JPH0263106A - Capacitor element - Google Patents

Abstract

PURPOSE:To enhance an electrostatic capacitance without lowering a mounting density by a method wherein a lower-layer electrode applied to the uneven surface of an insulating substrate and an upper-layer electrode on the electrode are provided. CONSTITUTION:One part of the surface of an insulating substrate (an insulating substrate composed of, e.g., alumina) 11 is sawtooth-shaped. A lower-layer electrode 12 is formed on this sawtooth-shaped surface 11a. The lower-layer electrode 12 is formed on the insulating substrate 11 by baking a conductor paste of, e.g., Ag, Pd, Cu or the line. In addition, an upper-layer electrode 14 is formed on the lower-layer electrode 12 via a dielectric 13 so as to be partly overlapped; a printed capacitor element 15 is constituted of the lower-layer electrode 12, the dielectric 13 and the upper-layer electrode 14. Since the lower-layer electrode 12, the dielectric 13 and the upper-layer electrode 14 are formed one after another on the surface 11a of the insulating substrate 11 and the printed capacitor element 15 is then constituted, areas of the lower-layer electrode 12 and the upper-layer electrode 14 are expanded with a projected area identical to a projected area of a conventional printed capacitor element. Accordingly, an electrostatic capacitance can be increased.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to improvements in capacitor elements.

(Prior Art) As is well known, printed capacitor elements are often used as a component of hybrid integrated circuits.

Conventionally, as a printed capacitor element, for example, the one shown in Fig. 2 (A
) and (B) are known. 1 in this diagram is
A-203 with a flat main surface, A-I! This is an insulating substrate made of N or the like. On this insulating substrate 1, a lower layer electrode 2 is provided.
, a dielectric layer 3 and an upper layer electrode 4 are respectively formed to constitute a printed capacitor element 5.

However, according to the printed capacitor element 5 of FIG. 2, since the main surface of the insulating substrate 1 is flat, sufficient capacitance cannot be obtained. In addition, if the area occupied by the printed capacitor element is increased to obtain sufficient capacitance,
A problem arises in that the packaging density of the elements is reduced.

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a capacitor element that can improve capacitance without reducing packaging density.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides an insulating substrate having an uneven surface, a lower electrode deposited on the uneven surface of the insulating substrate, and a dielectric layer on the lower electrode. This is a patented sensor element characterized by comprising an upper layer electrode formed through the body.

In the present invention, examples of the material of the insulating substrate include alumina, lt'N, magnesia, zirconia, quartz glass, carbon steel, and aluminum.

In the present invention, the shape of the uneven surface of the insulating substrate may specifically be, for example, a sawtooth shape or a wavy shape. Further, the uneven surface portion may be provided on at least a portion of the main surface of the insulating substrate.

In the present invention, the upper layer electrode and the lower layer electrode are generally formed by printing, but the invention is not limited thereto. However, if the shape of the uneven surface of the main surface of the insulating substrate is sawtooth or wavy, the electrodes can be formed by printing, but in the case of other shapes, the electrodes can be formed by another means different from printing. It is desirable to form a

(Function) According to the present invention, since the main surface of the insulating substrate on which the capacitor element is to be formed has a sawtooth or wavy cross-sectional shape, the capacitor element formed on the insulating substrate is Since it is formed on the uneven surface portion, it becomes possible to increase the capacitance with the same projected area as that of a conventional printed capacitor.

(Example) An embodiment of the present invention is shown in FIG. 1(A) below.

This will be explained with reference to (B). Here, FIG. 1(A) is a perspective view, and FIG. 1(B) is a plan view taken along the line X--X of FIG. 1(A).

11 in the figure is an insulating substrate made of, for example, alumina. A part of the surface of this insulating substrate 11 has a sawtooth shape. A lower electrode 12 is formed on the sawtooth surface 11a of the insulating substrate 11.

Here, the lower electrode 12 is placed on the insulating substrate ll, for example, by A.
It is formed by printing a conductive paste such as gPd or Cu and then firing it. Further, an upper layer electrode 14 is formed on the lower layer electrode 12 with a dielectric 13 interposed therebetween so as to partially overlap with each other, and a printed capacitor element 15 is constituted by the lower layer electrode 12, the dielectric 13, and the upper layer electrode 14. Here, the upper layer electrode 14 is made of, for example, AgPd on a part of the insulating substrate 11 and the dielectric 13.

It is formed by printing a conductor paste such as Cu or Au, and then firing it.

According to the above embodiment, the printed capacitor element 15 is constructed by sequentially forming the lower electrode 12, the dielectric 13, and the upper electrode 14 on the sawtooth surface 11a of the insulating substrate 11. Therefore, the areas of the lower layer electrode 12 and the upper layer electrode 14 are expanded with the same projected area as that of a conventional printed capacitor element. Therefore, the capacitance can be increased compared to the conventional one.

In the above embodiment, a part of the surface of the insulating substrate was described as having a sawtooth shape, but the present invention is not limited to this. For example, as shown in FIG. Effects can be obtained.

Further, in the above embodiment, the case where alumina was used as the material of the insulating substrate was described, but the invention is not limited to this.A)
Other ceramics such as N may also be used.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to provide a capacitor element that can improve capacitance without reducing packaging density.

[Brief explanation of the drawing]

FIG. 1(A) is a sectional view of a printed capacitor element according to another embodiment of the printing device according to one embodiment of the present invention. 11... Insulating substrate, 12... Lower layer electrode, 13...
Dielectric, 14... Upper layer electrode, 15... Printed capacitor element. Applicant's Representative Patent Attorney Takehiko Suzue Figure (B) Figure (B) District

Claims (1)

[Claims] It is characterized by comprising an insulating substrate having an uneven surface, a lower layer electrode deposited on the uneven surface of the insulating substrate, and an upper layer electrode formed on the lower layer electrode via a dielectric material. capacitor element.