JPS60242711A - Supporting structure of piezoelectric transducer - Google Patents

Abstract

PURPOSE:To suppress leakage of vibration, to reduce man-hour and to obtain high performance and low cost piezoelectric transducer by bending the tip of two rod or plate terminal conductors in the center axis of an oscillator chip in the region of <=0.5L, where L is the length of the base of the oscillation chip and fitting the tip directly with a prescribed gap. CONSTITUTION:The raw material of the piezoelectric transducer is crystal or ceramic, the shape is tuning fork, rectangular or disc shape and the vibrating mode is bending, thickness-shear, longitudinal, torsional, width-slip or their combinations. For example, tips 17a, 18a of two parallel lead terminals 17, 18 in parallel with U-shaped plane prolonged along a branch 16a of one terminal tuning fork crystal oscillating chip 16 are turned in U-form to the base 16b so as to fix directly int with the base 16b. Thus, the leakage of the vibration is suppressed by supporting the center of the base of the oscillating chip having a small vibration displacement with the two lead terminals in this way, then the support between the oscillating chip and the lead terminals is made stable, the man-hour is decreased and the piezoelectric transducer with high performance and low cost is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a support structure for a piezoelectric resonator such as a crystal resonator or a ceramic resonator.

[Prior art]

As an example of a conventional support structure for a piezoelectric resonator, a support structure for a tuning fork type crystal resonator is shown in FIG. FIG. 3A is a plan cross-sectional view, and FIG. CB) is a front cross-sectional view. In the same figure,
1 is a tuning fork type crystal oscillator piece, 2 is a lead terminal which also serves as a support for the tuning fork type crystal oscillator piece 1, 4 is a stem consisting of the lead terminal 2 and a hermetic glass 3 for fixing the lead terminal 2, and a two-dot chain line 5 shown in is a case. The cases will be omitted below.

Important characteristics that indicate the performance of a crystal resonator include frequency temperature characteristics and frequency change characteristics over time. A drawback that greatly affects the frequency characteristics and frequency change characteristics over time is vibration leakage. This vibration leakage is caused by the vibration of the tuning fork type crystal oscillator piece 1 in the lead terminal 2 in FIG. Stem 4. Case 5
A phenomenon that is transmitted to If this vibration leakage increases, the oscillation frequency of the vibrator changes greatly when external force is applied to the vibrator. For this reason, the structure of a conventional tuning fork type crystal resonator is such that a region with the smallest possible vibrational displacement is selected and supported, as shown in the figure.

The above-mentioned FIG. 1 shows a structure in which the base of the tuning fork type crystal oscillator piece 1 is directly fixed to the side surfaces of the two lead terminals 2α and 2b, and FIG. A structure is shown in which the base including the shaft is sandwiched between two lead terminals 9α and 9b and directly fixed. Furthermore, FIG. 3 shows a lead terminal 11α extended by applying oil to a branch of the tuning fork type crystal oscillator piece 10;
A structure is shown in which the tip of 11h is U-turned toward the base and is directly fixed to the base including the central axis of the tuning fork type crystal oscillator piece. The structure shown in the figure is used in a tuning fork type crystal resonator that utilizes elastic coupling of bending vibration and torsional vibration. Since the purpose of this coupled tuning fork type crystal resonator is to improve the frequency-temperature characteristics mentioned above, it requires a support structure with particularly little vibration leakage, and the unique structure shown in the figure was chosen.

Figure 4 (A) shows the vibration displacement of this coupled tuning fork type crystal resonator, with the bases A and B of the vibrator taken as 1 on the horizontal axis, and the displacement of the plate vibration on the vertical axis. be. The figure justifies the support structure that includes and supports the central portion of the base that undergoes the least displacement.

FIG. 4 CB) shows the vibrational displacement of this coupled tuning fork type crystal resonator, and shows the vibration displacement of the base 0. The horizontal axis is D and the vertical axis is the amount of displacement due to torsional vibration. Here, the base of the vibrator 0. If the distance between D is L, then the base of the vibrator, which has a small amount of displacement according to the same figure, is on the central axis of the tuning fork, and the distance between the base end C and the tuning fork arm is 0.
It goes up to 5L. From the above, if the point 0.5L from the base end C toward the tuning fork arm on the central axis of the tuning fork of the vibrator is set as E, then from the same figure, from the base end C to E where the amount of change is small on the central axis of the tuning fork. A support structure is selected that supports .

Regarding the conventional examples mentioned above, the support structures shown in Figures 2 and 6 South can eliminate vibration leakage, but the structure in which the U surface of the tuning fork-shaped crystal oscillator piece is vertically sandwiched and fixed with lead terminals causes a lot of problems. It has the disadvantage that it requires many man-hours and is not suitable for low cost. On the other hand, since the support structure shown in FIG. 1 is a support structure in which the center of the base of the tuning fork type crystal oscillation piece is removed, it still has the drawback that vibration leakage has not been sufficiently eliminated.

〔the purpose〕

The present invention eliminates the above-mentioned conventional drawbacks, and provides a high-performance, low-cost support structure for a piezoelectric vibrator that suppresses vibration leakage and reduces the number of man-hours.

〔overview〕

The supporting structure of the piezoelectric vibrator of the present invention is such that the blunt oscillating piece is located further below the bottom end of the oscillating piece in a portion including the central axis of the oscillating piece that is close to the bottom end of the U cell and does not reach both ends. When the tips of two rod-shaped or plate-shaped terminal conductors that penetrate through the located hermetic terminal and are parallel to the U-shaped surface, the length of the base of the oscillating piece is L, 0.5L
It is characterized in that it is bent in the direction of the center axis of the oscillating piece in the following areas and is directly fixed with a certain gap.

〔Example〕

The piezoelectric vibrator according to the present invention is made of crystal.

Ceramic, lithium niobate, lithium tantalate, etc. Shapes include tuning fork, rectangular, 1-disk, etc. Vibration forms include bending, thickness sliding, vertical, torsional, 9 width sliding, or combinations of these. It has become.

In this example, a support structure for a tuning fork type crystal resonator will be explained as an example.

FIG. 5(A) is a front view showing an embodiment of the present invention.

In the figure, the support structure of the tuning fork crystal resonator of this example is as follows:
The tuning fork-crystal oscillation piece 12 (hereinafter referred to as oscillation piece 12)
Close to the bottom end 12C on the prison facing 12α and both side ends 12d'
, 12d, penetrates the hermetic terminal 13 located further below the oscillating piece 12 in a portion including the central axis P of the oscillating piece 12 that does not reach ``, and the U-shaped surface 121
Two plate-shaped lead terminals 14.1 provided parallel to Z
The tips 14a and 15α of 5 are connected to the base 12h of the oscillating piece 12.
The oscillating piece 12 is bent in the direction of the central axis P of the oscillating piece 12 in an area of 0.5 L or less, where L is the length of the oscillating piece 12, and is directly fixed to the oscillating piece 12 with a certain gap S. Lead terminal 14
, 15 may be round bars. Also, the tip 1 of the lead terminal
4α and 15b may be parallel or inclined. Figure 5 (B).

(0) shows an enlarged view of the shape of the tips 14α and 15α of the lead terminals. FIG. 6 is a front view showing another embodiment, in which tips 17α of two lead terminals 17 and 18 parallel to the U-shaped plane extended along the branch 16α of the tuning fork type crystal oscillator piece 16; 18α to the base 16b side and the base 1
6h shows a structure that is directly fixed. The lead terminal 1
7. The shape of the tip of 18 is similar to that shown in FIGS. 5(E) and (0). [Effect] As described above, according to the present invention, two leads are connected to the center of the base of the small oscillating piece for vibration displacement. By supporting with terminals, vibration leakage can be suppressed, and since the support structure fixes the oscillating piece and the two lead terminals in the same plane, the support of the oscillating piece and lead terminals is stable and the number of man-hours can be reduced. Therefore, a high-performance, low-cost piezoelectric vibrator can be obtained.

The effect of this example is particularly remarkable in the piezoelectric vibrator that combines the above-mentioned bending vibration and torsional vibration.

[Brief explanation of drawings]

1 to 3 show conventional examples of support structures for piezoelectric vibrators. FIG. 4 is an explanatory diagram showing vibration displacement of a coupled tuning fork type crystal resonator. FIGS. 5 and 6 show embodiments of the present invention. 12... Oscillation piece 13... Hermetic terminal 14, i... 1, 5... Lead terminal 16...
...Oscillating piece 17.18...Is it more than the lead terminal? (A) (B) (.) +5 factor 6 factor

Claims (1)

[Claims] Penetrating a hermetic terminal located further below the bottom end of the oscillating piece in a portion where the oscillating piece includes a central axis of the oscillating piece that is close to the bottom end on the U-shaped surface and does not reach both sides;
And the tips of the two rod-shaped or plate-shaped terminal conductors provided parallel to the front He U prison surface make the base length of the oscillating piece L.
1. A support structure for a piezoelectric vibrator, characterized in that the oscillation piece is bent in the direction of the center axis of the oscillation piece in an area of 0.5L or less, and is directly fixed to the oscillation piece with a certain gap.