JPH06244670A - Piezoelectric parts - Google Patents

Abstract

PURPOSE:To adjust a frequency from the outside of electronic parts and to match the frequency with a specified value by providing a translucent hole at a sealing member so as to adjust the frequency by transmitting laser beams. CONSTITUTION:A sealing member 13 is composed of ceramic substrates 13a and 13b in a box shape, vertically crimps a piezoelectric element 12 with respective right and left side walls, extends the terminal part of the piezoelectric element 12 to the out side of the side walls and connects the pulledout electrode part to an external electrode 15. On the other hand, a translucent hole 14 is formed by mounting any translucent member at the central openings of the respective substrates 13a and 13b. Then, the piezoelectric element 12 and sealing member 13 formed by adjusting the frequency while applying resin resist or the like are prepared, the piezoelectric element 12 is crimped by forming a space for vibration between the side walls of the substrates 13a and 13b, and the element is adhered and sealed. Next, the frequency of piezoelectric parts 11 is measured and when it gets out of the specified value, the frequency is adjusted and matched to the specified value by irradiating the parts with the laser beams from the translucent hole 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type piezoelectric component capable of adjusting a frequency at a product stage and conforming to a standard, for example, a non-conformance caused by a frequency mismatch of a piezoelectric component utilizing an energy trapping type vibration mode. The present invention relates to a chip-type piezoelectric component capable of preventing the generation of non-defective products and improving the product yield.

[0002]

2. Description of the Related Art Conventionally, as a piezoelectric component, one having a structure as shown in FIGS. 4 and 5 has been known. In the piezoelectric component 1 shown in FIGS. 4 and 5, the first electrode 4 and the second electrode 5 are provided on both main surfaces of the front and back of the piezoelectric substrate 3 so as to partially oppose each other. The piezoelectric element 2 that generates a mode, a case 6 that accommodates the electrodes of the piezoelectric element 2 so as not to hinder the vibration of the opposing vibration portion, a lid 7 that seals the case 6, and the like are included.
As shown in FIG. 3, the piezoelectric element 2 has a piezoelectric substrate 3 made of strip-shaped piezoelectric ceramics on one main surface thereof.
A first electrode 4 extending beyond the central portion from one edge of
A second electrode 5 extending beyond the central portion from the other end of the other main surface of the piezoelectric substrate 3 is provided, and the central portions of the first and second electrodes 4 and 5 are opposed to each other across the piezoelectric substrate 3. The vibrating portion is formed and the portion extending to the end is used as the extraction electrode 4a or 5a. The case 6 has a space formed by the side walls so that the vibration of the vibrating portion of the piezoelectric element 2 is not hindered, and mounting steps 8 are provided on both side wall surfaces of the case 6 from the surface of each mounting step 8. An internal electrode 9 is provided so as to extend to the upper surface of the edge. The piezoelectric element 2 is housed in the space of the case 6,
After the lid 7 is adhered and sealed, the external electrodes 10, 10 which are electrically connected to the internal electrodes 9 are provided at the end of the case 6 and the lid 7. Since the frequency of the piezoelectric component 1 having the above-described configuration cannot be adjusted in a product state, the piezoelectric element 2 alone is performed as follows before the piezoelectric element 2 is enclosed in the sealing member. The thickness of the piezoelectric substrate 3 is adjusted. The thickness of the metal thin film electrode attached to the piezoelectric element 2 is adjusted. Adjust by applying a thin layer of resin resist near the vibrating electrode.

[0003]

However, as described above, in the conventional piezoelectric component, the frequency is adjusted before it is enclosed in the sealing member, so that the resonance frequency can be obtained even if the waveform characteristic is the reference type. However, there was a problem that the product deviated from the standard and a few% of defective products were generated.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a piezoelectric component capable of adjusting the frequency in a product state.

[0005]

In a piezoelectric component according to the present invention, electrodes are provided on both main surfaces of the front and back of a piezoelectric substrate, the electrodes facing each other with the substrate sandwiched therebetween, and the electrodes facing a part of the electrode. In a piezoelectric component including a piezoelectric element having a vibrating portion and a sealing member having the piezoelectric element sealed to form a vibration space, a transparent member for transmitting a laser beam to the sealing member to adjust a frequency. It is characterized in that an optical hole is provided.

[0006]

As described above, in the piezoelectric component according to the present invention, the electrodes, which are partially opposed to each other with the substrates sandwiched, are provided on the front and back main surfaces of the piezoelectric substrate, and the vibrating portion is provided at the part where the electrodes are partially opposed. And a sealing member that seals the piezoelectric element by forming a cavity for vibration, and the sealing member is provided with a light-transmitting hole. After the piezoelectric element is housed in a sealing member and sealed to form a rectangular chip, a long-wavelength laser beam is emitted from the translucent hole to the electrode of the vibrating portion of the piezoelectric element in the sealing member or the resin resist. The frequency is adjusted by irradiating and destroying the polarization degree from the outside of the piezoelectric component, or evaporating and degenerating the resin resist. As a result, since the frequency is adjusted with the actually used piezoelectric parts, the waveform characteristics and resonance frequency can be adjusted to the reference values, which can reduce the number of defective products and improve the yield, and the reliability of the products. It is possible to improve the sex.

[0007]

EXAMPLES Examples of the present invention will be described below. Figure 1
FIG. 4 is a cross-sectional view illustrating a piezoelectric component according to an exemplary embodiment of the present invention. As shown in FIG. 1, the piezoelectric component 11 includes a piezoelectric element 12 and a sealing member 1 that forms a space to accommodate and seal the piezoelectric element 12 so as not to disturb the vibration of a vibrating portion.
3 and a translucent hole 14 formed in the sealing member 13. In the piezoelectric element 12 of the present embodiment, electrodes 4 and 5 are provided on both main surfaces of the front and back of the piezoelectric substrate 3 so as to partially oppose each other, and an energy trap type thickness shear vibration mode is generated.

As shown in FIG. 1, the sealing member 13 according to the present embodiment is a box-shaped ceramic substrate 13a,
13b, and the piezoelectric element 12 is sandwiched between the left and right side walls of each of the substrates 13a and 13b from above and below. The end portion of the piezoelectric element 12 is extended to the outside of the side wall, and the extraction electrode portion is connected to the external electrode 15
Connected to. The transparent hole 14 is formed on each of the substrates 13a, 13
A transparent material is adhered to the opening at the center of b. As the translucent material, a CO ₂ laser,
Resins, ceramics, etc. may be used as long as they can transmit light having a long wavelength (several μm) such as YAG laser.
The material does not matter.

A method of manufacturing the piezoelectric component 11 according to this embodiment will be described below. First, the piezoelectric element 12 formed by adjusting the frequency by applying a resin resist or the like, and the sealing member 13 having the translucent hole 14 are prepared. Next, the piezoelectric element 12
Is a box-shaped ceramic substrate 13a, 1
A space for vibration is formed and sandwiched between the side walls of 3b, and the space is bonded and sealed. Next, the frequency of the piezoelectric component 11 is measured,
If it is out of the specified value, laser light is radiated from the translucent hole 14 to adjust the value to match the specified value. That is, when the frequency is low, the resin resist is irradiated and evaporated from the vibrating part to increase the frequency. Conversely, when the frequency is high, the electrode of the vibrating part is irradiated to adjust the polarization degree to adjust the frequency. cut back. The laser light is CO ₂ laser, YAG
Light with a long wavelength (several μm) such as a laser is used. According to the present embodiment, it is possible to irradiate a laser beam from outside the electronic component 11 at the product stage to adjust the frequency and adjust it to a specified value. As a result, it is possible to reduce the generation of defective products and improve the yield.

FIG. 2 is a sectional view for explaining another embodiment of the piezoelectric component of the present invention. As shown in FIG. 2, the piezoelectric component 16 includes the piezoelectric element 2 formed as shown in FIG.
This piezoelectric element 2 should not vibrate in the vibrating section,
It is composed of a sealing member 17 that forms a space to accommodate and seal it, and a translucent hole 18 formed in the sealing member 17. The piezoelectric element 2 of this embodiment produces an energy trap type thickness longitudinal vibration mode. The sealing member 17 is a case 17
a and a lid 17b, and translucent holes 18 are formed in the surfaces of the case 17a and the lid 17b, which face each other. In the case 17a, a space is formed by the side walls so as not to disturb the vibration of the vibrating portion of the piezoelectric element 2, and mounting steps are provided on both side wall surfaces, and extend from the surface of each mounting step to the upper surface of the edge of the case. Internal electrodes 19 are provided. The external electrode 2 is housed in the space of the case 17a, and the lid 17b is adhered and sealed and then electrically connected to each internal electrode 19.
0 is provided at the end of the surface. In addition, the configuration is similar to that of the above embodiment.

In the method of manufacturing the piezoelectric component 16 according to the present embodiment, first, the frequency is adjusted by coating a resin resist or the like, and the piezoelectric element 2 and the translucent hole 18 configured as described above are formed.
A sealing member 17 having the above is prepared. Next, the piezoelectric element 2
Then, a space for vibration is formed in the case 17a, the space is accommodated, the electrodes are electrically connected to the internal electrodes 19 by a conductive adhesive or the like, and then the lid 17b is bonded to seal the piezoelectric element 2. Then, in the same manner as in the above embodiment, the laser light is transmitted through the transparent hole 18
And adjust the frequency by irradiating.

In the above embodiment, the translucent hole is formed on the surface of the sealing member facing the two main surfaces of the front and back of the piezoelectric element, but it may be formed on one surface. Further, the sealing member may have a configuration different from that of the above embodiment. Also,
The manufacturing method is not limited to the above embodiment, and the order of manufacturing steps can be appropriately changed. In addition, the present invention is not limited to the above-described embodiment, and in short, any structure may be used as long as the sealing member is provided with a portion formed of a translucent member.

[0013]

As described above, according to the piezoelectric component of the present invention, it is possible to adjust the frequency from the outside of the electronic component at the product stage and adjust it to the specified value. As a result, it is possible to reduce the generation of defective products and improve the yield.

[Brief description of drawings]

FIG. 1 is a sectional view showing a piezoelectric component according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a piezoelectric component according to another embodiment of the present invention.

FIG. 3 is a perspective view illustrating a piezoelectric element.

FIG. 4 is a sectional view showing a conventional piezoelectric component.

FIG. 5 is a perspective view showing a conventional piezoelectric component.

[Explanation of symbols]

2,12 Piezoelectric element 3 Piezoelectric substrate 4 First electrode 5 Second electrode 11,16 Piezoelectric component 13,17 Sealing member 1
4,18 Translucent hole

Claims (1)

[Claims] 1. A piezoelectric element in which electrodes are provided on both main surfaces of the front and back of a piezoelectric substrate, the electrodes facing each other with the substrate sandwiched therebetween, and a vibrating portion is formed in a portion facing the electrodes, and the piezoelectric element. In a piezoelectric component including a sealing member that forms a space for vibration and is sealed, a transparent hole for transmitting a laser beam to adjust a frequency is provided in the sealing member. parts.