JP2669099B2 - Resonator using third harmonic and manufacturing method thereof - Google Patents

Description

The present invention relates to an oscillator using a piezoelectric resonator and a method for manufacturing the same, and more particularly to an oscillator using a third harmonic and a method for manufacturing the same.

(Prior Art) As shown in FIG. 7, a piezoelectric resonator element in an oscillator is provided on a main surface on the front side and the back side of the piezoelectric substrate 20.
A vibration electrode 22 is provided to face each other. The front and rear vibrating electrodes 22 are respectively connected to terminal electrodes 24 via lead electrodes, lead terminals 26 are soldered to the front terminal electrodes 24, and lead terminals 28 are soldered to the rear terminal electrodes 24. . Such a piezoelectric resonator element is molded with resin 30 and has a cavity in the vibrating part so as not to suppress vibration.
32 are formed.

(Problems to be Solved by the Invention) In the resonator using the third harmonic having such a structure, the cavity 32
In some cases, the fundamental wave is strongly excited due to the variation in the size of the piezoelectric substrate 20 or the variation in the characteristics of the piezoelectric substrate 20 itself, and the fundamental wave may be oscillated due to the characteristics of the oscillation circuit.

An object of the present invention is to provide an oscillator that can suppress the fundamental wave without affecting the third harmonic.

Another object of the present invention is to provide a method for manufacturing an oscillator that can suppress the fundamental wave without affecting the third harmonic by a simple process.

(Means for Solving the Problems) According to the present invention, a piezoelectric substrate has oscillating electrodes opposed to each other with the piezoelectric substrate sandwiched between the main surfaces on the front side and the back side thereof. A dummy electrode is provided in a region outside the region where the second harmonic is excited and in which the fundamental wave is excited, and solder is attached to the dummy electrode or a part of the lead terminal is soldered. This is a third harmonic utilizing oscillator provided with a mass suppression region for wave suppression.

In the manufacturing method of the present invention, the vibrating electrode and the terminal electrode connected to the vibrating electrode are provided on both main surfaces, and at least one of the main surfaces is a region outside the region where the third harmonic is excited and the fundamental wave is excited. A step of preparing a piezoelectric substrate having a dummy electrode provided so as to cover an area to be formed, a step of preparing at least one pair of terminals to which solder is applied in advance on at least one surface, and a step in which solder is applied in advance. Heating the terminal with hot air to melt the solder and connect the terminal electrode and the dummy electrode.

(Function) FIG. 4 shows the fundamental wave F1 and the third harmonic in the piezoelectric resonator element.
The displacement of F3 is shown. 2 is a piezoelectric substrate, and 4 and 8 are vibrating electrodes. In the region indicated by d, there is a displacement of the fundamental wave,
There is no displacement of the third harmonic. By arranging a dummy electrode in this area d and attaching solder thereto, or extending a part of the lead terminal and soldering to the dummy electrode,
The mass of the region d is added, and the displacement of the fundamental wave F1 is forcibly and selectively damped by the mass to form a third harmonic oscillator.

(Embodiment) Fig. 1 shows an embodiment, in which (A) is a plan view on the front side and (B) is a plan view on the back side. However, illustration of the mold member is omitted. 2A and 2B show the piezoelectric substrate in the embodiment, FIG. 2A is a plan view on the front side, FIG. 2B is a plan view on the back side, and FIG. 3 shows lead terminals used in the embodiment. It is a thing.

In FIG. 1, reference numeral 2 denotes a piezoelectric substrate such as a piezoelectric ceramic substrate. A vibration electrode 4 is formed at the center of the main surface on the front side, and is connected to a terminal electrode 6 via an extraction electrode. The terminal electrode 6 is an electrode to which a lead terminal is connected. The terminal electrode 6 is connected to a dummy electrode 6a disposed at the end of the piezoelectric substrate corresponding to the area d in FIG. Also on the back side of the piezoelectric substrate 2, the vibration electrode 8 is arranged at the center, and the front side vibration electrode 4 and the back side vibration electrode 8 are opposed to each other with the piezoelectric substrate 2 interposed therebetween. The vibrating electrode 8 is also connected to the terminal electrode 10 via the extraction electrode, and the terminal electrode 10 has a region d in FIG.
Is connected to the dummy electrode 10a arranged at the end of the piezoelectric substrate. The dummy electrodes 6a and 10a are used to suppress the vibration of the fundamental wave by adding a mass by connecting a part of the lead terminals by soldering.

As shown in FIG. 3, the lead terminals 12 and 14 are soldered and connected to the dummy electrodes 6a and 10a, respectively, in addition to the portions for external connection and the portions soldered to the terminal electrodes 6 and 10, respectively. Dummy lead terminals 12a and 14a are provided.

When the lead terminals 12, 12a are connected by soldering to the terminal electrode 6 and the dummy electrode 6a, and the lead terminals 14, 14a are connected by soldering to the terminal electrode 10 and the dummy electrode 10a, the dummy electrode portion 6a , 10a adds mass by the solder and the terminals 12a, 14a, and the fundamental wave F1 is suppressed.

A cavity is formed in the vibrating portion with the lead terminals 12 and 14 connected, and the piezoelectric resonator element is moded by the resin.

 Next, the manufacturing method of this embodiment will be described.

As shown in FIG.
6,6a and the back side electrodes 8,10,10a are formed. On the other hand, solder is applied in advance to the lead terminals 12, 12a, 14, 14a having the shape shown in FIG.

The lead terminals 12, 12a, 14, 14a on which the solder is formed are superimposed on the corresponding electrodes 6, 6a, 10, 10a of the piezoelectric substrate 2, hot air is blown to melt the solder, and then cooled naturally. As a result, the lead terminals 12, 12a, 14, 14a are connected to the electrodes 6, 6a, 10,
Solder to 10a, it is possible to achieve the soldering and the addition of the damping mass to the dummy electrode in one process.

 5 and 6 show another embodiment.

A vibrating electrode 4 is formed on the front main surface of the piezoelectric substrate 2, and a terminal electrode 6 is formed via a lead electrode. The vibrating electrode and the terminal electrode connected to the vibrating electrode via the extraction electrode are also formed on the back main surface. Dummy electrodes 16 (17) are formed on the front and back sides of the piezoelectric substrate 2 in a region where the fundamental wave is displaced outside the vibration region of the third harmonic.

As shown in FIG. 6, the dummy electrodes 16 and 17 have solder 16b formed on the dummy electrode 16a on the front side of the piezoelectric substrate 2 and solder 17b formed on the dummy electrode 17a on the back surface of the piezoelectric substrate 2. There is.

The lead terminal 18 is connected by soldering only to the terminal electrode 6 on the front side, the lead terminal 19 is connected by soldering only to the terminal electrode 10 on the back side, and the lead terminals 18 and 19 extend to the dummy electrodes 16 and 17. Not not.

In any of the embodiments, the distance (g in FIG. 6) between the vibrating electrodes 4, 8 and the mass-added regions 6a, 10a, 16, 17 depends on the thickness of the piezoelectric substrate 2, but is about 0.1 to 1 mm. It is advisable to do.

(Effect of the Invention) In the oscillator using the third harmonic of the present invention, the region outside the region where the third harmonic is excited on at least one main surface of the piezoelectric substrate of the piezoelectric resonator element and which is the fundamental wave Is provided in the area within the area where is excited by the solder or a part of the solder and the lead terminal, so that the fundamental wave can be effectively suppressed without significantly changing the conventional production equipment. .

In the manufacturing method of the present invention, a piezoelectric substrate having oscillating electrodes on both main surfaces is prepared, a dummy electrode is provided on at least one main surface of the piezoelectric substrate, and at least one pair in which solder is previously applied to at least one surface. Prepare the terminal of
Since the terminals are connected to the dummy electrodes by heating the terminals with hot air to melt the solder, soldering and addition of a damping mass to the dummy electrodes can be achieved in one step.

[Brief description of the drawings]

FIG. 1 shows an embodiment, (A) is a plan view of the front side, (B) is a plan view of the back side, and FIG. 2 is a piezoelectric substrate in the same embodiment. A) is a plan view of the front side, (B) is a plan view of the back side, FIG. 3 is a plan view showing the lead terminals used in the same embodiment, and FIG.
FIG. 5 is a view showing the displacement of the next harmonic, FIG. 5 is a plan view showing another embodiment, FIG. 6 is a sectional view taken along line XX in FIG. 5, and FIG.
The figure shows a conventional oscillator, (A) is a front sectional view, and (B) is a side sectional view. 2 …… Piezoelectric substrate, 4,8 …… Vibration electrode, 6,10 …… Terminal electrode, 6a, 10a, 16a, 17a …… Dummy electrode, 12,14,18,19 ……
Lead terminals, 12a, 14a …… Part of the lead terminals, 16b, 17b…
…solder.

Claims (2)

(57) [Claims] 1. A region on a front surface and a back surface of a piezoelectric substrate, having vibrating electrodes opposed to each other with the piezoelectric substrate interposed therebetween, and a third harmonic on at least one main surface of the piezoelectric substrate being excited. A dummy electrode is provided in a region outside the fundamental wave where the fundamental wave is excited, and a mass adding region for fundamental wave suppression is provided by attaching solder to the dummy electrode or soldering a part of a lead terminal. A third-harmonic-based oscillator. 2. A vibrating electrode and a terminal electrode connected to the vibrating electrode on both main surfaces, and a fundamental wave is excited on at least one of the main surfaces in a region outside a region where a third harmonic is excited. A step of preparing a piezoelectric substrate having a dummy electrode provided so as to cover the area, a step of preparing at least a pair of terminals having solder applied to at least one surface in advance, and the terminals to which the solder has been applied in advance Connecting the terminal electrode and the dummy electrode by heating the substrate with hot air to melt the solder.