JPH0314363B2 - - Google Patents

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a rectangular piezoelectric vibrator.

[Prior art]

FIG. 1 shows the structure of a conventional rectangular piezoelectric vibrator. Although rectangular piezoelectric vibrators are typified by crystal vibrators, ceramic vibrators, etc., the present invention will be explained with reference to the crystal vibrator. FIGS. 1A to 1C are also sectional views showing conventional excitation of the crystal resonator. In the figure A, a rectangular crystal oscillator piece 1 having excitation electrodes 2 on the front and back surfaces is fixed to two lead terminals 4a and 4b which are hermetically sealed to a plug 3, and hermetically sealed by a cylindrical case 5. This shows the current configuration.
In the figure B, a rectangular crystal oscillation piece 6 having excitation electrodes 7 on the front and back surfaces is fixed to the end face of a plug 8, and two lead terminals 9 hermetically sealed to the plug 8 and the excitation electrode 7 are joined together and hermetically sealed by a cylindrical case 10. The same figure C shows a rectangular crystal oscillation piece 11 having excitation electrodes 12 on the front and back surfaces, and the crystal oscillation piece 11.
lead terminals 14 and 15 for supporting the longitudinal ends 11a and 11b and for taking out external electrodes in mutually opposite directions in the longitudinal direction; a pair of plugs 16 for hermetically sealing the lead terminals 14 and 15; 17
and a cylindrical case 1 that connects the plugs 16 and 17.
8, and is hermetically sealed by the plugs 16, 17 and the cylindrical case 18.

In the conventional excitation described above, the structure in which the crystal oscillator piece is fixed and cantilevered by two lead terminals at a position far from the center axis of the crystal oscillator piece shown in Fig. This has the disadvantage that it hits and causes the oscillation to stop. In addition, the structure shown in Figure B in which the central axis of the crystal oscillator piece is sandwiched and fixed between two lead terminals is effective for eliminating the above-mentioned drawbacks of the conventional method, but in order to obtain this structure, the crystal oscillation piece This has the disadvantage that the piece must be fixed to the lead terminal in an unstable position, which increases the number of assembly steps. Figure C eliminates all of the above drawbacks, and has a structure in which the central axis is fixed with lead terminals at both ends of the crystal oscillator piece, and the lead terminals are taken out at both ends of the cylindrical case in opposite directions. Since it can be fixed to the lead terminal in a stable position, assembly is easy and the number of assembly steps can be reduced.

By the way, in recent years light electronic devices, measuring instruments, etc.
Naturally, piezoelectric vibrators including crystal vibrators, which are their component parts, are also required to be thinner, shorter, smaller, and lower in price. In particular, how to meet the market demand for lower prices for crystal resonators and the like that have a small number of parts has become a major issue. The purpose of the present invention is also to reduce the cost, and specifically, it is an improvement on the conventional structure shown in FIG. 1C.

〔the purpose〕

The present invention aims to provide a low-cost piezoelectric vibrator.

〔overview〕

The piezoelectric vibrator of the present invention includes a piezoelectric oscillation piece having excitation electrodes on the front and back surfaces of a rectangular piezoelectric plate, and supports both ends of the piezoelectric oscillation piece in the longitudinal direction, and external electrodes are taken out in mutually opposite directions in the longitudinal direction. A piezoelectric vibrator includes a support part and a case that seals the piezoelectric oscillating piece. It consists of a bottom end to which the end of the piece is directly fixed, an opening connected to the case, and an inclined surface connecting the opening and the bottom end, and the bottom end is selected from non-circular shapes. The piezoelectric oscillating piece has a planar shape such that at least the inclined surface has a portion whose minimum inclination angle is the inclined surface facing the front and back surfaces of the piezoelectric oscillating piece. It is characterized by the above configuration.

〔Example〕

Examples of the present invention are shown in FIGS. 2 and 3. Second
Figure A is a plan sectional view, Figure B is a front sectional view, and Figures 3A and 3B are perspective views. In the figure, the piezoelectric vibrator of the present invention has excitation electrodes 1 on the front and back surfaces of a rectangular electric plate.
It is made of a conductive material that supports a crystal oscillation piece 21 having 9 and 20 and both ends 21a and 21b in the longitudinal direction of the crystal oscillation piece 21, and also serves as a terminal from which external electrodes are taken out in opposite directions in the longitudinal direction. It consists of sealing caps 22, 23 and a case 24 made of a transparent material such as glass, which connects the sealing caps 22, 23.
(shown in a perspective view in FIG. 4) is a bottom end 2 to which both ends 21a and 21b of the crystal oscillation piece 21 are directly fixed.
2a, 23a, openings 22b, 23b connected to the case 24, and inclined surfaces 22c, 23c formed of flat or curved surfaces connecting the openings 22b, 23b and the bottom ends 22a, 23a. The bottom end portion 22a23a has a planar shape selected from a rectangular shape shown in the figure, as well as a non-circular shape such as an oval shape and an elliptical shape, and the inclined surfaces 22c and 23c face the front and back surfaces of the crystal oscillation piece 21. Inclined surface 22c″, 23
c'' is the minimum inclination angle. In this example, the excitation electrodes 19 and 20 are connected to both ends 21 of the crystal oscillation piece 21 in order to obtain stable conduction.
It is desirable to form them continuously up to a, 21b and their respective opposing surfaces. The sealing caps 22 and 23 also serve as external electrodes, and also serve as the crystal oscillator piece 2.
1 to the bottom ends 22a, 22b of the sealing cap by means such as brazing, thermocompression bonding, welding, or adhesive, it is desirable that the wall be as thin as possible, but impact resistance should also be taken into account. It is necessary to form. Also, the bottom end 22 of the sealing cap
Since the ends 21a and 21b of the crystal oscillation piece are fixed to a and 22b, the ends 21a and 22b of the crystal oscillation piece are fixed to each other.
It is formed into a non-circular planar shape consisting of a flat surface slightly larger than 1b, or a non-circular planar shape consisting of a concave portion with a rectangular cross section or a circular cross section. The case 24 has a cylindrical shape similar to the conventional example, a rectangular cylindrical shape,
It may be in the shape of an elliptical cylinder or the like, and if a transparent material such as glass is used, it becomes possible to adjust the frequency using a laser beam after hermetically sealing. The method for manufacturing the crystal resonator of this example will be described below with reference to perspective views of FIGS. 4A to 4E.
In the manufacturing method of this example, first, the sealing cap 22 (in this example, the sealing caps have the same shape, so 22, 2
3)) (see figure A). At this time, it is effective for positioning if the outer shape of the sealing cap is formed into a non-circular shape. This is particularly effective when a plurality of guide holes are provided in a receiving plate or the like and a large number of guide holes are to be assembled at the same time, so-called batch assembly. Next, the case 24 is press-fitted or slid into the sealing cap 22 and joined by means such as brazing, welding, adhesive bonding, etc. (FIG. B). Next, using the case 24 as a guide, the end portion 21 of the crystal oscillation piece 21 is
a is located at the non-circular bottom end 22a formed in the sealing cap 22 (FIG. C). In this case, stable supply can be achieved by applying slight vibration to the sealing cap 22. Next, the sealing cap 23 is press-fitted along the case 24 in alignment with the end 21b of the crystal oscillation piece 21 positioned in the sealing cap 22 (FIG. 1D).
In this case, positioning of the sealing cap 23 with respect to the sealing cap 22 can be carried out extremely easily and with high precision due to the non-circular external shape of each cap. Furthermore, the case 24 and the sealing cap 23 are joined together by brazing, welding, adhesive bonding, or the like (FIG. E). Next, the ends 21a and 21b of the crystal oscillation piece 21 and the sealing cap 2
The bottom ends 22a and 22b of 2 and 23 are fixed together.
As the fixing means, the excitation electrodes 19, 20 provided in advance at the ends 21a, 21b of the crystal oscillation piece 21 or the bottom ends 22 of the sealing caps 22, 23 may be used.
Solder is applied to a and 22b by plating or other means, and the sealing caps 22 and 23 are attached in the state shown in FIG. 4E.
The sealing cap 2 can be fixed by heating the bottom end of the cap, or by using conductive adhesive.
A means is selected that ensures electrical continuity between 2 and 23 and the crystal oscillation piece 21 and shock resistance. Further, the sealing cap and the crystal oscillator piece and the sealing cap and the case can be bonded at the same time.

〔effect〕

As described above, according to the present invention, one sealing cap serves both to take out the external electrode and to support the piezoelectric oscillation piece, so the lead terminals of the conventional example are not required, and the number of parts and assembly steps are reduced. , a low-cost piezoelectric vibrator can be obtained. 2. Because the end of the piezoelectric oscillation piece is directly fixed to the sealing cap, a piezoelectric vibrator with excellent impact resistance can be obtained. 3. The outer shape of the sealing cap is formed into a non-circular shape, making alignment easy and simple. The bottom end of the four-sealing cap is non-circular, and the angle of inclination of the sloped surface following the bottom end is formed to correspond to the front and back surfaces of the piezoelectric oscillator piece. A small piezoelectric vibrator can be obtained because the piezoelectric oscillation piece is directly fixed to the sealing cap (5), which enables stable supply of the oscillation piece.

[Brief explanation of the drawing]

Fig. 1 is a conventional example of a rectangular piezoelectric vibrator, Fig. 2 is a sectional view showing an embodiment of the present invention, Fig. 3 is a perspective view showing an embodiment of the present invention, and Fig. 4 is a piezoelectric vibrator of the present invention. FIG. 3 is a perspective view for explaining a method of manufacturing a child. 19, 20...Excitation electrode, 21...Crystal oscillation piece, 22, 23...Sealing cap, 22a, 22
b...Bottom end, 24...Case.

Claims (1)

[Claims] 1. A piezoelectric vibrator consisting of a piezoelectric oscillation piece having excitation electrodes on the front and back surfaces of a rectangular piezoelectric plate, and a case that supports both longitudinal ends of the piezoelectric oscillation piece and takes out external electrodes from near both longitudinal ends, The case consists of a pair of sealing caps and a case connecting the sealing caps, and the sealing cap projects outward and has a bottom end in which an end of the piezoelectric oscillation piece is directly accommodated and fixed; consisting of an opening connected to the case and an inclined surface connecting the opening and the bottom end,
The bottom end has a non-circular shape approximating the end of the piezoelectric oscillation piece, and at least the inclined surface allows the end of the piezoelectric oscillation piece to be connected to the bottom end when the piezoelectric oscillation piece is assembled into the sealing cap. A piezoelectric vibrator characterized by serving as a guide slope that leads to.