JP2553038Y2 - Ceramic resonator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to a ceramic resonance device used for a ceramic resonance type electrostatic sensor or the like.

[Conventional technology]

2. Description of the Related Art In recent years, video disk devices such as a VHD system that detects information recorded on an information medium as a change in capacitance have become widespread. In a signal pickup device used in this device, a dielectric resonator having a large Q is used as a resonator instead of a coaxial resonator using a strip line. The use of the dielectric resonator has an advantage that the pickup device can be simply and small-sized.

[Problems to be solved by the invention]

However, when used in a small video disk device or in a similar device, it may be used in a very narrow space. Therefore, it is necessary to further reduce the size of the ceramic resonance device including the case, the circuit board, and the ceramic resonator.

In order to further reduce the size of the ceramic resonator, the length of the ceramic resonator may be shortened first, but then the resonance frequency becomes extremely high, so that the oscillation circuit or the detection circuit connected to the ceramic resonator becomes The influence of the impedance and the stray distributed capacitance on peripheral circuits such as transistors of the circuit increases, and this also has a limit. Also,
When the cross-sectional area of the ceramic resonator is reduced, Q decreases,
There is a problem that the frequency characteristics deteriorate. Furthermore, if the dielectric constant of the ceramic resonator is increased, the length of the ceramic resonator can be shortened and the device can be miniaturized. However, this also has a limit in terms of material. From these various limits, the minimum cross-sectional dimension of the ceramic resonator was considered to be 4 × 4 mm.

The present inventor repeated the trial production and the experiment, and, while promoting the miniaturization of the ceramic resonator, placed the ceramic resonator on the ground plane of the circuit board, and opposed the ground to the ground of the ceramic resonator facing this ground plane. By connecting the plane to the ground potential, a decrease in Q could be prevented. The present invention has been made in view of this point, and an object of the present invention is to provide a ceramic resonator capable of miniaturizing a ceramic resonator.

[Means for solving the problem]

The present invention is configured as follows to achieve the above object. That is, the present invention provides a ceramic resonator in which a ceramic resonator is mounted on a ground mounting surface of a conductor formed on a surface of a circuit board by soldering a bottom side thereof, wherein the circuit board has a U-shape. The three sides are surrounded by a U-shaped wall of the conductor case and fixedly accommodated in a form in which one is opened, and the ground mounting surface is conductively connected to the conductor case. On the opening side of the U-shaped wall, the conductor lid of the conductor case is covered on the ground-facing plane side of the ceramic resonator facing the ground mounting surface, and the ground-facing plane is in contact with the conductor lid. The ground-facing plane is conductively connected to the ground of the conductor case via the ground. An output conductor pattern is provided at a position facing the opening side of the conductor case separately from the mounting surface, the ceramic resonator is mounted with its output terminal side facing the opening side of the conductor case, and the output terminal is connected to the output terminal. It is characterized by being connected to a conductor pattern.

[Action]

In the present invention, a ceramic resonator is connected and fixed to the upper side of the ground mounting surface formed on the surface of the circuit board by soldering, and the conductor lid is placed over the upper side in a contact state.
The plane facing the ground of the ceramic resonator via this conductor lid is connected to the ground of the conductor case to improve the Q. Even if the ceramic resonator is miniaturized, the characteristics of the ceramic resonator deteriorate. Is prevented.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 and 2 show a first embodiment of the ceramic resonator device according to the present invention. In these figures,
On the upper surface side of the printed circuit board 6 functioning as a circuit board, a ground mounting surface 7 and an output conductor pattern 8 are formed in a separated and insulated state by a conductor such as copper foil. As shown in FIG. 3, an appropriate number of ground lead patterns 12 for connecting the same surface 7 to the ground are provided on the ground mounting surface 7.
Are branched. A ceramic resonator 9 is mounted on the ground mounting surface 7 and fixed by soldering. At the time of this soldering, for example, a solder paste is previously provided on the bottom surface side of the ceramic resonator 9, and the bottom surface of the ceramic resonator 9 is placed on the ground mounting surface 7 and heated with a solder iron or blows hot air. This is done by: In the mounted state of the ceramic resonator 9, the electrode 10 of the output terminal of the ceramic resonator 9 is connected to the output conductor pattern 8 using solder.

The printed circuit board 6 on which the ceramic resonator 9 is mounted has a U-shaped conductor case 11 made of a metal plate such as copper, and three sides thereof are surrounded by the U-shaped wall surface of the conductor case 11 and one side is opened. That is, the three sides of the printed circuit board 6 abut on the three wall surfaces of the conductor case at the center thereof, and the remaining sides of the printed circuit board 6 are accommodated and fixed such that they are located on the side without the wall surface of the conductor case. In the accommodation fixed state,
The ground mounting surface 7 is connected to the conductor case 11 by soldering at one or more points using a ground lead pattern 12. This ground mounting surface 7 and conductor case
The connection point (the number of ground lead patterns) to 11 is appropriately determined by the resonance frequency of the ceramic resonator 9. When the resonance frequency is high, it is preferable to increase the connection point. , Resonance frequency 1G Hz
~ 3 GHz, in this case at least 3
It is desirable that the connection be made at points or more. As shown in FIGS. 1 and 2, the ceramic resonator 9 is mounted on the ground mounting surface 7 with the electrode 10 serving as an output terminal facing the opening side of the U-shaped wall of the conductor case 11. ing. An output conductor pattern 8 is provided on the surface of the printed circuit board 6 at a position adjacent to the ground mounting surface 7 and facing the opening surface of the U-shaped wall of the conductor case 11,
The electrode 10 is connected to the output conductor pattern 8. By setting the opening surface of the conductor case 11 to, for example, the VHD video disk side, the tip side of the output conductor pattern 8 faces the video disk, and the information recorded on the video disk is detected as a change in capacitance.

The conductor case 11 is connected to ground and serves as a ground, and a conductor cover 13 formed of a plate of a conductor metal such as copper is fitted over the upper surface of the conductor case 11 on the opening side. The end face side of the conductor lid 13 is connected to a side plate of the conductor case 11 using solder. The area of the conductor lid 13 is formed to be sufficiently larger than the ground-facing plane 14 of the ceramic resonator 9, and the ground-facing plane 14 of the ceramic resonator 9 is
13 and is soldered to the lower surface of the conductor lid 13. This solder connection is performed, for example, by applying a solder paste on the ground-facing flat surface 14 of the ceramic resonator 9 in advance, placing the conductor lid 13 on the upper side of the ceramic resonator 9, and making contact with the conductor case 11. Heating is performed with a soldering iron from above, or hot air is blown from above the conductor lid 13.

According to the present embodiment configured as described above, the ground-opposing plane 14 side of the ceramic resonator 9 is conductively connected to the ground of the conductor case 11 by the conductor lid 13.
The Q of the ceramic resonator 9 can be greatly improved. In the present embodiment, the cross section of the ceramic resonator 9 is 3 × 3 m
Despite the miniaturization far exceeding the conventionally limited size of m, compared with the conventional mounting method, that is, the mounting method in which the ground-facing plane of the ceramic resonator 9 is not electrically connected to the ground, Was improved by 30% or more, and the overall characteristics were improved by 50% or more. As a result, it is possible to obtain the same characteristics as when a ceramic resonator having a cross section of 5 × 5 mm is mounted by the conventional mounting method, and to achieve ultra-miniaturization of the ceramic resonator without causing deterioration in characteristics. Was completed.

FIG. 4 shows a main configuration of a second embodiment of the ceramic resonator according to the present invention. The difference between the second embodiment and the first embodiment is that the conductor cover 13 is formed of a spring plate, and the conductor cover of the spring plate is engaged with the conductor case 11 while being fitted into the conductor case 11. It is configured as follows. The central portion of the conductor lid 13 is formed in a flat plate shape so as to be able to come into close contact with the ground-facing flat surface 14 of the ceramic resonator 9. Waveforms 15 are formed on both left and right sides to provide a spring cushion. Both ends are bent upward to form a fitting portion 16. The fitting portion 16 has an engagement hole 17 formed therein. On the other hand, an engagement protrusion 18 is formed on the side plate side of the conductor case 11 facing the engagement hole 17.

In this configuration, by fitting the conductor lid 13 from above the conductor case 11, the fitting portion 16
When the engagement hole 17 reaches the position facing the engagement protrusion 18, the engagement protrusion 18 engages with the engagement hole 17 and is The lid 13 is engaged and fixed, and the conductor lid 13 is prevented from coming off. In this state,
The ground facing plane 14 is pressed against the central portion of the conductor lid 13 and abuts in close contact therewith. The ground facing plane 14 of the ceramic resonator 9 is conductively connected to the ground of the conductor case 11 via the conductor lid 13. As described above, since the ground facing plane 14 is conductively connected to the ground, a large improvement in Q is achieved, and as in the first embodiment, a very small ceramic Resonant devices can be created.

Note that the present invention is not limited to the above embodiments, and various embodiments can be adopted. For example, in each of the above embodiments, a printed circuit board is used as a circuit board.
Instead of this printed board, a multilayer board may be used.

Further, in the second embodiment, in order to engage and fix the conductor cover 13 to the conductor case 11, the engagement protrusion 18 is provided on the conductor case 11 side, and the engagement hole 17 is provided on the conductor cover 13 side. Reverse this,
An engagement hole may be provided on the conductor case 11 side, and an engagement protrusion may be provided on the conductor lid 13 side. However, if the engagement hole 17 is provided on the conductor lid 13 side as in the above-described embodiment, the effect that the thickness of the conductor lid 13 at the engagement portion can be reduced can be obtained.

[Effect of the invention]

In the present invention, a ceramic resonator is mounted on the ground mounting surface, a conductor cover is placed on the ground-facing plane of the ceramic resonator, and the ground-facing plane is conductively connected to the ground via the conductor lid. The Q of the resonator is greatly improved, and even if the ceramic resonator is extremely small, which has never been considered in the past, a significant reduction in characteristics does not occur and a very small ceramic resonator with high sensitivity is provided. It is possible to do. In addition, since the connection of the ground-facing surface to the ground is performed using the cover of the conductor case, it is not necessary to separately prepare a lead wire or a conductor electrode for ground connection, and the device configuration can be simplified.

Further, the weight of the device can be reduced by miniaturizing the device, and the handling of the device becomes very easy.

Furthermore, since the Q can be improved with a simple configuration in which the ground-facing plane of the ceramic resonator is connected to the ground, the ceramic resonator of the present invention having excellent performance can be easily manufactured and can be manufactured at low cost. Can be provided. Further, since the output conductor pattern connected to the output terminal of the ceramic resonator is provided on the circuit board at a position facing the opening surface of the U-shaped wall of the conductor case, the output conductor pattern is provided through the opening of the conductor case. For example, it is possible to detect the information recorded on the video disk based on a change in capacitance by making the leading end side of the conductor pattern face a VHD video disk, for example, and it is suitable as information reading means for these VHD video disks. is there.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing a first embodiment of a ceramic resonator according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a circuit of the ceramic resonator in the embodiment. FIG. 4 is a perspective view showing a state of being mounted on a substrate, and FIG. 4 is a longitudinal sectional front view showing a second embodiment of the ceramic resonator according to the present invention. 6 ... printed circuit board, 7 ... ground mounting surface, 8 ... output conductor pattern, 9 ... ceramic resonator, 10 ... electrode, 11 ... conductor case, 12 ... ground lead pattern, 13 ... conductor cover , 14... Ground opposing plane, 15... Corrugation, 16... Fitting part, 17... Engaging hole, 18.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-14301 (JP, A) JP-A-61-208902 (JP, A) JP-A-4-8510 (JP, U) JP-A-63 102312 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A ceramic resonator in which a ceramic resonator is mounted on a ground mounting surface of a conductor formed on a surface of a circuit board by soldering a bottom side thereof, wherein the circuit board has a U-shape. The three sides are surrounded by a U-shaped wall of the conductor case and fixedly accommodated in a form in which one is opened, and the ground mounting surface is conductively connected to the conductor case. On the opening side of the U-shaped wall, the conductor lid of the conductor case is covered on the ground-facing plane side of the ceramic resonator facing the ground mounting surface, and the ground-facing plane is in contact with the conductor lid. The ground-facing plane is conductively connected to the ground of the conductor case via the ground, and the ground mounting surface is formed on the circuit board surface on which the ground mounting surface is formed. An output conductor pattern is provided at a position facing the opening side of the conductor case separately from the conductor case, and the ceramic resonator is mounted with its output terminal side facing the opening side of the conductor case, and its output terminal is connected to the output conductor pattern. A ceramic resonance device connected to the ceramic resonator.