFR on the green sheet,
A photomask with a radial pattern of thin lines is placed on top of the photomask, and the photomask is exposed to actinic rays using a high-pressure mercury lamp or the like to cure the photosensitive resin composition in the irradiated area, and then the photomask is peeled off. , a method of developing with an aqueous sodium carbonate solution is mentioned. Alternatively, a thin line pattern of an organic material may be formed on a support such as a glass plate, a stainless steel plate, an aluminum plate, etc. by the above method, and then transferred onto a green sheet.

Next, a plurality of green sheets with radial fine line patterns formed thereon as described above are laminated and pressed together, and then fired to form a circular surface. Any method may be adopted, such as a radial pattern. Examples include a method in which a green sheet on which a fine line pattern is formed is cut into a donut shape, laminated and crimped, and then fired, and a green sheet on which a fine line pattern is formed is laminated and crimped and then processed into a cylindrical shape. .

The number of laminated layers may be determined appropriately depending on the size of the desired ceramic composite, but if it is too thick, it will be difficult to press and bond and the fine line pattern will be difficult to be wrapped by the green sheet, so the thickness of the green sheet and fine line pattern should be When ordering lOμ shoes, it is preferable to laminate about 50 to 1000 sheets, and in order to obtain a thicker one, you can laminate multiple sheets that have been laminated once and press them again, and the crimping conditions also vary. Although it may be determined as appropriate, the pressure is preferably 1 to 10 minutes at 30 to 120°C.

The firing method may be appropriately determined depending on the ceramic powder used, but preferably the temperature is raised at a rate of 1 to 1 b/hr, or the temperature is raised to 400 to 600°C while repeating temperature maintenance to form a fine line pattern. While volatilizing the photosensitive resin composition, the green sheet is degreased, and then the temperature is raised again and fired at 900 to 1650°C for 1 to 24 hours.

When the firing is completed, a cylindrical body is formed from the green sheet, and the organic material forming the fine line pattern is volatilized, forming a large number of pores extending toward the inner and outer surfaces of the cylindrical body. Thereafter, the pores are filled with a conductive material to obtain an anisotropic ceramic composite.

Any method may be used to fill the pores of the cylinder with the conductive material in the form of a powder or a linear body, such as a method of press-fitting the conductive material into the pores.

If the diameter of the pores is small, it is preferable to melt the metal and press-fit it in. In this case, if the temperature of the fired body is low, the metal will adhere to the side walls of the pores, making it impossible to inject the metal. , the fired body is heated to a temperature slightly lower than the melting point of the metal to be press-fitted, and the molten metal is heated at a rate of 10 to 300 kg/cm.
A method of press-fitting at a pressure of 2 is preferable.

In addition, when using a conductive paste, it is sufficient to press the conductive paste into the hole as described above and then harden it. If the conductive paste is a baked type containing glass frit, etc., After press-fitting, it may be heated and fired.

Next, a method for manufacturing a ceramic composite according to method (2) above will be explained.

Any method may be used to form a radial thin line pattern made of a conductive material on a green sheet, and examples thereof include the following methods.

■A method of printing conductive paste on a green sheet and curing it.

■ A plate or foil of a conductive material, a photosensitive resin composition layer (DFR), and a photomask are sequentially laminated on a green sheet, and after curing the exposed photosensitive resin composition by irradiating with actinic rays, a photomask is formed. A method in which the uncured photosensitive resin composition is removed, developed, the exposed conductive material is etched, and the cured photosensitive resin composition is further removed.

■A method in which a fine line pattern of conductive material is formed on a support such as a stainless steel plate, and this fine line pattern is transferred onto a green sheet.

Since the conductive paste used in method ① above involves a firing process in the subsequent process, it is preferable to use a type of baking that includes glass frit.Also, any method including printing may be used, but radial fine wire Screen printing is preferably employed when making the width of the pattern very fine, on the order of microns.

Method (2) is a method that has been conventionally used in manufacturing circuit boards, and any conventionally known photosensitive resin composition (DFR) can be used.

For example, a layer of conductive material such as copper or silver is formed on a green sheet by adhesion, electrolytic plating method, electroless plating method, etc., DFR is crimped or heat-sealed on top of the layer, and then a radial pattern is placed on top of the layer. Photomasks each having a fine line pattern are laminated and exposed to actinic rays using a high-pressure mercury lamp or the like to cure the photosensitive resin composition in the irradiated areas.Then, the photomasks are peeled off and the photosensitive resin in the uncured areas is exposed. The composition is removed and developed with a developer such as an alkaline aqueous solution or trichloroethane, and the exposed conductive material is etched with a 42° Baume ferric chloride aqueous solution, etc., and then cured with a sodium hydroxide aqueous solution, methylene chloride, etc. By removing the synthetic resin composition, a radial fine line pattern is formed.

In the method (2) above, any method may be used to form a conductive radial pattern on the support. For example, (A) A conductive paste is formed on the support in the same manner as in the method (2) above. How to print and cure.

(B) A method of forming a radial fine line pattern on a support in the same manner as the method (■) above.

(C) A photosensitive resin composition (DFR) and a photomask provided with a radial thin line pattern are laminated on a support, and exposed by irradiation with active light using a high-pressure mercury lamp or the like, and the photosensitive resin composition in the irradiated area is removed. is cured, then the photomask is peeled off, the uncured portion of the photosensitive resin composition is removed and developed using a developer such as an alkaline aqueous solution or trichloroethane, and then a conductive material such as copper or silver is plated electrolessly or electrolytically. Here are some ways to do it. Note that after electroless or electrolytic plating, the cured portion of the cured photosensitive resin composition may be removed using an aqueous sodium hydroxide solution, methylene chloride, or the like, if necessary.

A plurality of green sheets on which a radial fine line pattern is formed using the conductive material are laminated and pressed together and fired to form an anisotropic ceramic composite. ). Further, the same applies to the method of forming the material into a cylindrical shape.

Note that both the radial thin line pattern made of organic material and the pattern made of conductive material may be formed on one side of the green sheet, or may be formed on both sides. , green sheets with and without a thin line pattern may be alternately laminated.

By the method described above, a large number of linear conductors made of a conductive material are attached to a cylinder made of electrically insulating ceramics, each independently oriented in the direction of the inner and outer surfaces of the cylinder. A buried cylindrical ceramic composite is obtained. This ceramic composite has a cylindrical shape, but by cutting the cylindrical body in the axial direction with an I/-zer, etc., it is possible to create an anisotropic ceramic composite in the shape of a semi-cylindrical part with a part of the circumference. obtained from

(Example) Next, the present invention will be explained in detail based on an example. Hereinafter, the term "parts" simply means "parts by weight J."

Example 1 96 parts of alumina powder with an average particle size of 2 μm, average particle size of 0.8
4 parts of micron MgO-3i02-CaO glass frit powder, 23 parts of polyvinyl butyral, 5.2 parts of dibutyl terephthalate, 30 parts of methyl ethyl ketone, and 40 parts of toluene were fed into an alumina ball mill and kneaded for 3 hours to obtain a slurry. The resulting slurry was applied onto a doctor blade and dried to obtain a 10100×100 green sheet with a thickness of 50 μm.

60 parts of methyl methacrylate-n-butyl methacrylate-acrylic acid copolymer (6/2/2.14W=150,000),
2.2'dis(4-methacryloxyjethoxyphenyl)propane 15 parts, hexamethylene diacrylate 15 parts
1 part, 2 parts of 2.4-dimethylthioxanthone, 2 parts of ethyl p-dimethylaminobenzoate, 0.05 parts of malachite green, 0.1 part of paramethoxyphenol and 200 parts of methyl ethyl ketone were uniformly dissolved to obtain a photosensitive solution. The obtained photosensitive liquid was applied onto a polyethylene terephthalate film having a thickness of 20 μm and dried to obtain a DFR having a thickness of 25 μm.

The obtained DFR was thermally laminated on the above green sheet, and a negative photomask having a diameter of 5Q++ m, a line width at the outer periphery of 30 μm, and a radial fine line pattern with a line spacing of 50 μm was closely attached to the polyethylene terephthalate film that was the support of the DFR. Next, the photomask was removed, the polyethylene terephthalate film was peeled off, and a 1% by weight aqueous solution of sodium carbonate was added to it at 30°C.
Kg/cm2 was sprayed and developed. Strike the sensitivity 77
When measured with a 21-step step tablet, it was 6 steps. After drying, the sheet has an outer diameter of 50+am and an inner diameter of 4011mm!
When cut into a donut shape and then observed, the line width was 30 μm and the line spacing was 50 t at the outer periphery of the donut shaped green sheet.
, t ta , a pattern with a line spacing of 24AZ11 and a line spacing of 4θμ was accurately formed at the inner circumference.

By the above method, the polyethylene terephthalate film was peeled off from the green sheet on which the pattern was formed, and a donut-shaped green sheet was layered (501), and
℃ and 30 kg/cm2 for 1 minute to obtain a laminate having an outer diameter of 50 mm, an inner diameter of 40 mm, and a height of 25 m.

The obtained laminate was supplied to a heating furnace, heated at a rate of 1.5°C/hr, held at 500°C for 2 hours to volatilize DFR and degreased, and then heated at a rate of 100°C/hr to 1650°C.
The ceramic was fired for 2 hours to obtain a cylindrical porous ceramic having a large number of independent pores extending from the inner surface to the opposing outer surface.

After polishing the obtained porous ceramics, it was fixed in a mold, preheated to 650°C, and then molten aluminum was supplied,
When pressurized for 3 minutes at 150 kg/cm2 and cooled, a ceramic composite whose pores were filled with aluminum was obtained. The height direction (axial direction) of the obtained composite
When the specific resistance of the was measured using a high resistance measuring device, it was found to be 4.8X1
It was 0"Ωcm. In addition, gold was deposited on the entire inner surface of the composite, and gold was deposited on an area of 10 mm of IOX on the outer surface, and the specific resistance during this time was measured with a resistance measuring device.
It was 5.9X 10-'Ω·CII+.

Example 2 Using the DFR and green sheets obtained in Example 1, a stage and DF were heat-sealed in the same manner as in Example 1.
A negative photomask having a diameter of 50III+, a ti width of 25 μm at the outer periphery, and a radial fine line pattern with a line spacing of 40 μm was brought into close contact with the polyethylene terephthalate film serving as the support for R, and exposed in the same manner as in Example 1. I developed it. The sensitivity was 6 steps. After drying,
When the green sheet is cut into a donut shape with an outer diameter of 50 mm and an inner diameter of 40 mm, and the donut-shaped green sheet is then observed, the line width is 2 at the outer periphery of the donut-shaped green sheet.
A pattern with a line width of 5 μm, a vA pitch of 40 μm, a line width of 20 μm at the inner peripheral portion, and a line spacing of 32 μm was accurately formed.

The obtained sheet was laminated and fired in the same manner as in Example 1 to obtain a cylindrical porous ceramic having a large number of independent pores on the outer surface facing from the inner surface.

The obtained porous ceramic was treated in the same manner as in Example 1,
A ceramic composite was obtained by filling with aluminum.

Next, when the specific resistance of the composite was measured in the same manner as in Example 1, the specific resistance in the height direction was 7.9XIO''
Ω・cm, and the specific resistance from the inner surface to the outer surface is 5.3X
It was IO-'Ω·Cl11.

Example 3 The porous ceramic obtained in Example 1 was supplied to a mold, and after preheating to 370°C, molten zinc was supplied to the mold,
Pressure was applied for 3 minutes at 140 Kg/c+*2, and the mixture was cooled to obtain a ceramic composite whose pores were filled with zinc.

When the specific resistance of the composite was measured in the same manner as in Example 1, the specific resistance in the height direction was 6.3 x 1014Ω.
・cm, and the specific resistance from the inner surface to the outer surface is 6.2XI
It was Q-'Ω·cm.

Example 4 The porous ceramic obtained in Example 1 was supplied to a mold, and a conductive paste (Ag:Pd=95:5, TR4940 manufactured by Kuninaka Massey Co., Ltd.) was applied for 3 minutes at 30 kg/cm2. to fill the holes with conductive paste, and then
The ceramic composite was obtained by supplying it to a heating furnace at 0° C. and baking it for 20 minutes.

When the specific resistance of the composite was measured in the same manner as in Example 1, the specific resistance in the height direction was 5. l×1014Ω
・cps, and the specific resistance from the inner surface to the outer surface is 2, lX
It was 10 −3 Ω·cm.

Example 5 The DFR obtained in Example 1 was placed on a stainless steel plate at 2 kg/kg.
A negative photomask having a diameter of 59 mm, a line width of 30 μm at the outer periphery, and a radial fine line pattern with a line spacing of 50 μm was brought into close contact with the polyethylene terephthalate film serving as the support of the DFR by pressure bonding at a pressure of cta2, and Example 1
Exposure and development were carried out in the same manner as in . When the sensitivity was measured, it was 6 steps.

Next, copper electrolytic plating was performed to form thin copper wires between the thin resist wires, which were then pressed onto the green sheet at a pressure of 5 kg/cm 2 to transfer the copper wires to the green sheet. The conditions for electrolytic plating were as follows. The stainless steel plate was degreased, washed with water, etched with a 20% ammonium persulfate solution, washed again with water and 20% sulfuric acid, and then plated with sulfuric acid steel at a current density of 3^/d 2 for 35 minutes. The composition of the plating bath at this time was 80 g/l of copper Vi acid, [#11
180g/I, chlorine ion 50mg/! , additive (manufactured by Okuno Pharmaceutical Co., Ltd., Top Lucina 81MV) was 5 ml/l, and the thickness of the copper wire was about 25 μm.

The green sheet with the obtained copper wire transferred to it has an outer diameter of 50 m.
It was cut into a donut shape with an inner diameter of 40 mm, laminated and fired in the same manner as in Example 1 to obtain a ceramic composite.

Next, the specific resistance of the composite was measured in the same manner as in Example 1, and the specific resistance in the height direction was 4.0XLO"
Ω・CQI, and the specific resistance from the inner surface to the outer surface is 3.2
X10-'Ω・cl! It was l.

(Effects of the Invention) As described above, in the ceramic composite of the present invention, the conductor embedded in the cylinder is oriented toward the inner and outer surfaces of the cylinder, and both ends of the conductor are inside the cylinder. Since it is exposed on the outer surface, electrical conduction occurs only in the direction of the inner and outer surfaces of the cylindrical body through this conductor, resulting in excellent anisotropy. Moreover, the thickness of the ceramic composite can be appropriately increased, which is practical.

that's all Applicant: Sekisui Chemical Co., Ltd. Representative: Hiroshi 1) Kaoru

Claims (1)

[Claims] 1. A cylindrical body made of electrically insulating ceramics,
A large number of linear conductors made of conductive material are buried independently and oriented toward the inner and outer surfaces of the cylinder, and both ends of the conductors are exposed on the inner and outer surfaces of the cylinder. A ceramic composite that is characterized by: