JPH0246713A - Manufacture of ceramic capacitor - Google Patents

Abstract

PURPOSE:To enable ultra compact ceramic capacitors to be mass-produced efficiently at low installation cost by a method wherein an ion-implating device is used as a furnace for the formation of the first and the second electrodes, a dielectric layers and a film as well as for the baking process. CONSTITUTION:A common conductor 12a is formed on an insulating substrate 11 along one side edge in the long direction of the substrate 11; multiple conductors 12b at specified intervals are arranged in a line so that Pt may be ion-plated to form the first electrode 13 between the common conductor 12a and respective conductors 12b using a mask on the conductors 12b partly overlapped with the common conductor 12a; then a dielectric layer 14 is formed on the first electrode 13 as well as between the first electrode 13 and the conductors 12b; successively Pt is deposited in specified thickness using a mask extending over the dielectric layer 14 and respective conductors 12b to form the second electrodes 15. Finally, leads terminals 16, 17 respectively contact-fixed to the common conductor 12a and the conductors 12b using solder, etc., are equally led out in the same long direction of the other side edge on the insulating substrate 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a boundary layer type ceramic capacitor.

(Prior Art) Porcelain capacitors are capacitors that use fired porcelain as a dielectric material, and those using barium titanate fired porcelain have a characteristic of having an extremely high dielectric constant.

In particular, barium titanate-based boundary layer type porcelain capacitors are made by applying a mixture of Bigest Mn0z+CuO□, etc. in a slurry state to an element whose main component is semiconducting barium titanate (BaTiOg), and then firing it at a high temperature. Manufactured by applying electrode metal paste on both sides and then baking.
The dielectric constant is about 10 to 500 times that of a normal barium titanate type, and there is an advantage that a small-sized, large-capacity capacitor can be obtained.

However, since conventional barium titanate-based elements are usually formed from powdered barium titanate by mold pressing, there is a limit to miniaturization, and it is not possible to take advantage of the characteristics of boundary layer type ceramic capacitors, which have a large capacity. The current situation is that this is not the case.

For this purpose, conventionally, a dielectric sintered body containing barium titanate as a main component is evaporated by an arc discharge type ion plating method, and this is deposited as a thin film on the first electrode metal layer. Subsequently, attempts have been made to form a second electrode metal layer on this thin film (Japanese Unexamined Patent Application Publication No. 1983-1999).
No. 35415).

[Problem to be solved by the invention] However, conventional attempts of this kind have been limited to the production of ceramic capacitors whose main component is barium titanate, and which are mainly composed of alkaline earth metals and titanate compounds having a perovskite structure. No ceramic capacitors were seen.

The present inventor conducted experiments and research on a method for manufacturing a ceramic capacitor mainly composed of an alkaline earth metal and a titanate compound having a perovskite structure, and found that a method using an ion plating method is extremely effective. I found out.

The ion plating method is attracting attention as a new vapor deposition method. This method is a method in which particles ejected from an evaporation source are collided with gas ions, etc. to ionize or excite them, giving them functionality, bonding the particles with each other, and depositing them on metals, crystals, ceramics, etc. It is possible to form extremely thin films with a thickness of several tens of microliters, which could not be obtained using vacuum evaporation or sputtering methods. In addition, it has the characteristic that it is possible to form monosynthetic films of compounds and composite materials.

The present invention has been made based on this knowledge, and its purpose is to provide a method for manufacturing a ceramic capacitor that allows the size of fired porcelain to be reduced.

[Means to solve the problem]

The method for manufacturing a ceramic capacitor according to the present invention includes forming a first electrode by ion-plating Pt on an insulating substrate, and then adding a dielectric component of titanium oxide or titanate ceramic, a semiconductor agent, and a sintering aid. A dielectric layer is formed by depositing the raw material containing Pt using an ion plating device, and Pt is further deposited on a second electrode using an ion plate while maintaining an insulating relationship with the first electrode.
Form an electrode, and then use an ion plating device to
Calcined in a reducing atmosphere above 00”l and then at 800°C
Firing is performed in the above oxidizing atmosphere.

[Effect]

According to the present invention, the dielectric material can be formed into a thin film, making it possible to significantly reduce the size of the device.

(The following is a blank space) [Example 1] Table 1 PL (platinum) was placed in the crucible of an ion plating device, and an insulating substrate made of alumina ceramic with a mirror-finished surface was placed with a mask placed thereon. ~1
A first electrode is formed by ion-plating Pt on an insulating substrate under an Ar atmosphere of 0-' Torr, and then B is placed in a crucible.
aTi0. Using an ion plating apparatus containing a dielectric raw material containing as a main component, a dielectric thin film is ion plated on the first electrode at a rate of about 2 to 3 minutes per 1 μm in thickness in an Ar atmosphere.

As the raw material for the dielectric material, a powder containing BaTiOz as the main component, mixed with La,03 as a semiconductor agent and MnO2 as a sintering aid in the mole percentages shown in Table 1 was used.

Of course, a sintered body obtained by heat-treating these materials at 1100-1300°C may also be used.

Next, using a mask at a position corresponding to the first electrode on the dielectric layer, a Pt thin film is patterned again under the same conditions as when the first electrode was ion plated, and a second electrode is formed. form.

Then, using a heater for setting the substrate temperature installed in the same ion plating equipment, the insulating substrate temperature was set to 1300℃.
C. and fired in a nitrogen or nitrogen or hydrogen atmosphere for 4 hours, and then further fired in an oxygen atmosphere at 800.degree. C. for 2 hours to form a porcelain capacitor.

Note that this firing process may be performed continuously as described above, but it goes without saying that it may be performed individually.

[Example 2] Table 2 An insulating substrate made of alumina ceramic with a mirror-finished surface was placed in an ion plating apparatus, and at the same time, Pt was placed in the crucible, and 1O-' to 10-"
A first electrode was formed by ion-plating Pt on an insulating substrate in an atmosphere of 1°', and then the crucible of the ion plating device was changed to a crucible containing a dielectric raw material containing 5rTi03 as a main component. Replace with io-"~10-'To
A thin dielectric layer is deposited on the first electrode under an atmosphere of rr. As the raw material for the dielectric layer, a powder containing 5rTi03 as the main component, mixed with Nb2O2 as a semiconductor agent and MnO as a sintering agent in the mole percentage shown in Table 2 was used. Of course, such a mixed powder is heated to 1100 to 1300℃.
Needless to say, a sintered body obtained by heat treatment may also be used.

Next, using a mask on the thin film dielectric layer and at a position corresponding to the first electrode, a Pt thin film was ion plated again under the same conditions as the first electrode. Form an electrode. Thereafter, the insulating substrate temperature was heated to 1450°C using a heater for setting the substrate temperature in the same ion plating equipment, and baked in a nitrogen or nitrogen/hydrogen atmosphere for 4 hours, and then heated to 1000°C. A ceramic capacitor is constructed by firing in an oxygen atmosphere for 2 hours. Note that this firing process may be performed continuously or individually.

[Example 3] Table 3 An insulating substrate made of alumina ceramic with a mirror-finished surface was placed in an ion plating apparatus, Pt was housed in a crucible, and Ar of 10-''-10-' Torr was placed.
The first step is to ion plate Pt on an insulating substrate in an atmosphere.
Form an electrode.

Next, the crucible of the ion plating device was replaced with a crucible containing a dielectric raw material whose main component was BaTi0°.
A dielectric layer is formed on the first electrode using an ion plate under a measuring atmosphere of -2 to 10 Torr.

As the dielectric raw material, a powder containing BaTiOz as a main component, mixed with CaTiO:+, CeOz as a semiconducting agent, and MnO as a sintering aid in the mol% shown in Table 3 is used.

Needless to say, a sintered body obtained by heat-treating these mixed powders at 1150'C may also be used.

Again, using a mask under the same conditions as those for forming the first electrode, Pt is patterned on the dielectric layer at a position corresponding to the first electrode, thereby forming a second electrode. Thereafter, in the same ion plating apparatus, the insulating substrate was heated to 1400°C using a heater provided to set the substrate temperature, and then heated with nitrogen or nitrogen.

A ceramic capacitor is obtained by firing in a hydrogen atmosphere for 2 hours and then in a too'c oxygen atmosphere for 2 hours.

Note that the firing process may be performed continuously or individually.

[Example 4] Table (blank below) This example shows the case where it is configured as a capacitor array.
It is a sectional view taken along the line -■. On an insulating substrate 1 made of a magnetic material such as alumina ceramic and having a mirror-finished surface, two sets of conductors 2a and 2b are placed at a required distance in the longitudinal direction of the insulating substrate 1 using an ion plating device. After forming the conductors 2a and 2b separately, a mask is placed over the insulating substrate l to form a Pt film between both conductors 2a and 2b, and between one conductor 2.
The first electrode 3 is patterned by placing an ion plate on the electrode 3 in a partially overlapping state.

Next, in the crucible of the ion plating apparatus, a powder (or sintered body) as a dielectric material is placed, and an insulating substrate 1 with a mask placed on the top surface is placed.
The dielectric layer 4 is formed by ion plating the thin film under reduced pressure of 0-' Torr. CaT as dielectric raw material
A powder containing iOs as a main component and mixed with DyzO++, CuO□, which is a semiconducting agent, MnO□, which is a sintering aid, and BizOz, in the mole percentages shown in Table 4, is used. Of course, instead of using the mixed powder, a sintered body obtained by sintering the mixed powder may be used.

Pt is ion plated again using a mask under substantially the same conditions as when the first electrode 3 was formed, and the second electrode 5 is formed. After that, in the same ion plating apparatus, the temperature of the insulating substrate 1 was adjusted to 1400'' using a heater for controlling the substrate temperature.
Heat to C and nitrogen or nitrogen.

Calcined for 4 hours in a mixed atmosphere with hydrogen, followed by 1000
C. for 2 hours in an oxygen atmosphere to form a capacitor array of ceramic capacitors. It goes without saying that this firing process may be performed continuously or individually. 6 is a lead terminal connected and fixed to the same end of each conductor 2a, 2b.

Therefore, the capacitor array configured in this way is
As shown in the figure, the first electrode 3 is connected to the conductor 2a, and the first electrode 3 is connected to the conductor 2b, with a dielectric layer 4 interposed between the lead terminals 6 on the insulating substrate 1 along its longitudinal direction. This results in a state in which a plurality of ceramic capacitors C3 are formed in an array with the second electrodes 5 facing each other.

[Example 5] This example shows a case where it is configured as a capacitor array having another structure, and FIG. 4 is a schematic plan view thereof, and FIG. 5 is a cross section taken along the line V-V in FIG. 4. 2, a common conductor 1 is placed on an insulating substrate 11 along one longitudinal edge of the insulating substrate 11.
2a, a plurality of conductors 12b are formed in a straight line at a required interval from the common conductor 12a, and the common conductor 12a and each conductor 12 are formed using a mask on the common conductor 12a.
b, and in a state where it partially overlaps the common conductor 12a, Pt is ion plated to form the first electrode 13, and then, as in the case of Example 4, the first electrode 13 is formed. A dielectric layer 14 is formed on the dielectric layer 13 and between the first electrode 13 and the conductor 12b, and then Pt is deposited to a required thickness on the dielectric layer 14 and on each conductor 12b using a mask. Two electrodes 15 are configured.

Reference numerals 16 and 17 denote lead terminals which are fixed in contact with the common conductor 12a and the conductor 12b by soldering or the like, respectively, and are led out in the same direction toward the other longitudinal edge of the insulating substrate 11.

Therefore, the capacitor array configured in this way is the sixth
As shown in the figure, the common conductor 12a and the conductor 1
2b, a first electrode 13 connected to the common conductor 12a with a dielectric 14 in between, and a second electrode 15 in contact with the conductor 12b.
A plurality of ceramic capacitors C2 are arranged in a vertically opposing manner.

In addition, in Examples 1 to 5 described above, one dielectric layer 4.14
Although the structure in which the electrodes are sandwiched between the first electrodes 3, 13 and the second electrodes 5, 15 has been described, the present invention is not limited to this, and a multilayer type structure in which a plurality of dielectric layers are alternately stacked with the electrodes interposed between the electrodes has been described. Needless to say, it is good as a capacitor.

〔effect〕

As described above, in the method of the present invention, the ion plating apparatus is used as the first ion plating apparatus. By using the furnace for forming the second electrode and dielectric layer, as well as for film formation and firing, the equipment cost is low and ultra-small ceramic capacitors can be efficiently mass-produced. It has excellent effects.

[Brief explanation of the drawing]

1 is a schematic plan view showing a capacitor play according to a fourth embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ of FIG. 1, FIG. 3 is an equivalent circuit diagram thereof, and FIG. is a schematic plan view showing a capacitor array of Example 5 of the present invention,
FIG. 5 is a sectional view taken along line V-V in FIG. 4, and FIG. 6 is an equivalent circuit diagram thereof. 1... Insulating substrate 2a, 2b... Conductor 3... First electrode 4... Dielectric 5... Second electrode 6, 7...
-Lead terminal 11...Insulating substrate 12a...Common conductor 12b...Conductor 13...First electrode 14...
Dielectric 15...Second electrode patent Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Noboru Kono

Claims (2)

[Claims] 1. A step of forming a first electrode by ion-plating Pt on an insulating substrate, and forming a raw material containing titanium oxide or titanate ceramic as a dielectric component, a semiconducting agent, and a sintering aid on the first electrode. forming a dielectric layer by ion plating Pt on the dielectric layer while maintaining an insulated state from the first electrode; forming a second electrode by ion plating Pt on the dielectric layer while maintaining an insulated state from the first electrode; A method for manufacturing a ceramic capacitor, comprising the step of firing in a reducing atmosphere at 1000° C. or higher using a plating device. 2. The dielectric component is a titanate-based compound containing an alkaline earth metal having a perovskite structure, and is SrTiO.
_3, MgTiO_3, CaTiO_3, BaTiO_
3, (Ba, Sr) (Ti, Sn) O_3 complex oxide, (Ba, Sr) TiO_3 complex oxide, (Mg, S
r,Ca)TiO_3-based composite oxide, (Sr,Ca)T
The method for manufacturing a ceramic capacitor according to claim 1, comprising one or more types of iO_3-based composite oxides.