JPS5855687B2 - Piezoelectric vibrator and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piezoelectric vibrator with an improved support structure for a piezoelectric diaphragm, and a method for manufacturing the same.

What is shown in FIG. 1 is a conventional piezoelectric vibrator of this type.

That is, 1 is a piezoelectric diaphragm (hereinafter simply referred to as a "piezoelectric plate") made of crystal, lithium tantalate, lithium niobate, piezoelectric ceramic, or the like.

), and a pair of excitation electrodes 2 and 3 are arranged at the center of both mold surfaces by vacuum deposition.

The piezoelectric plate 1 has notches 6 and 7 provided in the conductive support arms 4 and 5.
and is supported on the base 8 by conductive adhesive.

The support arms 4 and 5 have lead wires 9 and 1 fixed through the base 8.
Therefore, the excitation electrodes 2 and 3 are connected to the lead wires 9 and 1 through the connection electrodes extending to the periphery of the piezoelectric plate 1, respectively.
Connected to 0.

To manufacture such a conventional piezoelectric vibrator, a basic deposition mask is used to perform vacuum deposition on the positions of the piezoelectric plate that will become the excitation electrodes, and then assembled as shown in Fig. 1. In order to match the predetermined resonance frequency, a fine adjustment vapor deposition mask is used to perform fine adjustment vapor deposition on the positions of the excitation electrodes 2 and 3 formed by basic vapor deposition.

If the fine-tuning vapor deposition is not performed exactly on top of the basic vapor deposition film described above, it will induce generation of spurious and fluctuations in operating capacitance and operating inductance when the vibrator is excited.

As is clear from the diagram, in the conventional piezoelectric vibrator described above, the support mechanism is weak compared to the weight of the piezoelectric plate, and positioning is performed by batches, so the position of the piezoelectric plate is difficult to adjust during assembly. As a result, the piezoelectric plate is fixed to the support arm with the base vapor deposited excitation electrode position having a considerable error from the predetermined position, and it is extremely difficult to align the position for fine adjustment vapor deposition in the next process. cormorant.

The present invention has been made to solve the above-mentioned difficulties.

That is, an object of the present invention is to provide a piezoelectric vibrator that can be easily and accurately aligned with the geometrical position of a base-deposited excitation electrode when performing fine-tuning vapor deposition, and a method for manufacturing the same. be.

Another object of the present invention is to provide a piezoelectric vibrator and a method for manufacturing the same, which can improve manufacturing efficiency.

The present invention will be explained below with reference to illustrated embodiments.

FIG. 2 is a perspective view showing an embodiment of the dual-mode piezoelectric vibrator according to the present invention, showing a state before the piezoelectric plate is assembled to the holding frame.

FIG. 3 is a front view after the previous assembly.

The piezoelectric plate 11 has two excitation electrodes 12 at the center of one main surface.
, 13, one excitation electrode 14 is arranged as a common electrode on the other opposing main surface, and the excitation electrodes 12 and 14 and the excitation electrodes 13 and 14 form two pairs of excitation electrodes with the piezoelectric plate 11 in between.

The holding frame 15 surrounds the outline of the main surface of the piezoelectric plate 11 in its main surface shape, and is provided with a through hole 16 having a dimension larger than the outline of the main surface of the piezoelectric plate 11. Lead wires 17, 18° 19 are fixed through the wires.

The material of the holding frame is an insulating material such as plastic, ceramic, epoxy resin, or glass.

The lead wires 17, 18, 19 are made of a metal with spring properties such as phosphor bronze or aluminum copper, and the portions protruding into the through holes are connected to the support portions 20, 21, 22 and the piezoelectric plate 11. In order to reduce the mechanical force applied to the vibration of the piezoelectric plate 11 due to fixation, it is made thinner (smaller in width) than the lead line outside the holding frame 15.

The main surfaces of the support lines 20, 21, and 22 have a shape in which both left and right ends (ll) of the main surfaces are connected around the convex end (1).

The recesses 23, 24, and 25 of the holding frame 15 are gaps so that the supporting parts 20, 2L22 and the holding frame 15 around them do not come into contact with each other.

The positioning jig 26 has fitting tools 27, 28, 29 standing on its main surface, and is provided with protrusions 33, 34, 35° 36 whose main surfaces are the bottom surfaces of the grooves 30° 31, 32. .

These fitting tools 27, 28, 29 have an inner dimension slightly larger than a predetermined outline dimension of the main surface of the piezoelectric plate 11,
The piezoelectric plate 11 has an outer dimension slightly smaller than the inner dimension of the predetermined through-hole portion 16 and stands on the main surface of the jig 26, and its head is tapered so that the outer side is higher than the inner side.
facilitates insertion.

The grooves 30, 31 and 32 are connected to the leader lines 17 and 32, respectively.
18.19 has width and depth dimensions for insertion.

Therefore, as shown in FIG. 3, the piezoelectric plate 11 is
7, 28, and 29 into the through-hole portion 16 of the holding frame 15, and then enter the inside where the fitting tools 27, 28, and 29 stand, and connect each connection electrode of the excitation electrodes 12, 14, and 13 to the support portion 20. ,2
1.22 are aligned and placed, and the conductive adhesive 3
It is fixed by 7.

Note that the shaded areas in FIG. 3 indicate the components of the positioning jig.

4A and 4B show the attachment of the piezoelectric plate 11 to the piezoelectric plate 11 around the support portion 20.

FIG. 6 is a partially enlarged view of the front and back surfaces.

Since the support part 20 has the shape described above, the adhesive 37 is applied within the outline of the support part 20 (the hollow-shaped part).
It is evenly incorporated and applied.

After the adhesive 37 is fixed, the positioning jig 26 is attached to the holding frame 1.
removed from 5.

The above explanation is for manufacturing one piezoelectric vibrator, but if two or more piezoelectric vibrators are to be manufactured efficiently, two or more positioning jigs 26 shown in FIG. 2 may be arranged side by side or connected. Alternatively, there is also a method of using a positioning jig 38 as shown in FIG.

Although FIG. 3 shows three piezoelectric vibrators, for convenience of explanation, the one on the left side will be explained.

The positioning jig 38 has the above-mentioned welt fitting tool 27°28.29
Fitting tools 271, 281, 291 (shaded areas) and projections 39 (shaded areas) similar to the above are arranged on the main surface thereof.

Lead wires 171°181 fixed through the holding frame 151
．． 191 is connected or integrally formed with the common holder 40, and the hole 41 provided in the common holder 40 has a position and size that allows the projection 39 described above to pass through.

Therefore, the piezoelectric plate 111 is connected to the fitting tool 271.28L291
The second and subsequent piezoelectric plates are similarly set in a predetermined position by the insertion of the common holder 40 and the fitting of the hole 41 and the protrusion 39 into the common holder 40 .

Note that the illustrated notches 42, 43, and 44 are cuts for separating and cutting each of the lead wires 171, 181, and 191 from the common holder 40 after assembly.

Thus, according to the present invention, the piezoelectric plate can be precisely aligned to a predetermined position before being fixed to the support, so that the position of the base-deposited excitation electrode is also uniform with respect to the support mechanism, and the next step When performing fine-tuned deposition, it can be applied precisely on top of the previous basic deposition.

In addition, since the holding frame surrounds the outline of the main surface of the piezoelectric plate, it has the advantage of serving as a protection mechanism for the piezoelectric plate and its supporting portion, and having a durable function against drops and impacts.

Although the embodiments show a piezoelectric plate having two pairs of excitation electrodes, those skilled in the art will easily understand that the present invention is applicable not only to one pair but also to three or more pairs.

[Brief explanation of drawings]

Fig. 1 A and B are front and side views showing a conventional piezoelectric vibrator, Fig. 2 is a perspective view showing a piezoelectric vibrator according to an embodiment of the present invention and its manufacturing method, and Fig. 3 is a previous assembly. The rear plan view, FIG. 4A and the opening are partially enlarged views of the front and back surfaces showing fixation with the piezoelectric plate at the support part, and FIG. 5 is a piezoelectric vibrator according to another embodiment of the present invention and its manufacturing method. FIG. 11...Piezoelectric diaphragm, 12,13.14...
...Excitation electrode, 15...Holding frame, 16...
...Through hole part, 20゜21.22...Support part,
27, 28, 29... Fitting tool.

Claims (1)

[Scope of Claims] 1. A piezoelectric vibrator in which a piezoelectric diaphragm having at least one pair of excitation electrodes disposed on its main surface is fixed to a support portion that is fixed through an insulating holding frame, wherein the main surface of the holding frame is a through-hole portion whose surface surrounds the contour of the main surface of the piezoelectric diaphragm and has a dimension larger than the contour, and a dimension between each side surface of the piezoelectric diaphragm and the through-hole portion is such that a fitting tool is inserted thereinto; A piezoelectric vibrator comprising: the piezoelectric diaphragm housed in the through hole. 2. A piezoelectric vibrator in which a piezoelectric diaphragm having at least one pair of excitation electrodes disposed on its main surface is fixed to a support portion that is fixed through an insulating holding frame, wherein the main surface of the holding frame is larger than the outline. The piezoelectric diaphragm is aligned at a predetermined position by inserting a fitting tool between the side surfaces of the piezoelectric diaphragm and the through-hole portion, the fitting having a through-hole portion having a dimension, and having a size to be inserted between each side surface of the piezoelectric diaphragm and the through-hole portion. and then fixing the piezoelectric diaphragm to the support portion.