JPH0210817A - Ceramic substrate - Google Patents

Abstract

PURPOSE:To miniaturize a ceramic substrate, and to increase functions by not only incorporating a high dielectric constant system capacitor having a single component under the state, in which the capacitor is separated sufficiently by a low dielectric constant region (a second region) but also incorporating regions having different components in a high dielectric constant region and the low dielectric constant region. CONSTITUTION:A doctor blade is molded while using polyvinyl butyral as a binder, and hollowed out to a specified shape as a member 1. Both surfaces are coated with paste 2 composed of Al2O3 in order to separate each function of a first region. A molded form in a second region is buried into a first region, and a green sheet to which the first region, the second region and a third region are formed is acquired. The green sheet is de-binder baked, and baked in a reducing atmosphere consisting of nitrogen and hydrogen. Accordingly, the first region and second region of a semiconductor porcelain obtained is coated with a grain boundary insulating agent made up of Bi2O3 and CuO, and baked in air, thus shaping an insulating layer on a grain boundary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a ceramic that can be used as an electronic material such as a ceramic base for a current reader.

[Conventional technology]

Conventionally, an electronic circuit board has been separated into 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 have been separated as elements and mounted on the base. was.

That is, for example, in a conventional ceramic board, the board mainly has a built-in conductor and a resistor, and the capacitor is attached as a chip component by soldering. For this reason, there was a limit to the miniaturization of electronic circuits.

In recent years, attempts have been made to incorporate a plurality of capacitors within the same ceramic substrate by varying the dielectric constant within the same substrate.

Also, attempts have been made to coat a substrate with a high dielectric constant composition with a subcomponent to form a low dielectric constant portion and incorporate a plurality of capacitors therein.

[Problems to be solved by the invention] However, in the past, the method of forming different dielectric parts on the same substrate was extremely difficult, which is obvious when considering the complexity of producing a multilayer ceramic capacitor, for example. Thus, at present, a substrate incorporating a plurality of capacitors has not yet been realized or put into practical use. Furthermore, the method of applying subcomponents to a substrate with a high electrical constant composition does not allow for the inclusion of compositions with different properties such as dielectric constant, electrical loss, insulation resistance, temperature characteristics, etc. The current situation is that it can only be built-in.

(Objective of the Invention and Means for Solving the Problems) An object of the present invention is to form a single-component high dielectric constant capacitor in a state where it is sufficiently separated in a low dielectric constant region (second region). The object of the present invention is to provide a circuit board and an electronic circuit board that are not only built-in but also have regions with different components, such as the high dielectric constant region and the low dielectric constant region, that are further miniaturized and have additional functions. .

The above purpose is aimed at the third area, for example, JP-A-61-241
In order to embed 906, a high dielectric constant composition that has been hollowed out at a predetermined position in advance, for example, Japanese Patent Application No. 124530/1986.
Al2 was added to the molded body for the purpose of sufficiently separating each function.
Apply a subcomponent consisting of O3. Further, a molded body forming a third region, which has been treated in advance so as to be embedded in the molded body having a high dielectric constant composition, is embedded in a predetermined position of the molded body having a high dielectric constant composition. The molded body thus treated is fired in an atmosphere to form a semiconductor porcelain, and the subcomponent consisting of Al2O3 is diffused into the interior through the firing to reduce the telephone call rate and form a separation band. Further, by this firing, the composition of the third region is firmly bonded to the sintered body. Next, in order to insulate the grain boundaries of the semiconductor porcelain thus obtained, an insulating agent such as Bi203 or CuO is applied to the first region, the first region and the second region, or the entire porcelain. , and then fired in the atmosphere to obtain dielectric porcelain with diffusion and grain boundaries made into insulators.

Furthermore, electrodes are formed on this dielectric material, and electronic circuit components are mounted on the ceramic to form an electronic circuit substrate, thereby achieving the object of the present invention.

〔Example〕

Next, the present invention will be explained in detail.

Example 1 For the first region, each raw material was weighed as shown in Table 1, and pulverized and mixed in a wet ball mill for 12 hours. After drying this product, it was calcined in the air at 1100°C for 5 hours. next,
The mixture was pulverized and mixed in a wet ball mill for 18 hours, and after drying, it was molded with a doctor blade using polyvinyl butyral as a binder, and hollowed out into a predetermined shape such as member 1 in FIG. Similarly, as a publicly known temperature compensation composition, a second
As shown in the table, each raw material was weighed and pulverized and mixed in a wet ball mill for 12 hours. After drying, this product was molded with a doctor blade using a binder made of polyvinyl butyral so as to match the firing shrinkage rate of the molded product in the first region, and hollowed out into a shape that could be embedded in the first region. next,
In order to separate the functions of each of the first regions, paste 2 consisting of A 1203 was applied to both sides (FIG. 2).

Next, the molded body of the second region was embedded in the first region (FIG. 3) to obtain a green sheet provided with the first region, the second region, and the third region 3.

Next, after baking this product at 900°C to remove the binder,
140 in a reducing atmosphere consisting of 90% nitrogen and 10% hydrogen.
It was baked at 0°C for 2 hours. A grain boundary insulating agent made of Bi203 and CuO was applied to the first and second regions of the semiconductor porcelain obtained in this way, and fired in air at 1200°C for 1 hour to form an insulating layer at the grain boundaries. . In this case, electrodes are formed in the first region, the second region, and the third region to form a capacitor built-in substrate, and the electrical characteristics of each of the first region, the second region, and the third region are determined. I measured it. The results are shown in Table 3.

Example 2 Linear shrinkage rate and bending strength of a sintered body from a green sheet in the third area when the shrinkage rate of the molded body in the third area was changed by the amount of binder with the same composition as in Example 1. The relationship is shown in Table 4.

As is clear from the above, the ceramic substrate of the present invention
If so, it is possible to have a plurality of capacitor functional parts in a sufficiently separated state.

(eo l) [Effects of the Invention] According to the ceramic substrate of the present invention, as described above, a plurality of capacitor functional parts can be incorporated in a sufficiently separated state, thereby realizing a miniaturized and multifunctional circuit. Obtain a substrate and an electronic circuit substrate.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a first region hollowed out in a mosaic shape. FIG. 2 is a schematic diagram showing a second region coated with a subcomponent consisting of AI, 03 on the first region. FIG. 3 is a schematic diagram of embedding a third region having a different component into a molded body having a first region and a second region. 1... Member, 2... Subcomponent of Al2O, 3...
・Third area

Claims (1)

[Claims] SrTiO_3 or BaTiO_ containing valence control agent
3 as a main component, and a first region consisting of a molded body hollowed out in a mosaic shape, and a predetermined surface of the first region, Al_
A second region coated with a subcomponent consisting of 2O_3, and a third region having a different composition from the first region and the second region and made of a molded body embedded in the hollowed out part of the first region. 1. A ceramic substrate having three or more functional parts separated from each other by firing in a neutral or atmosphere after forming a ceramic substrate.