JPH0360506A - Piezoelectric vibrator - Google Patents

Abstract

PURPOSE:To reduce distortion to be generated in a piezoelectric piece and to prevent a frequency from changing by forming one end side of a piezoelectric piece holding member in the shape of a plate, forming an upper end part, linking part and lower end part by double bending the plate-shaped side, providing a slit in the linking part and connecting the both end outer peripheral parts of the piezoelectric piece to the lower end part. CONSTITUTION:For a holding member 7, forming one end side in the shape of the plate and double bending, an upper end part 9, linking part 10 and lower end part 11 are formed and a slit 12 is provided in the linking part 10. The upper end part 9 is made coincident with the upper surface of a wall and one end side is arranged respectively on the both end sides of a hole part 8. Then, the both end outer peripheral parts of a crystal piece 1 are connected onto the lower end part 11 of the holding member 7. The other end side to be linked to the upper end side 9 and to be an external terminal is extended along an outer surface. Accordingly, for the holding member 7, the strength of the linking part 10 is weakened by the slit 12 and elastic structure is obtained. Accordingly, for example, even when thermal expansion is generated in a horizontal direction in the crystal piece 1 and holding member 7, the distortion is not generated in the crystal piece 1 since the linking part 10 is deformed in the same direction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is applied to piezoelectric vibrators, and particularly relates to a holding member for a crystal vibrator that prevents frequency changes due to thermal expansion.

(Background of the Invention) Quartz crystal resonators are useful as oscillators and filter elements in various electronic devices because of their excellent resonant sharpness. In recent years, high precision has been desired due to the strictness of various specifications. For example, preventing frequency changes due to thermal expansion is also a factor in maintaining high accuracy.

(Conventional technology) FIG. 4 is a sectional view of a crystal resonator illustrating a conventional example.

The crystal resonator is constructed by placing a crystal piece 1, for example AT-cut, on a holding member 3 of a base 2. Opposing excitation electrodes 4 are formed on both main surfaces of the crystal blank l. Then, the extraction electrodes 5 are extended to the outer circumferences of the ends in opposite directions. The base 2 is made of ceramic, for example, and external lead-out electrodes 6 are metallized on the front and back surfaces. The holding member 3 is, for example, a cylindrical metal body, and is fixed to the tip side of the external lead-out electrode 6. The outer periphery of both ends of the crystal piece l is connected electrically and mechanically.

(Problems with the Prior Art) However, in the crystal resonator having the above configuration, the F4@ outer circumferential portion of the crystal piece t is simply fixed to the holding member 3 made of a metal body, thereby forming a rigid structure. Therefore, for something like this, 1
For example, even if there is thermal expansion, it cannot be absorbed and distortion occurs in the crystal blank 1.

Then, a frequency change is caused based on the stress sensitivity characteristics of the crystal piece 1 (this results in impairing the frequency temperature characteristics of the crystal resonator).

(Objective of the Invention) An object of the present invention is to provide a piezoelectric vibrator that prevents frequency changes by reducing strain generated in a piezoelectric piece due to thermal expansion.

(Solution Means) In the present invention, one end side of the holding member is made into a flat plate shape and double bent to form an upper end portion, a connecting portion, and a lower end portion, a slit is provided in the connecting portion, and a piezoelectric material is provided in the lower end portion. The solution is to connect the outer peripheries of both ends of the pieces. An embodiment of the present invention will be described below.

(Example) Figure s1 is a cross-sectional view of a crystal resonator illustrating an example of the present invention, where (a) is a cross-sectional view of the crystal resonator, and (b) is a view of a holding member. Note that the same parts as those in the previous embodiment drawings are given the same numbers and the explanation thereof will be simplified.

The crystal resonator is an excitation type (not shown) of the AT-cut crystal piece 1 [4] as described above, and the output voltage f! The outer peripheries of both extended ends of i5 are connected by the holding member 7 of the base 2.

The base 2 is made of ceramic, for example, and has eight holes in which the crystal piece 1 is accommodated. The holding member 7 has one end shaped like a flat plate and is bent double, and has an upper end 9, a connecting part 10, and a lower end 11.
, and a slit 12 is provided in the connecting portion 10. Then, the upper end 9 is placed on the upper surface of the wall, one end is placed on both ends of the hole 8, and the outer periphery of both ends of the crystal piece (■) is electrically and mechanically placed on the lower end (1) of the holding part N7. For example, the connection is made using a conductive adhesive. Further, the other end side, which is connected to the end side 9 and becomes the outer end tie 3, extends along the outer surface.

In such a structure, the holding part N7 has an elastic structure because the strength of the connecting part 10 is weakened by the slit A2. Therefore, even if there is thermal expansion in the horizontal direction in the crystal blank 1 and the holding member 7, for example, the connecting part 10 deforms in the same direction as shown in FIGS. 2(a) and 2(b). No distortion occurs. Therefore, frequency changes due to stress sensitivity characteristics can be prevented and original temperature characteristics can be obtained.

(Other Matters) In the above embodiment, the other end of the holding member extends along the outer surface as an external terminal, but the invention is not limited to this, and for example, as shown in $31:l, the other end The side may be folded back and connected to a metallized electrode (not shown) of the base 2, which can be changed at any time. In addition, the holding member 7
Although the upper end portion 9, the connecting portion 10, and the lower end portion 11 are illustrated as being perpendicular to each other, the connecting portion 10 may be inclined in advance, for example, in a Z shape. Basically, the longer the length, the longer the length. The effect is great. Further, although the piezoelectric vibrator has been described as a crystal vibrator, it is of course applicable to a piezoelectric vibrator made of other piezoelectric materials.

(Effects of the Invention) In the present invention, one end side of the holding member is made into a flat plate shape and bent double to form an upper end portion, a connecting portion, and a lower end portion, a slit is provided in the connecting portion, and a slit is provided in the lower end portion. The outer periphery of both ends of the piezoelectric piece is connected.

It is possible to provide a piezoelectric vibrator that prevents frequency changes by reducing strain generated in the piezoelectric piece.

[Brief explanation of drawings]

FIG. 1 is a diagram of a crystal resonator illustrating an embodiment of the present invention, in which (a) is a cross-sectional view, and (b) is a view of the tip end side of the holding member. FIG. 2 is a sectional view of the distal end side of the holding member for explaining the operation of the same embodiment. FIG. 3 is a partial sectional view of a crystal resonator illustrating another embodiment of the present invention. FIG. 4 is a diagram of a crystal resonator to explain a conventional example. FIG. 5(a) is a cross-sectional view, and FIG. 1(b) is a diagram of a crystal piece. Figure 2 Figure 4

Claims (1)

[Claims] In a piezoelectric vibrator in which the outer peripheral portions of both ends of a piezoelectric piece with electrodes extending from excitation electrodes on both principal surfaces are electrically and mechanically connected to one end side of a holding member, one end side of the holding member is made into a flat plate shape. A piezoelectric vibrator characterized in that the piezoelectric vibrator is double bent to form an upper end part, a connecting part, and a lower end part, a slit is provided in the connecting part, and outer peripheral parts of both ends of a piezoelectric piece are connected to the lower end part.