JPH1093378A - Piezo components - Google Patents

Abstract

(57) [Problem] To provide a piezoelectric component in which cracks of a piezoelectric vibrator are prevented from occurring and in which characteristics do not easily change. SOLUTION: A spring load acting on the leaf spring which holds each component housed in the case 74 between the inner wall of the case 74 and the leaf spring once the deformation amount of the leaf spring increases becomes a predetermined peak load. A leaf spring having a load characteristic that starts to decrease after the pressure has reached.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric component incorporating a piezoelectric vibrator.

[0002]

2. Description of the Related Art Conventionally, there has been known a piezoelectric component in which a piezoelectric vibrator made of ceramics or the like is incorporated and used as an oscillation circuit, a filter circuit, or the like. 5 is a cross-sectional view of a conventional piezoelectric component, FIG. 6 is a perspective view showing a piezoelectric resonator constituting the piezoelectric component shown in FIG. 5, and a terminal electrode plate sandwiching the piezoelectric vibrator, and FIG. FIG. 8 is a plan view of a leaf spring constituting the piezoelectric component shown in FIG. 5, FIG. 9 is a side view thereof, FIG. 10 is a graph showing load characteristics of the leaf spring shown in FIG. 8, and FIG. FIG. 12 is a perspective view showing a case that constitutes the piezoelectric component shown in FIG. 5, showing a state in which the components housed in the case are arranged.

In describing the piezoelectric component 50 shown in FIG. 5, first, the structure and operation of a piezoelectric vibrator constituting a piezoelectric component and a terminal electrode plate sandwiching the piezoelectric vibrator will be described. Here, as a representative, the structure and operation of the piezoelectric vibrator 54 shown in FIG. 5 and the terminal electrode plates 57 and 58 sandwiching the piezoelectric vibrator 54 will be described with reference to FIGS. Then, the leaf spring will be described with reference to FIGS.
2, a method of assembling the piezoelectric component will be described, and finally, the entire piezoelectric component shown in FIG. 6 will be described.

A piezoelectric vibrator 54 shown in FIG. 6 has a conductor film formed on a front surface 54a and a back surface 54b of the piezoelectric vibrator 54. On the other hand, the terminal electrode plates 57 and 58 are flat supporting portions 57 a and 58 for supporting the piezoelectric vibrator 54.
a, and as shown in FIG.
Conductive protrusions 57b and 58b are formed at the center of the portion a. The piezoelectric vibrator 54 has two terminal electrode plates 57, 5
8, the conductor film formed on the piezoelectric vibrator 54 and the protrusions 57b, 5 formed on the terminal electrode plates 57, 58.
8b is in electrical contact. Here, when a high-frequency voltage is applied between the two terminal electrode plates 57 and 58, the piezoelectric vibrator 54 resonates at a frequency unique to the piezoelectric vibrator 54.

A leaf spring 63 shown in FIG. 8 has a shape in which a center portion of each end face is cut out in a semicircular shape, and has a curved plate shape as shown in FIG. This leaf spring 63 shows a spring load characteristic as shown in FIG. 10 with respect to a load in a direction perpendicular to the paper surface of FIG. In this graph, the vertical axis represents the spring load acting on the leaf spring 63, and the horizontal axis represents the amount of deformation of the leaf spring 63 due to the spring load. From this graph, it can be seen that the amount of deformation of the leaf spring 63 with respect to the spring load monotonically increases.

Hereinafter, a method for storing each component stored in the case 64 will be described. First, the piezoelectric vibrator 52 is
Sandwiched between the electrode plate 59 and the terminal electrode plate 56, the terminal electrode plate 5
An insulating plate 61 is disposed on the back surface of the substrate 6, and a U-shaped electrode plate 62 is disposed so as to straddle these components. Further, the piezoelectric vibrator 51 is disposed on the back surface of the U-shaped electrode plate 62,
2 so as to sandwich the piezoelectric vibrator 51 therebetween.
Place. A leaf spring 63 is provided on the back surface of the terminal electrode plate 55.
Place. Further, the piezoelectric vibrator 53 is disposed on the surface opposite to the U-shaped electrode plate 62, and the electrode plate 60 is disposed so as to sandwich the piezoelectric vibrator 53 between the U-shaped electrode plate 62 and the U-shaped electrode plate 62. Further, the terminal electrode plate 57 is arranged on the back surface of the electrode plate 60, and the piezoelectric vibrator 54 is arranged on the back surface of the terminal electrode plate 57. Also,
The terminal electrode plate 58 is disposed so as to sandwich the piezoelectric vibrator 54 between the terminal electrode plate 57 and the terminal electrode plate 57. In this way, the components are arranged as shown in FIG.

Next, the array components 11 arranged as described above
0 using a jig or the like (not shown)
Is held with a force larger than the force received from the inner wall of the case 64 when the case 6 is stored in the case 64, and the case 6 shown in FIG.
Store in 4. By storing each component in the case 64 in this manner, the piezoelectric component 50 shown in FIG. 5 is configured.

[0008] The terminal electrode plate 55 constituting the piezoelectric component 50,
Leading ends of the extraction electrodes 55c, 56c, 57c, 58c for connection to external circuits are respectively provided at 56, 57, 58.
When a voltage is applied, each of the piezoelectric resonators resonates at a unique frequency and exhibits a function as a filter or the like. FIG. 13 is a diagram showing an equivalent circuit of the piezoelectric component shown in FIG.

The equivalent circuit shown in FIG. 13 is composed of an electrode plate 59 and a U-shaped electrode plate 62 shown in FIG.
2 and 53 are connected to each other, and the piezoelectric resonators 53 and 54 are connected to each other by the electrode plate 60 and the terminal electrode plate 57, thereby forming a ladder filter having a four-element structure.

[0010]

However, in the piezoelectric component 50 shown in FIG. 5, when the arrangement component 110 is stored in the case 64, the arrangement component 110 needs to be narrower than the interval between the inner walls of the case 64. 110 must be clamped with a force greater than the force received from the inner wall of the case 64, and there is a problem that cracks may occur in the piezoelectric vibrator when clamping is performed with such a large force.

When adjusting the frequency of the piezoelectric component 50, it is necessary to take out the components housed in the case 64 from the case 64 once.
There is also a problem that the load characteristic of the leaf spring 63 is changed by taking out each part from the above, and accordingly, the filter characteristic of the piezoelectric part is also changed. In view of the above circumstances, it is an object of the present invention to provide a piezoelectric component that prevents cracks in a piezoelectric vibrator and that does not easily change filter characteristics.

[0012]

The piezoelectric component of the present invention that achieves the above object comprises a box, a piezoelectric vibrator disposed in the box, and an electrode plate sandwiching the piezoelectric vibrator in the box. A piezoelectric component comprising a curved plate-shaped leaf spring for sandwiching the piezoelectric vibrator and the electrode plate between the inner wall of the box body and a reaction force acting on the inner wall of the box body. The leaf spring is characterized in that the leaf spring has a load characteristic in which the spring load acting on the leaf spring once reaches a predetermined peak load and then starts decreasing as the amount of deformation of the leaf spring increases.

Since the leaf spring constituting the piezoelectric component of the present invention has a load characteristic in which the spring load once reaches a predetermined peak load and then starts to decrease, the component disposed in the box has a peak load. There is no possibility that a larger force is applied, and cracks in the piezoelectric vibrator can be prevented by appropriately setting the peak load. In addition, the load characteristics of the leaf spring are hard to change, so that the filter characteristics of the piezoelectric component are also prevented from changing.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a cross-sectional view of one embodiment of the piezoelectric component of the present invention, FIG. 2 is a plan view of a leaf spring constituting the piezoelectric component shown in FIG. 1, and FIG. 3 is a leaf spring deformed by applying a load. FIG. 4 is a graph showing the load characteristics of the leaf spring shown in FIG.

The piezoelectric component 10 shown in FIG. 1 employs the leaf spring 63 shown in FIGS. 2 and 3 having the characteristics shown in FIG. 4 instead of the leaf spring 63 in the piezoelectric component 50 shown in FIG. It is comprised by. The leaf spring 13 has a curved plate shape, and has a projection 21 formed at the center as shown in FIG. 2, and is deformed into an arc shape by applying a load as shown in FIG. This leaf spring 13 has a load characteristic as shown in FIG.

In the graph shown in FIG. 4, the horizontal axis represents the amount of deformation of the leaf spring 13 and the vertical axis represents the spring load acting on the leaf spring 13. As shown in this graph, the load characteristic of the leaf spring 13 is represented by an upwardly convex parabola, and as the amount of deformation increases, the spring load once reaches a peak and then decreases.

As described above, the piezoelectric component 10 shown in FIG.
Since the plate spring 13 having the load characteristics shown in FIG. 4 is provided, the occurrence of cracks in the piezoelectric vibrator is prevented,
Changes in filter characteristics are also prevented.

[0018]

Embodiments of the present invention will be described below with reference to the drawings used in the description of the conventional example and the embodiments of the present invention. First, PZT prepared to a predetermined composition
The ceramic was formed into a plate and fired at 1300 ° C.
Next, a paste in which Ag and glass frit were mixed with an organic vehicle and a binder was printed on both surfaces of the ceramics, baked, and further polarized at 2500 V to obtain a PZT veneer. Next, this was cut into a predetermined size to obtain a piezoelectric vibrator. Also, a phosphor bronze plate having a thickness of 0.1 mm is prepared, and a projection having a height of 0.1 mm is formed on the phosphor bronze plate.
An electrode plate was obtained by performing Ag plating with a thickness of 5 μm. The leaf spring has a shape of a curved plate having a thickness of 0.1 mm and a diameter of 4.5 mm, and a projection having a height of 0.1 mm is formed at a central portion.
Those having the load characteristics shown in FIG.

Next, in order to construct a ladder type filter as shown in FIG. 13, a piezoelectric vibrator, terminal electrode plates, electrode plates, U-shaped electrode plates, insulating plates and leaf springs are arranged as shown in FIG. Then, it was stored in the case shown in FIG. Thus, the piezoelectric component 10 shown in FIG. 1 was manufactured. Since the above-described piezoelectric component 10 uses a leaf spring having the load characteristics shown in FIG. 4, no cracks in the piezoelectric vibrator are observed, and even if each component is taken out of the case, the filter characteristics of the piezoelectric component change. I was not able to admit.

[0020]

As described above, according to the piezoelectric component of the present invention, cracks in the piezoelectric vibrator are prevented, and changes in the characteristics of the piezoelectric component are also prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of a piezoelectric component of the present invention.

FIG. 2 is a plan view of a leaf spring constituting the piezoelectric component shown in FIG.

FIG. 3 is a sectional view of a leaf spring deformed by applying a load.

FIG. 4 is a graph showing a load characteristic of the leaf spring shown in FIG. 2;

FIG. 5 is a sectional view of a conventional piezoelectric component.

6 is a perspective view showing a piezoelectric resonator constituting the piezoelectric component shown in FIG. 5 and a terminal electrode plate sandwiching the piezoelectric resonator.

FIG. 7 is a side view showing a piezoelectric resonator constituting the piezoelectric component shown in FIG. 5 and a terminal electrode plate sandwiching the piezoelectric vibrator.

FIG. 8 is a plan view of a leaf spring constituting the piezoelectric component shown in FIG.

FIG. 9 is a side view of a leaf spring constituting the piezoelectric component shown in FIG.

FIG. 10 is a graph showing load characteristics of the leaf spring shown in FIG.

FIG. 11 is a diagram showing an arrangement state of each component stored in a case.

FIG. 12 is a perspective view showing a case constituting the piezoelectric component shown in FIG.

13 is a diagram showing an equivalent circuit of the piezoelectric component shown in FIG.

[Explanation of symbols]

 13 leaf spring 51, 52, 53, 54 piezoelectric vibrator 54a front surface 54b back surface 55, 56, 57, 58 terminal electrode plate 57a, 58a support portion 57b, 58b projection 59, 60 electrode plate 61 insulating plate 62 U-shaped electrode plate 64 cases 110 arrangement parts

Claims (1)

[Claims] 1. A box, a piezoelectric vibrator disposed in the box, an electrode plate sandwiching the piezoelectric vibrator in the box, and a reaction force applied to an inner wall of the box to form the box. A piezoelectric component comprising: a curved plate-shaped leaf spring that sandwiches the piezoelectric vibrator and the electrode plate between an inner wall on the opposite side; and wherein the leaf spring is configured such that as the amount of deformation of the leaf spring increases, A piezoelectric component having a load characteristic in which a spring load acting on a spring once reaches a predetermined peak load and then starts decreasing.