JPH05254863A - Ceramic substrate, ceramic printed circuit board and its production - Google Patents

Abstract

PURPOSE:To obtain a ceramic substrate having low dielectric constant and dielectric loss, high mechanical strength and excellent quality at a low cost by converting the main crystal of a specific formed material to a crystal having the composition of anorthite, cordierite alpha and cordierite beta. CONSTITUTION:A chemical composition (A) is produced by compounding 45-65 wt.% of SiO2, 20-30wt.% of A12O3, 5-15wt.% of CaO and 5-15wt.% of MgO in terms of oxide. A formed material (B) of a crystallized glass is formed mainly from a crystallized glass consisting of the component A. The component B is calcined to obtain the objective ceramic substrate C composed of the crystallized glass containing anorthite, cordierite alpha and cordierite beta as the main crystals of the crystallized glass. As necessary, the substrate C is produced by adding <=20wt.% of a borosilicate glass to the component A. A ceramic printed circuit board is produced by integrally applying a circuit to the formed product B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate such as an electronic circuit substrate, an electronic component substrate and the like, and a ceramic circuit wiring board in which circuit wiring is provided on the substrate, particularly a high frequency circuit substrate and a high speed signal. The present invention relates to a ceramics substrate having suitable characteristics for use as a circuit board for use in the same, and a ceramics circuit wiring board thereof.

[0002]

2. Description of the Related Art Ceramic substrates made of ceramics such as alumina are used as substrates for mounting electronic circuits having electronic components such as ICs and LSIs as mounting elements. On the other hand, in the electronic equipment field, on the other hand, high-density mounting elements, high-speed signal transmission, widespread use of mobile communication, etc. In addition, high density wiring, high speed, and high frequency are required. To meet the demands for high-speed signal transmission and high frequency for such mounting substrates, it is strongly required to lower the dielectric constant and lower the dielectric loss of the substrate material (dielectric layer).
In other words, since the propagation delay time of a signal is proportional to the square root of the dielectric constant (ε), it is necessary to lower the dielectric constant of the substrate material for high-speed signal transmission, and it is necessary to improve the high-frequency insulation in high-frequency electric fields. Again, it is essential to lower the dielectric constant of the substrate material.

Further, the dielectric loss (tan δ) affects the transmission loss of signals. The signal current is converted into heat energy by the electromagnetic field generated in the substrate material near the circuit due to the signal current, which causes a signal transmission loss. Since this transmission loss is proportional to the dielectric loss and the square of the frequency, it becomes larger as the frequency becomes higher. Therefore, a low dielectric loss of the substrate material is essential for a high frequency substrate. Further, for high-speed signal propagation, it is necessary to shorten the wiring length, that is, to increase the circuit density. Therefore, it is required to form fine wiring as much as possible on the substrate or to form three-dimensional wiring. Therefore, in any case, the surface of the substrate needs to be as smooth as possible. In particular, when a circuit is formed by the thin film method, it is strongly required to finish the surface of the substrate as smooth as possible.

[0004] When considering more properties required as a high-frequency substrate and a high-speed signal transmission substrate quantitatively, dielectric constant of about at alumina substrate which is used as the mounting substrate conventionally at a high frequency region of 1 MH _Z On the other hand, glass ceramics, which is known as low dielectric loss ceramics, has a high dielectric constant of about 6, but has a large dielectric loss of 0.005, and both the dielectric constant and the dielectric loss are extremely small. Has the drawbacks that it is extremely difficult to mold and becomes expensive, and that the mechanical properties are even worse. Therefore, as a substrate for high frequency and a substrate for high speed signal transmission, satisfactory ones have not been obtained at present.

In addition, the mechanical properties of the substrate are also extremely important practical requirements, and in particular, a bending strength of 1500 kg / cm ² is required to withstand the element mounting process and actual use as a mounting substrate. Further, the mounting substrate may form a circuit by a thick film method. This method is a method of forming a circuit by printing a circuit of a silver-based conductive paste on a substrate and baking it at 800 to 900 ° C. It is an essential requirement that the substrate not be deformed such as warped, twisted, or distorted during the firing, that is, have high thermal creep resistance.

There is also a strict requirement for the smoothness of the substrate. For example, in the case of a thin film substrate, the surface roughness (Ra) defined as the center line average roughness related to the amplitude of fine irregularities on the surface is 0.2 μm or less. Required to be. However, the value of the surface of a ceramic substrate molded by a normal method is larger by one digit or more, so at the current production stage, the surface of this substrate is mechanically polished or a glass glaze is coated on the surface to reduce the value to less than the above value. Finishing is performed so that the surface roughness of As a result, the mounting substrate has complicated processing steps, is extremely poor in productivity, and is therefore expensive in price.

[0007]

Under such technical background, the present invention has a low dielectric constant, a low dielectric loss of electrical characteristics, high strength, high heat and creep mechanical and thermal characteristics, and a high degree of surface smoothness. It is an object of the present invention to provide a ceramic substrate suitable for use as a high-frequency substrate and a high-speed signal transmission substrate having excellent properties, and a ceramic circuit wiring board having circuit wiring provided thereon. Provided is a method for manufacturing an inexpensive ceramic substrate and a ceramic circuit wiring board, which are fired at a much lower temperature than before by a high green sheet method, and a green sheet which can be used as the ceramic substrate and the ceramic circuit wiring board by low temperature firing. The purpose is that.

[0008]

As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that a ceramic substrate made of crystallized glass having a specific composition achieves the above-mentioned object, and arrived at the present invention.

That is, the present invention uses SiO _{2 in} terms of oxide.
A crystallized glass molded body whose main component is a crystallized glass having a chemical composition of 45 to 65% by weight, Al ₂ 0 ₃ 20 to 30% by weight, Ca 0 5 to 15% by weight, and Mg 0 5 to 15% by weight, The main crystal of the present crystallized glass is made of anorthite, cordierite α and cordierite β, and a ceramic substrate, and the crystallized glass molded body containing the crystallized glass as a main component is provided with circuit wiring. Is a ceramic circuit wiring board consisting of
0 ₂ 45 to 65% by weight, Al ₂ O ₃ 20 to 30% by weight, Ca 05 to 15
The present invention is directed to a green sheet comprising a glass powder raw material whose main component is a glass powder having a chemical composition of 50% by weight and Mg0 5 to 15% by weight, and a plasticizing and coagulating composition. A sheet or a green sheet circuit wiring processed body obtained by subjecting this green sheet to circuit wiring is fired at a firing temperature of 900 to 1000 ° C for 0.7 to 20 hours or at a firing temperature of 1000 to 1200 ° C for 10 to 40 minutes. The gist is a method for manufacturing a ceramic substrate or a ceramic circuit wiring board made of crystallized glass.

The present invention will be described in detail below. The ceramic substrate or the ceramic circuit wiring board base material of the present invention has a chemical composition of SiO ₂ 45 to 65% by weight, Al ₂ O ₃ 20 to 30% by weight, Ca 0 5 to 15% by weight, and Mg 0 5 to 15% by weight in terms of oxide. It is composed of a crystallized glass molded body whose main component is crystallized glass having a composition. Here, the crystallized glass having the above chemical composition (hereinafter referred to as the present crystallized glass) is a single ceramic compound composed of silicon Si, aluminum Al, calcium Ca, magnesium Mg, and oxygen 0. When expressed in the form of a hybrid of metal oxides, the structure is mainly represented by the above-mentioned respective weight% compositions, and in some cases, a carbonate group derived from a raw material described later, an anion group such as a hydroxyl group and the above A trace amount of impurities consisting of salts with each metal cation group may be mixed.

The present crystallized glass is completely amorphous at least near room temperature or quasi-amorphous with a slight amount of crystals, and crystallization becomes apparent by heat treatment at a certain temperature or higher. A glass having the above chemical composition (hereinafter referred to as the present latent crystal glass) was crystallized by the firing treatment of the present invention, and was almost completely crystallized from a multiphase composition in which a crystalline phase and an amorphous phase were mixed. It means a glass structure up to a quasi-single phase composition.

The ceramic substrate or the ceramic circuit wiring board base material of the present invention contains the above-mentioned crystallized glass as a main component, and its abundance is preferably 80% by weight or more. Of course, the effect of the present invention is sufficiently exhibited even with 100% by weight of the crystallized glass molded product, that is, the present crystallized glass alone. If the amount of the present crystallized glass is less than 80% by weight, the above-mentioned electrical properties and mechanical / thermal properties are likely to deteriorate.

Other glass or glass-ceramics are preferable as components other than the crystallized glass, and borosilicate glass is particularly excellent. That is, this crystallized glass
Compared to the present crystallized glass, the composite of 100-80% by weight and 0-20% by weight of borosilicate glass in which the crystallized glass phase and the amorphous glass phase are mixed with each other has a higher bending strength and heat-resistant creep. The mechanical and thermal characteristics such as properties are almost the same, and the surface smoothness and the dielectric characteristics are more excellent.

[0014] The main crystal of crystallized glass phase CaO · Al ₂ 0 ₃ ·
2Si0 ₂ Composition anorthite of, consisting _{2Mg0 · 2Al 2 0 3 · 5Si0} 2 composition of cordierite α and _{2Mg0 · 2Al 2 0 3 · 6Si0} 2 cordierite composition beta. 2Mg0 for other crystals
· 2Al ₂ 0 ₃ · 5Si0 ₂ Composition of indialite is present in small amounts. Each of these crystals can be identified by an X-ray diffraction image. That is, in the X-ray diffraction diagram showing the relationship between the diffraction angle and its X-ray intensity, the characteristic peak corresponding to each crystal is represented by the diffraction angle 2θ, anorthite is 28.0 °, cordierite α is 10.4 °, and cordierite β is 26.0 °. °, Indialite appears at 29.6 °. An example of such identification is as clearly shown in FIG.

Such anorthite and a crystallized glass having cordierite as a main crystal or a hybrid of the present crystallized glass and an amorphous glass such as borosilicate glass are excellent in the existence of the crystals themselves. In addition to exhibiting electrical, mechanical and thermal properties, it has a structure in which a single phase or both types of glass phases are homogeneous and have a high density and are mixed and filled, and their interfaces are firmly adhered. As a matter of course, there are almost no defects such as holes and cracks that are often observed in ordinary ceramic substrates. Therefore, although the ceramic substrate and the substrate of the ceramic circuit wiring board of the present invention are essentially crystallized glass, they have mechanical strength and chemical resistance comparable to those of high-performance ceramic substrates such as high-purity alumina substrates.

The ceramic circuit wiring board of the present invention is a structure in which circuit wiring is integrally provided on the above-mentioned crystallized glass molded body containing the present crystallized glass as a main component. The crystallized glass molded body is a sheet-shaped or board-shaped molded body, and the circuit wiring is a layered circuit of one step or multiple steps integrally formed on the surface or inside of the molded body, and as necessary. Thus, one or a plurality of rod-shaped or tubular conductors, that is, via holes connecting them are formed between a plurality of layers. Further, the circuit here means a conductor made of a sintered body of a good conductive metal such as gold or silver, which is continuous in a strip shape, or a resistor made of a layered metal, carbon, or ceramics in a part thereof if necessary, and And / or an electric circuit in which passive components such as a capacitor are integrally connected.

The green sheet of the present invention contains Si in terms of oxide.
Plasticizing and condensing glass powder raw material whose main component is glass powder having chemical composition of 0 ₂ 45 to 65% by weight, Al ₂ O ₃ 20 to 30% by weight, Ca 0 5 to 15% by weight, and Mg 0 5 to 15% by weight. 10. A latent sheet of the present invention, which is a flexible sheet containing a functional composition and has an average particle size of several μm or less, preferably 2 μm or less.
A sheet in which 90 to 80% by weight of a glass powder raw material consisting of 0 to 80% by weight and 0 to 20% by weight of borosilicate glass and 10 to 20% by weight of a plastic / coagulable composition are preferably used.

Here, the plasticizing and coagulable composition is a sheet formed by the molding aid, which is a mixed solution of a functional agent such as a binder, a plasticizer, a dispersant, and a solvent used in the production process of the green sheet. It is a solvent evaporation residue afterwards, which has the function of condensing the particles of the glass powder raw material, maintaining the sheet shape, and imparting plasticity to the sheet and processability for processing such as punching / outline processing and circuit printing processing. It is a substance that has. In the present green sheet, the plasticizing and coagulating composition is blended in a state where the particles of the glass powder raw material are filled almost uniformly. The green sheet preferably has a thickness of about 0.1 to 1.0 mm and a density of about 1.8 g / cm ³ .

Next, the manufacturing method of the present invention will be described in detail. The ceramic substrate of the present invention is obtained by firing the powder of the present crystallized glass, but it is difficult to adjust the shape of a predetermined molded body as it is. Therefore, a method of firing a preformed green sheet is adopted. Is desirable.

The glass powder raw material of the present invention is Si in terms of oxide.
0 ₂ 45 to 65% by weight, Al ₂ 0 ₃ 20 to 30% by weight, Ca 0 5 to 15%
Glass having a chemical composition of wt.%, Mg 0 5 to 15 wt.%,
That is, a powder of the present latent crystal glass or a mixed powder glass consisting of 100 to 80% by weight of the present latent crystal glass powder and 0 to 20% by weight of borosilicate glass powder is used.

As described above, the latent crystal glass is a glass having the above-mentioned chemical composition of a completely amorphous state or a quasi-amorphous state in which very few crystals are present near room temperature, but it is heated above the softening temperature, That is, it is a vitreous substance that becomes a crystallized glass by firing, and borosilicate glass is a normal amorphous glass having no crystallization ability.

[0022] The present potential crystal glass is silica sand (Si0 raw materials for _2),
Aluminum hydroxide (Al ₂ 0 ₃ material for), calcium carbonate (raw material Ca0), a raw material such as magnesium carbonate (raw material Ma0) was required amount weighed so as to satisfy the composition of the oxides of the present latent crystal glass , Homogenize after melting in a melting vessel such as a tank furnace or crucible, cast this in a mold, roughly crush the obtained glass block with a roll crusher, and then with a fine crusher such as a jet mill Prepare by grinding to a diameter of 10 μm.

90 to 80% by weight of the glass powder raw material, 10 to 20% by weight of a compounding agent such as a binder, a plasticizer and a dispersant, and 80 to 100% by weight of a solvent based on 100% by weight of the glass powder raw material.
The ingredients are blended and wet-milled and mixed by a wet-milling device such as a wet ball mill. At this time, the average particle diameter of the glass powder raw material is several μm
Grinding is continued until it becomes less than 2 μm. Raw slurry (mixing slip) as it is or by further performing operations such as defoaming and viscosity adjustment as necessary.
Is prepared. Here, the binder is a functional agent that bonds the powder particles of the glass powder raw material in the green sheet to maintain the sheet form, and polyvinyl butyral, polymethyl acrylate resin, etc. are used.

The plasticizer is a functional agent for improving the plasticity and processability of the green sheet, and dibutyl phthalate (DBP), dioctyl phthalate (DOP) and the like are used. The dispersant is a functional agent that improves the dispersibility of the glass powder raw material in the solvent in the raw material slurry, and methyl oleate or the like is used. Further, the solvent means (1) dissolving each of the above molding aids in the raw material slurry, (2) dispersing the glass powder raw material to impart fluidity to the raw material slurry, and (3) evaporating and solidifying in the casting process. It is a functional agent having a function of forming a sheet form, and an organic solvent such as toluene, methyl ethyl ketone, ethyl alcohol, propyl alcohol, azeotrope or a mixed solution thereof is used. As the molding aid, it is also effective to add a functional agent such as a sintering aid or a printability improving agent, if necessary, in addition to the above.

The raw material slurry thus prepared is supplied to a casting device equipped with a slurry measuring / supplying device, a doctor blade, a carrier tape conveyor and a heating / drying furnace to form a green sheet. The slurry cast in a predetermined thickness with a doctor blade evaporates the solvent in the drying process, and the remaining binder, plasticizer, dispersant and other molding aids remain, that is, the plastic / caking composition is glass. It is filled between the particles of the powder raw material to form a green sheet having tensile strength against external force such as tension, processability for processing such as punching, cutting, circuit printing, and appropriate hardness and flexibility.

The green sheet thus obtained is used as it is, or after being subjected to primary processing such as punching and outer shape processing, it is fired to obtain a ceramic substrate. Alternatively, after the same subsequent processing, the holes of the same substrate are made conductive and circuit wiring is formed on the surface of the substrate, and as it is, or if necessary, multilayer lamination molding is performed and then firing is performed to process into a ceramic circuit wiring board.
In addition, usually, a degreasing treatment for incineration and removal of the plastic / caking composition is performed prior to firing.

Here, the drilling process is a process of forming through holes penetrating both sides of the substrate by means of a drill, punch, press punching, electron beam or laser light beam, and the external process is a process such as trimming. Is. In addition, the circuit on the surface of the substrate is a band-shaped film made of a metal conductor having good electric conductivity such as copper, silver, gold, palladium, molybdenum, or tungsten, or if necessary, a part of the film functions as a resistor and / or a capacitor. The above band-shaped film including the band-shaped film that fulfills the above-mentioned purpose, and as a method for forming these circuits, a thick film method such as a printing method, a dry film resist method by photography, a liquid photoresist method, or a chemical plating method, a vapor deposition method, or a sputtering method is used. Method, ion plating method, CVD method, or other thin film method.
Among these methods, the printed circuit forming method using a conductive paste is particularly excellent in practicality. The conversion of the holes into conductors, that is, the formation of via holes is achieved by performing wall surface metallization or conductive paste filling by a method such as a printing method, a vacuum suction method, or a pressure filling method. The multi-layer lamination molding is one in which two to several layers of green sheets with circuit wiring are laminated and molded by applying a pressure of 50 to 150 Pa.

The firing of these ceramic substrates or ceramic circuit wiring boards is carried out at 900 to 1200 ° C. with air, hydrogen,
It is carried out in an atmosphere of an inert gas such as nitrogen or a reducing combustion gas. Normally, baking at 1000 to 1200 ° C for 10 to 40 minutes is suitable, but if baking at a low temperature is required,
It is preferable to employ firing conditions of 0.7 to 20 hours at 00 to 1000 ° C.

By the above firing, the plastic / coagulable composition present in the gaps between the glass powder raw material particles of the green sheet is evaporated / decomposed and vaporized, and the glass particles are sintered. At this time, the borosilicate glass particles become an amorphous glass phase, which is an amorphous glass phase and is filled in the gaps between the latent crystal glass particles.
The latent crystal glass particles are a crystallized glass phase in which crystals and amorphous glass are mixed.

The crystal of the present crystallized glass phase is a hybrid of a plurality of different crystals, the main crystals of which are anorthite and α.
Type and β type cordierite. The abundance of each of these crystals depends on the firing conditions during firing. That is, in the case of the standard firing conditions described above, the substrate of the present invention starts to crystallize at a firing temperature of 950 to 1000 ° C. and becomes a hybrid of anorthite and cordierite, and the firing temperature is further increased to 1200 ° C. When it exceeds, India light increases remarkably. Although the cordierite-based crystals composed of α-type and β-type are in a transformation relationship with each other, the abundance ratio changes depending on the firing conditions, that is, cordierite β is compared to cordierite α when the firing temperature is 1000 ° C or lower. However, when the temperature is higher than that, cordierite β decreases and cordierite α increases, and when the firing temperature exceeds 1200 ° C., cordierite β almost disappears and only cordierite α is left.

Since the presence of a large amount of indialite crystals at the above-mentioned firing temperature of more than 1200 ° C. has an unfavorable effect on the mechanical strength properties and surface smoothness,
Baking temperatures above 00 ° C are not preferred. Also, the firing temperature
When the temperature is lower than 900 ° C, the surface smoothness is good, but the ratio of crystals is reduced and sufficient mechanical strength cannot be obtained, which is not preferable.

[0032]

EXAMPLES The present invention will be described in more detail with reference to examples. In the following examples,% means% by weight. Example _{1 Si0 2 55%, Al 2} 0 3 29%, Ca0 6%, the glass powder having a chemical composition of Mg0 10%, toluene 50 as a solvent
%, Ethyl alcohol 43%, propyl alcohol 7% mixed solvent was added to the raw material weight 80%, and polyvinyl butyral resin as a binder, DBP as a plasticizer, and methyl oleate as a dispersant were added to the raw material weight at 10% each. %, 4% and 0.5% were added. This raw material was mixed and pulverized in a wet ball mill until the average particle diameter of the glass powder raw material became about 2 μm. This stock solution is defoamed, the viscosity is adjusted,
A raw material slurry having a viscosity of 10,000 cp was obtained.

This slurry was formed into a sheet by the doctor blade method to obtain a green sheet having a thickness of about 0.8 mm.
The green sheet density was 1.85 g / cm ² . Then, this green sheet is fired for 30 minutes at a predetermined temperature of 5 stages set to a firing temperature of 950 to 1250 ° C., and 5 times for each firing temperature.
A ceramic substrate of dots was obtained. For each of the prepared ceramic substrates, dielectric constant, dielectric loss, surface roughness, bending strength,
And the heat creep resistance was measured. The results are shown in Table 1.

[0034]

[Table 1]

Here, the dielectric constant and the dielectric loss were measured at a frequency of 1 using an impedance analyzer (4194A) manufactured by YHP.
It was measured by MH _Z. The surface roughness was measured using a surface roughness meter (ET-30K) manufactured by Kosaka Laboratory. Flexural strength is JIS-R 16
It depends on the method of 01. Heat creep resistance is 100 mm between samples
The maximum amount of deflection is measured after holding at 900 ° C for 30 minutes, and those with less than 500 are good (○),
Anything more than that was regarded as defective (x).

Further, the X-ray diffraction analysis was carried out for each of the samples Nos. 1, 2, 4, and 5, that is, the samples at the firing temperatures of 950 ° C., 1000 ° C., 1200 ° C., and 1250 ° C. The result is shown in FIG. Here, the identification of each crystal is performed by X-ray diffraction analysis in JCP.
It was performed based on the data file of DS.

Comparative Example 1 A cordierite-based crystallized glass substrate having the same dimensions and a borosilicate-alumina-based glass ceramic substrate, which is a representative example of glass ceramics, were prepared in the same manner as in Example 1, and the above respective characteristic values were set. It was measured. The firing conditions are as follows: firing temperature 1420 ° C, firing time 30 minutes, and firing temperature 900
The calcination time was 30 minutes. The results are shown in Table 2.

[0038]

[Table 2]

As is clear from the above results, the ceramic substrate of the present invention (Sample Nos. 2 to 4) has a dielectric constant of 6.2, a dielectric loss of 0.001, a surface roughness of 0.2 or less, and a bending strength of 1500.
It was found to have the expected excellent characteristics of good heat creep resistance at kg / cm ² or more. On the other hand, the substrate with a low baking temperature (Sample No. 1) has a low bending strength and poor thermal creep resistance, while the substrate with a high baking temperature (Sample No. 5) has a low bending strength. It was

It can be said that the characteristics of the substrate of the present invention are excellent and well-balanced substrate characteristics compared with the cordierite type crystallized glass substrate and the borosilicate-alumina type glass ceramics substrate. Moreover, the substrate of the present invention has a firing temperature range effective in production of 1000 to 1200 ° C. and a firing temperature range of 200 ° C. or more, but considering that the equivalent value of the cordierite-based crystallized glass substrate is extremely small at 20 ° C. Then productivity,
It is also seen that the quality is even better.

As is clear from FIG. 1 showing the result of X-ray diffraction analysis, the firing temperature was 950 ° C. under the conditions of this example.
However, it remains in the amorphous glass state, but the firing temperature is 1000.
It can be estimated that crystallization has started in the temperature range of 950 to 1000 ℃ because crystals have appeared on the ℃ substrate. From the comparison of the spectra of the calcination temperature of 1000 ℃ and the calcination temperature of 1200 ℃, It is understood that the main crystal becomes a hybrid of anorthite and cordierite α and β, and that crystallization of indiolite also progresses with crystallization of each of the above crystals in the firing temperature range of 1000 to 1200 ° C., , Firing temperature
From the comparison of the spectra of the substrate at 1200 ℃ and the substrate at 1250 ℃, anorthite decreased when the baking temperature exceeded 1250 ℃, and cordierite β almost disappeared, while cordierite α increased remarkably. It can be seen that the number of lights also increases and appears in the main crystal. From the comparison between this result and the values of the bending strengths of sample Nos. 4 and 5 in Table 1, it can be seen that the bending strength further decreases with the advent of indiolite.

Example 2 Glass powder having the chemical composition of SiO ₂ 55%, Al ₂ O ₃ 29%, Ca 0 6%, and Mg 0 10% was added to a solvent of toluene 50% as a solvent.
80% of a mixed solvent of ethyl alcohol 43% and propyl alcohol 7% was added to the raw material weight, and polyvinyl butyral resin as a binder, DBP as a plasticizer, and methyl oleate as a dispersant were added to the raw material weight at 10% each.
%, And 4% and 0.5% were added.

This raw material was mixed and pulverized by a wet ball mill until the average particle diameter of the glass powder raw material became about 2 μm. This stock solution was defoamed and the viscosity was adjusted to obtain a raw material slurry having a viscosity of 10,000 cp. This slurry was formed into a sheet by the doctor blade method to obtain a green sheet having a thickness of about 0.8 mm. The green sheet density was 1.85 g / cm ² . Then, this green sheet is baked at 900 ℃ for 20
Burned for hours. The dielectric constant, the dielectric loss, the surface roughness, the bending strength, and the thermal creep resistance of the obtained ceramic substrate were measured. The method of measuring each characteristic value is the same as in Example 1. The results are shown in Table 3.

[0044]

[Table 3]

As is clear from these results, the ceramic substrate of the present invention can obtain the characteristics intended by the present invention even if it is fired at an extremely low temperature of 900 ° C. according to the conventional common sense. With the advent of such low-temperature sintered substrates, low-melting conductors such as silver and copper can be co-fired, and because of their low conductor resistance, more multilayered substrates can be realized, and capacitors and resistors are formed inside. This means that it has a great advantage in that the circuit can be made significantly smaller and the reliability can be improved, and it is possible to develop new fields of application.

Example 3 Borosilicate glass powder was added to glass powder having the chemical composition of SiO ₂ 55%, Al ₂ O ₃ 29%, Ca 0 6%, and Mg 0 10% in an amount of 12% and 20% based on all glass powder raw materials. , 3 kinds of glass powder raw materials were added respectively so as to occupy 30%, and toluene 50%, ethyl alcohol 43%, propyl alcohol 7% mixed solvent as a solvent for each of these powder raw materials was added to the raw material weight. 80% addition, polyvinyl butyral resin as a binder, DBP as a plasticizer, and methyl oleate as a dispersant, 15% and 5%, respectively, of the raw material weight.
%, 0.5% were added.

This raw material was mixed and pulverized by a wet ball mill until the average particle diameter of the glass powder raw material became about 2 μm. This stock solution was defoamed and the viscosity was adjusted to obtain a raw material slurry having a viscosity of 15000 cp. This slurry was formed into a sheet by the doctor blade method to obtain a green sheet having a thickness of about 0.8 mm. The green sheet density was 1.83 g / cm ² . Then, this green sheet is baked at a firing temperature of 1000 ° C for 30
Bake for minutes. The dielectric constant, the dielectric loss, the surface roughness, the bending strength and the thermal creep resistance of each of the obtained prepared ceramic substrates were measured. The method of measuring each characteristic value is the same as in Example 1. The results are shown in Table 4.

[0048]

[Table 4]

As is apparent from the above results, the present latent crystal of Example 1 was obtained by firing the powder raw material in which 20 wt% or less of the borosilicate glass powder was mixed with the present latent crystal glass powder under the firing conditions of the present invention. It is possible to further reduce the surface roughness and the dielectric constant while maintaining the other substrate characteristics, as compared with the ceramic substrate obtained by firing the glass raw material of the glass powder alone.

[0050]

As described above, the ceramic substrate and the ceramic circuit wiring board of the present invention have small permittivity and dielectric loss, sufficiently high mechanical strength such as bending strength, and their surface is suitable for forming fine circuits. It has a high level of smoothness. Moreover, it can be sintered at a much lower temperature than conventional ceramics substrates such as alumina substrates, and has a wide calcination temperature range, which results in high productivity, high quality, and excellent economical efficiency. Therefore, the ceramic substrate and the ceramic circuit wiring board of the present invention can be suitably used as an inexpensive and highly reliable high frequency and high frequency substrate or circuit wiring board.

In addition to the usual circuit wiring boards, which are the main applications of the ceramic substrate of the present invention, substrates for electronic parts such as transistors, ICs, LSIs; memory disks such as magnetic disk substrates and magneto-optical disk substrates Substrate for use in various applications such as a color liquid crystal panel plate.

The green sheet of the present invention has excellent surface smoothness and can be sintered at a low temperature in a wide calcination temperature range, and can be easily made into the ceramic substrate and the ceramic circuit wiring board of the present invention by the manufacturing method of the present invention. Therefore, it can be used as a ceramic substrate for various purposes by firing it as it is, or after performing external shape / hole forming processing, and baking it. It can be suitably used as a high-performance multilayer printed circuit wiring board by subjecting it to circuit wiring processing such as conductor processing and multilayer lamination molding and firing.

[Brief description of drawings]

FIG. 1 is an X-ray diffraction diagram for explaining a crystal phase of a ceramic substrate prepared in Example 1 at various firing temperatures.

[Explanation of symbols]

 1 Diffraction peak of anorthite 2α Diffraction peak of cordierite α 2β Diffraction peak of cordierite β 3 Diffraction peak of indiolite

Claims (6)

[Claims] 1. Si 0 ₂ 45 to 65 wt% in terms of oxide, Al ₂ 0
₃ 20-30% by weight, Ca05-5% by weight, Mg05-5-15% by weight
2. A ceramic substrate comprising a crystallized glass molded body containing a crystallized glass having the chemical composition as a main component, wherein the main crystals of the crystallized glass are anorthite, cordierite α and cordierite β. 2. The ceramic substrate according to claim 1, which contains 20% by weight or less of borosilicate glass. 3. A ceramic circuit wiring board in which circuit wiring is integrally provided on the crystallized glass molded body containing crystallized glass as a main component according to claim 1. 4. O ₂ 45 to 65 wt% in terms of oxide, Al ₂ O
₃ 20-30% by weight, Ca05-5% by weight, Mg05-5-15% by weight
A green sheet comprising a glass powder raw material containing a glass powder having the above chemical composition as a main component, and a plasticizing / setting composition. 5. The green sheet according to claim 4, at a firing temperature of 900 to 1000 ° C. for 0.7 to 20 hours, or at a firing temperature of 1000 to 12
A method for producing a ceramic substrate made of crystallized glass, which comprises firing at 40 ° C for 10 to 40 minutes. 6. A green sheet circuit wiring processed body obtained by applying circuit wiring processing to the green sheet according to claim 4, at a baking temperature of 900 to 1000 ° C. for 0.7 to 20 hours, or a baking temperature of 1000 to 12
A method for manufacturing a ceramic circuit wiring board method comprising crystallized glass, which comprises firing at 40 ° C for 10 to 40 minutes.