JP3371818B2 - Resonator array, method of manufacturing the same, and vibration wave sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonator array having a plurality of resonators used for a vibration wave sensor such as an acoustic sensor, a method for manufacturing the resonator array, and a vibration wave sensor using the resonator array.

[0002]

2. Description of the Related Art A plurality of resonators having different resonance frequencies are arrayed and each resonator is selectively responsive to a vibration wave such as a sound wave at a specific resonance frequency to cause resonance. A vibration wave sensor such as a resonator array type acoustic sensor that detects the intensity of each frequency band of a vibration wave such as a sound wave by outputting the resonance level of the converted electric signal and outputting the electric wave has been reported (for example, W. Benecke et al., "A Frequency-Selective, Pi
ezoresistive Silicon Vibration Sensor, "Digest of
Technical Papers of TRANSDUCERS '85, pp.105-108 (1
985) or E. Peeters et al., "Vibration Signatu
re Analysis Sensors for Predictive Diagnostics, "P
roceedings of SPIE '97, vol.3224, pp-220-230 (199
7) Or, Sosei Harada et al., "Resonator Array Sensor t
oward Artifical Cochlear Modeling ”, June 1997 1997
Proceedings of the Japan Sensor Symposium, pp.99-102).

Since the resonance frequency of the resonator changes according to its length (the resonance frequency is inversely proportional to the square of the length of the resonator), in the conventional vibration wave sensor, the length of each resonator is adjusted. By doing so, a desired resonance frequency is realized in each resonator.

FIG. 7 is a perspective view showing a structure of a conventional resonator array, and a plurality of different lengths (five in the illustrated example).
The resonator 31 is cantilevered by the holder 32. The length of each resonator 31 is set so as to realize its own resonance frequency. The shortest resonator 31 corresponds to the highest resonance frequency and the longest resonator 31.
Corresponds to the lowest resonance frequency. In this case, the thickness of all parts of each resonator 31 is constant, and the thickness thereof is equal to the thickness of the holding body 32.

[0005]

As described above, in the conventional resonator array, since the desired resonance frequency is realized by setting the length of each resonator, it is necessary to realize a low resonance frequency. However, since a resonator having a long length is used, there is a problem that the resonator array becomes large as a whole.

By the way, the present inventor has found that when a notch (groove) is formed in a portion of the resonator array near the holder of the resonator, the resonance frequency of the resonator becomes low.

The present invention has been made in view of the above circumstances. By reducing the cross-sectional area (thickness) of the resonator in the vicinity of the holding body, the resonator can have a relatively short length. An object of the present invention is to provide a resonator array capable of realizing a low resonance frequency with a resonator and a method for manufacturing the resonator array.

Another object of the present invention is to provide a resonator wave having such a resonator array, which can realize a low resonance frequency with the resonator and can cope with a low frequency vibration wave even if the resonator array is small in size. To provide a sensor.

[0009]

A method of manufacturing a resonator array according to a first aspect of the present invention includes a plurality of resonators and a holder for holding the plurality of resonators , and the plurality of resonators. in the at least one resonator in the resonance that with different cross-sectional area at the portions and other portions of the carrier near
A method of manufacturing a sub-array, comprising:
At least one of the resonators in the vicinity of the holder
Anisotropic etching is performed on the part to make it thicker than other parts.
It is characterized by making thin .

[0010]

A resonator array according to claim 2Manufacturing method
Is a plurality of resonators and a holding body that holds the plurality of resonators.
AndHave,The thickness of the holder is set to the thickness of the resonator.It
Different fromLetting inA method of manufacturing a resonator array.
At least one of the plurality of resonators
Therefore, anisotropic etching is performed on the area near the holder.
To make the thickness thinner than other partsIt is characterized by

[0012]

A resonator array according to claim 3Manufacturing method
Is a plurality of resonators and a holding body that holds the plurality of resonators.
AndHave,At least two of the plurality of resonators
The cross-sectional area of the part of the
DifferentlyA method of manufacturing a resonator array.
At least one of the plurality of resonators
Therefore, anisotropic etching is performed on the area near the holder.
To make the thickness thinner than other partsIt is characterized by

[0014]

[0015]

In the resonator array manufacturing method according to any one of claims 1 to 3 , anisotropic etching is performed to reduce the thickness of the portion near the holder from other portions. Therefore, the thin portion can be easily formed.

According to a fourth aspect of the present invention, in the method of manufacturing a resonator array according to any one of the first to third aspects , the etching depth is controlled by changing the pattern size of the etching mask used in the anisotropic etching. It is characterized by doing.

In the method of manufacturing a resonator array according to the fourth aspect, the etching depth is controlled by making the sizes of the patterns of the etching mask different. Therefore, the thickness of each resonator can be easily controlled.

A vibration wave sensor according to a fifth aspect of the present invention includes a diaphragm for receiving a vibration wave propagating in a medium , a plurality of resonators connected to the diaphragm , and a plurality of resonance elements.
A holding body for holding a child, and
At least one resonator in the vicinity of the holding body
And a resonator array having different cross-sectional areas for other portions . Vibration according to claim 6
A wave sensor is a diaphragm that receives an oscillating wave propagating in a medium.
The ram and the diaphragm are connected to each other to cause multiple resonances.
A child and a holder for holding the plurality of resonators,
The thickness of the holder is different from the thickness of the resonator.
And a resonator array. In claim 7
The vibration wave sensor receives the vibration wave propagating in the medium.
Multiple diaphragms and a series of diaphragms
Of the resonator and a holding body that holds the plurality of resonators.
At least two of the plurality of resonators
The cross-sectional area of the portion near the holder in the
And a resonator array that is provided .

According to the vibration wave sensor of claims 5 to 7 ,
Since the thickness of the resonator near the holder is thin, a low resonance frequency can be realized even with a short resonator, and it is possible to handle vibration waves such as low-frequency sound waves without increasing the configuration. .

The vibration wave sensor according to claim 8 is the vibration wave sensor according to claim 5.
1 to 7, the thickness of at least a part of the diaphragm and / or the holding body is different from the thickness of a portion of the resonator other than the portion near the holding body. The resonator array according to claim 9 includes a plurality of resonator arrays.
A number of resonators and a holder for holding the plurality of resonators.
Of the plurality of resonators.
At least one resonator in the vicinity of the holding body
And make the cross-sectional area different from the other parts.
It is characterized by being Resonator array according to claim 10.
Is a plurality of resonators and a holding body that holds the plurality of resonators.
In the resonator array having
The holding member and the resonator having different thicknesses of the resonator
It is characterized in that the boundary between and is rounded. Claim
Item 11. The resonator array according to Item 11 includes a plurality of resonators and the plurality of resonators.
A resonator array having a holding body for holding the
And at least two resonators among the plurality of resonators
Of the cross-sectional area
Is different from each other.

In the vibration wave sensor of the eighth aspect , not only the portion of the resonator near the holder but also the diaphragm and / or the holder is made thin. Therefore, it is not necessary to selectively thin only the resonator, and its manufacture becomes easy,
In addition, the boundary between the resonator and the holder can be rounded, and cracks are less likely to occur. The resonator A according to claim 9.
Rays have at least one resonator with
The cross-sectional area differs between the part near the holder and the other parts.
The cross-sectional area of the area near the
If you make it smaller than the area,
Realizes lower resonance frequency with the same length resonator
it can. The resonator array according to claim 10,
The thickness of the resonator is different from the thickness of the resonator.
If you reduce the thickness of the
It is possible to realize a low resonance frequency with
Also, it is rounded so that cracks are less likely to occur. Claim
11 resonator arrays have at least two resonances
The individual cross-sectional areas of the child near the holder differ
And even if the two resonators have the same length, they are different
A resonance frequency can be realized.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. FIG. 1 is a perspective view showing a configuration example of a resonator array of the present invention, and a resonator array 10 has a configuration in which four resonators 1a to 1d are cantilevered by a holder 2. One resonator 1a among the four resonators 1a to 1d is the other three resonators 1b, 1c, 1
The length is shorter than d, and these three resonators 1b, 1c,
The lengths of 1d are equal. In addition, each of these resonators 1a to 1
The d and the holder 2 are made of semiconductor silicon, for example.

In each of the two resonators 1c and 1d, in the portion near the holding body 2, a part of the surface is lost from the interface with the holding body 2 for a proper distance, and the other portion is not formed. Is thinner than. The other two resonators 1a and 1b do not have such a thin portion and have the same thickness throughout. Each resonator 1a,
When the thicknesses of the holding body 2 vicinity portions in 1b, 1c, and 1d are ta, tb, tc, and td, respectively, ta = tb>tc> td
Meet the relationship.

When the same material is used, the longer the length, the lower the resonance frequency of the resonator. Further, in the case of the resonators having the same length, the resonance frequency becomes lower when the portion near the holding body 2 is made thinner than when not made thin, and the thinner the thickness, the lower the resonance frequency becomes. Will be lower. Therefore, in the example shown in FIG. 1, the resonance frequency of the resonator 1a is the highest, and then the resonance frequencies are sequentially decreased in the order of the resonators 1b, 1c, 1d, and the resonance frequency of the resonator 1d is the lowest.

FIG. 2 is a perspective view showing another configuration example of the resonator array of the present invention. In this example, four resonators 1 are provided only on one side of the holding body 2 as shown in FIG. Instead, four pairs of resonators 1 having the same resonance frequency are provided on both sides of the holding body 2. The pair of resonators 1 provided at the same position in the longitudinal direction of the holding body 2 have the same shape (same length, same thickness).

FIG. 3 is a perspective view showing still another configuration example of the resonator array of the present invention. Similar to the example shown in FIG. 1, the resonator array 10 has a configuration in which four resonators 1 are cantilevered by a holder 2. Four resonators 1 (resonator 1a,
1b, 1c, 1d) have different lengths, the resonator 1a has the shortest length, and the resonators 1b, 1c, 1d have the longest length. In each of the resonators 1a, 1b, 1c, 1d, in a portion in the vicinity of the holding body 2, a part of the surface is lost from the interface with the holding body 2 over a proper distance, and the thickness is larger than that of other portions. Is thin. Each of the resonators 1a, 1b, 1c and 1d has the same thickness in the vicinity of the holder 2.

Therefore, also in the example shown in FIG. 3, as in the example shown in FIG. 1, the resonance frequency of the resonator 1a is the highest, and then the resonance frequencies become lower in the order of the resonators 1b, 1c, 1d, and The resonance frequency of the child 1d is the lowest. That is, in the example of FIG. 1, different resonance frequencies are realized depending on the presence or absence of the thin portion of the resonator 1 and the difference in the thickness of the thin portion, but in the example of FIG. Different resonance frequencies are realized depending on the difference in height. However, in any of the examples, in order to realize a low resonance frequency, the portion in the vicinity of the holding body 2 is made thin, and the resonance frequency is lowered without lengthening the resonator 1.

In the example shown in FIG. 3, each of the resonators 1a, 1a
Not only the portions of b, 1c, and 1d near the holding body 2 are thin, but also the holding body 2 connected to this is thin. Further, the boundaries between the resonators 1a, 1b, 1c, 1d and the holder 2 are not angular as in FIGS. 1 and 2 but are rounded.

FIG. 4 is a perspective view showing still another configuration example of the resonator array of the present invention. In this example, in the configuration example of FIG. 3, four pairs of resonators 1 each having the same resonance frequency are provided on both sides of the holding body 2.

In the example shown in FIGS. 3 and 4, it is not necessary to selectively thin only the resonator 1 as in the examples shown in FIGS. 1 and 2, so that the later-described etching is easier to manufacture. Further, since the boundary portion between the resonator 1 and the holding body 2 is rounded, cracks are less likely to occur at that portion as compared with the examples shown in FIGS. 1 and 2, and the durability is high.

As described above, in the present invention, the low resonance frequency is realized by thinning the portion of the resonator 1 near the holding body 2, so that the length is relatively short.
A considerably low resonance frequency can be realized. That is, in the conventional example having the configuration shown in FIG. 7 described above, the desired resonance frequency is realized only by adjusting the length of the resonator 31.
In order to realize a low resonance frequency, a long resonator 31 has to be formed, and an increase in the size of the structure cannot be avoided. On the contrary, in the resonator array 10 of the present invention, the thickness of the portion of the resonator 1 near the holding body 2 is adjusted to achieve a low resonance frequency. However, a relatively short length can be dealt with, and an increase in size of the structure can be avoided.

The resonator array 10 of the present invention having such a configuration
As a method for manufacturing the, a method using laser processing and a method using photolithography technology are possible.
In the method using laser processing, a predetermined region of the resonator whose thickness is to be reduced is selectively irradiated with a laser beam, a part of the irradiation side is cut away, and the thickness of that part is reduced. Also,
In the method using the photolithography technique, a resist is selectively applied to a predetermined region of the resonator to be thinned, and then a part is removed by exposure / development processing by the photolithography method to remove the part. Reduce the thickness. In the anisotropic etching at this time, by changing the size of the pattern of the etching mask to be used, for example, when a silicon substrate is used, the etch stop on the (111) plane is used, and the pattern of the pattern is changed. The etching depth can be changed according to the size, and the thickness of the portion of the resonator 1 near the holder 2 can be adjusted according to the size of the etching mask pattern used.

FIG. 5 is a perspective view showing a structural example of an acoustic sensor which is an example of the vibration wave sensor of the present invention. In FIG. 5, the same parts as those in FIG. 1 are designated by the same reference numerals. A diaphragm 3 made of, for example, semiconductor silicon, which receives a sound wave as a vibration wave propagating in the air is connected to one end of the holder 2 of the resonator array 10. The example shown in FIG. 5 has a configuration in which the diaphragm 3 is provided in the resonator array 10 shown in FIG.

FIG. 6 is a perspective view showing a structural example of an acoustic sensor which is another example of the vibration wave sensor of the present invention. In FIG. 6, the same parts as those in FIG. 4 are designated by the same reference numerals. The example shown in FIG. 6 has a configuration in which the diaphragm 3 is provided in the resonator array 10 shown in FIG. In this example, the diaphragm 3 itself is also thinner than the portion of each resonator 1 other than the vicinity of the holding body 2.

An acoustic sensor having a configuration in which the diaphragm 3 is provided in the resonator array 10 shown in FIG. 2 or 3 described above is also possible, but the illustration thereof is omitted.

In the acoustic sensor of the present invention, when a sound wave propagating in the air is input to the diaphragm 3, the diaphragm 3 vibrates, the sound wave propagates to one end of the holding body 2, and is supported by the holding body 2 in a cantilevered manner. Resonator 1 (each resonator 1a, 1b,
1c, 1d) are propagated to the other end of the holder 2 while sequentially resonating at their respective inherent frequencies. Each resonator 1
a, 1b, 1c, and 1d resonate when a sound wave of its own frequency propagates and its tip end vibrates up and down. Therefore, the vertical vibrations of the resonators 1a, 1b, 1c, and 1d are electrically generated, for example. By detecting, frequency analysis of sound waves can be performed.

In such an acoustic sensor, the thickness of the portion of the resonator 1 near the holder 2 is reduced to realize a low resonance frequency, and even a resonator 1 having a relatively short length can generate a sound wave of a low frequency. It is possible to cope with this, and the size of the structure can be reduced.

In the above example, the case of having four resonators has been described, but the number of resonators may be any number as long as it is plural. Further, in order to realize a low resonance frequency, the portion of the two or four resonators near the holder is thinned, but the portion of the at least one resonator near the holder may be thinned. It is also possible to control the resonance frequency of each resonator by reducing the thickness of all the resonators near the holder and changing the thickness. Further, the thickness of the portions near the holder in the two resonators is made different, but there is also a mode in which the thicknesses are made equal and the resonator lengths are changed to realize different resonance frequencies. It is possible.

Further, in the above-mentioned example, the case of the cantilever resonator array has been described, but it goes without saying that the present invention can be applied to the structure of a cantilever resonator array. In the case of a doubly supported beam, a portion near at least one holding body of the resonator is made thinner than other portions.

Further, in the above-mentioned example, the acoustic sensor has been described with the vibration wave as the sound wave, but this is an example,
Of course, the present invention can be applied to a vibration wave sensor for vibration waves other than sound waves.

[0042]

EXAMPLES Next, specific numerical examples will be described. The resonator 1 having a length of 2.5 mm, a width of 80 μm, and a thickness of 10 μm was processed by laser beam processing so that a portion near the holder 2 was 0.5 mm in length from the boundary with the holder 2 and a width of 80 μm.
The surface was etched to a depth of 5 μm. Two types were prepared, one with a radius of R1 μm and the other without a corner of the thin portion.

The resonance frequency of the resonator 1 not forming the thin portion is 2190 kHz, whereas the resonance frequency of the resonator 1 forming the thin portion is irrespective of whether it is rounded or not. Child 1 had a frequency of 958 kHz. By reducing the thickness of the portion near the holding body 2,
It can be seen that the resonance frequency can be significantly lowered. In the case of the unrounded resonator 1, the resonator 1 was destroyed by vibration 10 ⁷ times (about 1 hour at 1 kHz), while in the case of the rounded resonator 1, 10 ⁹ times (1 k
It did not break until it vibrated 1,000 times at Hz.

A resist (thickness 10 μm) is applied to a portion of the resonator 1 having a length of 2.5 mm, a width of 80 μm and a thickness of 20 μm in the vicinity of the holding body 2 and the holding is performed by a photolithography method. The surface of the portion near the body 2 was etched from the boundary with the holder 2 to a length of 0.5 mm, a width of 80 μm, and a thickness of 10 μm. The resonance frequency of the resonator 1 having the thin portion formed in this manner was 1910 kHz, and it was possible to reduce the frequency.

[0045]

As described above, in the resonator array of the present invention, the portion near the holder of the resonator is thinned, so that even if the length of the resonator is relatively short, a low resonance frequency can be realized by the resonator. . Further, since the vibration wave sensor of the present invention is provided with such a resonator array, it is possible to cope with a low frequency vibration wave with a compact structure.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration example of a resonator array of the present invention.

FIG. 2 is a perspective view showing another configuration example of the resonator array of the present invention.

FIG. 3 is a perspective view showing still another configuration example of the resonator array of the present invention.

FIG. 4 is a perspective view showing still another configuration example of the resonator array of the present invention.

FIG. 5 is a perspective view showing a configuration example of a vibration wave sensor of the present invention.

FIG. 6 is a perspective view showing another configuration example of the vibration wave sensor of the present invention.

FIG. 7 is a perspective view showing a configuration example of a conventional resonator array.

[Explanation of symbols]

1, 1a, 1b, 1c, 1d resonator 2 holder 3 diaphragm 10 Resonator array

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01H 11/00

Claims (11)

(57) [Claims] 1. A plurality of resonators and a holder for holding the plurality of resonators , wherein at least one resonator among the plurality of resonators is provided in the vicinity of the holder. Resonator resonators with different cross-sectional areas
A method of manufacturing a ray, comprising:
A portion of at least one resonator near the holder
Anisotropic etching to reduce the thickness
A method of manufacturing a resonator array , which comprises: 2. A plurality of resonators, has a holder for holding a plurality of resonators, a resonator array that the thickness of the holding member was not thickness and different of the resonator Those who manufacture
And at least one of the plurality of resonators
Anisotropic etching is applied to the part of the resonator near the holder.
A method of manufacturing a resonator array , which is characterized in that the thickness is made thinner than that of other portions by performing bending . 3. A resonator having a plurality of resonators and a holder for holding the plurality of resonators , wherein at least two resonators of the plurality of resonators are cut off in the vicinity of the holder. Fabricate resonator arrays with different areas
A method comprising at least one of said plurality of resonators
In the resonator of the
A method of manufacturing a resonator array , wherein the thickness is made thinner than other portions by etching . 4. Use in the anisotropic etching
The size of the etching mask pattern is changed
Method for producing a co <br/> pendulum array according to claim 1 for controlling the quenching depth. 5. A diamond that receives an oscillating wave propagating in a medium.
A diaphragm, a plurality of resonators connected to the diaphragm, and
A holder for holding the plurality of resonators,
In at least one resonator of a pendulum, said holding
Use different cross-sectional areas for the part near the body and other parts
And a resonator array that is
Nsa. 6. A diaphragm for receiving an oscillating wave propagating in a medium , a plurality of resonators connected to the diaphragm , and
A holder for holding the plurality of resonators,
An oscillatory wave sensor , comprising: a resonator array having a thickness different from that of the resonator. 7. A diamond for receiving an oscillating wave propagating in a medium.
A diaphragm, a plurality of resonators connected to the diaphragm, and
A holder for holding the plurality of resonators,
The carrier in at least two resonators in a pendulum
Resonator arrays that have different cross-sectional areas in the vicinity
A vibration wave sensor comprising: 8. The diaphragm and / or the holding
The thickness of at least part of the body is such that the retention of the resonator is
6. The thickness of a portion other than the portion near the holding body is different.
The vibration wave sensor according to any one of to 7. 9. A plurality of resonators and holding the plurality of resonators
A resonator array having a holder for
At least one of the resonators of
Make the thickness near the holder thin and disconnect from the rest.
A resonator array characterized by having different areas. 10. A plurality of resonators and a plurality of resonators
In the resonator array having a holding body,
The thickness of the holding body is made different from that of the resonator, and the holding body is
The boundary with the resonator is rounded,
Resonator array. 11. A plurality of resonators and a plurality of resonators
A resonator array having a holding body,
In at least two of the number of resonators
By reducing the thickness of the part near the holder, the cross-sectional area can be
A resonator array characterized by being made.