JPH08139561A - Chip piezoelectric resonance component - Google Patents

Abstract

PURPOSE: To provide a chip piezoelectric resonance component which is easily reduced in size and easily manufactured, and utilizes a slide mode and has superior energy confinment efficiency. CONSTITUTION: On a base substrate 101, the piezoelectric resonator 102 is fixed by using conductive adhesives 103 and 104, and a cap material 117 is so fixed onto the base substrate 101 as to surround the piezoelectric resonator 102. When the piezoelectric resonator 102 has long side length (b), short side length (a) and a constituent material Poisson's ratio 6, the piezoelectric resonator is composed of an energy confined piezoelectric resonator which has a piezoelectric resonance part 108 having a ratio b/a within a range of ±10% based upon b/a=n(0.3δ+1.48) as the center and utilizes the slide mode.

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 resonance component suitable for surface mounting on, for example, a printed circuit board, and more particularly to a chip type piezoelectric resonance component using a piezoelectric resonator utilizing a sliding mode. Regarding

[0002]

2. Description of the Related Art FIG. 1 is a perspective view showing a conventional energy trap type piezoelectric resonator utilizing a sliding mode. The piezoelectric resonator 191 includes a rectangular plate-shaped piezoelectric ceramic plate 192. The piezoelectric ceramic plate 192 is polarized from one end surface 192a toward the other end surface 192b (the polarization direction is indicated by an arrow P). A resonance electrode 193 is formed on the upper surface 192c of the piezoelectric ceramic plate 192, and a resonance electrode 194 is formed on the lower surface 192d.

The resonance electrode 193 extends from the end surface 192b side toward the center. The resonance electrode 194 extends from the end surface 192a toward the center. The resonance electrodes 193 and 194 are overlapped in the central region of the piezoelectric ceramic plate 192 so as to face each other with the piezoelectric ceramic plate 192 in between.

In the piezoelectric resonator 191, the resonance electrodes 193,
By applying an AC voltage from 194, the resonance electrode 1
The region where 93 and 194 overlap, that is, the resonance part is excited in the slip mode. In this case, the energy of vibration is confined in the resonance part where the resonance electrodes 193 and 194 overlap each other, and does not leak much to the end faces 192a and 192b.

That is, the piezoelectric resonator 191 is an energy trap type piezoelectric resonator utilizing a sliding mode. Therefore, it can be fixed to the case material, the circuit board, or the like by mechanically holding it in the vicinity of the end surfaces 192a and 192b.

Energy trapping type piezoelectric resonator 191
Then, it is necessary that the energy of vibration is well confined in the resonance part. Otherwise, the end faces 192a, 19
When mechanically held in the portion on the 2b side, vibration is disturbed and desired resonance characteristics cannot be obtained.

In the piezoelectric resonator 191, in order to satisfactorily trap the vibration energy, it is necessary to lengthen the element length L. The resonance frequency of the piezoelectric resonator 191 depends on the thickness of the resonance portion, that is, the thickness t of the element. For example,
When the piezoelectric resonator 191 having a resonance frequency of 4 MHz is to be obtained, the thickness t is about 0.3 mm, and when the piezoelectric resonator 191 having a resonance frequency of 2 MHz is to be obtained, the thickness t is 0.6.
mm.

However, in order to reliably confine the vibration energy in the resonance portion, the length L of the element must be increased as the thickness t increases. For example, the thickness t is 0.3 mm at 4 MHz, but in this case, the length L must be about 5 mm in order to reliably confine the resonance energy in the resonance portion, and the thickness t is 2 mm at 2 MHz. Becomes 0.6 mm, but in this case the length L had to be increased to about 10 mm.

As a result, in the energy trap type piezoelectric resonator 1 utilizing the sliding mode, the element length dimension L
Was forced to grow. Therefore, the conventional energy trap type piezoelectric resonator 1 utilizing the sliding mode 1
When a chip-type piezoelectric resonance component was constructed using 91, the size of the entire component had to be increased.

It is an object of the present invention to provide a chip type piezoelectric resonance component using an energy trapping type piezoelectric resonator utilizing a sliding mode, which can effectively enhance the trapping efficiency of vibrational energy, and can improve the overall efficiency. It is an object of the present invention to provide a chip-type piezoelectric resonance component that can be downsized and can be easily manufactured.

[0011]

According to a broad aspect of the present invention, there are provided a base substrate, a piezoelectric resonator fixed directly or indirectly on the base substrate, and a piezoelectric resonator fixed on the base substrate. And a cap member fixed to the base substrate so as to be bent, wherein the piezoelectric resonator has a pair of opposing rectangular surfaces having long sides and short sides, and is polarized in a certain direction. And a first and second resonance electrodes for applying a voltage in a direction orthogonal to the polarization direction, which are disposed at a predetermined distance on the outer surface of the piezoelectric body. When the length of the long side of the rectangular surface of the piezoelectric body is b, the length of the short side is a, and the Poisson's ratio of the material forming the piezoelectric body is σ, the ratio b / a is

[0012]

[Equation 2]

Provided is a chip-type piezoelectric resonance component, which is a piezoelectric resonator utilizing a sliding mode and is within a range of ± 10% around a value satisfying (where n is an integer). To be done.

That is, the present invention is characterized in that the above-mentioned specific piezoelectric resonator is used, the piezoelectric resonator is fixed directly or indirectly to the base substrate, and the piezoelectric resonator is flexed on the base substrate. The cap material is fixed so that

The characteristics of the piezoelectric resonator used in the present invention are that the length of the long side of the rectangular surface of the piezoelectric body is b, the length of the short side is a, and the Poisson's ratio of the material forming the piezoelectric body is Is that the ratio b / a is within a range of ± 10% around a value satisfying the expression (1).

In the piezoelectric resonator, the AC voltage is applied from the first and second resonance electrodes, so that the AC voltage is applied in the direction orthogonal to the polarization direction. Therefore, the piezoelectric resonator is excited in the slip mode. Moreover, the ratio b /
a is ± 10 centered on a value that satisfies the above-mentioned formula (1).
%, The vibration of the slip mode is effectively confined in the piezoelectric resonator. Such a ratio b /
It has been experimentally confirmed by the inventor (singular) of the present invention that the vibration of the slip mode is effectively confined by setting a within the above specific range, which will be described in detail in Examples described later. .

In the piezoelectric resonator, the vibration of the slip mode is effectively trapped in the piezoelectric body of the piezoelectric resonator.
Therefore, when manufacturing parts using this piezoelectric resonator,
Since it is not necessary to damp the vibration on the support structure side,
The support structure can be simplified.

According to a particular aspect of the present invention, a support portion is connected to the piezoelectric body. In this case, the vibration of the slip mode is effectively trapped in the piezoelectric body, so that the size of the supporting portion can be reduced and the structure of the supporting portion can be simplified. Also, preferably, the supporting portions are connected to both sides of the piezoelectric body, so that the piezoelectric body can be supported more stably. Further, more preferably, the holding portion is connected to the support portions connected to both sides of the piezoelectric body. By using a member having a certain area as the holding portion, the holding portion can be used to easily and stably fix the member to another member.

Further, in a more specific aspect of the present invention, the piezoelectric body, the supporting portions (plurality) and the holding portions (plurality) are constituted by plate-shaped members, and thus the energy trapping having a plate-shaped shape as a whole. Type piezoelectric resonators are used.
In this case, the piezoelectric body, the supporting portions (plural) and the holding portions (plural)
Can be constructed by machining one piezoelectric substrate, and therefore, a piezoelectric resonator utilizing a plate-like energy trap type sliding mode can be easily obtained.

Further, in the structure in which the piezoelectric body, the supporting portions (plurality) and the holding portions (plurality) are formed by machining one piezoelectric substrate, it is preferable that the first and second piezoelectric substrates are formed on the piezoelectric substrate. The groove may be formed, and the piezoelectric body may be constituted by the piezoelectric substrate portion between the first and second grooves. In this case, the dimensions of the piezoelectric body can be defined by processing the first and second grooves.

In the present invention, the base substrate can be made of a material having a strength suitable for forming a chip type component such as a ceramic plate or a synthetic resin plate. Also, preferably, one or more terminal electrodes are formed on the base substrate. That is, by forming the terminal electrodes, it is possible to form a chip-type piezoelectric resonance component that can be surface-mounted on a printed circuit board or the like.

In the chip type piezoelectric resonance component of the present invention, it is preferable that the piezoelectric resonance portion of the piezoelectric resonator fixed to the base substrate is fixed to the base substrate with a gap having a predetermined thickness. For that purpose, preferably, a gap forming means for forming the gap is further provided.

The gap forming means can be composed of, for example, an adhesive for fixing the piezoelectric resonator and the base substrate. That is, the gap can be formed by the adhesive by controlling the thickness of the adhesive so that the gap can be formed. Further, in the structure in which the terminal electrode is formed on the base substrate, the piezoelectric resonator is fixed to the base substrate by using a conductive adhesive, and the piezoelectric resonator and the terminal electrode on the base substrate are electrically connected. Good.

Further, a metal terminal may be provided for electrically connecting the terminal electrode formed on the base substrate and the piezoelectric resonator, and in this case, the metal terminal constitutes the gap forming means. You may. That is, by selecting the length of the metal terminal so that the piezoelectric resonance portion of the piezoelectric resonator can form a gap of a predetermined thickness on the base substrate, the metal terminal also functions as a gap forming means. Good.

Further, in the present invention, in addition to the piezoelectric resonator fixed on the base substrate, one or more piezoelectric resonators may be further laminated. In this case, a filter circuit can be configured with a plurality of piezoelectric resonators, and thus a chip-type piezoelectric filter can be provided.

In the present invention, the piezoelectric resonator may be directly fixed on the base substrate by using a solder, a conductive adhesive, or a welding method such as resistance welding.
Alternatively, it may be indirectly fixed. Indirectly means being fixed between the base substrate and the piezoelectric resonator via another member, for example, another piezoelectric resonator or a dielectric substrate. As described above, in the present invention, the piezoelectric resonator utilizing the sliding mode may be directly fixed on the base substrate or may be indirectly fixed via another member.

[0027]

In the chip type piezoelectric resonance component of the present invention, the energy trap type piezoelectric resonator utilizing the sliding mode in which the ratio b / a is within the above specific range is used. In this piezoelectric resonator, vibration energy is effectively confined in the piezoelectric body, and even when mechanically supported by the side surface of the piezoelectric body on the short side, the vibration energy is reliably confined in the piezoelectric body.

Therefore, the support portion is connected to the piezoelectric body and is fixed to the base substrate using the support portion, or in the case of the piezoelectric resonator including only the piezoelectric body, the vibration node portion is used. The piezoelectric resonator can be fixed to the substrate, and in any case, the piezoelectric resonator can be fixed to the base substrate without disturbing the vibration of the piezoelectric body. Therefore, by fixing the cap material to the base substrate so as to surround and bend the piezoelectric resonator, it is possible to configure a chip-type piezoelectric resonance component of energy trapping type.

Therefore, as compared with the conventional chip-type piezoelectric resonance component, the chip-type piezoelectric resonance can be made more compact and can realize wide band characteristics, and can be effectively used particularly in the kHz band. It becomes possible to provide parts.

Further, when a piezoelectric resonator having a structure in which a supporting portion is connected to a piezoelectric body is used, the supporting portion can be used to fix the piezoelectric resonator to the base substrate. You can select the size required for fixation. Therefore, it is possible to provide an energy trap type chip-type piezoelectric resonance component having excellent mechanical strength without disturbing the vibration of the piezoelectric body.

Further, preferably, by providing the gap forming means, the vibration of the piezoelectric body is not disturbed, so that it is possible to provide a chip type piezoelectric resonance component with more stable characteristics.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be clarified by describing non-limiting embodiments of the present invention with reference to the drawings.

2 (a) and 2 (b) are a side view and a perspective view showing an energy trap type piezoelectric resonator used in the present invention. The piezoelectric resonator 11 is configured by using a rectangular plate-shaped piezoelectric ceramic plate 12. The piezoelectric ceramic plate 12 is polarized so that the polarization axes are aligned in the direction parallel to the main surface thereof, that is, in the direction of arrow P shown in the figure.

On the upper surface 12a of the piezoelectric ceramic plate 12, the first resonance electrode 13 is formed from the one end surface 12c toward the other end surface 12d side, but so as not to reach the other end surface 12d. Similarly, on the lower surface 12b of the piezoelectric ceramic plate 12, from the end surface 12d side to the end surface 12d side.
The second resonance electrode 14 is formed toward the c side, but so as not to reach the end face 12c.

The upper surface 12a of the piezoelectric ceramic plate 12
Has a first groove 15 extending in the width direction and a second groove 16 extending in the width direction on the lower surface 12b. Then, in the piezoelectric ceramic plate portion sandwiched by the first groove 15 and the second groove 16, the upper and lower first and second resonance electrodes 13 and 14 are overlapped with each other via the piezoelectric ceramic plate 12, and The resonance portion, that is, the piezoelectric portion in the present invention is constituted by. That is, the first and second grooves 15 and 16 are formed on the tip ends of the first and second resonance electrodes 13 and 14, respectively, and the resonance portion is formed between the first and second grooves. There is.

In the piezoelectric resonator 11, the length in the thickness direction of the piezoelectric ceramic plate 12 in the resonance portion, that is, the direction (first direction) connecting both end faces of the piezoelectric ceramic plate 12 is orthogonal to the first and second directions. The length of the resonance portion along the depth direction (second direction) of the groove is a, and the length of the resonance portion in the first direction is b.
(See FIG. 2A), and when the Poisson's ratio of the piezoelectric material forming the piezoelectric ceramic plate 12 is σ, the ratio b
/ A is

[0037]

(Equation 3)

± 10% around (where n is an integer)
It is within the range of. In other words, in the above-mentioned resonance part that constitutes the piezoelectric body of the present invention, the side surface thereof has a rectangular surface having a long side length b and a short side length a. Then, the groove 1 is adjusted so that the ratio b / a falls within the specific range.
5 and 16 are formed, and the dimensions of the resonance portion are determined thereby.

In the piezoelectric resonator 11 shown in FIGS. 2A and 2B, both sides 12 of the piezoelectric ceramic plate 12 are arranged.
No electrodes were formed between the first groove 15 and the end surface 12d and between the second groove 16 and the end surface 12c on the a and the lower surface 12b, respectively. However, FIG.
As shown in FIGS. 3A and 3B, on the upper surface 12a of the piezoelectric ceramic plate 12, the first groove 15 and the end surface 12d are formed.
An electrode 13a is formed in a region between the second groove 16 and the end face 12c on the lower surface 12b.
4a may be formed. In this structure, after forming the entire electrodes on both main surfaces of the piezoelectric ceramic plate 12, the first and second grooves 15 and 16 are formed, so that the first and second resonance electrodes 13 and 14 and the electrodes are formed. 13a and 14a can be formed, and the piezoelectric resonator can be configured with fewer steps.

By forming the grooves 15 and 16 so that the ratio b / a falls within the above-mentioned specific range, in this embodiment, the vibration energy in the resonance part due to the slip mode is effectively confined in the resonance part. . The reason for this is shown in FIG.
This will be described with reference to FIG.

Now, as shown in the side view of FIG.
It is assumed that the resonance electrodes 22 and 23 are formed on both main surfaces of the piezoelectric body 21 that is polarized in the direction of the arrow P, that is, in the direction parallel to the upper surface and the lower surface, and has a ratio b / a = 1.
In this case, by applying an AC voltage from the resonance electrodes 22 and 23, the piezoelectric body 21 vibrates in the ring-sliding mode. As a result, the vibration mode indicated by the broken line A and the broken line A
It vibrates between the vibration mode shown by and the vibration mode which is symmetrical.

The position of each part of the vibrating body 21 is shown in FIG.
It is shown in an xy coordinate system in (b). In this case, when vibrating, the corner portion A exhibits the largest displacement in both the x direction and the y direction. The point O, which is the center of the piezoelectric body 21, becomes a node point of vibration. On the other hand, displacement is also observed at the points O ₁ and O ₂ at the intermediate height position on the side surface of the piezoelectric body 21.

Therefore, since displacements are also observed at the points O ₁ and O ₂ , a ring-sliding mode resonator having a shape in which piezoelectric plates are connected to the outside of both side surfaces of the piezoelectric body 21 is formed. In this case, it is understood that the efficiency of confining vibration energy is not sufficient.

On the other hand, it was found that the displacement distribution is as shown in FIG. 5 when the ratio b / a has a certain value. That is, the piezoelectric body 31 shown in a schematic side view in FIG.
Will vibrate between the vibration mode indicated by the broken line B and the vibration mode that is symmetrical to the vibration mode. in this case,
The displacement vector on the short side has only a component in the x direction as shown in FIG. In addition, the side surfaces 31a and 31b of the piezoelectric body 31
Then, the displacement direction is reversed between the upper half portion and the lower half portion.

As a result of examining the above facts, the present inventor found that
As shown in FIG. 7, on the side surface 31a of the piezoelectric body 31, the support body 3 is provided downward from the vicinity of the point O ₁ at the half height position.
2 is connected, and on the side surface 31b side, if the support body 33 is connected upward from the vicinity of the point O ₂ at the half height position, the above x
It was thought that the leakage of the displacement in the direction to the supports 32 and 33 could be prevented.

Therefore, the ratio b / a is changed variously, and various piezoelectric materials are used to support the piezoelectric body 31 on the support bodies 32 and 33.
The displacement state of the structure in which the columns were connected was investigated. As a result, it was confirmed that there is the relationship shown in FIG. 8 between the Poisson's ratio σ and the ratio b / a of the piezoelectric material used. From the result of FIG. 8, the ratio b
/ A

[0047]

[Equation 4]

By selecting the thickness a of the piezoelectric body 31 and the length b of the vibrating portion so as to be set to
It has been found that the transmission of displacement to the 33 side can be reduced, in other words, the vibration energy can be effectively trapped in the vibrating body 31 portion.

In the model shown in FIG. 7, the piezoelectric body 3
On the side surface 31a of No. 1, the support 32 is provided downward from the vicinity of the point O ₁ at the half height position, and on the side surface 31b side,
The support 33 is connected above the vicinity of the point O ₂ at the height position of / 2, but the 1/2 height position in this case is not particularly limited. In other words, the grooves 15 formed in the piezoelectric ceramic plate 11 in the above-mentioned embodiment,
The depth of 16 does not necessarily need to be 1/2 or more of the thickness of the piezoelectric ceramic plate 12.

It was also found that the vibration energy can be similarly trapped not only when the ratio a / b satisfies the equation (2) but also when it is n times (n is an integer). As described above, it is confirmed that the transmission of vibration from the piezoelectric body 31 to the supports 32 and 33 can be effectively prevented by selecting the size of the resonance portion of the piezoelectric body so as to satisfy the equation (1). Was given. Based on this result, a piezoelectric material with Poisson's ratio σ = 0.31 was used by the finite element method, and b / a = 1.
When the displacement distribution of the piezoelectric vibrating body 31 in the case of 57 was examined, the results shown in FIG. 9 were obtained.

Further, the displacement distribution of the resonator in which the piezoelectric vibrating body 31 and the supporting portions 34 and 35 having the same width and thickness as the piezoelectric vibrating body 31 are integrally formed through the supporting portions 32A and 33B. Similarly, when examined by the finite element method, FIG.
The result shown in 0 was obtained.

As is apparent from FIG. 10, this resonator 3
6, it is understood that the vibration energy of the slip mode in the piezoelectric vibrating body 31 portion hardly leaks to the support portions 32A and 33B. That is, it can be seen that by selecting the ratio b / a so as to satisfy the expression (1), it is possible to configure a resonator using a slip mode having high energy trapping efficiency.

Next, for a given Poisson's ratio σ, n in the above equation (1) is changed from 0.85 to 1.1, and the displacement amount of the point P having the largest displacement amount shown in FIG. The ratio of the displacement amount at the small point Q, that is, the relative displacement (%) was measured. The results are shown in Fig. 11.

As is apparent from FIG. 11, the value of n is 0.
It can be seen that the relative displacement is 10% or less in the range of 9 to 1.1. On the other hand, it has been found that when the relative displacement is 10% or less, there is substantially no problem in forming a resonator. Therefore, ± 10 from the value that satisfies the formula (1)
Within the range of%, the vibration energy can be effectively trapped in the resonance part.

As described above, in the piezoelectric resonator utilizing the sliding vibration mode, the relation between the distance between the first and second resonant electrodes in the resonant portion and the length b of the resonant portion along the polarization direction is expressed by It was found that the energy trapping efficiency can be effectively increased by setting the value within the range of ± 10% from the value shown in (1).

Therefore, in the piezoelectric resonator 11 shown in FIGS. 2 and 3, the thickness a of the piezoelectric ceramic plate of the resonance portion and the length dimension b of the resonance portion along the polarization direction P are the values represented by the above equation (1). To ± 10%, the first and second grooves 15 and 16 are formed so that the energy trapping efficiency is improved. FIG. 12 is a side view showing a second example of the piezoelectric resonator used in the present invention,
It is a figure equivalent to FIG. 2 shown about the 1st Example.

In the piezoelectric resonator 41 of the second example, the upper surface 42a of the piezoelectric ceramic plate 42 polarized in the direction of arrow P is used.
At the outer side of the first groove 45, a third groove 47
And the lower surface 4 of the piezoelectric ceramic plate 42 is formed.
Also on the 2b side, the fourth groove 48 is provided outside the second groove 46.
Are formed, and thereby the dynamic vibration absorbing portions 49 and 50 are configured. The dynamic vibration absorbing portions 49, 50 resonate with the leaked vibration and act to cancel the leaked vibration by a known dynamic vibration absorbing phenomenon. Therefore, the dimensions of the dynamic vibration absorbing portions 49 and 50 are selected to be the size that cancels the vibration due to the dynamic vibration absorbing phenomenon.

The piezoelectric resonator 41 is the same as that of the first embodiment except that the dynamic vibration absorbing portions 49 and 50 are formed by forming the third and fourth grooves 47 and 48. Therefore, the other parts are given the corresponding reference numerals, and the description thereof is omitted.

In the piezoelectric resonator 41, the dimensional ratio b / a in the resonance portion is within the range of ± 10% from the value expressed by the equation (1), so that the vibration energy is effectively trapped in the resonance portion. In addition, the slightly leaked vibrations are canceled by the dynamic vibration absorbing parts 49 and 50 by the dynamic vibration absorbing phenomenon. Therefore, when the piezoelectric resonator 41 is mechanically held by the holding portions 51 and 52 outside the third and fourth grooves 47 and 48, the resonance characteristics are hardly deteriorated. Therefore, compared with the first example, the energy trapping efficiency can be further enhanced, and a smaller piezoelectric resonator can be provided.

In the first and second examples described above, the piezoelectric resonator utilizing the thickness-sliding mode has been described. However, the piezoelectric resonator of the present invention has other modes such as a width-sliding mode if it is a sliding vibration mode. It can also be applied to a slip mode piezoelectric resonator.

The piezoelectric resonator 61 shown in FIG. 13A is a piezoelectric resonator utilizing the width-sliding mode. With reference to FIG. 13, the piezoelectric resonator 61 is configured using a rectangular plate-shaped piezoelectric ceramic plate 62. Piezoelectric ceramic plate 62
Is polarized in the direction of arrow P. That is, polarization processing is performed in a direction parallel to the upper surface 62a of the piezoelectric ceramic plate 62.

A pair of resonance electrodes 63 and 64 are formed along both edges of the piezoelectric ceramic plate 62. The extending direction of the resonance electrodes 63 and 64 is parallel to the polarization direction P, and the resonance electrodes 63 and 64 are opposed to each other on the upper surface 62a of the piezoelectric ceramic plate 62 at a predetermined distance in the central region.

A first groove 65 is provided on the tip side of the resonance electrode 63, and a second groove 6 is provided on the tip side of the second resonance electrode 64.
6 are formed, whereby the first and second grooves 6 are formed.
A resonance part sandwiched between 5, 66 is formed. The resonance portion, that is, the portion forming the piezoelectric body of the present invention has a rectangular shape in the upper surface and the lower surface. When the length of the upper surface of the resonance part in the short side direction (second direction) is a, and the length of the long side of the resonance part, that is, the direction along the polarization direction P (first direction) is b, the ratio is By setting b / a within the range of ± 10% from the value shown in the formula (1), it is possible to effectively trap the vibration energy in the resonance part, as in the first embodiment.

Further, as shown in FIG. 13B, the polarization axis direction P may be a direction (second direction) orthogonal to the longitudinal direction of the piezoelectric ceramic plate 62. In this case, the resonance electrodes 63 and 64 extend in parallel with the short sides of the piezoelectric ceramic plate 62, and the direction in which the electric field is applied to the resonance portion is the longitudinal direction of the piezoelectric ceramic plate 62. Also in the configuration shown in FIG. 13B, the first and second
So that the shape of the upper surface of the resonance part between the grooves 65 and 66 is within a range of ± 10% from the value shown in the above equation (1).
The ratio b / a is selected. Therefore, the vibration energy of the slip mode can be effectively confined in the resonance portion.

First Embodiment FIG. 14 is an exploded perspective view of a chip type piezoelectric resonance component according to the first embodiment of the present invention.

In this embodiment, the energy trap type piezoelectric resonator 102 utilizing the sliding mode is fixed on the base substrate 101 using conductive adhesives 103 and 104.

The base substrate 101 is made of an insulating ceramic such as alumina, or an appropriate insulating material such as synthetic resin. The base substrate 101 has a rectangular plate shape and has notches 101a and 101b on one side surface.
However, 101c and 101d are formed on the other side surface.

The terminal electrode 10 is formed on the base substrate 101.
5, 106 are formed. The terminal electrode 105 is formed so as to reach the inner peripheral surfaces of the notches 101a and 101c. Similarly, the terminal electrode 106 also has the notches 101b and 101.
It is formed so as to reach d.

The terminal electrodes 105 and 106 can be formed by vapor deposition, plating or sputtering, or by applying a conductive paste and curing it. The piezoelectric resonator 102 is configured using a piezoelectric ceramic plate that is polarized in the direction of arrow P, that is, in the direction parallel to the main surface. First and second rectangular piezoelectric ceramic plates
By forming the grooves 107a and 107b of
The piezoelectric resonance portion 108 having a rectangular planar shape is formed between the second grooves 107a and 107b. This piezoelectric resonator 108
The ratio b / a between the length b of the long side and the length a of the short side is within ± 10% centered on the value satisfying the above-mentioned formula (1).

The support portion 10 is provided on the side of the piezoelectric resonance portion 108.
9,110 are lined up. Supports 109, 110
Is a piezoelectric substrate portion lateral to the first and second grooves 107a and 107b. In addition, holding portions 111 and 112 are connected to the outside of the support portions 109 and 110.

On the other hand, in the piezoelectric resonance portion 108, the first and second resonance electrodes 113, 1 are provided on the pair of side surfaces facing each other.
14 is formed. The first resonance electrode 113 is connected to the connection electrode 115 formed on the end surface of the holding unit 111. Similarly, the resonance electrode 114 is connected to the connection electrode 116 formed on the end surface of the holding portion 112. The connection electrodes 115 and 116 are formed so as to reach the lower surfaces of the holding portions 111 and 112, though not necessarily clear in FIG.

Holding portion 11 for connecting electrodes 115 and 116
The conductive adhesive 103,
It is joined to the terminal electrodes 105 and 106 by 104. Therefore, by applying an AC voltage from the terminal electrodes 105 and 106, the piezoelectric resonance part 108 is excited in the above-mentioned slip mode, and the vibration energy is confined in the piezoelectric resonance part 108.

On the other hand, the conductive adhesives 103 and 104 are applied so as to have a predetermined thickness as shown. Therefore, a gap X corresponding to the thickness of the conductive adhesives 103 and 104 is formed between the lower surface of the piezoelectric resonance portion 108 and the lower surface of the base substrate 101. Therefore, the piezoelectric resonator 108
Vibration is not prevented by fixing the piezoelectric resonator 102 to the base substrate 101.

As the conductive adhesives 103 and 104, any suitable conductive adhesive known in the related art can be used. Instead of the conductive adhesives 103 and 104, other materials such as solder or silver solder can be used. Terminal electrode 10 using the conductive bonding material of
The connection electrodes 115 and 116 may be bonded to the electrodes 5 and 106.

In this embodiment, the cap member 117 is fixed to the base substrate 101 so as to surround the piezoelectric resonator 102 fixed on the base substrate 101. The cap member 117 is made of an appropriate material such as metal or synthetic resin, but has a shape that opens downward. The cap material 117 is fixed to the base substrate 101 with an insulating adhesive.

The cap material 117 is applied to the base substrate 101.
FIG. 15 shows a chip-type piezoelectric resonance component of this example obtained by fixing it to the. In the chip-type piezoelectric resonance component 118 of the present embodiment, the piezoelectric resonator 102 is sealed inside by fixing the cap member 117 to the base substrate 101. Further, since the terminal electrodes 105 and 106 are formed on the base substrate 101, they can be easily surface-mounted on the connection lands and wiring patterns on the printed circuit board. Therefore, like other chip-type electronic components, as surface mountable electronic components,
The energy trap type piezoelectric resonator can be provided.

Further, the chip-type piezoelectric resonance component 118 is a component having a relatively small number of points of the base substrate 101, the piezoelectric resonator 102 and the cap material 113, and is a chip-type piezoelectric resonance component excellent in the energy trapping efficiency as described above. Can be easily provided.

Notches 101a, 101b, 101
c and 101d are the terminal electrodes 105 and 106 as described above.
It is provided to increase the bonding area when bonding to a printed circuit board or the like by utilizing. Notches 101a-1
01d does not necessarily have to be provided.

Second Embodiment FIG. 16 is an exploded perspective view for explaining a chip type piezoelectric resonance component according to a second embodiment of the present invention.

In the chip type piezoelectric resonance component of this embodiment, the rectangular plate-shaped piezoelectric resonator 1 is mounted on the rectangular plate-shaped base substrate 101.
22 is fixed using adhesives 123a to 123d. The base substrate 101 has the same structure as the base substrate 101 (see FIG. 14) used in the first embodiment. Therefore, the same portions are denoted by the same reference numerals, and detailed description thereof will be omitted.

The feature of this embodiment is that the piezoelectric resonator 122 is
It does not have the supporting portion and the holding portion described above, and is configured by only a rectangular plate-shaped piezoelectric resonance portion. That is, in the piezoelectric resonator 122, the ratio b / a of the length b of the long side to the length a of the short side is ± 10% around a value satisfying the expression (1).
It is constituted by using a piezoelectric ceramic plate which is within the range. This piezoelectric ceramic plate is polarized in the direction of arrow P shown in the drawing, and first and second resonance electrodes 113 and 114 are formed on a pair of side surfaces facing each other. Therefore, by applying an AC voltage from the resonance electrodes 113 and 114, the piezoelectric resonator 122 is excited in the sliding mode as described above, and the vibration energy is confined in the piezoelectric resonator 122.

Further, in this embodiment, the piezoelectric resonator 12 described above is used.
In order not to prevent the vibration due to the sliding mode of No. 2, the piezoelectric resonator 122 has the adhesive 123 at the corners of the lower surface of the piezoelectric resonator 122 which are diagonally opposed to each other.
It is fixed to the base substrate 101 by using b and 123c.

The adhesives 123b and 123c are made of a conductive adhesive. Therefore, the resonance electrode 113 is electrically connected to the terminal electrode 105, and the resonance electrode 114 is electrically connected to the terminal electrode 106.

The adhesives 123b and 123c are applied so as to have a predetermined thickness as shown in the figure. Therefore, the adhesives 123b and 123c are applied between the upper surface of the base substrate 101 and the lower surface of the piezoelectric resonator 122. A gap X corresponding to the thickness is formed.

A cap material 117 is formed on the base substrate 101.
Is fixed. The cap material 117 has the same structure as the cap material 117 (FIG. 14) used in the first embodiment, and is fixed to the base substrate 101 by an insulating adhesive.

As described above, the chip type piezoelectric resonance component 128 according to the second embodiment shown in FIG. 17 is obtained. Also in the chip type piezoelectric resonance component 128, the base substrate 101
By using the terminal electrodes 105 and 106 provided above, it can be easily surface-mounted on a printed circuit board or the like. Further, similarly to the first embodiment, the chip type piezoelectric resonance component can be easily provided only by assembling the base substrate 101, the piezoelectric resonator 122, and the cap member 117 as described above.

Moreover, in the second embodiment, the piezoelectric resonator 1
22 does not have a supporting portion and a holding portion, and is simply configured by using a rectangular plate-shaped piezoelectric resonator 122 having a predetermined dimensional ratio.
As compared with the first embodiment, the energy trap type chip type piezoelectric resonance component can be provided more easily.

Third Embodiment FIG. 18 is a perspective view for explaining a chip type piezoelectric resonance component according to a third embodiment of the present invention. The chip-type piezoelectric resonance component of the third embodiment corresponds to a modification of the chip-type piezoelectric resonance component of the second embodiment. Therefore, only the points different from the chip type piezoelectric resonance component 128 of the second embodiment will be explained,
The same parts are designated by the same reference numerals, and the description given for the second embodiment is incorporated.

Also in this embodiment, the rectangular plate-shaped piezoelectric resonator 122 is used. However, the first resonance electrode 11
3 is a connection electrode 1 formed on the end face of the piezoelectric resonator 122.
22a. Similarly, the resonance electrode 114 also
Connection electrode 12 formed on the other end surface of the piezoelectric resonator 122
It is connected to 2b.

Further, in this embodiment, the adhesive 123b, 1
Metal terminals 124 and 125 are used instead of 23c. The metal terminals 124 and 125 have a T shape. The upper end of the metal terminal 124 is joined to the connection electrode 122a with solder or a conductive adhesive,
The lower end of 4 is joined to the terminal electrode 105 with a conductive adhesive or solder. Similarly, the upper end of the metal terminal 125 is the connection electrode 122b, and the lower end of the metal terminal 125 is the terminal electrode 1.
It is joined to 06 with a conductive adhesive or solder.

When the piezoelectric resonator 122 is fixed on the base substrate 101 by the metal terminals 124 and 125, a gap X having a predetermined thickness is provided between the upper surface of the base substrate 101 and the lower surface of the piezoelectric resonator 122. Are formed.
Therefore, the vibration due to the slip mode of the piezoelectric resonator 122 is not disturbed by the fixing by the metal terminals 124 and 125. That is, in this embodiment, the metal terminals 124,
125 forms the gap forming means. The other points are similar to those of the second embodiment.

Also in the third embodiment, the chip type piezoelectric resonance component includes the base substrate 101 and the plate-shaped piezoelectric resonator 122.
Also, the cap member 117 can be easily configured with relatively few parts.

Moreover, since the piezoelectric resonator 122 does not have a supporting portion and a holding portion as in the second embodiment, it is easy to prepare a rectangular plate-shaped piezoelectric ceramic plate and form the above electrodes. Can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a conventional piezoelectric resonator utilizing a thickness shear vibration mode.

2 (a) and 2 (b) are a side view and a perspective view of an energy trap type piezoelectric resonator used in the present invention.

3A and 3B are a side view and a perspective view for explaining a modified example of the piezoelectric resonator shown in FIG.

FIG. 4 (a) and (b) show the ratio b / a = 1, respectively.
FIG. 5 is a schematic side view for explaining the slip mode in the case of FIG. 9 and a schematic view showing the position of the vibrating body.

FIG. 5 is a schematic side view showing the displacement distribution of the piezoelectric vibrating body when the ratio b / a = 0.3σ + 1.48.

6 is a schematic side view showing a displacement vector distribution on a side surface when the vibration shown in FIG. 5 occurs.

7 is a schematic side view showing a displacement distribution in the x direction when a support is connected to the piezoelectric vibrating body shown in FIG.

FIG. 8 is a diagram showing a relationship between a ratio b / a and a Poisson's ratio σ.

FIG. 9: Poisson's ratio σ = 0.31, ratio b / a = 1.57
FIG. 6 is a diagram showing a displacement distribution analyzed by the finite element method of the piezoelectric vibrating body in the case of.

10 is a first and second outside of the piezoelectric vibrating body shown in FIG.
FIG. 6 is a diagram showing a displacement distribution of a piezoelectric resonator provided with a holding portion via the groove of FIG.

FIG. 11 is a diagram showing a relationship between a ratio b / a × n and a relative displacement amount.

FIG. 12 is a side view showing another example of the piezoelectric resonator used in the present invention.

13 (a) and 13 (b) are perspective views for explaining still another example of the energy trap type piezoelectric resonator used in the present invention.

FIG. 14 is an exploded perspective view of the chip type piezoelectric resonance component according to the first embodiment of the present invention.

FIG. 15 is a perspective view showing a chip type piezoelectric resonance component of the first embodiment.

FIG. 16 is an exploded perspective view of a chip type piezoelectric resonance component according to a second embodiment.

FIG. 17 is a perspective view of a chip type piezoelectric resonance component of the second embodiment.

FIG. 18 is an exploded perspective view for explaining a chip type piezoelectric resonance component according to a third embodiment.

[Explanation of symbols]

 101 ... Base substrate 102 ... Energy trap type piezoelectric resonator 103, 104 ... Conductive adhesive 105, 106 ... Terminal electrodes 107a, 107b ... First and second grooves 108 ... Piezoelectric resonance section 109, 110 ... Support section 111, 112 ... Holding part 113, 114 ... Resonance electrode 115, 116 ... Connection electrode 117 ... Cap material 118 ... Chip-type piezoelectric resonance component 122 ... Chip-type piezoelectric resonator 123b, 123c ... Conductive adhesive 124, 125 ... Metal terminal 128 ... Chip type piezoelectric resonance component X ... Gap

Claims (6)

[Claims] 1. A base substrate, a piezoelectric resonator fixed directly or indirectly on the base substrate, and a cap member fixed to the base substrate so as to surround the piezoelectric resonator fixed on the base substrate. The piezoelectric resonator has a pair of opposing rectangular surfaces having a long side and a short side, and is polarized in a certain direction, and an outer surface of the piezoelectric body. At a predetermined distance, and is provided with first and second resonance electrodes for applying a voltage in a direction orthogonal to the polarization direction, and the long side of the rectangular surface of the piezoelectric body is long. Where b is the short side length, a is the short side length, and σ is the Poisson's ratio of the material forming the piezoelectric body, the ratio b / a is given by A chip-type piezoelectric resonance component, characterized in that it is a piezoelectric resonator utilizing a sliding mode, which is within a range of ± 10% around a value satisfying (where n is an integer). 2. The chip-type piezoelectric resonance according to claim 1, wherein the piezoelectric resonator further includes a support portion connected to the piezoelectric body, and the piezoelectric resonator is fixed to a base substrate at the support portion. parts. 3. The chip type piezoelectric resonance according to claim 1, further comprising gap forming means for fixing the piezoelectric resonator to the base substrate with a gap having a predetermined thickness from the base substrate. parts. 4. The chip-type piezoelectric resonance component according to claim 3, wherein the gap forming means is an adhesive for fixing the piezoelectric resonator and the base substrate. 5. A terminal electrode formed on the base substrate for connecting to the outside is further provided, wherein the gap forming means is a metal terminal, and the metal terminal serves to electrically connect the piezoelectric resonator and the terminal electrode. 4. The chip type piezoelectric resonance component according to claim 3, wherein the chip type piezoelectric resonance components are electrically connected. 6. A terminal electrode formed on the base substrate is further provided, wherein the adhesive is a conductive adhesive, and the terminal electrode and the piezoelectric resonator are electrically connected by the conductive adhesive. The chip-type piezoelectric resonance component according to claim 4, wherein