JPH0865075A - Piezoelectric resonator - Google Patents

Abstract

PURPOSE: To obtain a piezoelectric resonator where the space between an input/ output leading out electrode and a ground leading out electrode is wide and productivity is excellent. CONSTITUTION: On the front and back surfaces of a piezoelectric body mother board, band-shaped vibration electrodes 2 to 4 extending in the long side direction of a board 1 are provided and leading out electrodes 5 to 7b extending from these vibration electrodes 2 to 4 in the short side direction of the board 1 are provided. The electrode width of each of the leading out electrodes 5 to 7b formed on the board 1 is set to the value of the summation of the dimension which is twice as large as the electrode width of the leading out electrode of a piezoelectric resonator and the blade thickness dimension of a cutting cutter. Piezoelectric resonators 111 and 112 are segmented by cutting the board 1 along the center line of the leading out electrodes 5 to 7b, that is along an alternate long and short dash line 10 by the cutting cutter at a leading out pitch P1 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric resonator, and more particularly to a piezoelectric resonator used in trap circuits, filter circuits and the like.

[0002]

2. Description of the Related Art As a conventional piezoelectric resonator, for example, as shown in FIG. 5, vibrating electrodes 32 and 33 and lead electrodes 35 and 36 are provided on the surface of a piezoelectric substrate 31, and vibrating electrode 34 is provided on the back surface. There is known one provided with the extraction electrodes 37a and 37b. Extraction electrodes 35, 36, 37a, 37
b is arranged near the center of the piezoelectric substrate 31, and is designed so that the extraction electrodes 35 to 37b are not easily cut when the piezoelectric resonator is cut out from the piezoelectric mother board.

In this piezoelectric resonator, however, if the extraction electrode 35 is the input electrode, the extraction electrode 36 is the output electrode, and the extraction electrodes 37a and 37b are the ground electrodes, the input extraction electrode 35 and the ground extraction electrode 37a are close to each other or output. Extraction electrode 36 and ground extraction electrode 37b
Approaching causes the generation of unnecessary vibration and deteriorates the resonance frequency characteristic. Therefore, although the conductor width of the extraction electrode is narrowed, a thin conductor width easily causes processing defects such as chipping and disconnection,
It hindered the improvement of productivity.

Therefore, an object of the present invention is to provide a piezoelectric resonator having a wide interval between the input / output extraction electrode and the ground extraction electrode and excellent productivity.

[0005]

In order to solve the above problems, the piezoelectric resonator according to the present invention has a strip-shaped vibration extending in the long side direction of the motherboard at the center of the front and back sides of the elongated piezoelectric mother board. Electrodes are provided, extraction electrodes extending from the vibrating electrode in the short side direction of the motherboard are provided at a predetermined extraction pitch, and the extraction electrodes are cut out in the short side direction so as to divide the extraction electrode into two at the extraction pitch. One of the lead electrodes divided into two is provided at the side edge of the piezoelectric substrate.

With the above structure, the cut-out piezoelectric resonator is always provided with the extraction electrode along the side edge of the piezoelectric substrate. Therefore, the distance between the input / output extraction electrode and the ground extraction electrode becomes wider than that of the conventional piezoelectric resonator. Moreover, since the electrode width of the extraction electrode formed on the front and back surfaces of the mother board is at least twice the electrode width of the extraction electrode of the piezoelectric resonator, it is easy to form the extraction electrode, and processing such as chipping or disconnection is performed. Defects are reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the piezoelectric resonator according to the present invention will be described below with reference to the accompanying drawings. In this example, a case of a three-terminal piezoelectric resonator will be described. As shown in FIG. 1, the piezoelectric mother board 1 has an elongated shape, and strip-shaped vibrating electrodes 2 and 3 extending in the long side direction of the board 1 are provided opposite to each other at the center of the surface. Extraction electrodes 5 and 6 drawn out from the boards 2 and 3 in the short side direction of the board 1 are extended to the edge of the board 1. Similarly, board 1
A strip-shaped vibrating electrode 4 extending in the long side direction of the board 1 is provided in the center of the back surface of the board 1.
Has been extended to the edge. As the material of the piezoelectric mother board 1, ceramics such as barium titanate or PZT is used. As the material of the piezoelectric mother board 1, besides ceramics, quartz or LiTaO _{3 is used.}
And so on. Each of the electrodes 2 to 7b is made of Cu, Ag, Ag-Pd
It is made of a conductive material such as, and is formed by means such as print drying, sputtering or vapor deposition.

Here, the lead-out pitch of the lead-out electrodes 5, 6, 7a and 7b is P ₁ . The electrode widths of the extraction electrodes 5 to 7b formed on the board 1 are the same as those of the piezoelectric resonator 11 ₁ , which will be described later.
It is set to 11 ₂ value which is the sum of the blade thickness dimension of 2 times the dimension and cut cutter electrode width of the lead electrode 5～7B.
Therefore, the extraction electrodes 5 formed on the front and back surfaces of the board 1
The electrode width of 7b becomes remarkably larger than that of the conventional piezoelectric resonator, and processing defects such as chipping and disconnection are reduced.

Next, the board 1 is cut by a cutting cutter (not shown) at a drawing pitch P ₁ along the center line of the drawing electrodes 5 to 7b, that is, the alternate long and short dash line 10. At this time, the reference position of the cutting cutter is performed using the extraction electrodes 4 to 7b, but the extraction electrodes 5 to 7b.
Since the conductor width of is large, accurate reference positioning can be performed,
Workability is also good.

As shown in FIG. 2, the piezo-resonator 11 ₁ cut out has vibrating electrodes 2 and 3 placed at the center of the surface of a piezoelectric substrate 12, and the vibrating electrodes 2 and 3 form the piezoelectric substrate 12 respectively. Along the right and left edges of the extraction electrode 5,
6 extends to the end of the piezoelectric substrate 12. Similarly, the vibrating electrode 4 is provided at the center of the back surface of the piezoelectric substrate 12, and the extraction electrodes 7 a and 7 b are formed along the left side edge and the right side edge of the piezoelectric substrate 12 from the vibrating electrode 4 and the end portions of the piezoelectric substrate 12 are formed. Has been extended to.

Further, in the piezoelectric resonator 11 ₂ cut out together with the piezoelectric resonator 11 ₁ , as shown in FIG. 3, the arrangement of the extraction electrodes 5 to 7b is symmetrical with respect to the piezoelectric resonator 11 ₁ . ing. In the state of the motherboard 1, the piezoelectric resonator 11
₁ and 11 ₂ are adjacent, an input lead-out electrode 5 of the piezoelectric resonator 11 ₂ is integral with the input lead-out electrode 5 of the piezoelectric resonator 11 _1. Similarly, the output lead-out electrode 6 of the piezoelectric resonator 11 ₂ is integrated with the output lead-out electrode 6 of the piezoelectric resonator 11 _1, the piezoelectric resonator 11 _second ground lead electrode 7a, 7b
Are the ground extraction electrodes 7 of the piezoelectric resonator 11 _1.
It is integrated with a and 7b.

In the piezoelectric resonators 11 ₁ and 11 ₂ , when the extraction electrode 5 is an input electrode, the extraction electrode 6 is an output electrode, and the extraction electrodes 7a and 7b are ground electrodes, the distance between the input extraction electrode 5 and the ground extraction electrode 7a is large. Alternatively, since the distance between the output extraction electrode 6 and the ground extraction electrode 7b is wider than that of the conventional piezoelectric resonator, unnecessary vibration is less likely to occur and the resonance frequency characteristic is improved. FIG. 4 is an electrical equivalent circuit diagram of the piezoelectric resonators 11 ₁ and 11 ₂ thus obtained.

The piezoelectric resonator according to the present invention is not limited to the above embodiment, but can be variously modified within the scope of the invention. In particular, the shape of the vibrating electrode is arbitrary.

[0014]

As is apparent from the above description, according to the present invention, the electrode width of the extraction electrode formed on the front and back surfaces of the piezoelectric mother board is at least twice the electrode width of the extraction electrode of the piezoelectric resonator. Therefore, the extraction electrode can be easily formed, and processing defects such as chipping and disconnection can be reduced.

Further, since the lead electrode has a large conductor width, the cutout reference position can be accurately set when cutting out the piezoelectric resonator from the piezoelectric mother board, and the workability is also improved. Further, since the extraction electrode is always provided along the side edge of the piezoelectric substrate, the distance between the input / output extraction electrode and the ground extraction electrode can be made wider than that of the conventional piezoelectric resonator, and the resonance frequency characteristic is improved. Can be made.

[Brief description of drawings]

FIG. 1 is a plan view showing a piezoelectric mother board of a piezoelectric resonator according to the present invention.

FIG. 2 is a plan view showing a piezoelectric resonator cut out from the piezoelectric mother board shown in FIG.

FIG. 3 is a plan view showing another piezoelectric resonator cut out from the piezoelectric mother board shown in FIG.

FIG. 4 is an electrical equivalent circuit diagram of a piezoelectric resonator.

FIG. 5 is a plan view showing a conventional piezoelectric resonator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Piezoelectric mother board 2, 3, 4 ... Vibration electrode 5, 6, 7a, 7b ... Extraction electrode 11 ₁ , 11 ₂ ... Piezoelectric resonator 12 ... Piezoelectric substrate P ₁ ... Extraction pitch

Claims (1)

[Claims] 1. A strip-shaped vibrating electrode extending in the long side direction of the mother board is provided at the center of the front and back of a long piezoelectric substrate, and a lead electrode extending in the short side direction of the mother board is drawn out from the vibrating electrode in a predetermined manner. Set up on the pitch,
The piezoelectric element is characterized in that the lead-out electrode is cut out in the short side direction from the motherboard at the lead-out pitch so as to be divided into two, and one lead-out electrode of the two lead-out electrodes is provided on a side edge of the piezoelectric substrate. Resonator.