JP3444419B2 - Surface acoustic wave device and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave device having a comb-shaped electrode for converting between an electric signal and a surface acoustic wave, and more particularly to a surface acoustic wave device having an improved extraction electrode structure. The present invention relates to a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, surface acoustic wave devices (hereinafter referred to as "SAW (Surface)" have been used as resonators, bandpass filters, etc. in electronic parts and communication parts such as mobile phones and television receivers.
"Acoustic Wave) devices") are used.

Various devices into which such a SAW device is to be incorporated have become small in size, and as a result,
There is a strong demand for downsizing such SAW devices.

[0004]

As one solution to such a problem, a SAW device as shown in FIG. 20 has been proposed.

The SAW device 1 comprises a piezoelectric substrate 2 having a comb-shaped electrode formed thereon, and a cap 6 mounted so as to cover the electrode portion of the piezoelectric substrate 2 in an airtight state.

As shown in the plan view of FIG. 21, the piezoelectric substrate 2
Are formed larger than the cap 6, and on the surface of the piezoelectric substrate 2, comb-shaped electrodes (ID
T (Inter Digital Transduce)
r)) 3 and a reflector 4.

The piezoelectric substrate 2 is formed of quartz, for example, in a rectangular plate shape. The IDTs 3 and 3 and the reflectors 4 and 4 are formed on the surface of the piezoelectric substrate 2 in a thin film shape by vapor deposition, sputtering, or the like, and then formed into a comb shape by photolithography or the like. Note that one of the interdigital electrodes is omitted for convenience of illustration.

Specifically, the IDT 3 and the IDT 3 are formed such that the comb-tooth portions of the two comb-shaped electrodes are alternately inserted at a predetermined distance. This IDT3
Has a function of converting between an electric signal and a surface acoustic wave (SAW) through the external terminals 5 and 5 that are electrically connected.

The reflector 4 is formed such that a plurality of electrode fingers are arranged in parallel at a predetermined pitch so that both ends in the longitudinal direction are short-circuited. The reflector 4 has a function of reflecting the surface acoustic wave propagating from the IDT 3 and confining the energy of the surface acoustic wave inside.

In such a structure, when an electric signal is input to the IDT 3 via the external terminal 5, it is converted into a surface acoustic wave by the piezoelectric effect. This surface acoustic wave is
Propagation in the direction orthogonal to the longitudinal direction of the electrode finger of T3,
The reflector 4 is radiated from both sides of the IDT 3. At this time,
A surface acoustic wave having a wavelength equal to the propagation velocity determined by the material of the piezoelectric substrate 2, the thickness of the electrode, the width of the electrode, etc. and the electrode period of the electrode finger of the IDT 3 is excited most strongly. This surface acoustic wave is reflected by the reflector 4 in multiple stages, returned to the IDT 3, and output via the external terminal 5.

On the other hand, in recent years, various types of information equipment and the like in which SAW devices are mounted tend to be extremely miniaturized, and depending on the purpose of the mounted equipment, high frequency compatible SAW devices and low Various SAW devices such as frequency-compatible SAW devices also need to be further downsized.

However, the SAW device 1 described above requires the extraction electrode 5a for connecting to the external terminals 5 and 5, and as is apparent from FIGS. 20 and 21, the piezoelectric substrate 2 is used.
Is formed larger than the cap 6, and the extraction electrodes 5a and 5a are formed on the surface of the piezoelectric substrate 2 exposed to the outside of the cap 6 and electrically connected to the external terminals 5 and 5, respectively. . Therefore, the size of the piezoelectric substrate 2 larger than the cap 6 hinders downsizing of the device.

There is also a method in which the surface of the piezoelectric substrate 2 is processed or a notch is provided in the cap 6 so as to draw out a conducting wire from the external terminals 5 and 5 inside the cap 6, but in this case, the cap is used. There is a problem that the notch processing is required in 6 and the manufacturing process becomes complicated accordingly.

An object of the present invention is to solve the above problems and provide a surface acoustic wave device which can be formed in a small size and can be easily manufactured because it is not necessary to perform a predetermined process on a cap, and a manufacturing method thereof. It is to be.

[0015]

According to the invention of claim 1, the above-mentioned object is that the piezoelectric substrate having the interdigital transducer and the cap are joined together via a sealing material, and the outside of the sealing material is provided. A surface acoustic wave in which an end face of a conducting wire drawn from a terminal of the electrode is arranged on the end face, and a lead-out electrode is formed by coating a region around the end face of the conducting wire with a conducting metal. Achieved by the device.

According to the structure of the first aspect, the piezoelectric substrate having the interdigital transducer and the cap are joined together via the sealing material, and the outer end surface of the sealing material is drawn out from the terminal of the electrode. Since the end face of the conducting wire is arranged, it is not necessary to provide the conducting wire or an electrode or the like in place of the conducting wire and draw it out of the cap. Therefore, the cap and the piezoelectric substrate can have substantially the same size.
It is desirable to simultaneously cut the cap and the piezoelectric substrate by dicing. However, in the prior art, it is necessary to provide a notch in the cap to expose the electrode 5a , or as another method, it is necessary to provide a via hole in the cap and provide an electrode connected to the via hole in the cap. Therefore, in the present application, the number of processing steps can be significantly reduced and the manufacturing becomes easy as compared with the conventional example.

Further, since the end face of the conducting wire is arranged on the outer end face of the sealing material, that is, the conducting wire is surrounded by the sealing material, the conducting wire is interposed between the cap and the piezoelectric substrate. Therefore, the clearance can be made uniform by the wire diameter.

According to a second aspect of the present invention, in the structure of the first aspect, the piezoelectric substrate and the cap have substantially the same shape.

According to the structure of the second aspect, since the piezoelectric substrate and the cap have almost the same shape, the size can be remarkably reduced as compared with the SAW chip, which has been considered conventionally and has a large substrate side.

According to a third aspect of the present invention, in the structure of the first or second aspect, the conducting wire extends so as to avoid a position overlapping above the interdigital electrode on the piezoelectric substrate.

According to the structure of claim 3, laser light is radiated to the electrodes on the piezoelectric substrate through the transparent cap,
Even when the frequency is adjusted, the conducting wire does not obstruct the optical path.

Further, according to the invention of claim 4, a wafer-shaped material for a piezoelectric substrate formed of a piezoelectric material and a wafer-shaped material for a cap are prepared, and a wafer for a piezoelectric substrate is prepared. A plurality of interdigital electrodes are simultaneously formed on the surface of the material in the shape of a unit for each unit of size to be an individual product. The terminals are bonded with a conductive wire, and a sealing material is applied to the periphery of the wafer-shaped material for the cap or the wafer-shaped material for the piezoelectric substrate in units of individual product sizes. With the coated surface of the material inside, the wafer-shaped material for the cap,
A state in which the sealing material is cured by stacking the wafer-shaped material for the piezoelectric substrate so as to face the electrode formation surface, and then the wafer-shaped material for the cap is stacked on the wafer-shaped material for the piezoelectric substrate. At each unit of the size to be an individual product in, to expose the end surface of the conductive wire to the cut surface of the sealing material, for each diced chip, given a predetermined mask, the end surface of the conductive wire This is achieved by a method of manufacturing a surface acoustic wave device, in which a peripheral region is coated with a conductive metal.

According to the structure of claim 4, both the wafer for forming the piezoelectric substrate and the plate-like material for the cap can be subjected to the steps up to sealing in the state of the wafer. Therefore, the work up to encapsulation can be carried out simultaneously on a large number of chips, resulting in extremely high manufacturing efficiency. Further, the wafer for forming the piezoelectric substrate does not require special grinding or the like for forming a clearance or passing an electrode with respect to the plate-shaped material for the cap, which is troublesome. There is no work, and manufacturing is easy also in this respect.

According to a fifth aspect of the present invention, in the structure of the fourth aspect, the piezoelectric substrate and the cap have substantially the same shape.

According to a sixth aspect of the present invention, in the structure of the fourth or fifth aspect, the conductive line is connected so as to extend obliquely with respect to the extending direction of the electrode fingers of the interdigital transducer.

According to the structure of claim 6, the cut end face of the conducting wire becomes substantially elliptical when cut into the size of each product unit. Therefore, the area for contacting the extraction electrode is larger than that of the circular cross section, and the electrical connection is ensured.

According to a seventh aspect of the present invention, in the structure of the sixth aspect, the conducting wire is connected so as to extend while avoiding a position overlapping above the interdigital electrode.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a schematic configuration of a SAW device according to a first embodiment of the present invention, and FIG.
3 is a schematic cross-sectional view taken along line AA of FIG.

This SAW device 10 is provided with a piezoelectric substrate 12 on the surface of which a comb-shaped electrode 13 and a reflector 14 which are interdigital electrodes are formed, and a cap 16 which covers the electrode forming portion of the piezoelectric substrate 12 in an airtight state. There is.

The piezoelectric substrate 12 is made of, for example, a single crystal substrate such as quartz, lithium tantalate, or LBO, or a multilayer film substrate such as ZnO / Si as a piezoelectric material.
The shape of 2 is, for example, a rectangular plate shape as illustrated.

For the cap 16, for example, a material having a coefficient of thermal expansion close to that of the piezoelectric substrate is suitable. For example, the same piezoelectric material, preferably the same shape as the piezoelectric substrate 12 and the same outer shape, is used. It is made of a transparent material that transmits light. In FIG. 1, the cap 16 is shown transparent except for the portion where the electrode is formed on the surface.

A sealing material 17 is provided on the periphery of the piezoelectric substrate 12.
Are arranged. The sealing material 17 is filled between the peripheral portions of both the piezoelectric substrate 12 and the cap 16 to seal the piezoelectric substrate 1.
2 and the cap 16 are fixed, and as shown in FIG. 2, a space S is formed inside to perform airtight sealing. As the sealing material 17, for example,
Low melting point glass, insulating adhesive, etc. are used.

Comb-shaped electrode (IDT) 13 and reflector 14
Is formed so that a conductive metal such as aluminum or titanium is formed into a thin film on the surface of the piezoelectric substrate 12 by vapor deposition, sputtering, or the like, and is then formed into a comb shape by photolithography or the like. Comb-shaped electrode (IDT) 1
The configurations of 3 and the reflector 14 will be described in detail later with reference to other drawings.

The IDT 13 is formed in a region covered with the cap 16 as shown in FIG. Each external terminal 2
5 and 26 have one ends 18a and 19 of the conducting wires 18 and 19, respectively.
a is connected. The other end 1 of the conducting wires 18 and 19
8b and 19b extend into the sealing materials 17 and 17 filled between the piezoelectric substrate 12 and the cap 16, and the end faces of the other ends 18b and 19b of the conducting wires 18 and 19 are the sealing materials. It is located so as to face the outer end surfaces 17a, 17a of the 17, 17.

Further, as shown in FIGS. 1 and 2, the other ends 18b and 19b of the respective conducting lines 18 and 19 are provided.
The lead-out electrodes 21 and 22 are formed by covering the outer surfaces of both ends of the SAW device 10 including the periphery of the end surface of FIG. These lead-out electrodes 21 and 22 are in contact with the end faces of the other ends of the conducting wires 18 and 19, respectively, so that the IDs formed on the piezoelectric substrate 12 are formed.
It is electrically connected to T13.

The SAW device 10 of this embodiment is configured as described above, and the manufacturing method thereof will be described in detail below.

FIG. 3 shows how the piezoelectric substrate 12 is formed. First, as a piezoelectric material, for example, a single crystal substrate such as quartz, lithium tantalate, LBO, or ZnO / S is used.
A predetermined electrode pattern is formed on the wafer 31 made of a multilayer substrate such as i. In the case shown, for example, the wafer 31
In the subsequent process, the virtual cutting lines C1, C2, C3
An example is shown in which nine piezoelectric substrates 12 are formed by cutting at C4.

The electrode pattern formed here is a unit of one piezoelectric substrate 12, and a set of comb-shaped electrodes (IDT) 1 is formed.
3 and the respective reflectors 14 and 14 arranged on both sides thereof. In this case, electrodes are formed on the wafer 3
The piezoelectric substrate 12 included in 1 is collectively formed, and a conductive metal such as aluminum or titanium is formed into a thin film by vapor deposition, sputtering, or the like, and then formed into a comb shape by photolithography or the like. Then, as shown in one piezoelectric substrate 12 in FIG. 3, the external terminals 25 and 26 are simultaneously formed for each piezoelectric substrate 12.

Next, as shown in FIG. 4, the conducting wire is connected. A metal that extends well and has a low electric resistance is suitable for the conducting wire. For example, a gold (Au) wire is preferably used. Then, one end of each of the gold wires 18 and 19 is connected to the piezoelectric substrate 1
For example, it is bonded to the external terminal 25 on 2, and the same gold wires 18 and 19 are obliquely extended, and the other end is bonded to the external terminal 26 of another adjacent piezoelectric substrate 12. At this time,
The gold wire is prevented from crossing over the electrodes of the IDT 13 and the reflector 14. These are cut along the virtual cutting lines C1, C2, C3, C4 in a later process,
The conducting wire 18 connected to the external terminal 25 and the conducting wire 19 connected to the external terminal 26 are configured respectively.

Here, FIG. 5 is a partially enlarged plan view showing the manner of bonding the conducting wire described in FIG. The state of the electrodes formed on the piezoelectric substrate 12 will be described with reference to this drawing.

In the figure, the IDT 13 is formed such that a plurality of electrode fingers 13a are juxtaposed at a predetermined pitch so that the ends in the longitudinal direction are alternately short-circuited. Ie 2
The comb-tooth portions of the two comb-shaped electrodes are formed so as to interleave with each other at a predetermined distance. This IDT13
Have external terminals 25 and 26 at positions diagonal to each other near both ends in the longitudinal direction of the piezoelectric substrate 12. That is, the external terminal 25 is provided from one end of the piezoelectric substrate 12 in the short side direction, and the external connection terminal 26 is the piezoelectric substrate 1.
It is provided from the other end in the short side direction of 2. As a result, the IDT 13 has a function of converting between an electric signal and a surface acoustic wave (SAW) via the external terminals 25 and 26 that are electrically connected.

Reflectors 14 and 14 are provided on both sides of the IDT 13 with a predetermined gap therebetween.
The reflector 14 is formed such that the plurality of electrode fingers 14a are arranged in parallel at a predetermined pitch and each end portion in the longitudinal direction is short-circuited, as in the IDT 13.

Then, for example, in the two reflectors 14 having the same structure, the electrode finger 14a has the electrode finger 13 of the IDT 13.
It is formed so as to be parallel to a and sandwich the IDT 13 at a predetermined distance in the propagation direction of the surface acoustic wave, that is, in the direction orthogonal to the longitudinal direction of the electrode fingers 13a of the IDT 13. The reflectors 14 and 14 have a function of reflecting the surface acoustic wave propagating from the IDT 13 and confining the energy of the surface acoustic wave inside.

The conductive lines 18 and 19 are connected to the external terminals 26 on the piezoelectric substrate 12 on the left side in FIG. 5 and the external terminals 25 on the piezoelectric substrate 12 on the right side adjacent to the piezoelectric substrate 12.
It is provided to connect with.

Next, as shown in FIG. 6, a thin plate-shaped material 32 for forming a cap is prepared. The plate-shaped material 32 is preferably selected from a material having a coefficient of thermal expansion that matches or is very close to that of the wafer 31 for forming the piezoelectric substrate 12. For example, SiO ₂ or glass is suitable. The same piezoelectric material as 31 may be used.

FIG. 7 shows how the sealing material 33 is applied to the plate-shaped material 32 for the cap. The plate-shaped material 32 for the cap has an imaginary cutting line C5 as shown.
It will be divided in a later step along C6, C7, and C8.
The cutting lines C5, C6, C7, C8 are provided at positions corresponding to the virtual cutting lines C1, C2, C3, C4 (see FIGS. 3 and 4) on the side of the wafer 31. It is cut at the same time as C1, C2, C3 and C4.

The plate-shaped material 32 for the cap has a cutting line C.
For each unit divided by 5, C6, C7, C8,
The sealing material 33 is applied so as to surround the inner periphery thereof, and one divided sealing material corresponds to the sealing material 17 described in FIGS. 1 and 2. As the sealing material used here, a material having an insulating property and excellent adhesion to the substrate is suitable, and for example, a glass frit or an insulating adhesive is used. Specifically, this sealing material is, for example, using a screen used for screen printing, on the lower surface of the plate-shaped material 32 for the cap of FIG. 7, by cutting lines C5, C6, C7, C8. It is applied so as to surround the inner circumference of the divided area.

Therefore, the plate-shaped material 32 for the cap is used.
However, unlike the piezoelectric device described with reference to FIG. 20, it is not necessary to perform a troublesome work such as forming a gap for drawing out an electrode, and the process proceeds to the next step without any processing.

Here, as described above, instead of applying the sealing material 33 to the plate-shaped material 32 for the cap, at the position corresponding to this, sealing is performed on the wafer 31 side which is the substrate side by the same method. The material 33 may be applied.

Then, as shown in FIG. 8, for example, in a vacuum atmosphere, on the wafer 31 described in FIG.
The plate-shaped material 32 for the cap described in FIG. 7 is overlaid.
As a result, the wafer 31 and the plate-shaped material 32 for the cap are formed.
The sealing material 33 is interposed between the and. At the same time, the conducting wires 18 and 19 enter the sealing material 33 and are surrounded by the sealing material 33. Further, in this state, the cutting lines C5, C6, C7, and C8 of the plate-shaped material 32 for the cap are the same as the wafer 31.
It is located above the cutting lines C1, C2, C3, C4 on the side. By heating in this state, the sealing material 33
By curing, the plurality of piezoelectric substrates are simultaneously sealed with the cap.

Then, as shown in FIG. 9, the cutting line C5,
By cutting along C6, C7, and C8 with a dicing plate or the like, each piezoelectric substrate 12 is cut into a size (SAW device chip).

In this state, the end faces of the other ends 18b and 19b of the conducting wires 18 and 19 are exposed at the cut surfaces in the longitudinal direction of the piezoelectric substrate 12, respectively.

Finally, as shown in FIG. 10, a mask 28 is formed at the center of the cut one-chip processed product, and conductive metal is sputtered or vapor-deposited at both ends not hidden by the mask 28. By applying the coating method, the extraction electrodes 21 and 22 as shown in FIG. 1 are formed.

Since the SAW device 10 is manufactured as described above, since the piezoelectric substrate 12 and the cap 16 have substantially the same shape, the SAW shown in FIG.
Compared with the chip 1, it is possible to obtain a much smaller SAW device. Of course, as compared with the case where the piezoelectric substrate 12 is housed in the ceramic package, a much smaller surface acoustic wave device can be obtained.

Both the wafer 31 for forming the piezoelectric substrate 12 and the plate-shaped material 32 for the cap can be subjected to the steps up to sealing in the wafer state. For this reason, the work up to sealing of many chips can be carried out at the same time, and the manufacturing efficiency is extremely high. Further, the wafer 31 for forming the piezoelectric substrate 12 also forms a clearance with respect to the plate-shaped material 32 for the cap,
Since no special grinding process or the like is required to pass the electrode through, there is no troublesome work, and the manufacturing is easy in this respect as well.

Further, in the wafer state, since the sealing member 17 is used for sealing, a large number of products are sealed at the same time, and the space between the cap 16 and the piezoelectric substrate 12 is surrounded by the sealing material 17 and is electrically conductive. Since the wire is interposed, the clearance CR (see FIG. 2) of all products can be made the same depending on the wire diameter.

Further, in particular, the conducting wires 18 and 19 are arranged above the piezoelectric substrate 12 so as not to overlap the electrodes of the IDT 13 and the reflector 14, so that the laser light is transmitted through the transparent cap. Even when the frequency is adjusted by irradiating the electrodes on the piezoelectric substrate 12, the conducting lines 18 and 19 do not interfere with the optical path.

Further, the conductive lines 18 and 19 extend obliquely, and when cut along the cutting lines C5, C6, C7 and C8, the end faces of the other ends 18b and 19b of the conductive lines 18 and 19 are It becomes almost oval. Therefore, the extraction electrode 2
The area for contacting the first and the second terminals 22 is larger than that in the case where the area is circular, and the electrical connection is assured accordingly.

FIG. 11 shows the piezoelectric substrate 48 of the SAW device according to the second embodiment. The piezoelectric substrate 48 is
The piezoelectric substrate 12 is made of the same material as the piezoelectric substrate 12 of the first embodiment, and is manufactured by almost the same process, except for the electrode pattern formed on the surface thereof. Below, the first
The same points as those of the first embodiment will be denoted by the same reference numerals, redundant description will be omitted, and different points will be mainly described.

In FIG. 11, the IDT 43 has two external terminals 46 and 47 at one end (upper side in the drawing) of the piezoelectric substrate 48, and the other end (lower side in the drawing) of the piezoelectric substrate 48. The side) is provided with one external terminal 45. In the wafer state, this piezoelectric substrate 48 is adjacent to another piezoelectric substrate 48 adjacent to each other in the left-right direction before being separated in a pattern whose top and bottom are opposite to those shown in the drawing. Also,
The other piezoelectric substrate 48 adjacent in the vertical direction has the IDT 4
The three external terminals 45 are adjacent to each other so as to face each other.

As a result, the conducting wire 1 is connected to the external terminal 46.
1 is bonded to one end portion 18a of FIG.
1, another piezoelectric substrate 4 (not shown) adjacent to the left side
8 extending toward the external terminal 46,
The other end 18b of 8 is cut in the cutting step described above. In addition, the external terminal 47 has one end portion 19 of the conducting wire 19.
a is bonded, and the other end side is the external terminal 4 of another piezoelectric substrate 48 (not shown) adjacent to the right side in FIG.
7, the other end 19b of the conducting wire 19
Is cut in the cutting step described above. Further, one end portion 41a of the conducting wire 41 is bonded to the external terminal 45, and the other end side extends toward the external terminal 45 of another piezoelectric substrate 48 (not shown) adjacent to the lower side in FIG. The other end 41b of the conducting wire 41 is cut in the cutting step described above.

As a result, the SAW device 40 using this piezoelectric substrate 48 has a form as shown in FIG. That is, although the cap 16 is the same as that of the first embodiment, the lead electrode 42 is formed in a region around the end surface 41b of the conducting wire 41 corresponding to the external terminal 45 of the piezoelectric substrate 48.

As described above, the SAW device 40 is the same as the first embodiment except that the three lead electrodes 21, 22, 42 are provided corresponding to the three external terminals 45, 46, 47 of the IDT 43. Is the same as and has the same effect.

The SAW device 50 of FIG. 13 is a modified example of the second embodiment, and is provided with the extraction electrode 42a which does not cover the central portion of the cap 16 with the conductive metal. This prevents the extraction electrode from blocking the optical path of the laser light when the above-mentioned frequency adjustment is performed using the laser light through the transparent cap 16.

FIG. 14 shows the piezoelectric substrate 52 of the SAW device according to the third embodiment. The piezoelectric substrate 52 is
The piezoelectric substrate 12 is made of the same material as the piezoelectric substrate 12 of the first embodiment, and is manufactured by almost the same process, except for the electrode pattern formed on the surface thereof. Below, the first
The same points as those of the first embodiment will be denoted by the same reference numerals, redundant description will be omitted, and different points will be mainly described.

In FIG. 14, the IDT 83 is symmetrical with respect to the upper, lower, left, and right centerlines, and is provided with two IDTs 83, 83 having the same structure and a reflector 84 arranged between the IDTs 83, 83. And each IDT 83,
The reflectors 14 and 14 are also arranged outside 83. The IDTs 83, 83 have two external terminals, whereby four external terminals 65, 66, 67, 68 are formed near the corners of the rectangular piezoelectric substrate 52. ing. In the state of a wafer, this piezoelectric substrate 52 is connected to another piezoelectric substrate 52 adjacent in the left-right direction before being separated by connecting the external terminals 65, 66, 67, 68 of the IDTs 83, 83 with conductive wires. Has been done. That is, one end 71a of the conducting wire 71 is bonded to the external terminal 65, and the other end extends toward the external terminal 68 of another piezoelectric substrate 52 (not shown) adjacent to the left side in FIG. This conducting wire 71 is preferably bent slightly inward so that the other end 7
1b is cut in the cutting step described above. One end 72a of the conducting wire 72 is bonded to the external terminal 66, and the other end extends toward the external terminal 67 of another piezoelectric substrate 52 (not shown) adjacent to the left side in FIG. The wire 72 is preferably deflected slightly inward and the other end 72b is cut in the cutting process described above. One end portion 73a of the conducting wire 73 is bonded to the external terminal 67, and the other end side extends toward the external terminal 66 of another piezoelectric substrate 52 (not shown) adjacent to the right side in FIG. The wire 73 is preferably bent slightly inward, and the other end 73b is cut in the cutting process described above. One end 74a of the conducting wire 74 is bonded to the external terminal 68, and the other end extends toward the external terminal 65 of another piezoelectric substrate 52 (not shown) adjacent to the right side in FIG. The wire 74 is preferably deflected slightly inward and the other end 74b is
It is cut in the cutting step described above.

As a result, the SAW device 60 using this piezoelectric substrate 52 has a form as shown in FIG. That is, the cap 16 is the same as that of the first embodiment, but the external terminals 65, 66, 67 of the piezoelectric substrate 52,
Corresponding to 68, each extraction electrode is formed in a region around the end face of each conduction line. Therefore, the extraction electrodes 61, 62, 63, 63 are formed at the corners of the rectangular parallelepiped, respectively.

As described above, the SAW device 60 has the four external terminals 65, 66, 6 of the IDTs 83, 83.
Corresponding to 7, 68, four extraction electrodes 61, 62,
The third embodiment is the same as the first embodiment except that it is provided with 63 and 64, and exhibits the same effect.

FIGS. 16 and 17 show a configuration example of the cut end face which is slightly different from the above method. The piezoelectric substrate 12 and the piezoelectric substrate 12 are formed adjacent to each other on a common wafer. The IDT external terminal 85 of one piezoelectric substrate 12 and the IDT external terminal 86 of the other piezoelectric substrate 12 are connected by a plurality of, in this case, three conducting wires 81. Thereby, the electrical connection can be made more reliable.

Further, in this case, the substrate and the cap are cut at the positions of the cutting line MC1 and the cutting line MC2, and the cutting line M
If the conducting wire 81 is cut at the cutting line MC3 between the C1 and the cutting line MC2, the other end side 81b of the conducting wire 81 hangs down at the cutting surface of the piezoelectric substrate 12, as shown in FIG. As a result, the electrical connection with the lead electrode formed of the conductive metal coated thereon can be made more reliable.

FIG. 18 shows that the piezoelectric substrate 12 and the piezoelectric substrate 12 adjacent thereto have external terminals 83 at diagonal positions.
And external terminals 84 are arranged. In this case, if the conducting wire 87 is connected between the external terminal 83 of the piezoelectric substrate 12 and the external terminal 84 of another adjacent piezoelectric substrate 12, the conducting wire 87 is connected.
Will extend obliquely with respect to the cutting line MC4 as shown. For this reason, the cut end face of the conducting wire 87 is as shown in FIG.
As shown in FIG. 9, the cross section is substantially elliptical, and the area of the cut surface is larger than that in the case where the cross section is circular. This allows
The electrical connection with the lead-out electrode formed of the conductive metal coated thereon becomes more reliable. Such a configuration
This is common to the first embodiment, and is similar to FIGS.
Is for explaining the effect in a case where the conducting wire is arranged so as to extend obliquely with respect to the extending direction of the electrode fingers of the IDT, that is, the same direction as the cutting line, and is cut.

The present invention is not limited to the above-mentioned embodiments, but is applied to all forms of SAW devices without departing from the spirit of the invention described in the claims.

In particular, the individual configurations of the above-mentioned embodiments are as follows.
They may be omitted if necessary, or may be arbitrarily combined with other configurations different from these or the individual configurations.

[0075]

As described above, according to the present invention, there is provided a surface acoustic wave device which can be formed in a small size and can be easily manufactured because it is not necessary to perform a predetermined process on the cap, and a manufacturing method thereof. Can be provided.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a first embodiment of a SAW device of the present invention.

FIG. 2 is a schematic cross-sectional view taken along the line AA of the SAW device shown in FIG.

3 is a schematic perspective view showing a state in which electrodes are formed on a wafer for manufacturing a piezoelectric substrate in a manufacturing process of the SAW device of FIG.

4 is a schematic perspective view showing a state in which a conductive wire is provided on a wafer for manufacturing a piezoelectric substrate in a manufacturing process of the SAW device of FIG.

5 is a partially enlarged plan view showing a state in which a conductive wire is provided on a wafer for manufacturing a piezoelectric substrate in the manufacturing process of the SAW device of FIG.

6 is a schematic perspective view showing a wafer for manufacturing a cap in the manufacturing process of the SAW device of FIG.

7 is a schematic perspective view showing a state in which a sealing material is applied to a wafer for manufacturing the cap of FIG.

FIG. 8 shows a wafer for manufacturing the piezoelectric substrate of FIG.
Schematic perspective view showing a state in which wafers for manufacturing the cap of FIG.

FIG. 9 is a schematic perspective view showing a state of being diced from the state of FIG. 8 along a cutting line.

10 is a schematic perspective view showing a state where one chip is masked after the cutting step of FIG. 8;

FIG. 11 is a schematic plan view of a piezoelectric substrate according to a second embodiment of a SAW device.

FIG. 12 is a schematic perspective view showing a second embodiment of the SAW device of the present invention.

13 is a schematic perspective view showing a modified example of the SAW device of FIG.

FIG. 14 is a schematic plan view of a piezoelectric substrate according to a third embodiment of a SAW device.

FIG. 15 is a schematic perspective view showing a third embodiment of the SAW device of the present invention.

FIG. 16 is a partial plan view showing another example of connection of external terminals.

FIG. 17 is a partial side view showing another example of connection of external terminals.

FIG. 18 is a partial plan view showing how external terminals are connected by diagonally extending conductive lines.

FIG. 19 is a schematic view showing a cut surface along a cutting line in FIG. 18.

FIG. 20 is a schematic perspective view showing a SAW device.

21 is a schematic plan view of the SAW device of FIG.

22 is a schematic front view of the SAW device of FIG.

[Explanation of symbols]

10, 40, 50, 60 SAW device (surface acoustic wave device) 12 Piezoelectric substrate 13 Comb-shaped electrode (IDT) 13a Electrode finger 14 Reflector 16 Cap 17 Sealing material 18 Conducting wire 19 Conducting wire 21 Leading electrode 22 Leading electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H03H 9/145 H03H 3/08 H03H 9/25

Claims (7)

(57) [Claims] 1. A piezoelectric substrate on which a comb-shaped electrode is formed and a cap are joined via a sealing material, and an end face of a conducting wire drawn from a terminal of the electrode is arranged on an outer end face of the sealing material. The surface acoustic wave device is characterized in that a lead-out electrode is formed by coating a region around the end face of the conducting wire with a conducting metal. 2. The surface acoustic wave device according to claim 1, wherein the piezoelectric substrate and the cap have substantially the same shape. 3. The surface acoustic wave device according to claim 1, wherein the conducting wire extends so as to avoid a position overlapping the interdigital electrode on the piezoelectric substrate. . 4. A wafer-shaped material for a piezoelectric substrate formed of a piezoelectric material and a wafer-shaped material for a cap are prepared, and individual products are provided on the surface of the wafer-shaped material for the piezoelectric substrate. Multiple sets of interdigital electrodes are simultaneously formed for each unit of size, and terminals on adjacent piezoelectric substrates, which are individual products in this wafer-shaped material for piezoelectric substrates, are bonded to each other by conductive lines, With respect to the wafer-shaped material or the wafer-shaped material for the piezoelectric substrate, the sealing material is applied to the peripheral portion for each unit of the size to be an individual product, and the sealing material is applied to the inside, and A wafer-shaped material is laminated so as to face the electrode forming surface of the wafer-shaped material for the piezoelectric substrate to cure the sealing material, and then the wafer-shaped material for the piezoelectric substrate is bonded to the wafer-shaped material for the cap. Of material Dicing is performed in each unit of a size that becomes an individual product in a twisted state, the end face of the conducting wire is exposed on the cut surface of the sealing material, and a predetermined mask is applied to each dicing chip to obtain the conducting wire. A method for manufacturing a surface acoustic wave device, characterized in that a conductive metal is coated on a region around an end surface of the surface acoustic wave device. 5. The method of manufacturing a surface acoustic wave device according to claim 4, wherein the piezoelectric substrate and the cap have substantially the same shape. 6. The surface acoustic wave according to claim 4, wherein the conducting wire is connected so as to extend obliquely with respect to the extending direction of the electrode fingers of the interdigital transducer. Device manufacturing method. 7. The method for manufacturing a surface acoustic wave device according to claim 6, wherein the conductive wire is connected so as to extend so as to avoid a position overlapping the interdigital electrode.