JP2000165190A - Surface acoustic wave element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface acoustic wave element where a change in a frequency characteristic due to heat, vibration, shock and directly delivered wave is prevented so as to obtain a stable frequency characteristic and to provide its manufacturing method. SOLUTION: In the surface acoustic wave element 1000 having a base 30 formed with signal electrodes 31a, 31b, 31c, 31d to receive/output an electric signal, a surface acoustic wave element chip 20 that is supported by the base 30 and where interdigital electrodes 21, 22 are formed on a piezoelectric substrate 24, and a cover 40 to seal the surface acoustic wave element chip 20, the surface acoustic wave element chip 20 is supported by the base 30 with a hanging wire 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved surface acoustic wave device and a method of manufacturing the same, and more particularly, to a surface acoustic wave device capable of uniformizing and stabilizing the frequency characteristics of a surface acoustic wave device piece and a method of manufacturing the same. It is about the method.

[0002]

2. Description of the Related Art Surface acoustic wave devices are used in television receivers, portable telephones and the like. FIG. 23 is a cross-sectional view showing an example of a conventional surface acoustic wave element. The surface acoustic wave element 1 will be described with reference to FIG.

The surface acoustic wave element 1 shown in FIG. 23 has a substrate 2, a surface acoustic wave element piece 3, an electrode 4, and the like. The surface acoustic wave element piece 3 has an interdigital electrode (Interdi) on a piezoelectric substrate made of a piezoelectric element such as quartz or ceramic.
digital Transducer) (hereinafter “IDT”)
) Is formed, and the surface acoustic wave element piece 3 is
Is fixed by an adhesive 5. The adhesive 5 is applied over the entire surface acoustic wave element piece 3. An electrode 4 is fixed to the substrate 2 and the surface acoustic wave element piece 3
The electrodes 4 are electrically connected by wires or the like.

Here, when heat is applied to the surface acoustic wave element 1, the heat causes the volumes of the substrate 2 and the surface acoustic wave element piece 3 to expand. However, since the linear expansion coefficients of the substrate 2 and the surface acoustic wave element piece 3 do not match, the surface acoustic wave element piece 3
, There is a problem that the center frequency fluctuates, for example.

In order to solve the above-mentioned problem, Japanese Utility Model Laid-Open No. Sho 62-127121 and Japanese Utility Model Laid-Open Publication No.
Various attempts have been made as described in JP-A-139-139 and the like. Here, FIG.
FIG. 2 is a cross-sectional view of the surface acoustic wave device disclosed in Japanese Patent Publication No.
The surface acoustic wave element 6 will be described with reference to FIG.

The surface acoustic wave element 6 shown in FIG. 24 has a cover 7, a surface acoustic wave element piece 8, a substrate 9, a signal electrode 9a, an adhesive 10, and the like. The surface acoustic wave element piece 8 is fixed to the substrate 9 with an adhesive 10, and the adhesive 10 is provided only at the central portion of the surface acoustic wave element piece 8. The surface acoustic wave element piece 8 is sealed by the lid 7 and the substrate 9. Since the adhesive 10 is applied only to the central portion,
An effect on the surface acoustic wave element piece 8 due to a thermal change of the substrate 9 is minimized to provide a surface acoustic wave element having no variation in frequency characteristics.

On the other hand, such a surface acoustic wave resonator or a surface acoustic wave filter may have two or more interdigital electrodes formed on a piezoelectric element. Between the two or more IDT electrodes, not only a surface wave propagating on the surface of the piezoelectric element but also a direct wave propagating in space propagates between each IDT. The direct wave affects the characteristics of the surface acoustic wave element and lowers the waveform disturbance and attenuation. Therefore,
Conventionally, various attempts have been made to prevent a direct wave from propagating between the IDT electrodes. FIG. 25 is a plan view of a surface acoustic wave element piece in a conventional surface acoustic wave element. .

The surface acoustic wave element piece 11 shown in FIG. 25 is, for example, a surface acoustic wave filter, and includes a piezoelectric substrate 12, a first I
DT13, second IDT14, third IDT15, reflector 1
6, 16, a ground portion 17 and the like. First
The IDT 13 converts, for example, an input electric signal into a surface acoustic wave, and the second IDT 14 and the third IDT 15 convert the surface acoustic wave into an electric signal and output it. Between the first IDT 13 and the second IDT 14 and between the first IDT 13 and the third IDT 1
5, ground portions 17, 17 are formed. The grounds 17, 17 are the first IDT 13 to the second IDT.
The propagation of a direct wave from T14 or the first IDT 13 to the third IDT 15 is prevented, and the filter characteristics and the attenuation characteristics are improved.

[0009]

However, the above-described surface acoustic wave device has the following problems.

In FIG. 24, the adhesive 10 is applied to the central portion of the surface acoustic wave element piece 8, but the adhesive 10 is not applied to the end of the surface acoustic wave element piece 8 and is held at all. Not in a state. Therefore, when the surface acoustic wave element 6 vibrates or when the surface acoustic wave element piece 8 is adhered at an angle, the end of the surface acoustic wave element piece 8 may come into contact with the substrate 9, and the surface acoustic wave element There is a problem that the frequency characteristic of No. 6 changes. The adhesive 10
When heat is applied to the surface acoustic wave element piece 8, stress is generated, and the stress affects the frequency characteristics of the surface acoustic wave element 6. In order to avoid the influence of the stress, for example, the design of the surface acoustic wave element piece 8 must be changed, for example, the IDT is not formed on the portion of the surface acoustic wave element piece 8 where the adhesive 10 is applied. There is.

In the surface acoustic wave element 11 shown in FIG. 25, ground portions 17 are formed to prevent direct waves. However, when the ground portions 17 are formed, the size of the piezoelectric substrate 12 becomes large, and there is a problem that the size reduction of the surface acoustic wave element piece 11 cannot be realized. Further, due to the presence of the ground portions 17, 17,
There is a problem that the degree of freedom in designing the electrodes of the surface acoustic wave element piece 11 is reduced.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a surface acoustic wave device capable of obtaining stable frequency characteristics by preventing a change in frequency characteristics due to heat, vibration, shock, and direct waves, and a method of manufacturing the same.

[0013]

According to the first aspect of the present invention, there is provided a substrate on which signal electrodes for inputting / outputting an electric signal are formed, and a substrate supported on the substrate and provided on a piezoelectric substrate. In a surface acoustic wave element having an interdigital electrode formed thereon and a lid for sealing the surface acoustic wave element, the surface acoustic wave element is suspended from the substrate. This is achieved by a surface acoustic wave element supported by wires.

According to the structure of the first aspect, the surface acoustic wave element piece is held by the hanging wire with respect to the substrate, and the surface acoustic wave element piece is not fixed to the substrate.

Thus, when heat is applied to the surface acoustic wave element, no stress is applied to the surface acoustic wave element piece from the substrate, so that the frequency of the surface acoustic wave element piece, such as the center frequency or the pass frequency band, is reduced. Characteristics do not change due to stress, and stable operation can be performed. Further, even when vibration is applied to the surface acoustic wave element, the surface acoustic wave element piece is suspended by the suspension line, so that the effect of the vibration is minimized and a stable frequency characteristic is obtained. be able to.

According to a second aspect of the present invention, in the configuration of the first aspect, the suspension line is achieved by a surface acoustic wave element that is an aluminum wire.

According to the second aspect of the present invention, by using an aluminum wire as the suspension wire, the strength of the suspension wire is improved as compared with the gold wire, the holding state of the surface acoustic wave element piece is stabilized, and the suspension wire is used. Can be lengthened.

According to a third aspect of the present invention, in the configuration according to any one of the first and second aspects, the suspension line has one end for transmitting and receiving an electric signal between the substrate and the surface acoustic wave element piece. The portion is connected to the interdigital electrode of the surface acoustic wave element piece, and the other end includes a surface acoustic wave element including a signal line connected to a signal electrode formed on the substrate. Is achieved.

According to the third aspect of the present invention, since the suspension line serves as a signal line, it is not necessary to separately provide a means for transmitting and receiving an electric signal between the substrate and the surface acoustic wave element piece. The surface acoustic wave device can be operated without extra wiring.

According to a fourth aspect of the present invention, in the configuration of any one of the first to third aspects, the suspension line has one end connected to a ground portion of the surface acoustic wave element piece, and This is achieved by a surface acoustic wave element including a ground line having an end connected to a ground electrode of the substrate.

According to the fourth aspect of the present invention, the suspension line functions as a ground line, so that the holding state of the surface acoustic wave element piece is strengthened, and a separate extra wiring for the ground is not required. Becomes

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the plurality of interdigital transducers are formed on the piezoelectric substrate, and the ground line extends between the plurality of interdigital transducers. This is achieved by a surface acoustic wave element formed to pass.

According to the fifth aspect of the present invention, the ground line is formed between the interdigital transducers, thereby preventing the ground line from propagating a direct wave output from each interdigital transducer. Has a shielding effect. This allows
The surface acoustic wave device can operate with stable frequency characteristics.

According to the sixth aspect of the present invention, in any one of the fourth and fifth aspects, the ground line is
A plurality of interdigital transducers are arranged between the interdigital transducers,
The plurality of ground lines are achieved by surface acoustic wave elements arranged close to or crossing each other.

According to this configuration, by arranging a plurality of ground lines between the interdigital electrodes, the shielding effect of the ground lines can be enhanced, and more stable frequency characteristics can be obtained. it can.

According to the seventh aspect of the present invention, in any one of the third to sixth aspects, the plurality of suspension lines are formed in a loop shape.
The signal line is achieved by a surface acoustic wave element formed by the lowest loop.

According to the seventh aspect of the present invention, in the suspension line holding the surface acoustic wave element piece, the signal line is formed so as to form the lowest loop. Thereby, when the surface acoustic wave element is subjected to vibration or impact, etc.,
Hanging lines other than the signal lines may come into contact with the lid, but among the hanging lines, the signal lines do not come into contact with the lid. Therefore,
The signal line is not short-circuited, and the surface acoustic wave element piece can perform a stable operation.

According to an eighth aspect of the present invention, in any one of the fourth to seventh aspects, the lid is formed of metal and is electrically connected to a ground electrode of the substrate. The ground line is achieved by a surface acoustic wave element formed to be in contact with the lid.

According to this configuration, when the surface acoustic wave element is subjected to vibration or impact, the ground wire is pressed by the lid, and the vibration of the surface acoustic wave element piece is minimized. . Therefore, a change in frequency characteristics due to vibration is suppressed, and the surface acoustic wave element piece can perform a stable operation. In addition, since the ground line is suppressed and electrically connected to the lid, a more effective shielding effect can be obtained with the ground line and the lid.

According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the surface acoustic wave element is held between the substrate and the surface acoustic wave element. This is achieved by the surface acoustic wave element in which the holding member is disposed.

According to the ninth aspect, the surface acoustic wave element is supported by the suspension line and the holding member, and the surface acoustic wave element is always held at a fixed position. As a result, even when the surface acoustic wave element is subjected to vibration or shock, the vibration of the surface acoustic wave element piece can be made extremely small, and the neck of the suspension line can be prevented from being cut off or separated, and the frequency characteristics can be reduced. Changes can be eliminated.

According to the tenth aspect, in the configuration of the ninth aspect, the holding member is achieved by a surface acoustic wave element formed of an elastic body.

According to the tenth aspect, the surface acoustic wave element is held by the suspension line and the elastic body, and the surface acoustic wave element is always held at a fixed position. Thus, even when the surface acoustic wave element is subjected to vibration or shock, the elastic material serves as a cushioning member, so that the vibration of the surface acoustic wave element piece can be extremely small, and the neck of the suspension line can be cut. Can be prevented, and the frequency characteristics can be prevented from changing.

According to the eleventh aspect, in the configuration of the ninth aspect, the holding member is achieved by a surface acoustic wave element formed by solidifying an adhesive.

According to the eleventh aspect, the surface acoustic wave element piece is held by the holding member which can be easily formed from the suspension wire and the adhesive, and the surface acoustic wave element piece is always held at a fixed position. . As a result, even when the surface acoustic wave element is subjected to vibration or shock, the vibration of the surface acoustic wave element piece can be made extremely small, preventing breakage of the suspension line neck and changing the frequency characteristics. Can be eliminated.

According to a twelfth aspect of the present invention, in the configuration of the ninth aspect, the holding member is achieved by a surface acoustic wave element formed by solidifying a silicon-based adhesive.

According to the twelfth aspect, the surface acoustic wave element is held by the holding member made of the suspension wire and the silicon-based adhesive, and the surface acoustic wave element is always held at a fixed position. As a result, even when the surface acoustic wave element is subjected to vibration or shock, the vibration of the surface acoustic wave element piece can be made extremely small, preventing breakage of the suspension line neck and changing the frequency characteristics. Can be eliminated.

According to a thirteenth aspect of the present invention, in the configuration of the ninth aspect, the adhesive is achieved by a surface acoustic wave element having a property of losing adhesive strength when irradiated with ultraviolet rays.

According to the structure of the thirteenth aspect, the surface acoustic wave element piece is held by the suspension wire and the adhesive, and the surface acoustic wave element piece is always held at a fixed position. As a result, even when the surface acoustic wave element is subjected to vibration or shock, the vibration of the surface acoustic wave element piece can be made extremely small, preventing breakage of the suspension line neck and changing the frequency characteristics. Can be eliminated. In addition, since the surface acoustic wave element piece is not bonded to the substrate, no stress is generated on the surface acoustic wave element piece, and the frequency characteristics do not change.

According to the fourteenth aspect of the present invention, the surface acoustic wave element is supported on the substrate, and the lid is placed on the substrate.
In the method of manufacturing a surface acoustic wave element for manufacturing a surface acoustic wave element, the surface acoustic wave element piece is supported by a support portion and positioned at a predetermined position on the substrate, and the substrate and the surface acoustic wave element piece are positioned. This is achieved by a method of manufacturing a surface acoustic wave element in which a hanging wire is formed between the substrate and the surface acoustic wave element piece to be held on the substrate.

According to this structure, the suspension line is formed in a state where the surface acoustic wave element pieces are supported and positioned, so that the displacement of the surface acoustic wave element pieces can be eliminated by moving the surface acoustic wave element pieces. A surface acoustic wave element can be manufactured with high accuracy, and work efficiency can be improved.

According to a fifteenth aspect of the present invention, in the configuration of the fourteenth aspect, when the surface acoustic wave element is held and positioned at a predetermined position on the substrate, the surface acoustic wave element is moved downward. This is achieved by a method of manufacturing a surface acoustic wave device that positions while supporting from the side.

According to the fifteenth aspect, the surface acoustic wave element is positioned at a predetermined position on the substrate while being supported from below, and the hanging wire is arranged between the surface acoustic wave element and the substrate. Is done. Since the suspension line is formed while the surface acoustic wave element is supported and fixed, the suspension line can be formed with high accuracy. Further, by supporting the surface acoustic wave element from below, the surface of the surface acoustic wave element on which the interdigital electrodes are formed can be easily processed, and the surface acoustic wave element can be manufactured efficiently. .

According to a sixteenth aspect of the present invention, in the configuration of the fourteenth aspect, when supporting the surface acoustic wave element piece and positioning the same at a predetermined position on the substrate, the side face of the surface acoustic wave piece is This is achieved by a method of manufacturing a surface acoustic wave element that positions while sandwiching and supporting it.

According to this configuration, the surface of the surface acoustic wave element on which the interdigital electrodes are formed is easily processed by supporting and fixing the surface acoustic wave element from the side. Thus, the suspension line can be formed accurately and efficiently.

According to a seventeenth aspect of the present invention, in the configuration of the fourteenth aspect, when positioning the surface acoustic wave element piece at a predetermined position on the substrate, an elastic body is disposed on the substrate, This is achieved by a method of manufacturing a surface acoustic wave element in which the surface acoustic wave element piece is arranged on an elastic body.

According to the seventeenth aspect, the surface acoustic wave element is positioned at a predetermined position on the substrate while being held by the elastic body, and the hanging wire is arranged between the surface acoustic wave element and the substrate. Is done. Since the suspension line is formed in a state where the surface acoustic wave element piece is held from the lower side and fixed, the suspension line can be formed accurately and efficiently. The elastic body can be used as a holding member.

According to the eighteenth aspect of the present invention, in the configuration of the fourteenth aspect, when positioning the surface acoustic wave element piece at a predetermined position on the substrate, an adhesive is applied to the substrate, This is achieved by a method of manufacturing a surface acoustic wave element in which the surface acoustic wave element piece is disposed on an adhesive.

According to the eighteenth aspect of the present invention, the surface acoustic wave element piece is held from below by the adhesive and is positioned at a predetermined position on the substrate in a fixed state, so that the surface acoustic wave element piece is Hanging lines are arranged between the substrates. Since the suspension line is formed while the surface acoustic wave element piece is held and fixed, the suspension line can be formed accurately and efficiently. The adhesive can be used as a holding member.

According to a nineteenth aspect of the present invention, in the configuration of the fourteenth aspect, the adhesive is achieved by a method of manufacturing a surface acoustic wave element that separates from the surface acoustic wave element by irradiating ultraviolet rays. You.

According to this structure, the adhesive is separated from the surface acoustic wave element when irradiated with ultraviolet rays, so that the generation of stress on the surface acoustic wave element caused by bonding to the substrate is prevented. At the same time, an adhesive can be used as a holding member.

[0052]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view showing a preferred embodiment of a surface acoustic wave device according to the present invention. The surface acoustic wave device 1000 will be described with reference to FIG.

The surface acoustic wave element 1000 shown in FIG. 1 includes a surface acoustic wave element piece 20, a substrate 30, a lid 40, a hanging wire 50, and the like. The substrate 30 and the lid 40 are fixed by glass fusion or seam welding or the like, and the surface acoustic wave element piece 20 is arranged at, for example, a substantially central portion of the substrate 30.

The substrate 30 has signal electrodes 31a, 31b, 3
1c, 31d and ground electrodes 32a, 32b are formed. The ground electrodes 32a and 32b are, for example,
0 is formed at a substantially central portion with respect to the longitudinal direction (direction of arrow X), and the signal electrodes 31a, 31b, 31
c and 31d are formed, for example, near corners of the substrate 30, respectively. Ground lines 61 and 62 are fixed to the ground electrodes 32a and 32b, respectively.
a, 31b, 31c, 31d have signal lines 51, 52, 5
3 and 54 are respectively fixed. In the present embodiment, each ground line and each signal line are also suspension lines.

FIG. 2 is a plan view of the surface acoustic wave element piece 20. The surface acoustic wave element piece 20 will be described with reference to FIG.

The surface acoustic wave element piece 20 shown in FIG.
T21, second IDT 22, reflectors 23, 23, piezoelectric substrate 24, and the like. The piezoelectric substrate 24 is, for example, a quartz plate, and the first IDT 21 and the second
The DT 22 and the reflector 23 are formed by a photolithography technique or the like. The first IDT 21 includes comb-shaped electrodes 21a and 21b composed of a plurality of electrode fingers, and the comb-shaped electrodes 21a and 21b are formed at a predetermined pitch. The connection terminals 21c, 2b are connected to the comb electrodes 21a, 21b.
1d is formed, and signal lines 51 and 52 are fixed to the connection terminals 21c and 21d, respectively. 1st I
When an electric signal is supplied from the signal lines 51 and 52 to the DT 21, a surface acoustic wave (Surface Acoustic W) is applied to the piezoelectric substrate 24 in the arrow X direction by the piezoelectric effect.
ave).

The second IDT 22 includes comb-shaped electrodes 22a and 22b composed of a plurality of electrode fingers.
2a and 22b are formed at a predetermined pitch. Connection terminals 22c and 22d are formed on the comb electrodes 22a and 22b, and the signal lines 5 are connected to the connection terminals 22c and 22d.
3 and 54 are respectively fixed. The second IDT 22 converts the excited surface acoustic wave into an electric signal and outputs the electric signal.

The reflectors 23, 23 are connected to the first IDT 21 and the second IDT 21.
The first IDT 2 is formed so as to sandwich the IDT 22.
The surface acoustic wave output from 1 is confined in the reflectors 23, 23. Longitudinal direction of piezoelectric substrate 24 (arrow X direction)
The ground portions 25 are formed at substantially the center of the. The ground lines 25, 25 have ground lines 61, 6
2 is connected.

With reference to FIG. 2, an operation example of the surface acoustic wave element piece 20 will be described. When a voltage is supplied to the first IDT 21 from the signal lines 51 and 52 of FIG.
A surface acoustic wave is generated from T21, and the surface acoustic wave propagates in the arrow X direction. This surface acoustic wave is the first IDT21,
The second IDT 22 and the electrode fingers of the reflectors 23, 23 are reflected in multiple stages and resonate. Then, the resonated surface acoustic waves are output from the second IDT 22 and output via the signal lines 53 and 54.

FIG. 3 is a cross-sectional view of the surface acoustic wave element 1000. The suspension line 50 will be described in detail with reference to FIGS.

The suspension line 50 shown in FIG. 1 is made of a thin metal wire such as an aluminum wire, and supports the surface acoustic wave element piece 20. By using an aluminum wire as the suspension line 50, the holding state of the surface acoustic wave element piece 20 is stabilized, and the length of the suspension line 50 can be increased. The suspension line 50 includes, for example, four signal lines 51, 52, 53, and 54.
And two ground lines 61 and 62. One end of each of the signal lines 51, 52, 53, and 54 is connected to each IDT2.
1, 22 are connected to the connection terminals 21c, 21d, 22c, 22d, and the other ends are connected to the signal electrodes 31a, 31b, 3d.
1c and 32d. Ground lines 61, 62
Has one end connected to the ground portions 25, 25, and the other end connected to the ground electrodes 32a, 32b.

The suspension line 50 is formed so that the surface acoustic wave element piece 20 is floated and supported on the substrate 30.
Thus, when heat is applied to the surface acoustic wave element 1000, it is possible to prevent the occurrence of stress due to the difference in the coefficient of linear expansion between the surface acoustic wave element piece 20 and the substrate 30. Therefore, the frequency characteristics such as the center frequency of the surface acoustic wave element piece 20 do not shift, and a stable operation can be performed.

In addition, since it is not necessary to use an adhesive when the substrate supports the surface acoustic wave element piece 20 as in the prior art, the stress generated between the adhesive and the surface acoustic wave element piece 20 is eliminated. Thus, the operation of the surface acoustic wave element piece 20 can be stabilized. At the same time, when heat is applied to the adhesive, a gas is generated, and the gas is generated by each ID of the surface acoustic wave element piece 20.
The T21, 22 and the reflector 23 do not corrode or adhere to the surface of the surface acoustic wave element piece 20, so that deterioration or change in frequency characteristics does not occur.

Here, FIG. 4 is a cross-sectional view of a peripheral portion of the signal line 51, and FIG. 5 is a cross-sectional view of the ground line 61. Referring to FIGS. The shape of the ground line 61 will be described in detail. Note that the signal line 51 has substantially the same shape as the signal lines 52, 53, and 54, and the ground line 61 has substantially the same shape as the ground line 62.

The signal line 51 shown in FIG. 4 is formed in a loop shape and supports the surface acoustic wave element piece 20, and its apex 51a
Are formed so as not to contact the lid 40. On the other hand, the ground line 61 in FIG. 5 is formed in a loop shape to support the surface acoustic wave element piece 20, and the vertex 61 a thereof is formed so as to be in contact with the lid 40. That is, as shown in FIG. 3, the apex 61a of the ground line 61 is formed so as to be higher than the apex 51a of the signal line 51.
Is formed at the lowest of the suspension lines 50. This is for the following reason.

In FIG. 3, when the surface acoustic wave element 1000 vibrates in the arrow Y direction or the arrow Z direction, the surface acoustic wave element piece 20 is suspended and supported. Vibrates in the direction or the arrow Z direction. At this time, if the ground line 61 is formed higher than the signal line 51, only the ground line 61 contacts the cover 40, and the signal line 51 does not contact the cover 40. Therefore,
A problem such as a short circuit caused by the signal line 51 contacting the lid 40 can be avoided, and a stable operation can be performed. In addition, the lid 40 in which the ground line 61 is the ground
, The supporting state of the surface acoustic wave element piece 20 is strengthened, and vibration can be minimized.
Changes in the frequency characteristics of the surface acoustic wave element piece 20 can be minimized.

Second Embodiment FIG. 6 is a plan view showing a surface acoustic wave element according to a second embodiment of the present invention, and FIG. 7 is a view showing a side surface shape of a ground line in FIG. The surface acoustic wave element 70 will be described in detail with reference to FIG. In the following embodiments, the same components as those of the surface acoustic wave device 1000 of FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

The surface acoustic wave element 70 of FIG. 6 differs from the surface acoustic wave element 1000 of FIG. 1 in the connection structure of the ground lines. In the surface acoustic wave device 70 of FIG. 6, a ground portion 80 is formed at a substantially central portion of the piezoelectric substrate 24 in the longitudinal direction (the direction of the arrow X). This ground portion 80 is
It is formed between the IDT 21 and the second IDT 22 in a substantially rectangular shape in the arrow Y direction. Ground line 81
Has one end connected to one end 80a of the ground portion 80 and the other end connected to the ground electrode 32b.
On the other hand, the ground line 82 has one end connected to the other end 80 b of the ground part 80 and the other end connected to the ground electrode 3.
2a. That is, as shown in FIG. 6, the ground lines 81 and 82 are close to each other, and as shown in FIG. 7, the ground lines 81 and 82 are formed to cross each other when viewed from the X direction.

As a result, the ground lines 81 and 82 have a shielding effect, and it is possible to prevent the frequency characteristics from deteriorating due to direct waves. Specifically, the ground lines 81, 8
2 is disposed between the first IDT 21 and the second IDT 22 to prevent transmission of a direct wave propagating in space from the first IDT 21, prevent deterioration of frequency characteristics due to the direct wave, and perform stable operation. be able to. That is, the two ground lines 81 and 82 are provided between the first IDT 21 and the second IDT 22 and the ground portion 80 is additionally provided, so that the shielding effect is further improved and the frequency characteristics are deteriorated by the direct wave. Can be prevented. In addition, one end 80a of the ground portion 80 and the ground electrode 32a, and the other end 80b of the ground portion 80
And the ground electrode 32b are preferably connected by a suspension line. Thereby, the shielding effect can be further enhanced.

In FIG. 6, four ground portions 83 are formed near the corners on the piezoelectric substrate 24, and four ground electrodes 35 are also formed on the substrate 30.
The ground portion 83 and the ground electrode 35 are connected to the ground line 8.
4. Thereby, the surface acoustic wave element piece 20 is more stably supported, and has more stable frequency characteristics. If only the surface acoustic wave element piece 20 needs to be supported, the ground electrode 3 may be used.
5 may be an isolated pattern. If necessary, the ground electrode 35 may have a structure (not shown),
A ground pattern may be used as in 2b.

Third Embodiment FIG. 8 is a sectional view showing a surface acoustic wave device according to a third embodiment of the present invention. Referring to FIG.
Will be described. In the following embodiment,
The same components as those of the surface acoustic wave device 1000 of FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

The surface acoustic wave element 90 of FIG. 8 differs from the surface acoustic wave element 1000 of FIG.
The point is that a pillow member as a holding member is arranged between the substrate and the substrate 30. In FIG. 8, the pillow member 91 is made of, for example, a silicon-based adhesive or an elastic body, and is applied and solidified on the substrate 30 using a micro syringe or the like and fixed. The pillow member 91 is, for example, substantially at the center position of the substrate 30 with respect to the arrow Y direction, and
It is preferable that the electrode fingers of the respective IDTs 21 and 22 and the reflector 23 are arranged below the region where the electrode fingers are not formed. This is to prevent the pillow member 91 from changing the frequency characteristics. The pillow member 91 holds the surface acoustic wave element piece 20 at a fixed position so as not to move in the directions of the arrows XYZ in FIG.

As a result, the pillow member 91 and the suspension line 51 always hold the surface acoustic wave element piece 20 at a fixed position, and it is possible to prevent a change in frequency characteristics due to impact, vibration, and the like. In addition, by arranging the pillow member 91, the swing width of the suspension line 51 becomes very small even when subjected to shock or vibration, so that the neck of the suspension line 51 can be prevented from being cut off or peeled off.

Fourth Embodiment FIG. 9 is a sectional view showing a fourth embodiment of a surface acoustic wave device according to the present invention. Referring to FIG.
0 will be described. In the following embodiments, the same components as those of the surface acoustic wave device 1000 of FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 9, the surface acoustic wave element piece 120
Are the first IDT 121, the second IDT 122, the third IDT
123, reflectors 124 and 124, a piezoelectric substrate 126, and the like. The first IDT is substantially at the center on the piezoelectric substrate 126.
The second IDT 122 is formed on both sides of the second IDT 122.
And the third IDT 123 are formed. Further, reflectors 124 and 124 are formed so as to sandwich the second IDT 122 and the third IDT 123.

The first IDT 121 is a comb-shaped electrode 121a,
The comb-shaped electrode 121a is connected to the signal electrode 131a via the signal line 151. The comb-shaped electrode 121b is connected to ground electrodes 132b and 132c via ground lines 161 and 162, respectively.

The second IDT 122 includes a comb-shaped electrode 122a,
The third IDT 123 includes comb-shaped electrodes 123a and 123b. Comb electrode 12
2b and the comb-shaped electrode 123b are electrically connected,
Each is connected to the signal electrode 131b via the signal line 152. Further, the comb-shaped electrode 122a and the comb-shaped electrode 1
23a is connected to ground electrodes 132a and 132d via ground lines 163 and 164, respectively.

Here, the first IDT 121 and the second IDT 1
22, the ground lines 162 and 164 pass between the first IDT 121 and the third IDT 123, and the ground lines 161 and 163 pass between the first IDT 121 and the third IDT 123. As a result, the ground lines 161, 162, 163, and 164 are respectively connected from the first IDT 121 to the second IDT 122 and the third IDT 122.
This has a shielding effect of preventing a direct wave from propagating to the 123. Further, since the ground line 161 and the ground line 163 and the ground line 162 and the ground line 164 are formed to cross each other, the shielding effect can be enhanced.

Therefore, it is possible to prevent the frequency characteristics from deteriorating due to the direct wave and to operate stably. In addition, since there is no ground area on the piezoelectric substrate 126 for preventing direct waves, the surface acoustic wave element piece 120 can be reduced in size, and the ground pattern can be simplified to facilitate manufacture, which facilitates pattern design. It can be carried out.

Further, in FIG. 9, four ground portions 125 are formed near corners on the piezoelectric substrate 126.
Four ground electrodes 135 are also formed on the substrate 130. The ground portion 125 and the ground electrode 135 are connected by a ground line 165, respectively. Thereby, the surface acoustic wave element piece 120 is more stably held, and has more stable frequency characteristics. The ground electrode 135 may have an isolated pattern if only the surface acoustic wave element piece 20 needs to be supported.
If necessary, the ground electrode 135 is formed by a structure (not shown) using the ground electrodes 132a, 132b, 132c, 1
What is necessary is just to make it a ground pattern like 32d.

Fifth Embodiment FIG. 10 is a flowchart showing a method for manufacturing a surface acoustic wave device according to the present invention. The method for manufacturing a surface acoustic wave device will be described in detail with reference to FIG. The method for manufacturing a surface acoustic wave element described below mainly takes into consideration the manufacture of the surface acoustic wave element 1000 shown in FIG.

In FIG. 10, first, the surface acoustic wave element piece 20 and the substrate 30 are prepared in advance (S1, S2). Specifically, when the surface acoustic wave element piece 20 is manufactured, electrode fingers made of aluminum or the like are formed in a predetermined pattern on the piezoelectric substrate 24 by a photolithography technique or the like, and the IDTs 21 and 22 and the reflectors are formed. 23 and ground part 2
5, 25 are formed. On the other hand, the substrate 30 has signal electrodes 31a, 31b, 31c, 31d and ground electrodes 32a, 32b formed at predetermined positions by sputtering or the like.

Next, the surface acoustic wave element piece 20 is held and placed at a predetermined position on the substrate 30 (S3). Specifically, as shown in FIG. 11, the support portion 300 holds the lower side of the surface acoustic wave element piece 20 and positions the substrate at a predetermined position on the substrate 30. For example, a slit portion 301 is formed in the support portion 300 so as not to hinder the operation of connecting the suspension wire 50 between the piezoelectric substrate 20 and the substrate 30.
Further, as shown in FIG. 12, the support portion 400 may hold and hold the side surface of the surface acoustic wave element piece 20 so as to be positioned at a predetermined position on the substrate 30.

Thereafter, the surface acoustic wave element piece 20 is
The suspension line 50 is stretched between the surface acoustic wave element piece 20 and the substrate 30 by, for example, an aluminum wire bonder while being supported by 00 or 400 (S4). At this time, for example, the ground lines 61 and 62 are
It is formed by adjustment or the like so as to draw an arch higher than 2, 53, 54. Also, the surface acoustic wave element piece 20 is
0 or 400 and the suspension line 5 is fixed.
Since 0 is formed, no displacement occurs due to the movement of the surface acoustic wave element piece 20, and the surface acoustic wave element 1000 can be manufactured with high accuracy.

As shown in FIG. 11 and FIG.
When 0 is used, the side or top surface of the surface acoustic wave element piece 20 is held by holding means (not shown). On the other hand, the support portion 400 holds the side surface of the surface acoustic wave element piece 20 and supports the lower surface. Therefore, regardless of whether the supporting portion 300 or the supporting portion 400 is used, the work can be easily performed on the surface of the surface acoustic wave element piece 20 on which the IDTs and the like are formed.

Finally, as shown in FIG. 13, a lid 40 formed in advance on the substrate 30 is covered and sealed (S5). More specifically, as shown in FIG. 13A, a lid 40 made of metal is placed on a substrate 30 formed in a box shape, and the substrate 30 and the lid 40 are welded and sealed by so-called seam welding. There is a way. As shown in FIG. 13B, there is a so-called low-melting glass sealing method in which a low-melting glass is applied between the lid 40 and the substrate 30 and sealed. In the case of FIG. 13A, between a surface acoustic wave element piece 20 and a box-shaped substrate 30, a holding member (not shown) will be described in a sixth embodiment described later. Is arranged.

Thus, when the surface acoustic wave element piece 20 is held on the substrate 30, it is not necessary to apply an adhesive, so that an adhesive applying step and an adhesive curing step are not required in the manufacturing process, which is efficient. Thus, the surface acoustic wave device 10 can be manufactured. Further, the occurrence of defective products due to excess or deficiency of the adhesive is eliminated, so that the yield can be suppressed. Furthermore, a change in frequency characteristics of the surface acoustic wave element piece 20 can be prevented by a gas generated by applying heat to the adhesive, and the surface acoustic wave element 1000 that performs stable operation can be provided.

Sixth Embodiment FIGS. 14 and 15 are views showing a second embodiment of the method of manufacturing a surface acoustic wave device according to the present invention. Referring to FIGS. The method for manufacturing the wave element will be described in detail.

In FIG. 14, first, the surface acoustic wave element piece 2
0 and the substrate 30 (S11, S12),
As shown in (A), the elastic body 500 is arranged and fixed on the substrate 30 (S13). The elastic body 500 is, for example, resin or rubber.

Then, the surface acoustic wave element piece 20 is mounted on the elastic body 500 (S14). Then FIG.
As shown in (B), the surface acoustic wave element piece 20 and the substrate 30
And a suspension line 50 is stretched between them. If necessary, the suspension line 50 is connected between the piezoelectric substrate 24 and the substrate 30 while holding the lower side of the surface acoustic wave element piece 20 using the support portion 300 shown in FIG. 11 (S15). Here, since the surface acoustic wave element piece 20 is placed on the elastic body 500, the surface acoustic wave element piece 20 moves due to friction, so that there is no displacement and the hanging line 50 can be formed reliably. Further, since the elastic body 500 can be used as it is as the pillow member 91 shown in FIG. 8, there is no need to separately provide a pillow member 91, and the surface acoustic wave element 10 can be efficiently provided.
Can be manufactured.

Thereafter, as shown in FIG. 13, the lid 40 is put on the substrate 30 and sealed (S16), and the surface acoustic wave element 1000 is completed.

Seventh Embodiment FIGS. 16 and 17 are views showing a third embodiment of the method of manufacturing a surface acoustic wave device according to the present invention.
The manufacturing method of the surface acoustic wave device will be described in detail with reference to FIGS.

In FIG. 16, the surface acoustic wave element piece 2 is
0 and the substrate 30 are produced (S21, S22), and a double-sided adhesive (adhesive) sheet 600 as an adhesive is applied to a predetermined position on the substrate 30 (S23). The double-sided adhesive (adhesive) sheet 600 is basically the same as the adhesive (adhesive) applied to the sheet used for dicing the semiconductor, but the adhesive (adhesive) is applied to the front and back of the sheet substrate. It has been applied.

The surface acoustic wave element 20 is placed under pressure on the double-sided adhesive (adhesive) sheet 600 (S24). As a result, the surface acoustic wave element piece 20 and the substrate 30 are fixed.

Then, as shown in FIGS. 17A and 17B, a suspension line 50 is stretched between the surface acoustic wave element piece 20 and the substrate 30 using, for example, an aluminum wire bonder (S26). Here, since the surface acoustic wave element piece 20 is fixed by the double-sided adhesive (adhesive) sheet 600, the displacement of the surface acoustic wave element piece 20 is eliminated, and the hanging line 50 can be formed reliably. . Further, this double-sided adhesive (adhesive) sheet 600 is used as it is in FIG.
Can be used as the pillow member 91 shown in FIG. 1, so that it is not necessary to separately provide the pillow member 91, and the surface acoustic wave element 1000 can be manufactured efficiently.

Thereafter, as shown in FIG. 17C, the double-sided adhesive (adhesive) sheet 600 is irradiated with an appropriate amount of ultraviolet rays, so that the fixed state between the double-sided adhesive (adhesive) sheet 600 and the surface acoustic wave element piece 20 is released. (S27). Next, as shown in FIG. 13, the lid 40 is put on the substrate 30 and sealed (S28), and the surface acoustic wave element 1000 is completed. By irradiating an appropriate amount of ultraviolet light and the presence of the sheet base material, the fixed state of the double-sided adhesive (adhesive) sheet 600 to the substrate 30 is maintained. There is no fear that the characteristics of the surface acoustic wave element are degraded by being separated from the surface acoustic wave element.

According to each of the above embodiments, the surface acoustic wave element piece 20 is held by the suspension line 50, that is, the surface acoustic wave element piece 20 is not held by the substrate 30. Even when heat, deformation, or the like is applied to the element 1000, its frequency characteristics do not change and stable operation can be performed. The above items will be specifically described with reference to FIGS.

FIG. 18 is a graph showing the frequency variation of the surface acoustic wave element before and after the lid 40 is seam-welded to the substrate 30. In the conventional surface acoustic wave device of FIG. 18A, the average of the frequency change ΔFr for each surface acoustic wave device is 36.2 (ppm), and the variation σ is 16.5 (p
pm). In contrast, the surface acoustic wave device of the present invention shown in FIG.
The average of Fr is 0.2 (ppm), and the variation σ is suppressed to 4.7 (ppm). Therefore, as can be seen from FIG. 18, the surface acoustic wave element of the present invention has a minimum amount of deformation due to welding and frequency change due to heat, and
Further, it can be seen that the variation σ of the frequency change amount is also small.

A surface acoustic wave element uses a quartz material as a resonator.
The resonance frequency depends on the temperature and the graph
In general, draw a parabola that is convex upward. Therefore, -30 ℃ ~ 60
Measure the resonance frequency between ° C and the top of the parabola at each temperature.
Temperature θmax corresponding to Is plotted. In FIG.
Θmax for each surface acoustic wave element FIG. Note that
In FIG. 19, the surface acoustic wave element = 29 ° C
It is designed to be.

FIG. 19A shows a conventional surface acoustic wave.
The element is θmax Are 27.03 ° C. and the variation σ is 1.
While the temperature is 16 ° C., the surface acoustic wave element of the present invention has θma
x Is 30.36 ° C. and the variation σ is 0.55 ° C.
You. As a result, the surface acoustic wave element of the present invention
Θmax designed for each wave element And you can get
In addition, it can be seen that the variation σ is small.

FIG. 20 shows the range from -55 ° C. (5 minutes) to 125 ° C.
FIG. 8 is a graph showing the amount of change in resonance frequency before and after performing a thermal shock test in which a (5 minute) cycle is repeated 500 times. In FIG. 20A,
The conventional surface acoustic wave element has a frequency variation ΔFr of 3.0.
(Ppm) to 10.7 (ppm), and the variation σ of the frequency variation ΔFr is 0.9 (ppm) to 1.9.
(Ppm). On the other hand, in FIG. 20B, the surface acoustic wave element of the present invention has a frequency variation ΔFr of 1.2.
(Ppm) to 7.3 (ppm), and the frequency variation Δ
The variation σ of Fr is 0.9 (ppm) to 1.9 (pp)
m). Therefore, as can be seen from FIG. 20, the surface acoustic wave element 10 of the present invention has a minimum change in frequency characteristics due to heat and a small variation σ in the frequency change ΔFr.

FIG. 21 is a graph showing the frequency change ΔFr between the resonance frequency before reflow and the resonance frequency after reflow when reflow is performed for a predetermined time. In FIG. 21A, in the conventional surface acoustic wave element, the average of the frequency change ΔFr is −0.6 (ppm) to 0.0 (ppm),
The variation σ of the frequency variation ΔFr is from 1.4 (ppm)
2.1 (ppm). On the other hand, in FIG. 21B, the surface acoustic wave device of the present invention has a frequency variation ΔF
r is −0.4 (ppm) to 0.0 (ppm), and the variation σ of the frequency variation ΔFr is 0.4 (ppm) to
0.7 (ppm). Therefore, as can be seen from FIG. 21, the surface acoustic wave element of the present invention has a minimum change in frequency characteristics due to heat and a small variation σ in the frequency change ΔFr.

FIG. 22 is a graph showing a change in resonance frequency when left at a high temperature. In FIG. 22A,
In the conventional surface acoustic wave element, the average of the frequency change ΔFr is 4.4 (ppm) to 5.3 (ppm), and the variation σ of the frequency change ΔFr is 2.1 (ppm) to 2.9.
(Ppm). On the other hand, in FIG. 22B, in the surface acoustic wave element of the present invention, the average of the frequency change ΔFr is 3.3 (ppm) to 4.5 (ppm), and the variation σ of the frequency change ΔFr is 0. 7 (ppm) ~
0.9 (ppm). Therefore, as can be seen from FIG. 22, the surface acoustic wave element of the present invention has a minimum change in frequency characteristics due to heat and a small variation σ in the frequency change ΔFr.

FIGS. 18 to 22 show that the surface acoustic wave device of the present invention has a minimum change in frequency characteristics due to deformation and heat.

The present invention is not limited to the above embodiment,
Various changes can be made without departing from the scope of the claims.

In each of the embodiments shown in FIGS. 1 to 9, only one ground line is connected to one ground electrode and ground portion, but a plurality of ground lines are connected to one ground electrode and ground portion. It may be formed.
Thereby, the earthquake resistance and the shock resistance of the surface acoustic wave element piece can be improved.

In the first embodiment shown in FIGS. 1 and 2, the ground lines 61 and 62 are provided substantially at the center of the piezoelectric substrate 24. However, as shown in FIG. A plurality of ground lines may be provided such that ground lines are provided at four corners of 24. Thereby, the support balance of the surface acoustic wave element piece 20 can be improved. Further, a signal is input from the first IDT 21 and an output terminal is connected to the second IDT 22, but a signal is input from the second IDT 22 and the first IDT 22
Alternatively, a signal may be output from 21.

In FIG. 7, the ground lines 81, 8
2 is formed at a height that does not contact the lid 40, but can operate with stable frequency characteristics even if the surface acoustic wave element 70 vibrates by bringing the ground lines 81 and 82 into contact with the lid 40. .

Further, in FIG. 8, the pillow members 91 are arranged substantially at the center of the surface acoustic wave element piece 20, but, for example, four pillow members 91 are arranged at the four corners of the piezoelectric substrate 24 where no IDT electrode pattern is formed. You may do it.

[0111]

According to the first aspect of the present invention, when a force or heat is applied to the surface acoustic wave element, no stress is applied to the surface acoustic wave element piece from the substrate. For example, a stable operation can be performed without changing the frequency characteristics such as the center frequency and the pass frequency band. Further, even when vibration is applied to the surface acoustic wave element, the surface acoustic wave element piece is suspended by the suspension line, so that the effect of the vibration is minimized and a stable frequency characteristic is obtained. be able to.

According to the second aspect of the invention, the strength of the suspension line is improved, the holding state of the surface acoustic wave element piece is stabilized, and the length of the suspension line can be increased.

According to the third aspect of the present invention, it is not necessary to separately provide a means for transmitting and receiving signals between the substrate and the surface acoustic wave element piece, and the surface acoustic wave element can be operated without extra wiring. Can be.

According to the fourth aspect of the present invention, the holding state of the surface acoustic wave element piece is strengthened, and a separate extra wiring for ground can be eliminated.

According to the fifth aspect of the present invention, the propagation of the direct wave output from each IDT is prevented,
The ground line can have a shielding effect. Therefore, by preventing the propagation of the direct wave, the surface acoustic wave element can obtain stable frequency characteristics.

According to the invention of claim 6, the shielding effect of the ground line can be enhanced and more stable frequency characteristics can be obtained.

According to the seventh aspect of the present invention, when the surface acoustic wave element is subjected to vibration or impact, the suspension line contacts the lid, but the signal line does not contact the lid. The signal line is not short-circuited, and the surface acoustic wave element piece can perform a stable operation.

According to the invention of claim 8, when the surface acoustic wave element is subjected to vibration or shock or the like, the ground line is pressed by the lid, and the vibration of the surface acoustic wave element piece is minimized. In addition, a change in frequency characteristics due to vibration is suppressed, and the surface acoustic wave element piece can perform a stable operation.

According to the ninth to thirteenth aspects,
Even if the surface acoustic wave element receives vibration or shock,
The vibration of the surface acoustic wave element piece can be made extremely small, and the breakage of the neck of the suspension line can be prevented, and the frequency characteristics can be prevented from changing.

According to the fourteenth aspect of the present invention, the displacement of the surface acoustic wave element is eliminated by moving the surface acoustic wave element piece, so that the surface acoustic wave element can be manufactured with high accuracy and the workability can be improved.

According to the fifteenth and sixteenth aspects,
Since the suspension line is formed while the surface acoustic wave element piece is held and fixed, the suspension line can be formed accurately and efficiently.

According to the seventeenth to nineteenth aspects of the present invention, the suspension line is formed while the surface acoustic wave element piece is held and fixed, so that the suspension line can be formed accurately and efficiently. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a preferred embodiment (first embodiment) of a surface acoustic wave device according to the present invention.

FIG. 2 is a plan view showing a preferred embodiment (first embodiment) of the surface acoustic wave device of the present invention.

FIG. 3 is a cross-sectional view showing a preferred embodiment (first embodiment) of the surface acoustic wave device of the present invention.

FIG. 4 is a cross-sectional view showing a peripheral portion of a signal line in the surface acoustic wave device of the present invention.

FIG. 5 is a cross-sectional view showing a portion around a ground line in the surface acoustic wave device of the present invention.

FIG. 6 is a plan view showing a surface acoustic wave element according to a second embodiment of the present invention.

FIG. 7 is a sectional view showing a portion around a ground line in a second embodiment of the surface acoustic wave device according to the present invention.

FIG. 8 is a cross-sectional view illustrating a surface acoustic wave device according to a third embodiment of the present invention.

FIG. 9 is a plan view showing a surface acoustic wave device according to a fourth embodiment of the present invention.

FIG. 10 is a flowchart showing a preferred embodiment (fifth embodiment) of the method for manufacturing a surface acoustic wave device according to the present invention.

FIG. 11 is a perspective view showing a state where a surface acoustic wave element piece is held in the method for manufacturing a surface acoustic wave element according to the present invention.

FIG. 12 is a perspective view showing a state where a surface acoustic wave element piece is held in the method for manufacturing a surface acoustic wave element of the present invention.

FIG. 13 is a cross-sectional view showing a state where a surface acoustic wave element piece is sealed in the method for manufacturing a surface acoustic wave element of the present invention.

FIG. 14 shows a sixth method of manufacturing a surface acoustic wave device according to the present invention.
The flowchart figure which shows Embodiment of FIG.

FIG. 15 shows a sixth method of manufacturing the surface acoustic wave device according to the present invention.
FIG. 7 is a schematic view showing a state of a manufacturing process according to the embodiment.

FIG. 16 shows a seventh method of manufacturing the surface acoustic wave device according to the present invention.
The flowchart figure which shows Embodiment of FIG.

FIG. 17 shows a seventh method of manufacturing a surface acoustic wave device according to the present invention.
FIG. 7 is a schematic view showing a state of a manufacturing process according to the embodiment.

FIG. 18 shows a surface acoustic wave element according to the related art and the present invention.
FIG. 4 is a graph showing frequency variation before and after seam welding.

FIG. 19 shows a conventional and surface acoustic wave device according to the present invention.
FIG. 4 is a graph showing peak temperatures in temperature characteristics.

FIG. 20 shows a surface acoustic wave device according to the related art and the present invention.
FIG. 4 is a graph showing the frequency change before and after the thermal shock test.

FIG. 21 shows a surface acoustic wave device according to the related art and the present invention.
FIG. 4 is a graph showing frequency change amounts before and after reflow.

FIG. 22 shows a surface acoustic wave device according to the related art and the present invention.
FIG. 4 is a graph showing frequency variation before and after high-temperature storage.

FIG. 23 is a sectional view showing an example of a conventional surface acoustic wave device.

FIG. 24 is a sectional view showing an example of another conventional surface acoustic wave element.

FIG. 25 is a plan view showing an example of another conventional surface acoustic wave element.

[Explanation of symbols]

 1000, 70, 90, 100: Surface acoustic wave element 20: Surface acoustic wave element piece 30: Substrate 31: Signal electrode 32: Ground electrode 40: Lid 50: Hanging Lines 51, 52, 53, 54: Signal line 61, 62: Ground line 91: Pillow member 500: Elastic body 600: Adhesive

Claims (19)

[Claims] 1. A substrate on which signal electrodes for inputting and outputting electric signals are formed, a surface acoustic wave element piece supported by the substrate and having interdigital electrodes formed on a piezoelectric substrate, A surface acoustic wave element having a lid for sealing the surface acoustic wave element piece, wherein the surface acoustic wave element piece is supported by a hanging wire with respect to the substrate. 2. The suspension line according to claim 1, wherein the suspension line is an aluminum wire.
3. The surface acoustic wave device according to claim 1. 3. The hanging line has one end connected to the interdigital transducer of the surface acoustic wave element piece for transmitting and receiving an electric signal between the substrate and the surface acoustic wave element piece, and the other end. The surface acoustic wave device according to claim 1, wherein the portion includes a signal line connected to the signal electrode. 4. The suspension line includes a ground line having one end connected to a ground portion of the surface acoustic wave element piece and the other end connected to a ground electrode formed on the substrate. The surface acoustic wave device according to any one of claims 1 to 3, wherein 5. The piezoelectric substrate according to claim 4, wherein a plurality of the interdigital electrodes are formed on the piezoelectric substrate, and the ground line is formed so as to pass between the plurality of the interdigital electrodes. Surface acoustic wave device. 6. The plurality of ground lines are arranged between the plurality of interdigital electrodes, and the plurality of ground lines are arranged close to or intersecting with each other. Item 6. A surface acoustic wave device according to any one of items 5. 7. The plurality of suspension lines are formed in a loop shape, and among the plurality of suspension lines, the signal line is formed by the lowest loop. 3. The surface acoustic wave device according to claim 1. 8. The lid according to claim 4, wherein the lid is made of a metal electrically connected to the ground electrode of the substrate, and the ground line is formed so as to contact the lid. Item 8. A surface acoustic wave device according to any one of items 7. 9. The device according to claim 1, wherein a holding member for holding the surface acoustic wave element is disposed between the substrate and the surface acoustic wave element. Surface acoustic wave device. 10. The surface acoustic wave device according to claim 9, wherein the holding member is formed of an elastic body. 11. The surface acoustic wave device according to claim 9, wherein the holding member is formed by solidifying an adhesive. 12. The surface acoustic wave device according to claim 9, wherein the holding member is formed by solidifying a silicon-based adhesive. 13. The surface acoustic wave device according to claim 11, wherein the adhesive has a property of losing an adhesive force when irradiated with ultraviolet rays. 14. A method of manufacturing a surface acoustic wave element in which a surface acoustic wave element piece is supported on a substrate and a cover is placed on the substrate, wherein the surface acoustic wave element piece is Supporting the substrate in a non-contact manner, positioning it at a predetermined position on the substrate, and supporting the surface acoustic wave element piece on the substrate, between the substrate and the surface acoustic wave element piece. A method for manufacturing a surface acoustic wave device, comprising forming a suspension line. 15. When supporting the surface acoustic wave element piece and positioning it at a predetermined position on the substrate, positioning is performed while supporting the surface acoustic wave element piece from below.
5. The method for manufacturing a surface acoustic wave device according to 4. 16. The surface acoustic wave element according to claim 14, wherein when positioning the surface acoustic wave element piece at a predetermined position on the substrate, the surface acoustic wave element piece is positioned while being sandwiched and supported from a side surface of the surface acoustic wave piece. Manufacturing method. 17. When positioning the surface acoustic wave element at a predetermined position on the substrate, an elastic body is arranged on the substrate, and the surface acoustic wave element is arranged on the elastic body. A method for manufacturing a surface acoustic wave device according to claim 14. 18. When positioning the surface acoustic wave element at a predetermined position on the substrate, an adhesive is applied to the substrate, and the surface acoustic wave element is disposed on the adhesive. A method for manufacturing a surface acoustic wave device according to claim 14. 19. The method for manufacturing a surface acoustic wave device according to claim 14, wherein the adhesive is separated from the surface acoustic wave device by irradiating ultraviolet rays.