KR100484078B1 - Surface acoustic wave device and its manufacture method, and electronic part using it - Google Patents

Abstract

A piezoelectric substrate, a comb-shaped electrode constituting an IDT on the substrate, a reflector electrode disposed close to the propagation direction of the surface wave generated from the IDT, and a comb-shaped electrode and a reflector electrode in place By providing a structure in which the short-circuit auxiliary electrodes having different widths are provided, the electric charges generated in the heat treatment process of the piezoelectric substrate and the like when the surface acoustic wave device is manufactured are made uniform throughout the surface of the surface of the surface acoustic wave device. It is an object to prevent the electrode from being damaged or the electrical characteristics deteriorated by the discharge generated from the accumulation of charge due to the pyroelectricity of the substrate even after separation by the surface wave device.

Description

Surface acoustic wave device and its manufacturing method and electronic component using the same {SURFACE ACOUSTIC WAVE DEVICE AND ITS MANUFACTURE METHOD, AND ELECTRONIC PART USING IT}

The present invention relates to a surface acoustic wave device used in a communication device, a manufacturing method thereof, and an electronic component using the same.

Conventionally, a surface acoustic wave device has a desired interdigital transducer (IDT) electrode and a grating reflector by forming a thin metal film on the entire surface of a piezoelectric substrate, and applying a resist thereon to expose, develop, and then etch. A plurality of desired electrode patterns such as a grating reflector electrode (hereinafter referred to as a reflector electrode), a dicing line surrounding them, and a thin wire connecting them, are formed and cut along the dicing line to provide individual elasticity. We manufacture surface wave device.

In this method, since the IDT electrode and the reflector electrode are electrically separated from each other by dicing the piezoelectric substrate, when the surface acoustic wave device is subjected to heat or distortion, the piezoelectric substrate has a pyroelectric effect. When charge is generated and the amount of charge between the electrodes becomes uneven, the electrodes are broken or discharged between the IDT electrodes and the reflector electrodes, or between the IDT electrodes and the reflector electrodes, and the characteristics of the surface acoustic wave device are deteriorated. .

As a means of solving this problem, the method of Unexamined-Japanese-Patent No. 11-298289 is known. That is, the short circuit thin line of the metal thin film surrounding the IDT electrode or the reflector electrode is provided inside the dicing line, and the short circuit thin line which electrically connects the short circuit thin line and the IDT electrode of these metal thin films is generated, The structure which electrically uniformizes an electric charge and prevents damage by electric discharge and deterioration of an electrical property is used. Moreover, a dicing line is a boundary line which cut | disconnects several surface acoustic wave devices formed on the piezoelectric board | substrate into individual pieces, and forms the material similar to IDT electrode etc. normally by photolithography and etching.

However, a short circuit thin wire of a metal thin film surrounding the IDT electrode or the reflector electrode is provided inside the dicing line, and a plurality of thin wires electrically connecting the short thin wire of the metal thin film and the IDT electrode are arranged. When the temperature fluctuates rapidly and the amount of generated charge is large, when the distance between electrodes is small, when the connected electrodes are separated, when the short thin wire of the metal thin film and the line connecting the IDT electrode are thin, In the case of a serpentine line or a part of the line is thinner than other parts, the generated charge cannot be sufficiently uniformed because the impedance between the lines becomes higher, so that discharge occurs between the electrodes, resulting in breakage of the electrodes or deterioration of electrical characteristics. I had a problem.

1A and 1B are a plan view showing the configuration of an electrode pattern of a surface acoustic wave device according to a first embodiment of the present invention, and a plan view showing a configuration formed of a plurality of substrates on a piezoelectric substrate;

2 is a cross-sectional view of an electronic component using the same surface acoustic wave device;

3 is a plan view showing the configuration of an electrode pattern of a surface acoustic wave device according to a second embodiment of the present invention;

4 is a plan view showing the configuration of an electrode pattern of a surface acoustic wave device according to a third embodiment of the present invention;

5A and 5B are plan views showing the structure of the electrode pattern of the surface acoustic wave device according to the fourth embodiment of the present invention, and a plan view showing a structure formed on the substrate having piezoelectric properties in a plurality;

6 is a plan view showing the configuration of an electrode pattern of a surface acoustic wave device according to a fifth embodiment of the present invention;

7 is a plan view showing the configuration of an electrode pattern of a surface acoustic wave device according to a sixth embodiment of the present invention;

8 is a plan view showing the configuration of an electrode pattern of a surface acoustic wave device according to a seventh embodiment of the present invention;

Fig. 9 is a plan view showing the configuration of electrode patterns of the surface acoustic wave device according to the eighth embodiment of the present invention.

SUMMARY OF THE INVENTION The present invention solves the above problems, and when the surface acoustic wave device is manufactured, electric charges generated during the heat treatment process of the piezoelectric substrate and the like are uniformized over the entire electrode surface of the surface acoustic wave device, and are separated into individual surface acoustic wave devices. Afterwards, an object of the present invention is to provide a surface acoustic wave device and a method of manufacturing the same, and an electronic component using the same, which prevents the electrode from being damaged or the electrical properties deteriorated by discharge due to the potential difference generated by the pyroelectricity of the substrate.

In order to solve this problem, the surface acoustic wave device of the present invention includes a substrate having piezoelectricity, a comb-shaped electrode constituting an IDT on the substrate, and a reflector electrode disposed close to the propagation direction of surface waves generated from the IDT. And a frame-shaped short-circuit auxiliary electrode having a width different depending on a place around the comb-shaped electrode and the reflector electrode.

Moreover, the manufacturing method of the surface acoustic wave device of this invention is a process of attaching a metal thin film on a piezoelectric board | substrate, the comb-shaped electrode which comprises IDT by etching this metal thin film, and the propagation direction of the surface wave generate | occur | produced by IDT. A step of providing a plurality of sets of reflector electrodes formed adjacent to each other, at least a plurality of frame-shaped short-circuit auxiliary electrodes having different widths according to places around the comb-shaped electrodes and the reflector electrodes, and a process of cutting between adjacent short-circuit auxiliary electrodes. It is a way to include.

Moreover, the electronic component of this invention is a base board which has a lead-out electrode and the terminal electrode which electrically connects with this lead-out electrode in a box-shaped bottom part, the cover for sealing the inside of the base board which covers this base board, and the base part of a base board The surface acoustic wave device arranged in the above, and a connecting member for electrically connecting the input / output terminal electrode of the surface acoustic wave device and the lead electrode of the base substrate, characterized by using the surface acoustic wave device having the above structure.

Best Mode for Carrying Out the Invention Embodiments of the present invention will be described below with reference to the drawings.

(Example 1)

1: A is a top view which shows the structure of the electrode pattern of the surface acoustic wave device in Example 1 of this invention, and FIG. 1B is a partial top view which shows the structure which provided the plurality of surface acoustic wave devices shown in FIG. 1A on a board | substrate. 2 is a cross-sectional view of an electronic component produced by sealing a surface acoustic wave device with a package consisting of a base substrate and a cover.

The surface acoustic wave device 10 of the present invention has a comb electrode 2 constituting an IDT on a substrate 1 having piezoelectricity, and a propagation direction of surface acoustic waves excited by the comb electrode 2. A pair of reflector electrodes 3 provided in the vicinity of the substrate are arranged at a predetermined distance, and the input / output lead-out electrodes 4a and 5a, the input / output terminal electrodes 4b and 5b and the comb-tooth electrodes are arranged from these comb-shaped electrodes 2. (2) The strip | belt-shaped connection electrode 18 which mutually connects is provided, and it has a structure which formed the frame-shaped short circuit auxiliary electrode 6 which differs in width | variety according to a place around these. The outer peripheral portion of the short-circuit auxiliary electrode 6 has a gap 8 partially left by dicing, and this gap 8 part is a portion where the surface of the substrate 1 is exposed. Further, bumps 7 are formed in predetermined portions of the short-circuit auxiliary electrode 6 and the input / output terminal electrodes 4b and 5b, and the bumps 7 and the lead electrodes 13 of the base substrate 9 are formed. Connected.

As shown in FIG. 2, the base substrate 9 has a box shape, and a lead electrode 13 is provided at the bottom thereof, and the lead electrode 13 is connected to an external terminal electrode 14. The bumps 7 formed in the predetermined portion of the surface acoustic wave device 10 are electrically connected to the lead electrodes 13 and mechanically fixed. The lid 15 is provided with an adhesive member 16 such as Au-Sn solder, and is bonded to the base substrate 9 by the adhesive member 16 to seal the inside to form an electronic component.

1 and 2 schematically show the configuration of this embodiment, and do not show the relative relationship between the respective dimensions. The same applies to the drawing of the surface acoustic wave device shown thereafter.

Depending on the material having piezoelectricity, dislocations are generated by pyroelectricity or piezoelectricity. When the amount of charge generated by these differences varies depending on the location, a potential difference occurs. When the potential difference is greater than or equal to an arbitrary value, there is a case of discharging the device and causing deterioration of the device or deterioration of electrical characteristics. In order to prevent this, it is an effective countermeasure to lower the potential generated by the pyroelectricity or piezoelectricity, or to bring the potential to the same potential as soon as possible.

The present invention is a method of balancing the potentials in the surface acoustic wave device 10 and reducing the generated potential difference as quickly as possible. The present invention provides a low impedance region in the electrode pattern of the surface acoustic wave device 10 as wide as possible. Based on finding that it is desirable to do

That is, the electrode pattern of the surface acoustic wave device 10 of the present invention is formed on the substrate 1 having piezoelectricity in the propagation direction of the comb-shaped electrode 2 constituting the IDT and the surface wave generated from the comb-shaped electrode 2. The reflector electrode 3 is arrange | positioned in the both sides of the comb-shaped electrode 2 adjacently, and the periphery of the comb-shaped electrode 2 and the reflector electrode 3 is surrounded by the frame-shaped short circuit auxiliary electrode 6. Here, the short-circuit auxiliary electrode 6 is connected to the lead electrode 13 of the base substrate 9 on which the surface acoustic wave device 10 is mounted, and the lead electrode 13 is connected to the terminal electrode 14. And also serves as a ground electrode. In addition, as seen from FIG. 1A, this short-circuit auxiliary electrode 6 has a substantially uniform frame shape on the electrode formation surface of the surface acoustic wave device 10, and has an inclination-free shape as a whole.

Moreover, strip | belt-shaped input / output lead-out electrodes 4a and 5a connected to the comb-shaped electrode 2 are provided facing each other, and are formed so that these areas may become substantially the same. In addition, the input / output terminal electrodes 4b and 5b connected to the input / output lead electrodes 4a and 5a are also provided to face each other, and their areas are also substantially the same. The reflector electrode 3 and the short-circuit auxiliary electrode 6 have an electrode configuration in an electrically open state.

As described above, in the surface acoustic wave device 10, the areas of the stripe-shaped input / output lead-out electrodes 4a and 5a and the input / output terminal electrodes 4b and 5b are made approximately equal, and the short-circuit auxiliary electrode 6 is inclined approximately evenly. The absence of a region allows the region to store a large amount of charge even when charge is generated due to the pyroelectricity of the substrate, so that the potential difference between the electrode patterns can be made very small. Therefore, even when the reflector electrode 3 and the comb-shaped electrode 2 are electrically open with the short-circuit auxiliary electrode 6, the electric charges generated in the reflector electrode 3 and the comb-shaped electrode 2 can be made uniform. There is no case where a potential difference is generated between them, and discharge can be prevented. As a result, it is possible to prevent the electrodes of the surface acoustic wave device 10 from breaking or deterioration of electrical characteristics. In addition, since the potential difference caused by the pyroelectricity is made uniform to reduce the potential difference between the electrode patterns, the short-circuit auxiliary electrode 6 has a wider electrode in the design possible range, so that the impedance can be made as small as possible and the comb-shaped electrode. (2) and reflector electrode 3 are preferably provided as adjacent as possible. For this purpose, the width of the frame-shaped short-circuit auxiliary electrode 6 should be the maximum width which can be designed according to the place, and therefore, as shown in the figure, the width varies according to the place.

In this way, the impedance is made small by surrounding the comb-shaped electrode 2 and the reflector electrode 3 by the short-circuit auxiliary electrode 6 that is as wide as possible, resulting in the pyroelectricity of the substrate 1. The potential difference generated by the accumulation of charge can be quickly uniformed. The equalization of the potential difference is more effective when the commonly connected electrode region including the short-circuit auxiliary electrode 6 occupies the surface acoustic wave device 10 is larger, and therefore the short-circuit auxiliary electrode 6 can be made thinner than that of the thin wire. It is desirable to widen one width.

In this embodiment, the short-circuit auxiliary electrode 6 is connected to the ground electrode in the terminal electrode 14 provided on the base substrate 9, and the charge generated in the substrate 1 is discharged from the short-circuit auxiliary electrode 6 to the terminal electrode. Since it can escape to outside through 14, the influence of the electric charge by the pyroelectricity to the surface acoustic wave device 10 can be greatly reduced.

The charge due to the pyroelectricity generated when the surface acoustic wave device 10 is heated is generated from the substrate 1 of the piezoelectric body having the pyroelectricity. Generation occurs from the surface acoustic wave device 10 as a whole. However, there are a plurality of independent electrode patterns in the surface acoustic wave device 10, and generally, the input / output terminal electrodes 4b and 5b having the widest area are likely to generate the largest potential. For this reason, the frame-shaped short-circuit auxiliary electrode 6 surrounds the comb-shaped electrode 2 and the reflector electrode 3, and is symmetrical with respect to the input-output terminal electrodes 4b and 5b, and is as wide as possible. When provided, since the electric charge which generate | occur | produced in the board | substrate 1 can be made uniform as a whole and a potential difference can be made small, discharge can be suppressed.

As a method of preventing damage to the surface acoustic wave device from discharge generation due to charge accumulation, for example, a portion having a narrow electrode gap is provided between adjacent electrodes in advance, and if the charge is accumulated to some extent, the surface acoustic wave device is not damaged. There is also a method of partially discharging in the range. However, this method is not preferable because the surface acoustic wave device is discharged during use to generate noise. Therefore, in order not to damage the surface acoustic wave device by discharge due to charge accumulation, the frame-shaped short-circuit auxiliary electrode 6 is as wide as possible adjacent to the comb-shaped electrode 2 and the reflector electrode 3. It is preferable to provide this widely.

In addition, the input / output lead-out electrodes 4a and 5a and the input / output terminal electrodes 4b and 5b are provided to face each other, and their areas are made substantially the same, or the frame-shaped short-circuit auxiliary electrodes 6 are arranged approximately equally as a whole. By doing so, since the area where the amount of charge is unevenly accumulated and can be eliminated, the potential difference can be made more uniform.

In addition, although the comb-shaped electrode 2 and the reflector electrode 3 were paired in this Example, this invention is not limited to this, The same effect is acquired even if it is a surface acoustic wave device of a multistage structure.

Next, the manufacturing method of the surface acoustic wave device 10 of this invention is demonstrated.

A metal thin film having a laminated structure is formed on the substrate 1 having piezoelectricity by, for example, sputtering. As the substrate 1, for example, a single crystal substrate of LiTaO ₃ or LiNbO ₃ can be used. As the metal thin film, after forming a titanium (Ti) film on the lower layer, an alloy film made of aluminum-scandium-copper (Al-Sc-Cu), and a film composed of a three-layered Ti film on the upper layer, An aluminum (Al) film is further formed by vapor deposition on the layer constitution film. Next, photoresist is apply | coated on said metal thin film, and a metal thin film is processed into a desired electrode pattern by a photolithographic process and an etching process. Next, if only the Al film of the uppermost layer of the comb-shaped electrode 2 is removed by etching by the photolithography process and the etching process, the input / output lead-out electrodes 4a and 5a, the input / output terminal electrodes 4b and 5b and the short-circuit auxiliary electrode are removed. On (6), an Al film which is a soft metal formed by vapor deposition can be left. In addition, when the Al film is removed by, for example, wet etching, the Al film can be easily removed using the selectivity of etching of Al and Ti. The state thus formed is shown in Fig. 1B.

Next, when the gap 8 of each short-circuit auxiliary electrode 6 of the adjacent surface acoustic wave devices 10 is cut by a dicing apparatus, the surface acoustic wave device 10 of a predetermined shape can be obtained. In the present embodiment, the dicing line is unnecessary because the dicing line is cut so that the center of the gap 8 of the short-circuit auxiliary electrode 6 is cut instead of the conventional dicing line to cut along the dicing line. The design of (10) can be simplified, and the surface acoustic wave device can be further miniaturized.

Moreover, as a metal thin film, it is not limited to the said material structure, Moreover, you may laminate | stack the film which consists of Al, Ti, Cu, Cr, Ni, or these alloys, Or Al film, Al-Cu alloy film, on it, Moreover, various materials and structures, such as a three-layered constituent film which consists of a Ti film, can be used for upper layer, and if it is one or more layers, what kind of layer may be laminated | stacked is not limited to the above order. By setting it as the electrode film of such a laminated structure, electric power resistance can be enlarged and it can be prevented from being damaged easily even if a discharge generate | occur | produces.

As a method of forming a film of a soft material, for example, an Al film, by vapor deposition on an electrode film except at least on the comb-shaped electrode 2 of the metal thin film having such a configuration, in the case where the surface layer of the electrode film is a Ti film, similarly by wet etching It is sufficient to selectively remove the etching, and in the case where the surface layer of the electrode film is an Al film, it can be easily prepared by a lift-off method in which a photoresist is formed on the comb-shaped electrode 2 beforehand and deposited.

Next, a process of mounting the surface acoustic wave device 10 thus obtained on the base substrate 9 to form an electronic component will be described with reference to FIG. 2. After aligning the lead electrode 13 provided at the bottom of the box-shaped base substrate 9 and the bumps 7 formed on the surface acoustic wave device 10, the electrical connection is performed and mechanically the surface acoustic wave device 10 is also electrically connected. Fix it. This bump connection may include a connection using a conductive resin, solder bonding by solder bumps, a surface of the lead electrode and the bump 7 formed of gold (Au), and Au-Au bonding using ultrasonic waves or the surface of the lead electrode. Various bonding methods, such as a tin (Sn) film and a bump 7 formed of Au and a Au-Sn eutectic bonding method, can be adopted. The bumps 7 may be formed by plating or may be formed by wire bonding.

After fixing and fixing the surface acoustic wave device 10 to the base substrate 9, the lid 15, on which the adhesive member 16 such as solder made of Au-Sn is formed, is brought into contact with the base substrate 9 to be heated and bonded. It fixes and obtains the electronic component of the sealed structure.

Such a bump bonding method can increase the contact area of the bumps 7 to be joined to the lead-out electrode 13, and thus has the characteristics of increasing the reliability of the bonding. However, on the other hand, when heat distortion occurs by heating at the time of bump bonding, peeling of an electrode film may occur, and conversely, the reliability of joining may fall. The present invention is based on the finding that when the film formed on the uppermost layer of the electrode film is formed by at least a vapor deposition method, the distortion generated during bump bonding can be alleviated and the peeling of the electrode film can be prevented. In addition, the formation of the deposited film also has the effect that the electrochemical corrosion of the electrode film is less likely to occur during processes such as cutting and washing.

This reason is presumed that in the film formation by the vapor deposition method, a thin film having the same orientation as the underlying material is easily formed, and as a result, the bonding between the metal particles is strong. Therefore, if at least the film of the uppermost layer of the electrode film in contact with the bump is formed by the vapor deposition method, even if distortion due to bonding occurs, peeling of the electrode film does not occur, and electrochemical corrosion can also be suppressed.

By the way, as a metal thin film formed by vapor deposition, the material which consists of a soft material has good adhesiveness with bump. As a soft material, Al-Cu alloy, Au, etc. which added at least 1 sort (s) of material which consists of Cu, Sc, Cr, Ni, Ti, etc. to aluminum and aluminum can be used, for example.

In addition to the uppermost layer of the electrode in contact with the bump, the same effect can be obtained by forming another layer by vapor deposition.

In addition, of course, the position which forms a bump is not limited to the position shown in FIG. 1A. In addition, the strip | belt-shaped input / output lead-out electrodes 4a and 5a do not need to have the same width, and just needs to have substantially the same area.

Since the input / output lead electrodes 4a and 5a and the input / output terminal electrodes 4b and 5b of the surface acoustic wave device 10 obtained in this way are electrically independent of each other, predetermined electrode patterns on the substrate 1 shown in FIG. In this state, the electrical characteristics can be measured by applying a probe to the input / output terminal electrodes 4b and 5b of each surface acoustic wave device 10. Therefore, characteristics can be selected before cutting the surface acoustic wave device 10 into individual pieces, and after cutting, the electronic components can be assembled using only good quality products.

As mentioned above, according to this invention, the electrode which surrounds the comb-shaped electrode 2 and the reflector electrode 3 by the frame-shaped short-circuit auxiliary electrode 6 which differs according to a place, and contacts at least the bump 7 at least. By forming the film of the uppermost layer of the film by a vapor deposition method, the potential difference generated by the pyroelectricity of the piezoelectric substrate 1 can be reduced. Moreover, peeling of the junction part of an electrode film, etc. can also be prevented and electrochemical corrosion can also be suppressed. In addition, when the electrode film of the laminated structure is used, the electric power resistance can be increased, so that even if discharge is generated by the accumulated charge, damage to the electrode film is less likely to occur, and discharge resistance can be further improved.

Moreover, about manufacture of the electronic component which mounted the surface acoustic wave device 10, not only the bump bonding method mentioned above but the method of connecting by wire bonding may be used, for example.

(Example 2)

Hereinafter, the surface acoustic wave device according to the second embodiment of the present invention will be described with reference to FIG. 3. In FIG. 3, the same code | symbol is attached | subjected about the same element as FIG. 1A.

A pair of three comb-shaped electrodes 201, 202, and 203 and a reflector electrode 3 are disposed at both ends thereof, and the comb-shaped electrode 202 at the center has input / output lead-out electrodes 4a, 5a, and input / output. The terminal electrodes 4b and 5b, the ground lead-out electrode 21a and the ground terminal electrode 21b are provided as shown. Frame-shaped short-circuit auxiliary electrodes 6 are formed so as to surround them, and with respect to this short-circuit auxiliary electrode 6, the reflector electrodes 3 on both sides and the comb-shaped electrodes 201 and 203 on both sides are respectively connected to the first connection electrode. Electrically connected with the 17 and the 2nd connection electrode 20 is carried out. The outer periphery of this short-circuit auxiliary electrode 6 has a gap 8 partially left by dicing, and the gap 8 part is exposed at the surface of the substrate 1. In addition, the other of the comb-shaped electrodes 201 and 203 on both sides is connected to each other by a band-shaped connecting electrode 18, and bumps 7 are formed at predetermined positions of the input / output electrodes 4b and 5b and the short-circuit auxiliary electrode 6. ), The surface acoustic wave device 100 is configured. Since the manufacturing method for making this surface acoustic wave device 100 into the electronic component shown in FIG. 2 is the same as that of 1st Example, description is abbreviate | omitted.

With such a configuration, the reflector electrode 3 and the comb-shaped electrodes 201 and 203 on both sides are connected to the short-circuit auxiliary electrode 6 via the band-shaped first connecting electrode 17 and the second connecting electrode. Therefore, a wide area of the surface acoustic wave device 100 is commonly connected to be at the same potential. As a result, even if the surface acoustic wave device 100 is subjected to temperature fluctuations and a potential is generated by the pyroelectricity of the substrate 1, the potential difference can be made very small, including the electrode pattern portion in the open state.

In addition, although the effect of electrically connecting the comb-shaped electrodes 201 and 203 and the reflector electrode 3 with the short-circuit auxiliary electrode 6 varies depending on the design of the electrode pattern, it is required to have a low impedance so that the potential can be made uniform. The electrode width and the number of the electrodes are not particularly limited, but it is natural that the width is as wide as possible and the number is more effective.

In this embodiment, since the electrodes including the comb-shaped electrodes 201 and 203 and the reflector electrode 3 are connected in common, even if different potentials are generated in each part, the same potential can be set, and the electrode is destroyed by discharge or the like. The excellent surface acoustic wave device 100 without deterioration of characteristics can be easily manufactured.

(Example 3)

The surface acoustic wave device according to the third embodiment of the present invention will be described with reference to FIG. 4. In FIG. 4, the same code | symbol is attached | subjected about the same element as FIG. 1A.

In this embodiment, the reflector electrode 19 is comprised by the serpentine line, and the both ends of this reflector electrode 19 are electrically connected with the comb-shaped electrode 2, respectively, as shown. That is, in this embodiment, it is the same as that of Example 1 except having set the structure which the reflector electrode 19 and the comb-shaped electrode 2 which consisted of the twisted line were electrically connected. The surface acoustic wave device 110 is also similar to the first embodiment in the method of manufacturing the electronic component using the base substrate 9 and the lid 15 shown in FIG.

In FIG. 4, the reflector electrode 19 comprised from the winding line is electrically connected with the comb-shaped electrode 2, and the signal to be used becomes a conduction state in direct current | flow and low frequency. However, in the high frequency band in which the surface acoustic wave device 110 operates, the serpentine line has a high impedance and becomes substantially open. On the other hand, since the reflector electrode 19 and the comb-shaped electrode 2 constituted by the serpentine line are electrically connected, the charge generated by the pyroelectricity of the piezoelectric substrate 1 can be uniformized in a wider electrode region. And the potential difference can be reduced.

That is, by electrically connecting the reflector electrode 19 and the comb-shaped electrode 2 which consist of a twisted line, in the high frequency area | region which is a practical use condition, the comb-shaped electrode 2 and the reflector electrode 19 are substantially In an open state, and a malfunction in the surface acoustic wave device 110 does not occur. On the other hand, with respect to the potential due to superconductivity, the comb-shaped electrode 2 and the reflector electrode 19 are electrically connected to each other, so that the potential difference can be reduced.

In addition to the strip-shaped input / output lead-out electrodes 4a and 5a connected to the comb-shaped electrode 2 provided so as to face each other, and their areas are substantially the same, the input / output lead-out electrodes 4a and Input-output terminal electrodes 4b and 5b connected to 5a are also provided to face each other, and their areas are also substantially the same. By such a configuration, it is possible to hardly generate a potential difference even when a potential occurs in each electrode pattern due to pyroelectricity, thereby providing an excellent surface acoustic wave device 110 without damage or deterioration of the electrode pattern due to discharge or the like. It can be produced simply.

(Example 4)

The surface acoustic wave device according to the fourth embodiment of the present invention will be described with reference to FIGS. 5A and 5B. FIG. 5A is a plan view showing the structure of an electrode pattern, and FIG. 5B is a partial plan view showing a structure formed on a plurality of substrates having piezoelectricity. In FIG. 5A and FIG. 5B, the same code | symbol is attached | subjected about the element same as FIG. 1A and 1B. The surface acoustic wave device 120 of this embodiment differs only in that the dicing line 80 is formed of the same electrode material on the outer circumference of the surface acoustic wave device 10 of the first embodiment. That is, normally, the dicing line 80 will disappear if it cut | disconnects a board | substrate along this dicing line, and makes it into individual pieces, but in this invention, even if dicing, it is set as the width which remains reliably on an outer peripheral part.

In the present embodiment, since the dicing line 80 electrically shorted in a frame shape together with the surface acoustic wave device 120 is provided on the substrate 1, a large temperature fluctuation occurs in the substrate state until dicing. Even if a large potential due to pyroelectricity is generated, the potential difference between the electrode patterns can be made uniform. Moreover, even when dicing is divided into individual pieces, since a part of dicing line 80 exists in the outer periphery part of surface acoustic wave device 120 in frame shape, the effect which makes a potential difference smaller becomes large. In addition, by cutting with the dicing apparatus along the dicing line 80, the position alignment operation | work according to cutting becomes easy.

Moreover, the same effect can be acquired also in the surface acoustic wave device provided with two or more sets of the comb-shaped electrode 2 and the reflector electrode 3.

The manufacturing method of the surface acoustic wave device 120 of this embodiment differs only by cutting along the dicing line 80 in dicing, and otherwise, it is the same as the manufacturing method of the surface acoustic wave device 10 of Example 1 Can be produced.

(Example 5)

The surface acoustic wave device according to Embodiment 5 of the present invention will be described with reference to FIG.

In FIG. 6, the same code | symbol is attached | subjected about the same element as FIG. The surface acoustic wave device 130 of this embodiment differs from the dicing line 80 by using the same material on the outer circumference of the surface acoustic wave device 100 of the third embodiment. Is the same. Also in this embodiment, the width of the dicing line is set to a width that remains reliably in the outer peripheral part even after dicing.

Since the pattern of the second connection electrode 20 for electrically connecting the comb-shaped electrodes 201 and 203 and the short-circuit auxiliary electrode 6 is not preferable to provide a region with high impedance in the middle of the pattern, for example, The shape of the pattern width gradually becoming thinner toward the short circuit auxiliary electrode 6 is preferable. Moreover, it is preferable to form the width | variety of this 2nd connection electrode 20 larger than the width of the dicing line 80. FIG.

Thus, the dicing line 80 is provided and formed so that the dicing line 80 may remain in a frame shape on the outer circumference even after cutting, thereby making it possible to stably and individually cut the temperature fluctuations during the working process in the substrate 1 state. As a result, it is possible to easily manufacture an excellent surface acoustic wave device and an electronic component using the same, which are free from breakage due to discharge or deterioration of characteristics even with respect to temperature fluctuations when mounted on a base substrate.

(Example 6)

The surface acoustic wave device according to the sixth embodiment of the present invention will be described with reference to FIG. 7 is a plan view showing the configuration of an electrode pattern of the surface acoustic wave device 140 according to the sixth embodiment of the present invention. In Fig. 7, the same elements as those in Fig. 6 are given the same reference numerals. As can be seen from the figure, the surface acoustic wave device 140 according to the present embodiment includes a third connection electrode for electrically connecting the dicing line 80 and the short-circuit auxiliary electrode 6 in the surface acoustic wave device 130 according to the fifth embodiment. 22). The manufacturing method and structure thereof which are mounted on a base substrate using the surface acoustic wave device 140 to form an electronic component are the same as those in the first embodiment. Moreover, also in this embodiment, the width of the dicing line 80 is made the width which remains reliably in an outer peripheral part after dicing.

Thus, by electrically connecting the short circuit auxiliary electrode 6 and the dicing line 80 with the 3rd connection electrode 22, even if an electric charge generate | occur | produces on the piezoelectric substrate 1, the comb-tooth electrodes of both ends will be carried out. Since the 201 and 203, the reflector electrode 3, the short-circuit auxiliary electrode 6, and the dicing line 80 are electrically connected in common, the potentials are the same in all of these electrodes, and the effect of preventing discharge from occurring due to the potential difference Becomes bigger.

The electrode pattern for electrically connecting the dicing line 80, the short-circuit auxiliary electrode 6, the comb-shaped electrodes 201 and 203 and the reflector electrode 3 at both ends may be linear or band-shaped as long as the impedance is low. Regardless, the number is not limited.

(Example 7)

The surface acoustic wave device according to the seventh embodiment of the present invention will be described with reference to FIG. In FIG. 8, the same code | symbol is attached | subjected to the same element as FIG. As can be seen from the figure, the surface acoustic wave device 150 of the present embodiment differs from the surface acoustic wave device 140 of the sixth embodiment in that the reflector electrode 3 is opened from the short-circuit auxiliary electrode. The structure and the manufacturing method are the same as those of the surface acoustic wave device 140.

With such a configuration, even when electric charges are generated on the piezoelectric substrate 1, the comb-shaped electrodes 201 and 203, the short-circuit auxiliary electrode 6, and the dicing line 80 at both ends are electrically connected to each other. Even when the electrode 202 and the reflector electrode 3 are in the electrically open state, the potential difference between them can be made small, and the occurrence of discharge can be suppressed, so that a highly reliable surface acoustic wave device and an electronic component can be realized using the same.

(Example 8)

The surface acoustic wave device according to the eighth embodiment of the present invention will be described with reference to FIG. 9 is a plan view showing the structure of the electrode pattern of the surface acoustic wave device 160 of the present embodiment, and the same reference numerals are assigned to the same elements as in FIG. 4. As can be seen from the figure, the surface acoustic wave device 160 of the present embodiment differs from the fact that the dicing line 80 is provided on the outer circumference of the surface acoustic wave device 110 of the third embodiment. And the production method is the same. Also in this embodiment, the width of the dicing line is set to the width remaining reliably in the outer peripheral portion even after dicing.

As described in the surface acoustic wave device 110 of the third embodiment, in the surface acoustic wave device 160 of the present embodiment, the reflector electrode 19 composed of a serpentine line is electrically connected to the comb-shaped electrode 2. . Thus, the reflector electrode 19 and the comb-shaped electrode 2 are in a conduction state in the DC and low frequency bands, but in the high frequency band in which the surface acoustic wave device operates, the serpentine lines have high impedance and are substantially open. In this state, the electrical characteristics in the surface acoustic wave device 160 are not particularly affected. This is the same as the surface acoustic wave device 110 of the third embodiment.

In the surface acoustic wave device 160 of the present embodiment, the reflector electrode 19 and the comb-shaped electrode 2, which are composed of a serpentine line, are electrically connected to each other, and the frame-shaped dicing is performed similarly to the frame-shaped short-circuit auxiliary electrode 6. Since the line 80 is provided, the electric charge generated by the pyroelectricity of the piezoelectric substrate 1 can be uniformized in each electrode pattern portion, so that the potential difference generated in each portion can be made smaller.

In addition, although the dicing line 80 and the short circuit auxiliary electrode 6 were electrically open in this Example, this invention is not limited to this, The short circuit auxiliary electrode 6 and the dicing line 80 are not limited to this. You may electrically connect with one or several connection electrode.

In the first to eighth embodiments, the surface acoustic wave device has been described in which one or two configurations of a comb-shaped electrode and a reflector electrode are provided. However, the present invention is not limited thereto, but the present invention is not limited thereto. The same effect can be obtained also in the case of the configuration.

As described above, according to the present invention, by providing a frame-shaped short-circuit auxiliary electrode having a width that varies depending on a place around the comb-shaped electrode and the reflector electrode, only in the processing step of the substrate unit when manufacturing the surface acoustic wave device. Furthermore, even after dicing and dividing into pieces, the potential difference between the electrode patterns can be reduced even if a potential is generated due to the pyroelectricity of the substrate due to temperature fluctuations. As a result, it is possible to easily produce a highly reliable surface acoustic wave device and an electronic component using the same without preventing the occurrence of discharge and without destroying or deteriorating characteristics.

Claims (43)

A substrate having piezoelectricity, A comb tooth electrode formed on the substrate; A reflector electrode formed close to the propagation direction of the surface wave generated from the comb teeth; A short-circuit auxiliary electrode having a frame shape that is different in width around the comb-shaped electrode and the reflector electrode and is approximately equal with respect to the comb-shaped electrode; And an input / output lead electrode connected to the comb-shaped electrode and an input / output terminal electrode connected to the input / output lead electrode at an inner circumference of the short circuit auxiliary electrode. The input lead-out electrode of the input-output lead-out electrode and the output lead-out electrode oppose each other, their areas are approximately equal, and the input terminal electrode and the output terminal electrode of the input-output terminal electrode also face each other, and their shape is approximately equal. Done, A surface acoustic wave device comprising a plurality of positions facing each other on the short-circuit auxiliary electrode and bumps serving as connection members on the input / output terminal electrodes. The method of claim 1, A surface acoustic wave device, characterized in that a dicing line is further provided on an outer circumference of the shorting auxiliary electrode. delete delete delete delete delete The method of claim 1, And the reflector electrode and the shorting auxiliary electrode are electrically connected. The method of claim 2, And the reflector electrode and the shorting auxiliary electrode are electrically connected. The method of claim 8, And the reflector electrode and the short-circuit auxiliary electrode are electrically connected by at least one linear or band-shaped first connecting electrode. The method of claim 9, And the reflector electrode and the short-circuit auxiliary electrode are electrically connected by at least one linear or band-shaped first connecting electrode. The method of claim 11, The surface acoustic wave device according to claim 1, wherein the width of the first connection electrode is at least larger than the width of the dicing line. The method of claim 1, A surface acoustic wave device comprising a portion of the comb-shaped electrode and a short-circuit auxiliary electrode electrically connected to each other. The method of claim 2, A surface acoustic wave device comprising a portion of the comb-shaped electrode and a short-circuit auxiliary electrode electrically connected to each other. The method of claim 13, At least three pairs or more of the comb-shaped electrodes are provided at predetermined positions, and the comb-shaped electrodes on both sides of the plurality of comb-shaped electrodes are connected to each other and electrically connected to a short-circuit auxiliary electrode. Surface acoustic wave device. The method of claim 14, At least three pairs or more of the comb-shaped electrodes are provided at predetermined positions, and the comb-shaped electrodes on both sides of the plurality of comb-shaped electrodes are connected to each other and electrically connected to a short-circuit auxiliary electrode. Surface acoustic wave device. The method of claim 13, And the comb-shaped electrode and the short-circuit auxiliary electrode are electrically connected by at least one linear or strip-shaped second connecting electrode. The method of claim 14, And the comb-shaped electrode and the short-circuit auxiliary electrode are electrically connected by at least one linear or strip-shaped second connecting electrode. The method of claim 2, And the dicing line and the short-circuit auxiliary electrode are electrically connected to each other. The method of claim 19, The dicing line and the short-circuit auxiliary electrode are electrically connected to each other by at least one linear or strip-shaped third connecting electrode. The method of claim 20, A surface acoustic wave device comprising a width of the third connection electrode wider than at least a width of a dicing line. The method according to claim 1 or 2, A surface acoustic wave device comprising the reflector electrode and the shorting auxiliary electrode in an electrically open state. The method according to claim 1 or 2, And the reflector electrode has a serpentine line structure, and both ends of the reflector electrode are electrically connected to the comb-shaped electrodes, respectively. The method according to claim 1 or 2, A surface acoustic wave device comprising the short-circuit auxiliary electrode as a ground electrode. The method of claim 1, The surface acoustic wave device as claimed in any one of the input / output terminal electrode, the input / output lead-out electrode, and the short-circuit auxiliary electrode, wherein at least an uppermost electrode film is formed by a deposition method. The method of claim 25, Surface acoustic wave device, characterized in that the electrode film of the uppermost layer is a material of a soft material. The method of claim 26, The surface electrode device of claim 1, wherein the uppermost electrode film is made of aluminum or an aluminum alloy. The method of claim 1, And at least the comb-shaped electrode, reflector electrode, input / output terminal electrode, input / output lead-out electrode, and short-circuit auxiliary electrode have a structure in which one or more kinds of metals are stacked. Attaching a metal thin film on a piezoelectric substrate; A comb-shaped electrode constituting an interdigital converter by etching the metal thin film, a reflector electrode formed to be close to a propagation direction of a surface wave excited by the interdigital converter, at least the comb-shaped electrode and the reflector A pattern processing step of forming a plurality of sets of frame-shaped short-circuit auxiliary electrodes that surround the electrodes and have different widths according to places; Cutting between adjacent short-circuit auxiliary electrodes Method for producing a surface acoustic wave device comprising a. The method of claim 29, And forming a dicing line on an outer circumferential portion of the shorting auxiliary electrode in the pattern processing step of the metal thin film. The method of claim 29, And processing to provide an input / output lead electrode connected to the comb-shaped electrode and an input / output terminal electrode connected to the input / output lead electrode in an inner peripheral portion of the frame-shaped short-circuit auxiliary electrode in the pattern processing of the metal thin film. The manufacturing method of the surface acoustic wave device. The method of claim 30, And processing to provide an input / output lead electrode connected to the comb-shaped electrode and an input / output terminal electrode connected to the input / output lead electrode in an inner peripheral portion of the frame-shaped short-circuit auxiliary electrode in the pattern processing of the metal thin film. The manufacturing method of the surface acoustic wave device. The method of claim 29 or 30, The manufacturing method of the surface acoustic wave device characterized by including the process of forming the connection electrode which electrically connects a short circuit auxiliary electrode and a reflector electrode, or a short circuit auxiliary electrode and a comb-tooth shaped electrode in the pattern processing process of the said metal thin film. 33. The method of claim 30 or 32, The manufacturing method of the surface acoustic wave device characterized by including the process of forming the connection electrode which electrically connects a short circuit auxiliary electrode and a reflector electrode, or a short circuit auxiliary electrode and a comb-tooth shaped electrode in the pattern processing process of the said metal thin film. 33. The method of claim 30 or 32, In the pattern processing process of the said metal thin film, the manufacturing method of the surface acoustic wave device containing the process of forming the connection electrode which electrically connects a short circuit auxiliary electrode and a dicing line. The method of claim 34, wherein In the pattern processing process of the said metal thin film, the manufacturing method of the surface acoustic wave device characterized by including the process of forming the connection electrode which electrically connects a short circuit auxiliary electrode and a dicing line. The method of claim 31 or 32, And at least one selected from the input / output lead-out electrode, the input / output terminal electrode, and the short-circuit auxiliary electrode to form the electrode layer of the uppermost layer by a deposition method. The method of claim 37, The top conductive film is a manufacturing method of a surface acoustic wave device, characterized in that using a material of a soft material. The method of claim 38, The top conductive film is a manufacturing method of a surface acoustic wave device, characterized in that the use of aluminum or aluminum alloy. The method of claim 29, The metal thin film is a method of manufacturing a surface acoustic wave device, characterized in that formed by laminating one or a plurality of metals. A base substrate having a lead-out electrode at the bottom of the box shape, and a terminal electrode conducting the lead-out electrode; A cover for sealing an inside of the base substrate covering the base substrate; A surface acoustic wave device disposed at a box-shaped bottom of the base substrate; And a connecting member for electrically connecting the input / output terminal electrode of the surface acoustic wave device and the lead electrode of the base substrate. The surface acoustic wave device is a surface acoustic wave device according to claim 1 or 2. Electronic component, characterized in that. 42. The method of claim 41 wherein The said electronic member is a wire which consists of aluminum or gold. 42. The method of claim 41 wherein And the connection member is a bump formed on the surface acoustic wave device.