JPS6348111Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a composite capacitor formed by forming a plurality of capacitors on a common base.

Mount various parts on the printed wiring board,
Conventionally, it has been widely used to form a desired circuit using this method. The capacitors used in such cases are generally disc-shaped capacitors, square plate-shaped capacitors, cylindrical capacitors, and the like. Disk-shaped capacitors and square plate-shaped capacitors have a pair of electrodes facing each other on both sides of a circular or square ceramic substrate. A cylindrical capacitor has a pair of electrodes formed on the inner and outer circumferential surfaces of a cylindrical ceramic. That is, each capacitor consisting of a pair of electrodes is formed independently. The use of such capacitors has limitations in increasing the mounting density of components on a circuit board. Another problem is that the cost is relatively high, and in order to further increase the capacity, the shape must be increased proportionately.

In order to solve these problems,
In Publication No. 133859, a capacitor element is constructed by depositing an electrode metal on a predetermined portion of a metal substrate via a dielectric layer, and other parts of the surface of the electrode metal except for the external terminal mounting portion are A capacitor device has been proposed in which a portion of the metal substrate is covered with a conductive layer electrically connected to the metal substrate via an insulating layer.

According to the capacitor device described above, a plurality of capacitors can be formed on one base. However, in the case of this capacitor device, in order to integrally form multiple capacitors, a dielectric layer, an electrode metal, an insulating layer, a conductive layer, etc. are sequentially formed on one surface of a common metal substrate. It must be formed by superimposing them on each other. Since they are stacked one after another on one surface of a common substrate in this way, they become thick and require a large number of manufacturing steps, making it difficult to achieve sufficient cost reductions. Can not. Furthermore, when they are stacked one on top of the other, one layer tends to penetrate between the other layers, resulting in changes in the resistance values of the electrode metals and conductive layers, or short circuits between them. Sometimes I put it away. In particular, other layers tend to penetrate into the dielectric layer, and this penetration may change the capacitance.

In order to form multiple capacitors integrally while correcting such drawbacks, a plurality of divided electrodes are placed on the surface of a common base made of a dielectric material having a predetermined dielectric constant, and a It is conceivable that an isolation electrode be formed thereon, and a common electrode facing the plurality of divided electrodes be formed on the back surface of the base body. In this case, divided electrodes are provided on the front and back surfaces of a common substrate made of dielectric material, respectively.
Since the isolation electrode and the common electrode are formed to constitute the capacitor element, it is possible to eliminate the problem caused by overlapping them in the order as in the above-mentioned Japanese Patent Laid-Open No. 133859/1983.

Next, a specific example of a composite capacitor constructed in this manner will be described with reference to reference examples shown in FIGS. 1 to 4.

As shown in Figure 1, this composite capacitor is
A common base 1 is provided, which is a rectangular plate-shaped dielectric material made of ceramic and having a predetermined thickness. This base 1 has a predetermined dielectric constant,
As shown in FIGS. 1 and 2, a plurality of, for example, four divided electrodes 2, 3, 4, 5
is formed by a conductive layer. These divided electrodes 2, 3, 4, and 5 are spaced apart from each other by a predetermined distance. Isolation electrodes 6 are also formed on the surface of the base 1 to extend between these divided electrodes 2, 3, 4, and 5, and these isolation electrodes 6 are connected to each other on the upper surface of the base 1. connected.

Note that this isolation electrode 6 is connected to this base 1.
This is to prevent mutual interference between the four capacitors formed above.

As shown in FIG. 3, a common electrode 7 is formed on the back surface of the base 1, covering almost the entire back surface of the base 1. As shown in FIG. This common electrode 7 is made of ceramic substrate 1
are opposed to the four divided electrodes 2, 3, 4, and 5 through the four capacitors 8,
9, 10, and 11 are formed (see FIG. 4). Note that on the front side of the base 1, the four divided electrodes 2,
Four lead wires 12, 13, 14, and 15 connected to electrodes 3, 4, and 5, respectively, and a lead wire 16 connected to isolation electrode 6 are attached. Further, a lead wire 17 connected to the common electrode 7 is attached to the back side of the base 1. Although not shown, the composite capacitor shown in FIG. 1 has a protective coating layer made of an insulating material after forming electrodes 2, 3, 4, 5, and 7 on the front and back sides of the base 1, respectively. It is formed on the outer circumferential surface of the cylindrical member, and is thus packaged as an exterior.

FIG. 4 shows four capacitors 8, 9, 10, which are compositely formed on a common substrate 1 in this way.
The lead wire 16 of the isolation electrode 6 and the lead wire 17 of the common electrode 7 are both grounded, and the lead wires 12 of the four divided electrodes 2, 3, 4, and 5 are connected to each other. ,13,
14 and 15 are connected to the power supply side, for example.

As described above, in this reference example, a plurality of divided electrodes and isolation electrodes are formed on one surface of a common base forming a dielectric medium, and a plurality of divided electrodes and isolation electrodes are formed on the other surface opposite to this surface. Since the electrode is formed, its thickness can be reduced, and it is possible to provide an electrode that is free from unnecessary short circuits and capacitance changes. Furthermore, according to this reference example, a plurality of capacitors can be formed on a common substrate, so that the integration density can be improved. Furthermore, since the divided electrodes and the common electrode can be formed simultaneously on a common substrate by a method such as chemical etching, the manufacturing process is simple and the cost of parts can be reduced. Furthermore, by changing the dielectric constant, thickness, and size of the electrodes of the common substrate, a capacitor of any desired capacity can be obtained, and a capacitor of relatively large capacity can also be obtained. Further, since isolation electrodes are formed between the divided electrodes, mutual interference of a plurality of capacitors formed on a common substrate can be effectively prevented.

However, the composite capacitor of the reference example described above has the following drawbacks.

That is, in the above reference example, a plurality of divided electrodes 2, 3, 4, 5 and an isolation electrode 6 are formed on one surface of the substrate 1, and a common electrode 7 is formed on the back surface of the substrate 1. , lead wires 12, 13, 14, 15, 16, and 17 are connected to each of these electrodes, respectively. As described above, since the common electrode 7 is formed on the back surface of the base 1, the lead wire 17 connected to the common electrode is located on the back surface side of the base 1. Therefore, all these lead wires 1
2 to 17 cannot be placed inline (in one row). It is also necessary to provide two lead wires 16 and 17 as ground wires, one for the isolation electrode and one for the common electrode. For this reason, it is difficult to mount this composite capacitor on, for example, a printed wiring board, and it is also inconvenient to handle.

The present invention was devised to correct the above-mentioned drawbacks of the above-mentioned reference example, and includes a common substrate made of a dielectric material having a predetermined dielectric constant, and a structure in which the surfaces of the common substrate are separated from each other. A plurality of divided electrodes are formed on the surface of the substrate excluding the portion where the divided electrodes are formed, so that the divided electrodes are located between the divided electrodes in a separated state. a common electrode formed on the back surface of the common base opposite to the plurality of divided electrodes; The present invention relates to a composite capacitor each having a conductive connection portion formed in a substantially U-shape over a front surface, an end surface, and a back surface. According to the composite capacitor configured in this way, the thickness can be reduced as in the case of the reference example above, there is no risk of unnecessary short circuits or capacitance changes, and the integration density can be improved. The manufacturing process is simple, the cost can be reduced, a large capacity can be easily obtained, and mutual interference between a plurality of capacitors can be effectively prevented. Furthermore, the number of required lead wires can be reduced, and these lead wires can be placed in-line, making it easy to mount onto a printed circuit board, etc., despite its simple structure. Moreover, the circuit pattern of the printed circuit board and the like can be simplified, and furthermore, it is easy to handle.

Next, an embodiment of the present invention will be described with reference to FIGS. 5 to 8. In this embodiment, the same reference numerals are given to the parts corresponding to those in the above-mentioned reference example, and the explanation of the parts having the same configuration is omitted.

In this embodiment, a substantially U-shaped conductive connection portion 18 is formed on the upper edge of the common substrate 1 in a substantially U-shape over the front surface, end surface, and back surface of the substrate 1 and is made of a conductive pattern. is formed.
The conductive connection portion 18 electrically connects the isolation electrode 6 on the front side of the base 1 and the common electrode 7 on the back side of the base 1. Therefore, the common electrode 7
is the lead wire 16 via the isolation electrode 6.
This eliminates the need to provide a lead wire to the common electrode 7. As a result, the five leads 12, 13, 1 of this composite capacitor
4, 15, and 16 are all arranged on the front side of the base 1, and are arranged in-line as shown in FIG.

Also, since the lead wire of the common electrode 7 can be omitted, one lead wire 16 is used as the ground wire.
Just set it up. Therefore, this composite capacitor is easy to handle and is easy to mount, for example, on a printed wiring board, and furthermore, the circuit pattern of the printed wiring board can be simplified.

According to the present invention described above, the effects achieved by the above-mentioned reference example can be achieved in the same way, and the drawbacks in the above-mentioned reference example can be corrected.

That is, since the present invention has the above-mentioned configuration, its thickness can be reduced, there is no risk of unnecessary short circuits or capacitance changes, and moreover, it is possible to mount multiple capacitors on a common substrate. Therefore, the integration density can be improved. Furthermore, since the divided electrodes and the common electrode can be simultaneously formed on a common substrate by a method such as chemical etching, the manufacturing process is simple.
Therefore, it is possible to reduce the cost of parts. Furthermore, by changing the dielectric constant, thickness, and size of the electrodes of the common substrate, a capacitor of any desired capacity can be obtained, and a capacitor of relatively large capacity can also be obtained. Further, since isolation electrodes are formed between the divided electrodes, mutual interference between a plurality of capacitors formed on a common substrate can be effectively prevented.

Furthermore, according to the present invention, in order to connect the isolation electrode and the common electrode, a conductive connecting portion is formed in a substantially U-shape over the front surface, end surface, and back surface of the common substrate. Since we set it up,
The isolation electrode lead wire can also be used as the common electrode lead wire, which not only reduces the number of required lead wires but also allows these lead wires to be placed in-line. Therefore, despite its simple structure, it is easy to mount on a printed wiring board, etc., and the circuit pattern of the printed wiring board can be simplified, and it is easy to handle. .

[Brief explanation of the drawing]

Figures 1 to 4 show reference examples for explaining the present invention, in which Figure 1 is a perspective view of a composite capacitor, Figure 2 is a front view of the same, and Figure 3 is a rear view of the same. FIG. 4 is an equivalent circuit diagram of the same as above. Figures 5 to 8 show an embodiment of the present invention, in which Figure 5 is a perspective view of a composite capacitor, Figure 6 is a rear view of the same, Figure 7 is a rear view of the same, and Figure 7 is a rear view of the same. FIG. 8 is an equivalent circuit diagram of the same as above. In the symbols used in the drawings, 1... Ceramic substrate, 2, 3, 4, 5... Divided electrode, 6... Isolation electrode, 7... Common electrode, 8, 9, 10,
11... Capacitor, 18... U-shaped conductive connection part.

Claims (1)

[Claims for Utility Model Registration] A common base made of a dielectric material having a predetermined permittivity, a plurality of divided electrodes formed on the surface of this common base in a state that they are separated from each other, and what are these divided electrodes? an isolation electrode formed on the surface of the substrate excluding the portion where the divided electrodes are formed, and facing the plurality of divided electrodes so as to be located between the divided electrodes in a separated state; In order to connect the common electrode formed on the back surface of the common base with the isolation electrode and the common electrode, the common base is formed in a substantially U-shape over the front surface, end surface, and back surface of the common base. A composite capacitor, each having a conductive connection.