JP3077535B2 - Chip type piezoelectric resonance component - Google Patents

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 slip-mode piezoelectric resonator. About.

[0002]

2. Description of the Related Art FIG. 1 is a perspective view showing a conventional energy trap type piezoelectric resonator utilizing a slip mode. The piezoelectric resonator 191 has a piezoelectric ceramic plate 192 having a rectangular plate shape. 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 face 192b toward the center. The resonance electrode 194 extends from the end face 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 via the piezoelectric ceramic plate 192.

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

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

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

In the piezoelectric resonator 191, it is necessary to increase the length L of the element in order to confine vibration energy well. The resonance frequency of the piezoelectric resonator 191 depends on the thickness of the resonance part, that is, the thickness t of the element. For example,
When trying to obtain a piezoelectric resonator 191 having a resonance frequency of 4 MHz, the thickness t is about 0.3 mm. When trying to obtain a 2 MHz piezoelectric resonator 191, the thickness t is 0.6.
mm.

However, in order to reliably confine the vibration energy to the resonance portion, the length L of the element must be increased as the thickness t increases. For example, when the frequency is 4 MHz, the thickness t is 0.3 mm. In this case, the length L must be about 5 mm in order to reliably confine the resonance energy in the resonance section. Is 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 slip mode, the length dimension L of the element
Had to be bigger. Therefore, the conventional energy trap type piezoelectric resonator 1 utilizing the slip mode is used.
When a chip-type piezoelectric resonance component is formed using the component 91, the dimensions of the entire component must be increased.

An object of the present invention is to provide a chip-type piezoelectric resonance component using an energy-trapping type piezoelectric resonator utilizing a slip mode, which can effectively increase the efficiency of trapping vibration energy and improve the overall efficiency. An object of the present invention is to provide a chip-type piezoelectric resonance component which can be reduced in size and can be easily manufactured.

[0011]

According to a broad aspect of the present invention, a base substrate, a piezoelectric resonator fixed directly or indirectly on the base substrate, and a piezoelectric resonator fixed on the base substrate are provided. A cap material fixed to the base substrate so as to be bent, wherein the piezoelectric resonator has a pair of opposed rectangular surfaces having a long side and a short side, and is polarized in a certain direction. A processed piezoelectric body, and first and second resonance electrodes that are arranged at a predetermined distance on an outer surface of the piezoelectric body and that apply a voltage in a direction orthogonal to the polarization direction. 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)

[0013] A chip-type piezoelectric resonance component is provided which is a piezoelectric resonator utilizing a slip mode, wherein the range is within ± 10% around a value satisfying (where n is an integer). Is 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 a base substrate, and the piezoelectric resonator is surrounded on the base substrate. The cap material is fixed so as to perform the operation.

The piezoelectric resonator used in the present invention is characterized in 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, the Poisson's ratio of the material constituting the piezoelectric body. Where σ is σ, the ratio b / a is within a range of ± 10% around a value satisfying the expression (1).

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

In the above-described piezoelectric resonator, the slip mode vibration is effectively confined in the piezoelectric body of the piezoelectric resonator.
Therefore, when manufacturing a component using this piezoelectric resonator,
Because there is no need to dampen vibrations on the support structure side,
The support structure can be simplified.

According to a specific aspect of the present invention, a support is connected to the piezoelectric body. In this case, since the slip mode vibration is effectively confined in the piezoelectric body, the size of the support portion can be reduced, and the structure of the support portion can be simplified. Preferably, the support is connected to both sides of the piezoelectric body, so that the piezoelectric body can be more stably supported. 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, it is possible to easily and stably fix it to another member using the holding portion.

Further, in a more specific aspect of the present invention, the piezoelectric body, the support portions (plural) and the holding portions (plural) are constituted by plate members, and therefore, the energy confinement having an overall plate shape is provided. Type piezoelectric resonator is used.
In this case, the piezoelectric body, the support part (plurality) and the holding part (plurality)
Can be configured by machining one piezoelectric substrate, and therefore a piezoelectric resonator utilizing a plate-like energy trap type slip mode can be easily obtained.

Further, in the structure in which the piezoelectric body, the support part (plural) and the holding part (plurality) are formed by machining one piezoelectric substrate, preferably, the first and second piezoelectric substrates are formed on the piezoelectric substrate. 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 formed of a material having a suitable strength for forming a chip-type component such as a ceramic plate or a synthetic resin plate. Preferably, one or more terminal electrodes are formed on the base substrate. That is, by forming the terminal electrodes, a chip-type piezoelectric resonance component that can be surface-mounted on a printed circuit board or the like can be configured.

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 predetermined gap therebetween. For this purpose, preferably, a gap forming means for forming the gap is further provided.

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

Further, a metal terminal may be provided for electrically connecting the terminal electrode formed on the base substrate and the piezoelectric resonator. In this case, the metal terminal constitutes the gap forming means. May be. That is, by selecting the length of the metal terminal so that the piezoelectric resonator of the piezoelectric resonator can form a gap having a predetermined thickness with respect to the base substrate, the metal terminal also functions as a gap forming unit. Is also good.

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

In the present invention, the piezoelectric resonator may be fixed directly on the base substrate by using a solder or a conductive adhesive, or by a welding method such as resistance welding.
Alternatively, it may be fixed indirectly. 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 using the slip 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, an energy trap type piezoelectric resonator utilizing a slip mode having a ratio b / a 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 on the short side surface of the piezoelectric body, the vibration energy is reliably confined in the piezoelectric body.

Therefore, the supporting portion is connected to the piezoelectric body and fixed to the base substrate using the supporting portion, or in the case of a piezoelectric resonator composed of only the piezoelectric body, the base portion is used using the vibration node portion. In any case, the piezoelectric resonator can be fixed to the base substrate without hindering the vibration of the piezoelectric body. Therefore, by fixing the cap material to the base substrate so as to surround the piezoelectric resonator, a chip-type piezoelectric resonance component of an energy trap type can be configured.

Therefore, as compared with the conventional chip-type piezoelectric resonance component, the chip-type piezoelectric resonance device can be more compact and can realize wide-band characteristics, and particularly can be effectively used in the kHz band. Parts can be provided.

When a piezoelectric resonator having a structure in which a support is connected to a piezoelectric body is used, the size of the support can be reduced because the support can be used to fix the piezoelectric resonator to a base substrate. The size required for fixing can be selected. Therefore, it is possible to provide an energy trap type chip-type piezoelectric resonance component having excellent mechanical strength without hindering the vibration of the piezoelectric body.

Further, preferably, by providing the gap forming means, the vibration of the piezoelectric body is not hindered, so that a chip-type piezoelectric resonance component having more stable characteristics can be provided.

[0032]

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

FIG. 2A and FIG. 2B 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 using a rectangular-plate-shaped piezoelectric ceramic plate 12. The piezoelectric ceramic plate 12 is polarized so that the polarization axes are aligned in a direction parallel to the main surface, that is, in the direction of arrow P in the drawing.

On the upper surface 12a of the piezoelectric ceramic plate 12, a first resonance electrode 13 is formed from one end face 12c to the other end face 12d, but not to the other end face 12d. Similarly, on the lower surface 12b of the piezoelectric ceramic plate 12, the
The second resonance electrode 14 is formed toward the c side but not to 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 is also formed on the lower surface 12b. In the portion of the piezoelectric ceramic plate sandwiched between the first groove 15 and the second groove 16, the upper and lower first and second resonance electrodes 13 and 14 are overlapped via the piezoelectric ceramic plate 12. The resonance part, that is, the piezoelectric body part in the present invention is constituted by these. That is, the first and second grooves 15 and 16 are formed on the distal ends of the first and second resonance electrodes 13 and 14, respectively, and a resonance section is formed between the first and second grooves. I have.

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) perpendicular to the direction connecting both end surfaces of the piezoelectric ceramic plate 12, and the first and second 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), 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. In other words, in the above-described resonating portion constituting the piezoelectric body of the present invention, the side surface 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 is within the specific range.
5, 16 are formed, which determine the dimensions of the resonating part.

In the piezoelectric resonator 11 shown in FIGS. 2A and 2B, both surfaces 12 of the piezoelectric ceramic plate 12 are formed.
No electrode was formed between the first groove 15 and the end surface 12d and between the second groove 16 and the end surface 12c on the lower surface 12a and the lower surface 12b, respectively. However, FIG.
As shown in FIGS. 3A and 3B, the first groove 15 and the end surface 12d are formed on the upper surface 12a of the piezoelectric ceramic plate 12.
The electrode 13a is formed in a region between the second groove 16 and the end surface 12c on the lower surface 12b.
4a may be formed. In this structure, after the whole surface electrodes are formed 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 electrode 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 such that the ratio b / a is within the above-mentioned specific range, in this embodiment, the vibration energy in the resonance section in the slip mode is effectively confined in the resonance section. . The reason for this is shown in FIGS.
This will be described with reference to FIG.

Now, as shown in the side view of FIG.
Assume a structure in which the resonance electrodes 22 and 23 are formed on both main surfaces of the piezoelectric body 21 which is polarized in the direction of the arrow P, that is, 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 a ring-sliding mode. As a result, the vibration state shown by the broken line A in the drawing and the broken line A
It vibrates between the vibration mode shown by the symbol and the vibration mode that is symmetrical.

The position of each part of the vibrating body 21 is shown in FIG.
(B) shows an xy coordinate system. 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, is a node point of vibration. On the other hand, displacement is also observed at points O ₁ and O ₂ at the intermediate height position on the side surface of the piezoelectric body 21.

Accordingly, displacement is observed at the points O ₁ and O ₂ , so that a ring-shaped sliding mode resonator having a shape in which a piezoelectric plate is further connected is formed outside both side surfaces of the piezoelectric body 21. In this case, the efficiency of confining vibration energy is not sufficient.

On the other hand, it was found that when the ratio b / a was a certain value, the displacement distribution was as shown in FIG. That is, the piezoelectric body 31 shown in a schematic side view in FIG.
Vibrates between a vibration mode indicated by a broken line B and a vibration mode that is symmetrical with the vibration mode. in this case,
The displacement vector on the short side has only the component in the x direction as shown in FIG. Also, 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.

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

Therefore, the ratio b / a is variously changed, and the supports 32 and 33 are attached to the piezoelectric body 31 using various piezoelectric materials.
The displacement state of the structure connected with was examined. As a result, it was confirmed that there is a relationship shown in FIG. 8 between the Poisson's ratio σ of the piezoelectric material used and the ratio b / a. From the results in 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 set the support 32,
It has been found that the transmission of the displacement to the side 33 can be reduced, in other words, the vibration energy can be effectively confined in the vibrating body 31.

Note that, in the model shown in FIG.
In one aspect 31a, the support 32 from the vicinity of O ₁ point 1/2 height position downward in a side 31b side, 1
Although the support 33 is connected above the vicinity of the point O _{2 at} the height position of, the height position of 支持 in this case is not particularly limited. In other words, the grooves 15 formed in the piezoelectric ceramic plate 11 in the above-described embodiment,
The depth of 16 is not necessarily required to be １ ／ or more of the thickness of the piezoelectric ceramic plate 12.

Further, it has been found that not only when the ratio a / b satisfies the expression (2) but also when it is n times (n is an integer), the vibration energy can be confined similarly. 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 expression (1). Was done. Based on this result, a piezoelectric material having a Poisson's ratio σ = 0.31 was used according to the finite element method, and b / a = 1.
When the displacement distribution of the piezoelectric vibrating body 31 at 57 was examined, the result shown in FIG. 9 was obtained.

Further, the displacement distribution of a resonator in which supporting portions 34 and 35 having the same width as that of the piezoelectric vibrating body 31 are integrally formed with such a piezoelectric vibrating body 31 via the supporting portions 32A and 33B. Fig. 1
0 was obtained.

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

Next, at a certain 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 amount of displacement at the small point Q, that is, the relative displacement (%) was measured. The results are shown in FIG.

As is clear from FIG. 11, when the value of n is 0.
In the range of 9 to 1.1, it is understood that the relative displacement is 10% or less. On the other hand, it has been found that when the relative displacement is 10% or less, there is substantially no problem in forming the resonator. Therefore, ± 10 from the value satisfying the expression (1)
%, The vibration energy can be effectively confined in the resonance part.

As described above, in the piezoelectric resonator using the slip vibration mode, the relationship between the distance between the first and second resonance electrodes in the resonance part and the length b of the resonance part along the polarization direction is expressed by the following equation. It was found that the energy confinement 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 resonating part and the length b of the resonating part along the polarization direction P are the values represented by the above formula (1). The first and second grooves 15 and 16 are formed so as to fall within a range of ± 10% from the above, thereby increasing the energy confinement efficiency. FIG. 12 is a side view showing a second example of the piezoelectric resonator used in the present invention,
FIG. 3 is a diagram corresponding to FIG. 2 showing the first embodiment.

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
At the outside of the first groove 45, the third groove 47
Are formed, while the lower surface 4 of the piezoelectric ceramic plate 42 is formed.
Also on the 2b side, a fourth groove 48 is provided outside the second groove 46.
Are formed, whereby the dynamic vibration absorbing portions 49 and 50 are formed. The dynamic vibration absorbing portions 49 and 50 resonate with the leaked vibration due to a known dynamic vibration absorbing phenomenon, and act to cancel the leaked vibration. Therefore, the dimensions of the dynamic vibration absorbing portions 49 and 50 are selected to be large enough to cancel the vibration due to the dynamic vibration absorbing phenomenon.

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

In the piezoelectric resonator 41, the dimensional ratio b / a in the resonance section is set within a range of ± 10% from the value represented by the equation (1), so that the vibration energy is effectively confined in the resonance section. Moreover, the slightly leaked vibration is canceled out by the dynamic vibration absorbing portions 49 and 50 due to the dynamic vibration absorbing phenomenon. Therefore, when the piezoelectric resonator 41 is mechanically held in the holding portions 51 and 52 outside the third and fourth grooves 47 and 48, the resonance characteristics hardly deteriorate. Therefore, the energy confinement efficiency can be further increased as compared with the first example, and a smaller piezoelectric resonator can be provided.

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

A piezoelectric resonator 61 shown in FIG. 13A is a piezoelectric resonator using a width-slip mode. Referring to FIG. 13, a piezoelectric resonator 61 is configured using a piezoelectric ceramic plate 62 having a rectangular plate shape. Piezoelectric ceramic plate 62
Are polarized in the direction of arrow P. That is, the polarization 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 direction in which the resonance electrodes 63 and 64 extend is parallel to the polarization direction P, and the resonance electrodes 63 and 64 are opposed to each other at a predetermined distance in the central region on the upper surface 62 a of the piezoelectric ceramic plate 62.

A first groove 65 is provided at the tip of the resonance electrode 63, and a second groove 6 is provided at the tip of the second resonance electrode 64.
6 are formed, whereby the first and second grooves 6 are formed.
A resonance portion sandwiched between 5, 66 is formed. The upper and lower surfaces of the resonating portion, that is, the portion constituting the piezoelectric body of the present invention, have rectangular shapes. Assuming that the length of the short side direction (second direction) of the upper surface of the resonance part is a and the length of the long side of the resonance part, that is, the direction (first direction) along the polarization direction P is b, By setting b / a within a range of ± 10% from the value shown in the equation (1), the vibration energy can be effectively confined 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 an 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.
So that the shape of the upper surface of the resonating portion 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 has been selected. Therefore, the vibration energy of the slip mode can be effectively confined in the resonance part.

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

In this embodiment, an energy trap type piezoelectric resonator 102 utilizing a sliding mode is fixed on a base substrate 101 by 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 a synthetic resin. The base substrate 101 has a rectangular plate shape, and has cutouts 101a and 101b on one side surface.
However, 101c and 101d are formed on the other side surface.

On the base substrate 101, the terminal electrodes 10
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 notch 101b, 101
d.

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

On the side of the piezoelectric resonance part 108, the support part 10
9,110 are linked. Supports 109, 110
Is a piezoelectric substrate portion on the side of the first and second grooves 107a and 107b. Further, 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 section 108, the first and second resonance electrodes 113, 1
14 are formed. The first resonance electrode 113 is connected to a connection electrode 115 formed on an end face of the holding section 111. Similarly, the resonance electrode 114 is connected to a connection electrode 116 formed on an end surface of the holding unit 112. Although not clearly shown in FIG. 14, the connection electrodes 115 and 116 are formed so as to reach the lower surfaces of the holding portions 111 and 112.

Holder 11 for connection electrodes 115 and 116
1, 112, the conductive adhesive 103,
The terminal 104 is joined to the terminal electrodes 105 and 106. Therefore, by applying an AC voltage from the terminal electrodes 105 and 106, the piezoelectric resonator 108 is excited in the slip mode described above, and the vibration energy is confined in the piezoelectric resonator 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 resonator 108 and the lower surface of the base substrate 101. Therefore, the piezoelectric resonance section 108
Is not hindered by fixing the piezoelectric resonator 102 to the base substrate 101.

As the conductive adhesives 103 and 104, conventionally known appropriate conductive adhesives can be used. However, in place of the conductive adhesives 103 and 104, other conductive adhesives such as solder and silver brazing are used. Terminal electrode 10 using a conductive bonding material of
The connection electrodes 115 and 116 may be joined to 5 and 106, respectively.

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 a metal or a synthetic resin, and has a shape opened downward. The cap member 117 is fixed to the base substrate 101 using an insulating adhesive.

The cap material 117 is applied to the base substrate 101.
FIG. 15 shows a chip-type piezoelectric resonance component of the present example obtained by fixing the piezoelectric resonator of the present embodiment. In the chip-type piezoelectric resonance component 118 of this embodiment, by fixing the cap member 117 to the base substrate 101, the piezoelectric resonator 102 is sealed inside. Further, since the terminal electrodes 105 and 106 are formed on the base substrate 101, the terminal electrodes 105 and 106 can be easily surface-mounted on 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 with a relatively small number of points of the base substrate 101, the piezoelectric resonator 102, and the cap material 113, and has the above-described chip-type piezoelectric resonance component excellent in energy trapping efficiency. Can be easily provided.

The notches 101a, 101b, 101
c and 101d are terminal electrodes 105 and 106 as described above.
It is provided in order to increase the bonding area when bonding to a printed circuit board or the like utilizing the above. Notches 101a-1
01d may not necessarily 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 configuration as the base substrate 101 (see FIG. 14) used in the first embodiment. Therefore, the same parts are denoted by the same reference numerals, and detailed description thereof will be omitted.

This embodiment is characterized in that the piezoelectric resonator 122 is
The present invention is characterized in that it does not have the above-mentioned support portion and holding portion, and is constituted only by 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).
Is formed using a piezoelectric ceramic plate within the range described above. The piezoelectric ceramic plate is polarized in a direction indicated by an arrow P, and first and second resonance electrodes 113 and 114 are formed on a pair of opposite side surfaces. Therefore, by applying an AC voltage from the resonance electrodes 113 and 114, the piezoelectric resonator 122 is excited in the slip mode as described above, and its vibration energy is confined in the piezoelectric resonator 122.

In this embodiment, the piezoelectric resonator 12
In order not to hinder the vibration caused by the slip mode 2, the piezoelectric resonator 122 is bonded to the adhesive 123 at the diagonally opposite corners on the lower surface of the piezoelectric resonator 122.
It is fixed to the base substrate 101 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 provided 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.

The cap material 117 is provided on the base substrate 101.
Is fixed. The cap member 117 has the same configuration as the cap member 117 (FIG. 14) used in the first embodiment, and is fixed to the base substrate 101 with an insulating adhesive.

As described above, the chip-type piezoelectric resonance component 128 according to the second embodiment shown in FIG. 17 is obtained. In the chip-type piezoelectric resonance component 128 as well, the base substrate 101
By using the terminal electrodes 105 and 106 provided on the upper surface, it can be easily surface-mounted on a printed circuit board or the like. Similarly to the first embodiment, a 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.

Further, in the second embodiment, the piezoelectric resonator 1
22 has no support portion and no holding portion, and is configured using only a rectangular plate-shaped piezoelectric resonator 122 having a predetermined dimensional ratio.
As compared with the first embodiment, it is possible to more easily provide the chip type piezoelectric resonance component of the energy trap type.

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 described.
The same reference numerals are given to the same parts, and the description given for the second embodiment will be referred to.

Also in this embodiment, a 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
Connection electrode 12 formed on the other end face of piezoelectric resonator 122
2b.

In this embodiment, the adhesives 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.
4 is joined to the terminal electrode 105 by 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
06 is connected by a conductive adhesive or solder or the like.

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 in the slip mode of the piezoelectric resonator 122 is not hindered by the fixing by the metal terminals 124 and 125. That is, in this embodiment, the metal terminals 124,
125 constitutes gap forming means. Other points are the same as in the second embodiment.

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

Further, 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-mentioned electrodes. Can be obtained.

[Brief description of the drawings]

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

FIGS. 2A and 2B are a side view and a perspective view of an energy trap type piezoelectric resonator used in the present invention.

FIGS. 3A and 3B are a side view and a perspective view for explaining a modification of the piezoelectric resonator shown in FIG. 2;

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

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

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

FIG. 7 is a schematic side view showing a displacement distribution in the x direction when a support is connected to the piezoelectric vibrator shown in FIG. 6;

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

FIG. 9: Poisson's ratio σ = 0.31, ratio b / a = 1.57
The figure which shows the displacement distribution analyzed by the finite element method of the piezoelectric vibrating body in the case of.

FIG. 10 shows first and second outer portions of the piezoelectric vibrator shown in FIG. 9;
The figure which shows the displacement distribution of the piezoelectric resonator which provided the holding | maintenance part via the groove | channel of FIG.

FIG. 11 is a diagram showing a relationship between n of 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.

FIGS. 13A and 13B are perspective views illustrating 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 the 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 according to a 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]

 DESCRIPTION OF SYMBOLS 101 ... Base substrate 102 ... Energy trap type piezoelectric resonator 103, 104 ... Conductive adhesive 105, 106 ... Terminal electrode 107a, 107b ... First and second groove 108 ... Piezoelectric resonance part 109, 110 ... Support part 111, 112 ... holding part 113, 114 ... resonance electrode 115, 116 ... connection electrode 117 ... cap material 118 ... chip-type piezoelectric resonance part 122 ... chip-type piezoelectric resonator 123b, 123c ... conductive adhesive 124, 125 ... metal terminal 128 ... Chip type piezoelectric resonance component X: gap

Claims (6)

(57) [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 opposed rectangular surfaces having a long side and a short side, and a piezoelectric body polarized in a certain direction, and an outer surface of the piezoelectric body And a first and a second resonance electrode for applying a voltage in a direction perpendicular to the polarization direction, the first and second resonance electrodes being arranged at a predetermined distance apart from each other, and Where b is the length of the short side, a is the Poisson's ratio of the material constituting the piezoelectric body, and σ is the ratio b / a. A chip-type piezoelectric resonance component characterized by being a piezoelectric resonator utilizing a slip mode, wherein the range is within ± 10% around a value satisfying (where n is an integer). 2. The chip-type piezoelectric resonator according to claim 1, wherein the piezoelectric resonator further includes a support connected to the piezoelectric body, and the piezoelectric resonator is fixed to the base substrate at the support. parts. 3. The chip-type piezoelectric resonance device according to claim 1, further comprising a 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 said gap forming means is an adhesive for fixing said piezoelectric resonator and a base substrate. 5. The semiconductor device according to claim 1, further comprising a terminal electrode formed on the base substrate for connection to the outside, wherein the gap forming means is a metal terminal, and the metal terminal electrically connects the piezoelectric resonator to the terminal electrode. 4. The chip-type piezoelectric resonance component according to claim 3, wherein the component is electrically connected. 6. The semiconductor device further comprising a terminal electrode formed on the base substrate, 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: