JPH0974048A - Variable ceramic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the side electrode of a variable ceramic capacitor being packaged on a packaging substrate and that of adjacent parts from being short- circuited. SOLUTION: A variable ceramic capacitor consists of a stator 2 with a stator electrode 3, a rotor 4 which is provided on the stator 2 and at the same time has a rotor electrode 5, a spring 6 which is provided on the rotor 4, and a shaft 7 which passes through the center of the spring 6, the rotor 4, and the stator 2 and becomes a center shaft. Then, cut-out parts 10 and 11 are provided at both edge parts of the stator 2, an end face electrode 12 which is connected to at least the stator electrode 3 is provided at one cut-out part 10, and an end-face electrode 13 which is connected to the rotor electrode 5, at least, via the spring 6 and the shaft 7 is provided at the other cut-out part 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type variable porcelain capacitor used in electronic equipment and the like.

[0002]

2. Description of the Related Art A conventional technique will be described below with reference to the drawings.

As shown in FIG. 6, a conventional variable porcelain capacitor 50 includes a stator 51 having a stator electrode 52.
A rotor 53 provided on the stator 51 and having a rotor electrode 54; a spring 55 provided on the rotor 53; and a central axis penetrating the spring 55, the rotor 53 and the central portion of the stator 51. Shaft 56 and a driver plate 57 provided on the spring 55 and engaged with the rotor 53. Side electrodes 58 connected to the stator electrode 52 are provided on outer peripheral side surfaces on both sides of the stator 51. Then, the side electrode 59 connected to the rotor electrode 54 via the spring 55 and the shaft 56 was formed.

[0004]

When such a variable porcelain capacitor 50 together with other components is mounted on a mounting board in a high density state, the side electrodes 58 and 59 of the variable porcelain capacitor 50 are provided at both ends of the stator 51. Since it is provided so as to be full, there is a problem that the side electrodes 58 and 59, especially both end portions, come into contact with the electrodes of the adjacent components to cause a short circuit.

Therefore, the present invention uses a variable porcelain capacitor 50.
It is an object of the present invention to prevent short circuit between the side surface electrodes 58 and 59 and the electrode of the adjacent component when is mounted on the mounting substrate together with other components in a high density state.

[0006]

In order to achieve this object, the variable porcelain capacitor of the present invention is provided with notches at both ends of the stator, and one of the notches is connected to at least the stator electrode. And an end face electrode connected to the rotor electrode via at least a shaft and a spring is provided in the other notch.

[0007]

With this structure, since the end face electrodes are provided in the notches provided on both ends of the stator, the end face electrodes are not exposed on both ends of the stator, and the variable porcelain capacitor using this stator for the mounting board is provided. When is mounted together with other components in a high-density state, the end face electrodes and the electrodes of components adjacent to each other are not short-circuited.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the variable porcelain capacitor 1 shown in FIG. 1 has a stator 2 having a stator electrode 3 on its upper surface, a rotor 4 provided on the stator 2 and having a rotor electrode 5, and this rotor. 4 has a spring 6 provided above it. Then, the shaft 7 that penetrates the spring 6, the rotor 4, and the stator 2
And the lower end of the shaft 7 is caulked with the lower surface of the stator 2 as shown in FIG.
It is rotatably pressed against. A driver plate 8 engaged with the rotor 4 is provided on the spring 6.

The stator 2 is formed of a dielectric ceramic, has a cylindrical through hole 9 for allowing the shaft 7 to penetrate therethrough, and notches 10 and 11 at both ends, respectively. The end face electrodes 12 and 13 are provided only in the portions 10 and 11.

The end face electrode 12 is electrically connected to the first bottom face electrode 17 provided on the bottom face of the stator electrode 3 and the stator 2, and the end face electrode 13 is shown in FIG.
As described above, the second lower surface electrode 18 provided on the lower surface of the stator 2 is electrically connected to the rotor electrode 5 of FIG. 2 via the shaft 7 and the spring 6 shown in FIG.

As described above, since the end face electrodes 12 and 13 are provided only in the notches 10 and 11 provided in the stator 2, the end face electrodes 12 and 13 are located from both ends of the stator 2.
Is not exposed, and when the variable porcelain capacitor 1 is mounted on the mounting substrate, the end face electrodes 12 and 13 do not short-circuit with the electrodes of other adjacent components.

Further, the stator 2 is capable of collectively forming a plurality of stators from a collective substrate. Here, as shown in FIG. 4, a four-collector collective substrate 14 will be described as an example.

The collective substrate 14 is a substrate made of a dielectric ceramic, and a V-shaped break groove 15 for dividing the substrate and the through holes 9 and 16 are arranged at predetermined intervals by a mold or the like. Next, the stator electrode 3 is printed on the front surface of the substrate, the first and second lower surface electrodes 17 and 18 are printed on the back surface as shown in FIG.
Is provided. After that, the collective substrate 14 is divided along the break grooves 15 to form four stators 2.

The break groove 15 has a hole 16 in one direction.
The holes 16 have a symmetrical shape after division, so that one hole 16 can form notches 10 and 11 of the same shape in the adjacent stators 2 and through holes. Since the electrode 19 is provided, the end face electrodes 12 and 13 can be formed at the same time.

Further, since the notches 10 and 11 provided on both sides of the stator 2 have the same shape, when the stator 2 is mounted on the mounting board, the end face electrodes 12 and 11 provided at the notches 10 and 11, The solder for mounting wraps around 13 in a well-balanced manner and the same solder fillet is formed, so that the mounting deviation of the variable porcelain capacitor and the Manhattan phenomenon (inversion phenomenon) can be prevented.

Further, if the hole 16 is formed in a long hole shape, the inside of the hole 16 has no corners, so that the through hole electrode 19 is formed.
Can be formed with a constant thickness, and the die used to form the hole 16 also has no corners, and the life of the die can be improved.

Further, as is clear from FIG. 5 showing the cross section AA of FIG. 4 of the mounting board 14, the ridge line portion 20 where the upper and lower surfaces of the mounting board 14 and the hole 16 intersect has a curved shape. The thickness of the electrodes applied to the ridge portion 20 can be made constant, and as a result, the end surface electrodes 12 and 13 of the stator 2 formed from the mounting board 14 and the end surface electrodes 12 and 13 are formed.
The electrodes 3, 17, 18 connected to the ridge line portion 2
It is possible to prevent electrical connection failure due to electrode breakage due to thinning of the electrode provided at 0.

[0019]

As described above, according to the present invention, since the end face electrodes are provided in the notches provided on the side faces of the stator, the end face electrodes are not exposed from both ends of the stator, and the stator is used. When the porcelain capacitor is mounted on the mounting board, it is possible to prevent a short circuit with electrodes of other adjacent components.

[Brief description of drawings]

FIG. 1 is a perspective view of a variable porcelain capacitor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the variable porcelain capacitor.

FIG. 3 is a sectional view of the variable porcelain capacitor.

FIG. 4 is a top view of an assembly board for forming a stator used in the variable porcelain capacitor.

5 is a sectional view taken along line AA of FIG.

FIG. 6 is an exploded perspective view of a conventional variable porcelain capacitor

[Explanation of symbols]

 2 stator 3 stator electrode 4 rotor 5 rotor electrode 6 spring 7 shaft 10,11 notch 12,13 end face electrode

Continuation of the front page (72) Inventor Toshiya Motooka 55-12, Hama Ozumi, Tanabe-cho, Tsuzuki-gun, Kyoto Prefecture Matsushita Nitto Electric Co., Ltd.

Claims (4)

[Claims] 1. A stator having a stator electrode, a rotor provided on the stator and having a rotor electrode, a spring provided on the rotor, and the spring and the central portion of the rotor and the stator. A shaft serving as a central axis is provided, and notches are provided at both ends of the stator, one notch is provided with at least an end surface electrode connected to the stator electrode, and the other notch is provided at the other notch. A variable porcelain capacitor provided with an end face electrode connected to a rotor electrode via at least a shaft and a spring. 2. The variable porcelain capacitor according to claim 1, wherein the corner portion of the cutout portion is curved. 3. The variable porcelain capacitor according to claim 1, wherein the notches provided on both ends of the stator have the same shape. 4. The variable porcelain capacitor according to claim 1, wherein a ridgeline portion where the cutout portion and the upper and lower surfaces of the stator intersect is curved.