JPH0513034U - Trimmer capacitors - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize an inexpensive trimmer capacitor that can adjust capacitance on both sides, is easy to surface mount, and has a simple structure. A trimmer capacitor is capable of adjusting electrostatic capacitance on both sides, and is rotatable independently of each other so that a flat plate-shaped dielectric body 3 and the dielectric body 3 are sandwiched and the facing area is variable. A pair of electrically conductive rotor elements 2a and 2b are housed in a case, and rotor electrodes (external terminals) for connecting the rotor elements 2a and 2b to both front and back main surfaces of the case.
4a and 4b are derived.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a trimmer capacitor, and more particularly to a trimmer capacitor whose capacitance can be adjusted from both sides.

[0002]

[Prior Art]

 The trimmer capacitor is for finely adjusting the electrostatic capacity, and is widely used in electronic devices such as electronic clocks, VTRs, and video cameras. When mounting this type of trimmer capacitor on the surface, if there is only one side where the capacitance can be adjusted, it is necessary to distinguish between the front and back sides when mounting it on the board. Therefore, there is a demand for a trimmer capacitor that can adjust the electrostatic capacitance on both sides without requiring the discrimination between the front and the back.

As a conventional technique capable of adjusting electrostatic capacitance on both sides, there is a trimmer capacitor disclosed in Japanese Patent Publication No. 52-44428. This trimmer capacitor consists of two dielectric discs with a conductive metal layer formed over almost half of them, a semicircular stator electrode and a rotor-side lead-out terminal arranged between the dielectric discs, and a dielectric disc. The outer surface of the plate is mainly equipped with a semicircular rotor electrode, a part of which always contacts the conductive metal layer. Further, a through hole is formed in the dielectric disk and the rotor electrode, and the rotor shaft is inserted into this through hole. Both ends of this rotor shaft are soldered to the rotor electrodes.

[0004]

[Problems to be solved by the device]

 In the above-mentioned conventional configuration, it is necessary to form a hole in the center of the ceramic dielectric disk. Generally, when drilling holes in ceramics, the perimeter of the holes is easily damaged by the shock of drilling, so drilling holes in ceramics is relatively difficult, and the drilling cost is high.

Further, in the conventional configuration, the rotor electrodes to be rotated are provided on the front and back sides of the trimmer capacitor, and these rotate in conjunction with each other. Therefore, when this is mounted on the front surface of the substrate, It is necessary to make holes in the substrate so as not to hinder the rotation of the rotor electrode.

Further, the conventional configuration has a problem that the number of parts is large, the manufacturing process is complicated, and the cost is high.

An object of the present invention is to provide an inexpensive trimmer capacitor whose capacitance can be adjusted on both sides, which can be easily surface-mounted, and has a simple structure.

[0008]

[Means for Solving the Problems]

 The trimmer capacitor according to the present invention is capable of adjusting the electrostatic capacitance on both sides. This capacitor has a flat plate-shaped dielectric member, and the dielectric member is sandwiched, and the trimmer capacitor is rotated independently of each other so that the facing area is variable. A possible pair of electrically conductive rotor elements and a pair of rotor elements are housed in a case having adjustment holes formed on both front and back main surfaces. The external terminals connected to the pair of rotor elements are led out to the front and back main surfaces of the case, respectively.

[0009]

[Action]

 In the trimmer capacitor of the present invention, by rotating only one of the pair of rotor elements that can rotate independently of each other, the facing area of the pair of rotor elements changes, and the capacitance can be adjusted. At this time, since the pair of rotor elements can rotate independently of each other, the rotation of one does not rotate the other. Therefore, it is not necessary to perform special processing on the substrate.

Further, in this trimmer capacitor, it is not necessary to process the through holes in the flat plate-shaped dielectric, and there is no damage due to the through hole processing. Therefore, the manufacturing process is simplified and the cost is reduced. Furthermore, since the external terminals connected to the pair of rotor elements are led out to the front and back main surfaces of the case, they can be easily mounted without distinguishing between the front and back.

[0011]

【Example】

 FIG. 1 is a plan view of a trimmer capacitor according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view thereof. In the figure, the trimmer capacitor is composed of a pair of resin-made stators 1a and 1b as a case, a pair of metal rotor elements 2a and 2b, and a ceramic dielectric material sandwiched between the rotor elements 2a and 2b. 3 and rotor electrodes 4a and 4b serving as external terminals.

The stators 1a and 1b are made of rectangular parallelepiped members and integrated with each other to form a case. Hole 7a having a small diameter hole serving as adjusting holes 5a, 5b at the center of stators 1a, 1b and a large diameter hole forming an internal space for accommodating rotor elements 2a, 2b and dielectric 3 after being integrated. , 7b are formed. Further, the stators 2a and 2b are provided with rotor electrodes 4a and 4b having an L-shaped cross section.

One end of each of the rotor electrodes 4a and 4b has a ring portion exposed at a step portion caused by the difference between the small diameter hole and the large diameter hole, and the other end is exposed to the outside of the case to serve as an external electrode. To use. A part of the rotor electrode 4a is embedded in the inside of the stator 1a from the ring portion to the other end, is then bent to be exposed on the surface of the stator 1a, and is then bent to form the stator 1a, 1b. Along the end surface of the stator 1b, further bent, and led out to the surface of the stator 1b. The rotor electrode 4b is also symmetrical with the rotor electrode 4a. That is, when the stator electrodes 1a and 1b are integrated with each other to form a case, the rotor electrodes 4a and 4b are respectively led to the front surface of the case, for example, the front surface of the stator 1a and the back surface of the case, for example, the front surface of the stator 1b. It will be. Due to the bending for guiding the rotor electrode 4a to the surface of the stator 1b, and the bending for guiding the rotor electrode 4b to the surface of the stator 1a, the stator 1a and the stator 1b are assembled in pressure contact with each other and assembled. Will be configured.

The rotor elements 2a and 2b are in the form of stepped cylinders, and the large diameter portions thereof are arranged concentrically so as to face each other. Semicircular cutouts 9a and 9b are formed on the bottom surfaces (surfaces contacting the dielectric 3) of the rotor elements 2a and 2b. Protrusions 11a and 11b for preventing the rotor elements 2a and 2b from collapsing due to the notches are formed at the outer peripheral end portions of the notches 9a and 9b. Further, adjustment grooves 8a and 8b for turning the rotor elements 2a and 2b by a driver or the like are formed on the heads of the rotor elements 2a and 2b. The rotor elements 2a, 2b are rotatably fitted in the holes 7a, 7b of the stators 1a, 1b. The ring portions of the rotor electrodes 4a and 4b are in pressure contact with the stepped portions of the rotor elements 2a and 2b.

As described above, in the configuration of this embodiment, the number of parts can be reduced. Moreover, since the pair of stators 1a and 1b and the pair of rotor electrodes 4a and 4b can be made of the same parts, the parts can be made common and simplified.

The dielectric 3 is provided so as to be sandwiched between the bottom surfaces of the rotor elements 2a and 2b. An electrostatic capacitance is obtained by the electric conductor 3, the rotor elements 2a and 2b that sandwich the electric body 3, and the rotor electrodes 4a and 4b that are pressed against the rotor elements 2a and 2b. The magnitude of this capacitance changes according to the overlapping area of the facing portions of the rotor elements 2a and 2b. For example, if the facing area is increased, the capacitance increases. In this adjustment, one of the rotor elements 2a, 2b is rotated by a driver using one of the adjustment grooves 8a, 8b provided on the heads of the rotor elements 2a, 2b, and one of the rotor elements 2a, 2b is rotated. On the other hand, this can be done by rotating the other rotor element 2b, 2a.

In this trimmer capacitor, the adjustment grooves 8a 1 and 8b 2 are exposed in the case including the stators 1a and 1b, so that the capacitance can be adjusted from both sides. In addition, since the heads of the rotor elements 2a and 2b are substantially flush with the stators 1a and 1b, and the rotor electrodes 4a and 4b are led out to the front and back main surfaces of the case, both sides are printed. Even if it is arranged on the circuit board side, it can be mounted on the surface of the board by electrical connection means such as soldering. Further, since the rollers 2a and 2b can rotate independently of each other, it is not necessary to perform special processing on the substrate surface in order to rotate the rotor element 2b on the substrate side.

At the time of assembly, the parts are concentrically overlapped as shown in FIG. 3, and the tips of the rotor electrodes 4a and 4b are bent as shown by the chain double-dashed line. This will allow easy assembly.

[Other Embodiments] (a) In the above embodiment, a disk-shaped dielectric is used, but in order to disable the rotation of this dielectric 3, as shown in FIG. Alternatively, rectangular recesses 10a and 10b may be provided in the opposing portions of the stators 1a and 1b, and the rectangular dielectric 3 may be fitted into the recesses 10a and 10b. Thereby, the rotation of the dielectric 3 can be restricted.

(B) A packing made of rubber or the like is interposed between the rotor electrodes 4a, 4b and the stators 1a, 1b so as to prevent the cleaning liquid from entering during flux cleaning performed after mounting on the substrate. Good.

(C) When the rotor elements 2a and 2b are made of aluminum or stainless steel, it is possible to solve the problem that the rotor elements 2a and 2b cannot rotate due to the solder that tends to enter during the soldering process.

(D) In the above embodiment, the two stators 1a and 1b were assembled by bending the rotor electrodes 4a and 4b. However, ultrasonic welding, adhesive bonding, two stator fittings, etc. You may carry out by another structure.

(E) In the above-described embodiment, the rotor electrodes 4a and 4b are exposed and extend on the end surface of the case. However, the rotor electrodes 4a and 4b are exposed on one main surface, for example, the surface and then pass through the inside of the stators 1a and 1b and then the other main surface. You may make it expose to a surface, for example, a back surface. $

[Effect of the device]

 In the trimmer capacitor of the present invention, the dielectric is sandwiched between a pair of rotor elements, and the rotor elements are independently rotatable so that the facing area is variable. It is possible to adjust the electrostatic capacity of. Also, since the external terminals are led out on both sides, surface mounting is possible without distinguishing between the front and back sides. Further, when the surface mounting is performed, processing on the substrate is not necessary and the number of parts is reduced, so that the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view of a trimmer capacitor according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the trimmer capacitor.

FIG. 3 is an exploded perspective view of the trimmer capacitor.

FIG. 4 is an exploded perspective view of a trimmer capacitor according to another embodiment.

[Explanation of symbols]

 2a, 2b rotor element 3 dielectrics 4a, 4b rotor electrodes 5a, 5b adjusting hole

Claims (1)

[Scope of utility model registration request] 1. A flat plate-shaped dielectric member and a dielectric member sandwiching the dielectric member in a case in which adjustment holes are formed on both front and back main surfaces, and rotatable independently of each other so that a facing area is variable. A trimmer capacitor in which a pair of conductive rotor elements are housed and external terminals connected to the rotor elements are led out to both front and back main surfaces of the case.