JPH0797451B2 - Ceramic, method for manufacturing the same, substrate for electronic circuit using the same, and electronic circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention can be used as an electronic material such as a ceramic, particularly an electronic component substrate such as a porcelain capacitor or a substrate for an electronic circuit containing an electronic component such as a ceramic substrate with a built-in capacitor. The present invention relates to a ceramic, a method for producing the ceramic, a substrate for an electronic circuit using the ceramic, and an electronic circuit.

[Conventional technology]

Conventionally, an electronic circuit substrate is configured to include only a conductor circuit, a conductor circuit and a resistor, or a conductor circuit and a resistor and a limited range of capacitors, and other functional parts are separated as elements and mounted on the substrate. It had been.

That is, for example, in the conventional porcelain substrate, the substrate having the conductor and the resistor built therein is the center, and the capacitor is mounted by soldering as a chip component or the like. Therefore, there is a limit to downsizing the electronic circuit. Fig. 12 shows one example. 121 is a porcelain substrate, 122 is a conductor circuit, 123 is a resistor, 124
Is a chip capacitor.

In recent years, attempts have been made to incorporate a plurality of capacitors in a substrate by changing the dielectric constant within the same porcelain substrate. That is, as shown in FIG.
This is an attempt to form a plurality of capacitors on the same substrate by separating the portions 131 and 133 having a high dielectric constant ε ₁ and the portion 132 having a low dielectric constant ε ₂ . However, conventionally,
It is very difficult to form different dielectric parts on the same substrate, and it is obvious that considering the complexity of making a monolithic ceramic capacitor, for example, a substrate containing multiple capacitors has not yet been realized. The current situation is that it has not been put to practical use. Also, the high dielectric constant parts 131, 13
It was also an important technical issue to keep 3 sufficiently isolated as the functional parts of the device so that they would not affect each other in the operation in a limited structure.

Further, the problem of the separation and incorporation of the functional portion related to the electronic component or the electronic circuit substrate as described above is not limited to the dielectric porcelain, and when two or more functional portions of the same type or different types are formed in the ceramic. It was usually revealed.

[Object and Summary of Invention]

A first object of the present invention is to provide a ceramic capable of defining and incorporating a plurality of functional parts in a sufficiently separated state.

A second object of the present invention is to provide a method of manufacturing a ceramic which can be formed in such a manner that a plurality of functional parts are sufficiently separated.

A third object of the present invention is that, as described above, the plurality of functional portions are made of ceramics that can be defined and incorporated in a sufficiently separated state, so that the functional portions are sufficiently separated from each other as element functional portions. An object of the present invention is to provide a substrate for an electronic circuit that can contain a plurality of constituent units of electronic components in a state.

The above-mentioned first object is achieved by a ceramic characterized in that it has regions having different inductivities in which the sizes of particles constituting the surface layer portion or the inside thereof are different from each other and are separated from each other.

The second purpose is to add a grain growth accelerator or to calcine at the surface layer portion or inside of the molded body in order to forcibly promote or suppress grain growth due to firing to form a portion having a different dielectric constant. This is achieved by a method for producing a ceramic, characterized in that the heating conditions of (4) are partially changed to form regions having different sizes of the constituent particles.

The third object is achieved by an electronic circuit substrate characterized by using a ceramic having regions having different dielectric constants having different sizes of particles constituting the surface layer portion or the inside thereof, which are separated from each other. It

Further, a ceramic having regions having different permittivities in which the sizes of particles constituting the surface layer portion or the inside are different from each other, and at least any one of a conductor, a resistor and an insulator are added to the ceramic. The above object is also achieved by an electronic circuit characterized by having.

[Specific Description and Examples of Invention]

The ceramic of the present invention can form two or more functional parts by forming regions having different permittivities, and as the functional part, for example, capacitors, resistors, insulators, diodes, transistors, and other electronic parts can be formed. Partial structural units can be exemplified. Such a functional part can be configured by separating the objects having different dielectric constants from each other and arranging them in the ceramic, or by separating the objects having different dielectric constants from each other. It can also be constructed by placing it in a ceramic.

The regions having different dielectric constants constituting the ceramic of the present invention have different dielectric constants due to the difference in size of the constituent particles, and even if the composition of the constituent particles is the same, regions having different dielectric constants are formed. be able to. Alternatively,
The dielectric constant can be more positively changed by changing the composition of the constituent particles or the particle structure or the fine structure (for example, crystal structure or amorphous network).

Hereinafter, a dielectric ceramic will be described in detail as one specific example of the ceramic of the present invention.

Dielectric porcelain is usually composed of, for example, BaTiO ₃ , SrTiO ₃ , MgTiO ₃ (Ba, S
r) (Ti, Sn) O ₃ -based composite oxide (including solid solution), (Ba, S
r) TiO ₃ composite oxide (including solid solution), (Mg, Sr, Ca) T
iO ₃ -based complex oxide (including solid solution), (Sr, Pb) TiO ₃ -based complex oxide (including solid solution), (SrCa) TiO ₃ -based complex oxide (including solid solution), Fe ₂ O ₃ , ZnO A method of obtaining a sintered body by molding and firing using one or two or more of the dielectric components such as, and La, D as a component necessary for forming a semiconductor in the dielectric component.
After adding and mixing oxides such as y, Nd, Y, Nb, Ta, Er, Gd, Ho, Ce, etc., a powdered compact is obtained, which is primarily fired into a semiconductor, and then on the fired body surface. Metals or metal participants (eg C
The resulting _{u, CuO, MnO 2, Tl} 2 O 3, PbO, P 2 O 5, Bi 2 O 3, Nb 2 O, ZnO , etc.) is applied, by allowed to form a grain boundary insulating layer by firing the secondary To be

The dielectric porcelain as the ceramic of the present invention is composed of, for example, the dielectric porcelain obtained through the above-mentioned semiconductor formation.

For example, regarding a plate-shaped dielectric ceramic, examples of shapes of regions and functional portions having different permittivities are as shown in FIGS. 1 to 4. In the example of FIGS. 2 to 4, 1
Is a plate-shaped dielectric ceramic, A is a region having a different dielectric constant, and B is
Is a functional portion, and A (B) is a functional portion at the same time as a region replaced by an object having a different dielectric constant.

In FIG. 1, an area A having a rectangular cross section that reaches both main surfaces of the plate-shaped dielectric ceramic 1 is provided.
Two functional parts B, B are provided which are separated from each other.

In the example of FIG. 2, regions A, A having rectangular cross sections are provided in the respective surface layer portions of both main surfaces of the porcelain 1, and the functional regions B, which are separated from each other, are sandwiched between the regions A, A. B is provided.

In the example of FIG. 3, an area A having a rectangular cross section is provided in the surface layer portion of one main surface of the porcelain 1, and two functional portions B and B separated from each other are provided across the area A. There is.

In the example of FIG. 4, regions A (B) having a rectangular cross section that are isolated from each other and reach both main surfaces of the porcelain 1 are provided to form two mutually separated functional portions.

In the example of FIGS. 1 to 4, one or two regions A replaced with objects having different dielectric constants are provided, but the present invention is not limited to this, and it is determined according to the desired number of functional portions. It goes without saying that three or more regions may be provided. Further, as described above, the porcelain 1 is mainly composed of a sintered body directly obtained from the dielectric component without undergoing semiconductor formation. For example, at least one of A, B and A (B) is used as the semiconductor. It can be replaced with a dielectric porcelain obtained through chemical conversion.

The functional part B or A (B) can be made of, for example, a high dielectric material. In this case, in the example of FIGS. 1 to 3, the area A is made of an object having a lower dielectric constant than B. Functional part B,
B can be sufficiently separated. Further, in the example of FIG. 4, the functional portion A (B) can be constituted by an object having a higher dielectric constant than the surroundings and separated.

As a method of providing a region replaced with an object having a different dielectric constant, for example, when the method for producing a ceramic of the present invention is carried out and a molded body is fired, grain growth due to firing occurs in the surface layer portion or inside of the molded body. It is forcibly promoted or suppressed to form a portion having a different dielectric constant. As a result, for example, the portions having a high dielectric constant by promoting the grain growth are provided apart from each other, or the portions having a low dielectric constant by suppressing the grain growth are sandwiched and secured to each other. Thereby, two or more high-dielectric-constant parts can be formed inside one ceramic.

The molded body includes, for example, a green compact (a powder-like solid of a raw material such as a metal oxide), a fired body or a sintered body (porcelain, etc.), and the like. Including a precursor for forming a body (for example, a powdered solid described above, a semiconductor porcelain obtained by primary firing when synthesizing a grain boundary insulating type high dielectric material, or a solid composed of semiconductor particle groups) Say something.

For example, a specific example of the method of the present invention will be described with respect to the dielectric ceramic obtained through the above-described semiconductor formation.

(I) When preparing a green compact, a desired portion having a high dielectric constant has, for example, an effect of promoting grain growth.
A raw material sufficiently added with SiO ₂ is filled, and the other portion, that is, a portion having a desired low dielectric constant is filled with a raw material with a reduced amount of SiO ₂ contributing to grain growth, and press molding is performed. In the porcelain in which the press-molded body is primary-fired to be semiconducting, and the additive is applied and then secondary-fired to insulate the grain boundaries, grain growth is sufficiently performed in the portion where SiO ₂ is sufficiently added, and high dielectric constant is achieved. However, the grain growth is insufficient in the SiO ₂ narrowed portion, resulting in a low dielectric constant.

Then, through a subsequent process for obtaining a porcelain substrate including firing, a porcelain substrate having a plurality of high dielectric portions defined therein is obtained. The high permittivity portions defined may have the same or different dielectric constants.

When grain growth or recrystallization is promoted to form a part having a high dielectric constant, the part of which grain size is not promoted is
It is preferably 1.5 times or more, and more preferably 4 times or more. On the other hand, in the case where a portion having a low dielectric constant is formed by suppressing grain growth or recrystallization, the grain size is not suppressed. /
It is preferably 3 or less, more preferably 1/4 or less.

Further, in the method of the present invention, as described above, by forming a region having a different dielectric constant due to the difference in the size of the constituent particles, and changing the composition or structure of the constituent material of this region or other parts. , The permittivity can be different.

The following method can be given as a specific method for changing the composition or the structure of the constituent substances to make the dielectric constants different.

(I) A method of forming an object having a different dielectric constant by providing a cavity in a molded body containing a dielectric or a precursor thereof and filling the void with a substance having a different dielectric constant.

The molded body refers to, for example, a green compact (a powdered solid of a metal oxide, which is a raw material), a fired body or a sintered body (porcelain, etc.), and forms a dielectric or a dielectric. That includes a precursor (for example, the above-mentioned powdered solid, or a solid composed of semiconductor porcelain or a group of semiconductor particles obtained by primary firing when synthesizing a grain boundary insulating high dielectric). .

The feature of this method is to provide a cavity in the molded body, fill the cavity with a substance having a different dielectric constant, and form a body having a different dielectric constant through a process such as firing, if necessary. Therefore, forming a single or multiple voids in the molded body,
For example, by filling a material with a low dielectric constant, the portion around the void that is to have a high dielectric constant is separated into two or more,
It is possible to define two or more high-dielectric parts that are separated from each other.

As a method of providing a void, for example, molding using a core,
Punching, laser processing, sand blasting, ultrasonic processing, electric discharge processing, grinding processing (diamond tool etc.), etching (lead resist, hydrofluoric acid treatment etc.) and the like can be mentioned.

Is filled into the cavity, for example, as a material having a low dielectric constant, for example, a melting point well lower ones still further than ceramic body, for example _{PbSiO 3, BSiO 3, LiSiO 3} , various crystallized glass is suitable . Alternatively, a powder having a different dielectric constant is selected by selecting a powder in which the kind of the above-mentioned dielectric component or the component necessary for forming the semiconductor used for forming the grain boundary insulating high dielectric is appropriately changed. You can also

(Ii) A method in which two or more kinds of dielectric-forming particles capable of forming objects having different dielectric constants are partitioned and filled to obtain a molded body.

The dielectric forming particle group, for example, a particle group such as metal oxides capable of forming a dielectric, a particle group of the dielectric itself, a semiconductor particle group for forming the grain boundary insulating high dielectric, Alternatively, it means a mixture of these. As a method of partitioning and packing two or more types of dielectric-forming particles,
For example, a mold used in room temperature compression molding is partitioned by a partitioning material made of a substance that can be volatilized by decomposition or evaporation by heating by firing an organic resin or the like, and each desired group of different kinds of dielectric-forming particles is formed. After filling, the partitioning material is volatilized by heating such as firing thereafter. Alternatively, there is a method in which as the partition material, a material that can be easily removed after the foreign material is packed in a mold, the foreign material is packed, the partition material is removed, and pressure molding is performed.

(Iii) A method in which the molded body is a semiconductor porcelain, and a diffusion layer from a diffusion source for forming an electronic component is formed inside the semiconductor porcelain to form an object having a different dielectric constant.

In this method, on the surface of the semiconductor porcelain obtained by the above-mentioned primary firing, as a diffusion source for electronic component formation,
For example, the above-mentioned metal or metal oxide is applied to the portions separated from each other to form a diffusion source layer, and then secondary firing is usually performed in an oxidizing atmosphere. By forming two or more spaced diffusion layers, two or more high dielectric portions are formed.

Alternatively, as a diffusion source capable of reducing the dielectric constant, for example, MgTi
O ₃ , SiO ₂ , Al ₂ O ₃ etc. layers are formed and a low dielectric constant diffusion layer is formed inside the semiconductor porcelain by secondary firing.
A high dielectric constant diffusion layer made of the above-mentioned metal or metal oxide is formed in the state of being separated from each other around the diffusion layer, or a high dielectric portion which does not undergo semiconductor formation is formed and two or more of them are formed. The high dielectric portion is separated via the diffusion layer having a low dielectric constant.

In this method, the diffusion source used may be appropriately changed, and the number of capacitor constituent units formed is not particularly limited.

(Iv) A method in which a molded body contains a dielectric or a precursor thereof and a body having a different dielectric constant is formed by partially melting the molded body.

The molded body has the same meaning as the molded body described in the item (i).

The feature of this method is that the molded body is partially melted to form portions having different dielectric constants. Therefore, by forming a single or a plurality of partial melted portions in the molded body and lowering the dielectric constant of each of these portions from, for example, the surroundings, these portions are sandwiched and the portion to be made to have a high dielectric constant is formed. It can be separated into two or more parts to define two or more high-dielectric parts that are separated from each other.

As a method of partial melting, for example, laser (CO ₂ laser, YAG laser, etc.) irradiation, electron beam irradiation, or the like is excellent.

When the ceramic of the present invention such as the porcelain thus obtained is used to form, for example, an electronic circuit substrate, a plurality of conductor portions (electrodes, lead portions, etc.) are provided on the surface of each high-dielectric-constant portion to form a plurality of A condenser can be built in. Furthermore, a conductor portion, a resistor or an insulator portion (for example, formed by an ordinary thin film or thick film forming method) is formed inside or around the porcelain substrate to provide many functional portions. It can be the substrate.

Hereinafter, the present invention will be described in more detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.

Example 1 FIG. 5 shows the process flow chart of this example. In this example, the raw material filling as shown in FIG. 6 is performed at the time of press molding, that is, it is made of a substance that decomposes at high temperature (for example, polyvinyl alcohol). The parts 63 and 64 partitioned by the thin partition plate 62 are filled with the raw material powder of the following composition table 65.
Is filled with the raw material powder of the following formulation table 2 and press-molded. Here, it is desirable that the partition plate that decomposes at a high temperature has a large number of small holes. The presence of the small holes reduces the likelihood that the molded material adjacent by the divider will separate when the divider decomposes at high temperatures.

A sintered body as shown in FIG. 7 is obtained by firing the molded body according to the process shown in FIG. The additive material is MnO ₂
It was used. Here, 71 and 72 parts are SiO ₂ which contributes to grain growth.
In the sintered compact, the grain growth is insufficient, and the high dielectric constant results in a high dielectric constant in the sintered body.Since the SiO ₂ that contributes to the grain growth is suppressed in the sintered body, the grain growth is insufficient in the sintered compact. It has a dielectric constant.

Table 1 below shows the average particle diameter and the dielectric constant ε of each of the high dielectric constant portions 71, 72 and the low dielectric constant portion 73.

(Formulation Table 1) BaTiO ₃ 93.0%, BaSnO ₂ 2.0%, La ₂ O ₃ 0.12%, SiO ₂ 2.0%, Al ₂ O ₃ 1.88%, SrTiO ₃ 1.0%.

(Formulation Table 2) BaTiO ₃ 94.9%, BaSnO ₂ 2.0%, La ₂ O ₃ 0.12%, SiO ₂ 0.1%, Al ₂ O ₃ 1.88%, SrTiO ₃ 1.0%.

By forming a predetermined conductor portion, resistor portion and insulator portion on the sintered body, a C, R built-in substrate can be obtained.

Embodiment 2 FIG. 8 shows a process flowchart of this embodiment. In this embodiment, raw material filling as shown in FIG. 9 is performed during press molding. That is, 93 and 94 are filled with the raw material powder of the following composition table 3, and 95 is filled with the raw material powder of the following composition table 4 in the part partitioned by the partition plate 92 which can be removed after filling the raw material. Then, press molding is performed. By firing this sintered body according to the process shown in FIG. 8, a sintered body as shown in FIG. 10 was obtained. Note that MnO ₂ was used as an additive. Here, 101 and 102 have sufficient grain growth in the sintered body because SiO ₂ is sufficiently present, and La ₂ O ₃ is sufficiently present so that the semiconductor is sufficiently made to have a high dielectric constant, and 103 is , SiO ₂ is suppressed, grain growth is insufficient in the sintered body, and La ₂ O ₃ is insufficient, so that semiconductor formation is insufficient, resulting in a low dielectric constant. Table 2 shows the respective dielectric constants ε. This sintered body has a CR built-in substrate by forming a predetermined conductor portion, resistor portion, and insulator portion on the sintered body having a high dielectric constant portion and a low dielectric constant portion in one substrate. can get.

(Formulation Table 3) BaTiO ₃ 93.0%, BaSnO ₂ 2.0%, La ₂ O ₃ 0.12%, SiO ₂ 2.0%, Al ₂ O ₃ 1.88%, SrTiO ₃ 1.0%.

(Formulation Table 4) BaTiO ₃ 93.0%, BaSnO ₂ 2.0%, La ₂ O ₃ 0.02%, SiO ₂ 0.1%, Al ₂ O ₃ 1.88%, SrTiO ₃ 1.0%.

Example 3 In this example, raw material filling as shown in FIG. 9 is performed at the time of press molding according to the process flowchart shown in FIG. That is, 93 and 94 are filled with the raw material powder of the following composition table 3, and 95 is filled with the raw material powder of the following composition table 4 in the part partitioned by the partition plate 92 which can be removed after filling the raw material. Then, press molding is performed. This sintered body is
By firing according to the steps shown in the figure, a sintered body as shown in FIG. 10 was obtained. Note that MnO ₂ was used as an additive. Here, 101 and 102 have a high dielectric constant because the raw materials of Recipe 3 are used and the grain growth is sufficient, and 103 is a low dielectric constant because the raw materials of Recipe 4 are used and the grain growth is insufficient. Becomes Table 2 shows the respective dielectric constants ε. This sintered body has a CR built-in substrate by forming a predetermined conductor portion, resistor portion, and insulator portion on the sintered body having a high dielectric constant portion and a low dielectric constant portion in one substrate. To be

(Formulation Table 5) BaTiO ₃ 93%, BaSnO ₂ 2.0%, La ₂ O ₃ 0.12%, SiO ₂ 2.0%, Al ₂ O ₃ 1.88%, SrTiO ₃ 1.0%.

(Formulation Table 6) BaTiO ₃ 85.9%, MgTiO ₃ 10.2%, TiO ₂ 2.8%, SiO ₂ 0.1%.

SrTiO ₃ 1.0%, Example 4 In this example, according to the process flow chart shown in FIG. 5, raw material filling as shown in FIG. 6 is performed at the time of press molding. That is, parts 63 and 64 partitioned by a thin partition plate 62 made of a substance that decomposes at a high temperature (for example, polyvinyl alcohol) are filled with the raw material powder of the following composition table 7, and 65 is the material of the following composition table 8. Fill with powder and press-mold.
Here, it is desirable that the partition plate that decomposes at high temperature has a large number of small holes If the small plate has the small holes, the molded material adjacent to the partition plate decomposes the partition plate at high temperature. At times, the chance of leaving is reduced.

By firing this molded body according to the process of FIG. 5,
A sintered body as shown in FIG. 7 is obtained. Here, the application of the additive was performed using MnO _{2 in} the 63 and 64 parts of the molded body and CuO in the 65 part. Here, 71 and 72 are SiO that contributes to grain growth.
₂ is present sufficiently, grain growth is sufficient in the sintered body, and MnO ₂ is used as a grain boundary insulating material, resulting in a high dielectric constant, and part 73 has SiO ₂ that contributes to grain growth suppressed. Therefore, grain growth is insufficient in the sintered body, and CuO is used as the grain boundary insulating material, resulting in a low dielectric constant.

Table 4 below shows the permittivity ε of each of the high dielectric portions 71, 72 and the low dielectric portion 73.

(Formulation Table 7) BaTiO ₃ 93.0%, BaSnO ₂ 2.0%, La ₂ O ₃ 0.12%, SiO ₂ 2.0%, Al ₂ O ₃ 1.88%, SrTiO ₃ 1.0%.

(Formulation Table 8) BaTiO ₃ 94.9%, BaSnO ₂ 2.0%, La ₂ O ₃ 0.12%, SiO ₂ 0.1%, Al ₂ O ₃ 1.88%, SrTiO ₃ 1.0%.

By forming a predetermined conductor portion, resistor portion and insulator portion on the sintered body, a C, R built-in substrate can be obtained.

Example 5 In this example, according to the process flow chart shown in FIG. 8, raw material filling as shown in FIG. 9 is performed at the time of press molding.
That is, the parts 93 and 94 partitioned by the partition plate 92 that can be removed after filling the raw material are filled with the raw material powder of the following recipe table 9, and 95 is filled with the raw material powder of the following recipe table 10, Then, press molding is performed. By firing this sintered body according to the process shown in FIG. 8, a sintered body as shown in FIG. 10 is obtained. The additives were applied by applying MnO ₂ to the 93, 94 parts and CuO to the 95 parts of the molded body. Where 1
01 and 102 have the composition of Recipe Table 9, the grain growth is sufficient, and since MnO ₂ is used as the grain boundary insulating material, the dielectric constant is high, and 103 is the composition of Recipe Table 10, and the grain growth is Is insufficient and CuO is used as the grain boundary insulating material, resulting in a low dielectric constant. The respective dielectric constants are shown in Table 5. This sintered body has a high dielectric constant part and a low dielectric constant part in one substrate, and by forming a predetermined conductor part, resistor part, and insulator part on the sintered body, a CR built-in substrate is obtained. To be

(Formulation Table 9) BaTiO ₃ 93%, BaSnO ₂ 2.0%, La ₂ O ₃ 0.12%, SiO ₂ 2.0%, Al ₂ O ₃ 1.88%, SrTiO ₃ 1.0%.

(Recipe 10) BaTiO ₃ 85.9%, MgTiO ₃ 10.2% TiO ₂ 2.8%, SiO ₂ 0.1%, SrTiO ₃ 1.0%.

Note that FIG. 11 shows an example of a porcelain substrate obtained by the method as shown in the above embodiment, for example. 11 (a) and (b)
Are a plan view and a cross-sectional view of a porcelain substrate, respectively.
Is a high dielectric portion, and 112 is a low dielectric portion. Also the 11th
FIG. 6C shows a porcelain substrate on which a conductor portion 113, a resistor portion 114, and an insulator portion 115 are further formed.

〔The invention's effect〕

The ceramic of the present invention can define a plurality of functional parts such as electronic component units. Therefore, an electronic component, an electronic circuit substrate, etc. configured by using this can incorporate a plurality of element functional parts such as capacitors of various capacities, and, for example, conductors, resistors, insulators, etc. can be provided on the substrate. By forming various functional portions, a small-sized and inexpensive electronic circuit substrate having many functional portions can be obtained. Further, in this way, the degree of freedom in designing capacitors, resistors, etc. in the substrate can be greatly improved.

[Brief description of drawings]

1 to 4 are sectional views of ceramics according to the present invention. FIG. 5 is a process explanatory view for explaining a manufacturing process of a porcelain substrate which is one embodiment of the present invention, FIG. 6 is a perspective view of a molding die used at this time, and FIG. The perspective view of the obtained porcelain substrate is shown. FIG. 8 is a process explanatory view for explaining a manufacturing process of a porcelain substrate which is one embodiment of the present invention, FIG. 9 is a perspective view of a molding die used at this time, and FIG. The perspective view of the obtained porcelain substrate is shown. 11A is a plan view of a porcelain substrate which is one embodiment of the present invention, FIG. 11B is a sectional view taken along line AA in FIG. 11A, and FIG.
FIG. 3 is a cross-sectional view of a porcelain substrate with built-in R and C in which functional parts such as conductors, resistors, and insulators are further formed on this porcelain substrate. FIG. 12 is a sectional view of a conventional porcelain substrate. FIG. 13 is a cross-sectional view of a porcelain substrate having a plurality of high-dielectric-constant portions according to a conventionally attempted method. A: area with different permittivity, B: functional part, A (B)
...... Regions and functional parts with different permittivities.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H05K 1/03 7011-4E

Claims (15)

[Claims] 1. A ceramic characterized by having regions having different dielectric constants in which the sizes of particles constituting the surface layer portion or the inside are different from each other. 2. The ceramic according to claim 1, wherein the ceramic is semiconductor porcelain. 3. A grain growth promoter is added or heating is performed during firing in order to forcibly promote or suppress grain growth due to firing to form a portion having a different dielectric constant in the surface layer portion or inside of the molded body. A method for producing a ceramic, characterized in that the conditions are partially changed to form regions having different grain sizes. 4. The ceramic according to claim 3, wherein the grain growth is promoted so that the grain size is 1.5 times or more higher than that of the portion where the grain growth is not promoted, and the dielectric constant is increased. Manufacturing method. 5. The grain size is controlled to be 2/3 or less of a portion where grain growth is not suppressed by the grain growth suppression, thereby lowering the dielectric constant. Ceramic manufacturing method. 6. The method for producing a ceramic according to claim 3, wherein a partial change in the heating condition during the firing is carried out by laser irradiation or electron beam irradiation. 7. The method of manufacturing a ceramic according to claim 3, wherein the ceramic is semiconductor porcelain. 8. The method for producing a ceramic according to claim 3, wherein the grain growth promoter is SiO ₂ . 9. The ceramic according to claim 3, further comprising a step of applying a diffusion source and further firing after forming regions having different sizes of the constituent particles. Production method. 10. The method for producing a ceramic according to claim 9, wherein the diffusion source is a metal or a metal oxide. 11. A substrate for an electronic circuit, comprising a ceramic having regions having different dielectric constants having different sizes of particles constituting the surface layer portion or the inside thereof, which are separated from each other. 12. The electronic circuit substrate according to claim 11, wherein the ceramic is further provided with at least one of a conductor, a resistor and an insulator. 13. The electronic circuit substrate according to claim 11, wherein the ceramic is semiconductor porcelain. 14. A ceramic having regions having different permittivities in which the size of particles constituting the surface layer portion or the inside is different from each other, and at least one of a conductor, a resistor and an insulator in the ceramic. An electronic circuit having one. 15. The electronic circuit according to claim 14, wherein the ceramic is semiconductor porcelain.