JPH057773Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a piezoelectric vibrator having a thin portion having a different thickness at its base.

[Prior Art] In order to process piezoelectric vibrators in large quantities with high precision, there is etching processing using photolithography. In recent years, as piezoelectric vibrators have become more compact, not only the vibrating part but also the base, which is hardly involved in vibration, have been integrally molded. In order to improve the characteristics of the piezoelectric vibrator, it is important to prevent the energy from the vibrating part from propagating to the base. For this reason, a method is used to prevent the spread of the virus by providing a through hole or the like in a part of the base.

However, although the provision of through holes drastically reduces the propagation of energy to the base and improves properties, it has the disadvantage of weakening mechanical strength.

[Problems to be Solved by the Invention] The present invention is a piezoelectric vibrator that prevents the propagation of energy to the base and also has improved mechanical strength.

[Structure of the present invention] The structure of the present invention is a piezoelectric vibrator that uses a rotating Y plate rotated by θ degrees around the X axis, and consists of a vibrating part and a base, which are integrally formed by etching using photolithography. In the piezoelectric vibrator, a dimension 1 of the thin section in the Z' axis direction of the thin section having different thicknesses in at least a portion of the base is equal to or less than t/tan θ, where the thickness t is the thickness dimension t.

[Operations and Examples] FIG. 1 is a perspective view of an AT cut vibrator 10, which is the most commonly used piezoelectric vibrator in which a vibrating part 11 and a base part 12 are integrally formed by etching using photolithography. . The bottom of the figure shows the axial direction.

For miniaturization, it has a rectangular shape with its longitudinal direction along the Z' axis, and is provided with a base 12 for connection to a holding system. A thin portion 13 having a different thickness is provided in a part of the base portion 12.

Figure 2 shows the thin section 1 seen from the direction of the arrow in Figure 1.
3, and the lower part of the figure shows the axial direction.
The rotating Y plate is rotated by an angle θ from the Z axis around the X axis, and θ is an AT cut of around 35 degrees. If the length l of the thin part 13 in the Z'-axis direction is set to a value smaller than t/tanθ, where the thickness is t, the thin part 13 as shown in Fig. 2 will be obtained. It becomes a hole.

In other words, this thin portion 13 utilizes the fact that the etching speed differs depending on the axial direction, and since the etching speed advances in the order of the Z-axis, X-axis, and Y-axis, when the l dimension is set to the above value, As shown in Figure 2, the thin part 1 remains in an S-shape and has different thickness dimensions.
It becomes 3.

As shown in FIG. 2, in the case of an AT cut, the cross-sectional shape of the thin portion remaining after etching is S-shaped, but in the case of a DT cut, etc., the partial cross-sectional shape of the thin portion is Z-shaped. Of course, it is necessary that the cut length l in the Z'-axis direction is the main surface angle θ from the Z'-axis, and satisfies the condition of t/tan θ or less.

In the present invention, thin portions 13 having different thickness dimensions are provided in at least a portion of the base portion 12, and since these are integrally molded by etching using photolithography, they can be easily provided. . Conventionally, this property was maintained only by the through holes, but it is also possible to increase the mechanical strength, and the propagation of energy from the vibrating part 11 to the base part 12 is reduced to a part of the base part 12. The provided thin portion 13 could sufficiently prevent this, and the characteristics of the AT cut vibrator 10 could be maintained.

[Effects of the present invention] The present invention is a piezoelectric vibrator consisting of a vibrating part and a base, which is integrally formed by etching using photolithography, and has thin parts with different thicknesses at the base. Since there are no through holes, the mechanical strength can be improved. Also,
Due to the thin part, energy propagation from the vibrating part to the base had the same effect as that of a through hole, and the characteristics of the piezoelectric vibrator could be improved. Furthermore, since this thin portion was formed by etching at the same time as the external shape of the piezoelectric vibrator, it could be easily formed without requiring any other man-hours.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the piezoelectric vibrator of the present invention, and FIG.
The figure is a partial sectional view of the thin section of FIG. 1. 10... piezoelectric vibrator, 11... vibrating section, 12...
...Base, 13... Thin part.

Claims (1)

[Scope of utility model registration request] In a piezoelectric vibrator that uses a quartz crystal plate whose rotating Y plate is rotated by θ degrees around the A piezoelectric vibrator characterized in that a dimension l of the thin portion in the Z'-axis direction is equal to or less than t/tanθ, where t is the thickness dimension.