JPH0746979Y2 - Piezoelectric resonator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a structure of a piezoelectric resonator, and more particularly to improvement of a resonator called a tuning fork type piezoelectric resonator.

[Problems to be Solved by Prior Art and Invention]

An example of a conventional piezoelectric resonator of this type is shown in FIG.
It shows in (b).

In the piezoelectric resonator 1 shown in FIG. 1A, the piezoelectric substrate 2 is formed in a substantially right-angled quadrangular shape in a plan view so as to be easily cut out from the mother substrate. Three slits (not shown) are engraved along the line. A tuning fork portion is formed by the slits, and a pair of terminal portions are arranged substantially in parallel on both sides of the tuning fork portion on the piezoelectric substrate 2.
There are three and three. Then, on both surfaces of the piezoelectric substrate 2, an adhesive layer 5, which is formed so as to surround the tuning fork portion,
The covering sheets 4 and 4 are bonded and fixed via 5.

Further, cutout portions 4a, 4a are provided on one end side of the covering sheet 4 corresponding to the terminal portions 3, 3, and the cutout portions 4a, 4a are provided.
Each of the terminal portions 3 and 3 is configured to be exposed via a and 4a.

When mounting the piezoelectric resonator 1 as described above on a substrate (not shown), by soldering a part of the terminal portion 3 exposed through the notch 4a and a predetermined portion on the substrate, The piezoelectric resonator 1 is fixed on the substrate.

However, in the piezoelectric resonator 1, there are only two places to be soldered on the substrate (a part of the terminal portion 3 exposed through the cutout portion 4a) and one end side from the central portion of the resonator body. When the piezoelectric resonator 1 is mounted on the board by soldering, the terminal portion 3 is damaged by an unexpected force acting in the direction of arrow 6, or the terminal portion 3 is damaged or soldered. Therefore, there is a problem that the piezoelectric resonator 1 is detached from the substrate due to the removal. This is because the soldered portion of the piezoelectric resonator 1 is displaced to one side from the central portion of the resonator body, so that when a force in the direction of arrow 6 is applied, the piezoelectric resonator 1 is relatively large. This is because torque acts.

On the other hand, in the piezoelectric resonator 7 shown in FIG. 2B, the cutouts 4a, 4a on the covering sheet 4 are provided in the substantially central portion of the main body of the piezoelectric resonator 7.

In the piezoelectric resonator 7 having the above structure, the influence on the force in the direction of the arrow 6 as described above can be relatively small,
As in the case of the piezoelectric resonator 1, since soldering is performed only at two places, it is easy to remove from the substrate and the terminal portion 3 is easily damaged.

Further, in the piezoelectric resonator 7, since the cutout portion 4a is provided in the substantially central portion of the resonator body, it is considerably close to the position of the tuning fork portion (not shown) on the piezoelectric substrate 2, and the tuning fork portion is sealed. There is a problem that the sex is impaired.

Therefore, it is an object of the present invention to provide a piezoelectric resonator having a good sealing property with respect to a tuning fork portion and having a structure capable of being firmly fixed to a substrate.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the main means adopted by the present invention is that the tuning fork is formed by engraving three substantially parallel slits on one end side of a piezoelectric substrate having a substantially right-angled quadrangular plane. And forming substantially parallel terminal portions on both sides of the tuning fork portion on the piezoelectric substrate, the piezoelectric substrate and a planar surface disposed facing the tuning fork portion of the piezoelectric substrate with a gap. A dummy substrate having a dummy terminal portion at both ends of its surface in the shape of a right-angled quadrangle is centered, and a planar substantially right-angled quadrangle-shaped covering sheet is adhered to both surfaces thereof via an adhesive layer formed to surround the tuning fork portion, This is a piezoelectric resonator according to a point in which four corners of the cover sheet on one surface side are cut out so that a part of the terminal portions on the piezoelectric substrate and the dummy substrate are exposed.

[Action]

Since the piezoelectric resonator according to the present invention is configured as described above, the adhesive layer formed so as to surround the tuning fork portion can secure a sufficient width dimension.

Further, when the piezoelectric resonator is mounted on the substrate, it is possible to solder by utilizing a part of the terminal portion exposed through each of the four cutout corners of the covering sheet, and thus the piezoelectric resonator is mounted. The resonator can be firmly fixed to the substrate.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. It should be noted that the following embodiments are examples of embodying the present invention and are not of the nature to limit the technical scope of the present invention.

FIG. 1 is a perspective view of a piezoelectric resonator according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the piezoelectric resonator.

In the piezoelectric resonator 9 according to this embodiment, as shown in FIGS.
As shown in the figure, three slits 11a, 11b, 11c are formed in parallel with each other on one end side of the piezoelectric substrate 10 having a substantially right-angled quadrangular shape in a plan view, and the slits 11a, 11b, 11c make tuning forks. Part 11
Are formed. Further, the tuning fork portion on the piezoelectric substrate 10
Terminal portions 12, 12 are provided on both sides of 11 substantially in parallel.

A dummy substrate 13 having a substantially right-angled quadrangular shape in a plan view is provided so as to face the tuning fork portion 11 of the piezoelectric substrate 10 with a gap 17 therebetween, and dummy terminals are provided at both ends of the surface of the dummy substrate 13. Department
14,14 are provided.

The dummy terminal portion 14 is not electrically connected to the terminal portion 12 of the tuning fork portion 11.

Then, with the piezoelectric substrate 10 and the dummy substrate 13 as the centers, on both surfaces thereof, via the mounting layers 15 and 15 formed so as to surround the tuning fork portion 11, a covering sheet 16 having a substantially right-angled quadrangular shape in plan view, 16 is fixed by adhesion. In this case, since a part of the adhesive in the adhesive layer 15 flows into both ends of the gap 17 (see FIG. 1), the airtightness of the tuning fork portion 11 is maintained.

Cutouts 16a, 16a, 16a, 16a are provided at the four corners of the cover sheet 16 on one surface side of the piezoelectric substrate 10, respectively, and the piezoelectric material is formed through the cutouts 16a. Board 1
0 and each of the terminal portions 12, 12 and 14, 14 of the dummy substrate 13 are exposed.

The piezoelectric resonator 9 according to this embodiment is configured as described above.

Therefore, in the piezoelectric resonator 9 having the above structure, the tuning fork portion 11
A space for piezoelectric vibration can be ensured relatively easily around, and the adhesive layer 15 formed so as to surround the tuning fork portion 11 can secure a sufficient width dimension,
Together with the action of a part of the adhesive flowing into both ends of the gap 17, the sealing property with respect to the tuning fork portion 11 is dramatically improved.

When mounting the piezoelectric resonator 9 on a substrate (not shown),
Terminal portions 12, 12 and 1 exposed through each of the four notches 16a
Since a part of each of the parts 4 and 14 can be used for soldering, the piezoelectric resonator 9 can be firmly fixed to the substrate.

[Effect of device]

As described above, the present invention forms a tuning fork portion by engraving three substantially parallel slits on one end side of a piezoelectric substrate having a substantially right-angled quadrangular plane as described above, and the tuning fork portion on the piezoelectric substrate is formed. Substantially parallel terminal portions are provided on both sides of the piezoelectric substrate, and the piezoelectric substrate and the dummy terminal portions are provided on both ends of the surface in a substantially right-angled quadrangular shape which is arranged facing the tuning fork portion of the piezoelectric substrate with a gap. A dummy substrate is used as a center, and a cover sheet having a substantially rectangular shape in a plane is adhered to both sides of the cover sheet via an adhesive layer formed so as to surround the tuning fork portion, and the four corners of the cover sheet on both sides of one side are bonded together. Since the piezoelectric resonator is characterized in that the piezoelectric substrate and a part of the terminal portion on the dummy substrate are exposed, a space for piezoelectric vibration is relatively provided around the tuning fork portion. It can be easily secured and its Good sealing properties, also can be firmly fixed to the substrate.

[Brief description of drawings]

1 is a perspective view of a piezoelectric resonator according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the piezoelectric resonator, and FIGS. 3 (a) and 3 (b) are conventional piezoelectric resonators, respectively. It is a perspective view. [Explanation of symbols] 9 ... Piezoelectric resonator 10 ... Piezoelectric substrate 11 ... Tuning fork part 11a, 11b, 11c, ... Slit 12 ... Terminal part 13 ... Dummy substrate 14 ... Dummy terminal part 15 ... Adhesion Layer 16 …… Coating sheet 16a …… Notch 17 …… Void

Claims (1)

[Scope of utility model registration request] 1. A tuning fork part is formed by engraving three substantially parallel slits on one end side of a piezoelectric substrate having a substantially right-angled quadrangular plane, and the tuning fork part is formed on both sides of the tuning fork part on the piezoelectric substrate. A parallel terminal portion is provided, and the piezoelectric substrate and a dummy substrate which is arranged in a substantially right-angled quadrangular shape in a plane facing the tuning fork portion of the piezoelectric substrate with a gap and has dummy terminal portions at both surface ends thereof are provided. As a center, a cover sheet having a substantially rectangular shape in a plane is adhered to both sides of the cover sheet through an adhesive layer formed so as to surround the tuning fork portion, and 4 of the cover sheets on one side are bonded.
A piezoelectric resonator characterized in that each corner is cut out so that a part of the terminal portion on the piezoelectric substrate and the dummy substrate is exposed.