JPH01201906A - Semiconductor ceramic capacitor - Google Patents

Abstract

PURPOSE:To simplify manufacturing process and to lower manufacturing cost, by employing a base metal foil as an inner electrode for capacitance. CONSTITUTION:An inner electrode 3 of an electrode for capacitance which employs base metal foil made of aluminum or the like is provided between barrier layer type semiconductor ceramic plates 1 through glass layers 2. With these inner electrodes 3, 3, 3..., the respective one ends are alternately in the lamination order connected to either of two edge electrodes 4 for the external connection, while the respective other ends are apart from the edge electrodes 4 on the non-connective side by a predetermined length, with parts of the inner electrodes 3 opposite each other lying one above another through the semiconductor ceramic plate 1. In addition, a plurality of holes are bored through the inner electrodes 3, 3, 3..., respectively. And glass paste is made to flow into the holes and then solidified, so that the semiconductor ceramic plates 1, 1, 1... are connected to each other. As a result, manufacturing process is simplified and manufacturing cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor ceramic capacitor in which semiconductor ceramic plates and capacitor electrodes are alternately laminated.

[Conventional technology]

With the miniaturization of electronic devices, the electronic components that make up the devices are becoming smaller and larger in capacity, and multilayer porcelain capacitors, which are made by laminating multiple sets of ceramic plates and electrodes, are increasingly being used as capacitors. , this multilayer ceramic capacitor is
Since noble metals such as palladium are used for the internal electrodes, the cost increases due to the increase in the number of laminated layers as the capacity increases.

On the other hand, semiconductor ceramic capacitors have an extremely high effective dielectric constant compared to other ceramic capacitors, but they have traditionally only been used as single-plate capacitors, and in order to increase their capacity they must be made extremely large. It won't happen.

[Problem to be solved by the invention]

In order to improve the drawbacks of conventional capacitors as mentioned above,
A laminated type semiconductor porcelain capacitor in which a plurality of semiconductor porcelain plates and electrodes are alternately laminated has been devised (Japanese Unexamined Patent Application Publication No. 1983-1999).
68612.56-64424.56-38813).

However, in all of these methods, the internal electrodes, which are capacitor electrodes, are formed using thick film technology, which requires relatively expensive equipment such as printing machines and firing furnaces for thick film formation, as well as complicated processes. Products that use silver for the internal electrodes have the disadvantage that insulation tends to deteriorate due to the movement of ions between adjacent electrodes, and because they are precious metals, they are expensive, making them difficult to put into practical use. .

The present invention has been made to solve these problems, and aims to provide a semiconductor ceramic capacitor that has a simple manufacturing process and is low cost.

[Means to solve the problem]

A semiconductor ceramic capacitor according to the present invention is a semiconductor ceramic capacitor in which semiconductor ceramic plates and capacitor electrodes are alternately laminated, and the laminated capacitor electrodes are alternately connected to two external electrodes in the lamination order. consisting of a capacitor electrode having a hole penetrating in the stacking direction, and a series of holes formed in the adjacent opposing surfaces of each stacked semiconductor ceramic plate and the holes in the capacitor electrode stacked between the adjacent opposing surfaces. It is characterized by comprising a glass layer.

[Function] The semiconductor ceramic capacitor according to the present invention discharges the charge stored in the capacitor electrode from two external electrodes in which the capacitor electrodes are alternately connected in the stacking order. In addition, each of the stacked semiconductor ceramic plates is formed in series with adjacent opposing surfaces of each semiconductor ceramic plate and a plurality of holes in the metal foil forming capacitance electrodes stacked between the adjacent opposing surfaces. fixed by a glass layer.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is a cross-sectional view schematically showing the structure of a semiconductor ceramic capacitor according to the present invention, in which LLI, . . .
It is, for example, a grain boundary insulation type semiconductor ceramic plate that insulates between electrodes. Internal electrodes 3, which are capacitive electrodes made of base metal foil such as aluminum, are provided between each semiconductor ceramic plate 1 via a glass layer 2, and these internal electrodes 3, 3,
3. . . ., one end of each is connected alternately to one of two end electrodes 4 for external connection in the stacked order, and the other end is connected partially to the opposing internal electrodes 3 through the semiconductor ceramic plate 1. Overlapping and unconnected end electrode 4
separated by a predetermined length from

Next, the manufacturing process of the semiconductor ceramic capacitor having the above structure will be explained. The grain boundary insulated semiconductor porcelain plate 1 is a known one, in which 0.2 mol χ of a semiconducting agent such as Nb2O5 is added to 5rTi03 powder, which is mixed with a binder, an organic solvent, and a plasticizer in a ball mill. Then, the slurry mixture is formed into a sheet with a doctor blade, this sheet is cut into the required size, and the sheet is fired in a reducing atmosphere containing several percent hydrogen to obtain semiconductor porcelain. D. A mixture of Bi2O3, PbO, CuO, etc. is applied and heat treated in air at 1000 to 1300[deg.] C. to diffuse into the grain boundaries of the semiconductor ceramic, thereby obtaining a semiconductor ceramic plate 1 in which the grain boundaries are made into insulators.

On the other hand, a glass paste is prepared by mixing lead borosilicate glass powder and an organic binder with a solvent, and this glass paste is applied to both surfaces of the semiconductor porcelain plate l by screen printing or the like to form glass layers 2, 2. do.

In addition, multiple holes are drilled in the aluminum gold B foil,
This aluminum metal foil is laminated in a quantity corresponding to the required capacity on the glass layers 2, 2 formed as described above, and one end of the aluminum metal foil coincides with one end of the semiconductor porcelain plate 1, and The opposing aluminum metal foils are arranged so that the opposing aluminum metal foils partially overlap each other with the semiconductor porcelain plate 1 in between, and are located within an appropriate length from the end of the semiconductor porcelain plate 1. The aluminum metal foils on both sides are laminated so that the ends thereof coincide with each other and are opposite to each other, thereby forming internal electrodes 3,3.

Each of the internal electrodes 3, 3 formed as described above is laminated with a semiconductor ceramic plate 1 having a glass layer 2 formed on both or one side thereof in the same manner as described above for insulation, and an internal electrode made of aluminum metal foil is placed thereon. 3 and repeat this process as many times as required. At this time, the internal electrodes 3 are stacked such that the side on which the end portions of the internal electrodes 3 coincide with the end portions of the semiconductor ceramic plate 1 is alternately opposite to the end portion of the internal electrodes 3 in the stacking order. Each layer is temporarily fixed with an organic adhesive or the like until the lamination is completed.

When the lamination is completed, the semiconductor ceramic plates LLL... and the internal electrodes 3, 3, 3... ...A commercially available silver paste was applied to the side surfaces of the stacked layers with their edges aligned alternately, and 60
The end electrodes 4, 4 are formed by baking at 0 to 800°C, and the internal electrodes 3, 3, 3. ... are connected in parallel.

Through this baking process, the glass layers 2, 2, 2. ... is melted, and the melted glass paste is applied to the internal electrodes 3, 3, 3 .
... solidifies after passing through the hole drilled in the aluminum metal foil forming the semiconductor porcelain plates LLL..., respectively.

In this example, aluminum was used as the metal foil forming the internal electrode for capacitance, but the metal foil is not limited to this, and base metal foils such as nickel foil, copper foil, tin foil, zinc foil, and lead foil may also be used. Inert gas (N2) if possible and necessary
The glass may be fired in an atmosphere.

Further, in this embodiment, a single layered semiconductor ceramic capacitor has been described in detail, but similar effects can be obtained when substrates on which a plurality of semiconductor ceramic capacitor elements are mounted are layered.

Furthermore, in this example, a grain boundary insulation type was used as the semiconductor ceramic plate of the semiconductor ceramic capacitor, but a reoxidation type,
Similar effects can be obtained even when a weir layer type semiconductor ceramic plate is used.

〔Effect of the invention〕

Since the semiconductor ceramic capacitor according to the present invention uses base metal foil as the internal electrode for capacitance, the manufacturing process eliminates the need for equipment for printing and firing metal paste, unlike conventional multilayer semiconductor ceramic capacitors. This has the excellent effect of simplifying the process and reducing manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing the structure of a semiconductor ceramic capacitor according to the present invention.

Claims (1)

[Claims] 1. In a semiconductor ceramic capacitor in which semiconductor ceramic plates and capacitor electrodes are alternately laminated, and the laminated capacitor electrodes are alternately connected to two external electrodes in the lamination order, a hole made of metal foil and penetrating in the lamination direction is used. It is characterized by comprising a capacitive electrode having the following properties, and a glass layer formed in series in the holes of the capacitive electrode laminated between the adjacent opposing surfaces of the stacked semiconductor ceramic plates and the stacked adjacent opposing surfaces. Semiconductor porcelain capacitor.