JP6567982B2 - Surface acoustic wave device and surface acoustic wave device using the same - Google Patents

Description

  The present invention relates to a surface acoustic wave device having a functional body provided on an element substrate.

  The surface acoustic wave device has an element substrate and a functional body provided on the element substrate, for example, an IDT electrode. The element electrode pads on the element substrate are electrically connected to the substrate electrode pads on the opposing circuit wiring board via solder bumps. Part of the element electrode pad is provided on a wiring pattern extending from the functional body to the outer peripheral side of the element substrate. An example of such a structure is disclosed in Patent Document 1.

JP 2013-12932 A

  In the surface acoustic wave device described above, a part of the element electrode pad is provided on the wiring pattern extending from the functional body to the outer peripheral side of the element substrate, and there is a problem that peeling is likely to occur at the interface with the wiring pattern. It was.

  The present invention has been made in view of the above problems, and an object thereof is to provide a surface acoustic wave device capable of improving the adhesion of an element electrode pad.

A surface acoustic wave device according to an aspect of the present invention includes an element substrate, a functional body provided on the element substrate, an element electrode pad provided around the functional body, and the functional electrode to the element electrode pad. And a wiring pattern electrically connected to the element electrode pad, the wiring pattern being provided on the element substrate and connected to the functional body. A first wiring pattern and a second wiring provided on the element substrate extending from an end of the first wiring pattern below the element electrode pad. The element electrode pad is provided on the second wiring pattern so as not to overlap the first wiring pattern in a plan view, and the first layer from the second wiring pattern side, The first layer A second layer provided on the second layer and a third layer provided on the second layer, wherein the first layer comprises a Ti layer or a Cr layer, and the second layer comprises a Ni layer. the third layer is characterized Rukoto such an Au layer.

According to the surface acoustic wave device of the present invention, the adhesion between the wiring pattern and the device electrode pad can be improved.

1 is a schematic longitudinal sectional view for explaining a surface acoustic wave device according to an embodiment of the present invention. 1 is a perspective view illustrating a surface acoustic wave device according to an embodiment of the present invention as seen through from above. (A) And (b) is the cut part end view cut | disconnected by the AA line of the element substrate shown in FIG.

  Hereinafter, a surface acoustic wave device according to an embodiment of the present invention will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and the dimensional ratios and the like on the drawings do not necessarily match the actual ones. In the surface acoustic wave device, either direction may be set upward or downward, but for convenience of explanation, an orthogonal coordinate system XYZ is defined, and the positive side in the Z direction is used as the upper side, and the word of the upper surface or the lower surface is used. And

  In the description of the embodiments and the like, components that are the same as or similar to those already described may be assigned the same reference numerals and descriptions thereof may be omitted.

<Embodiment>
A surface acoustic wave device 10 according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

  A surface acoustic wave device 10 according to the embodiment is configured as shown in FIGS. 1 and 2 and includes a surface acoustic wave element 2. The surface acoustic wave element 2 is provided on an element substrate 2a and an element substrate 2a. Function body 2b provided, element electrode pad 3 provided around function body 2b, and wiring extending from function body 2b toward element electrode pad 3 and electrically connected to element electrode pad 3 Pattern 7 is provided. As shown in FIG. 1, the surface acoustic wave element 2 has an element substrate 2a and a plurality of functional bodies 2b formed on one main surface of the element substrate 2a. Is mounted on the circuit wiring board 1 so as to have a space S.

  The surface acoustic wave element 2 is provided with a plurality of functional bodies 2b on one main surface of a quadrangular element substrate 2a in plan view, and a plurality of element electrode pads 3 provided around the plurality of functional bodies 2b. . The functional body 2 b is electrically connected to the element electrode pad 3 through the wiring pattern 7.

  The circuit wiring board 1 is provided with a plurality of substrate electrode pads 4 on the main surface (the upper surface of the circuit wiring board 1) facing one main surface of the element substrate 2a. And electrically connected to the element electrode pad 3.

  FIG. 2 is a perspective view showing a state in which the surface acoustic wave device 10 is seen through from above, and shows a plurality of functional bodies 2 b, element electrode pads 3, and wiring patterns 7 on the element substrate 2 a of the surface acoustic wave element 2. ing. FIG. 2 shows a state including the sealing resin layer 6. The surface acoustic wave element 2 has a plurality of functional bodies 2b formed on one main surface (lower surface) of the element substrate 2a, and has a substantially rectangular parallelepiped shape, for example.

  In the surface acoustic wave element 2, as shown in FIG. 2, a plurality of element electrode pads 3 are arranged around the functional body 2b of the element substrate 2a, and are electrically connected to the respective wiring patterns 7. Yes. The wiring pattern 7 extends from the functional body 2 b toward the element electrode pad 3, is formed along the outer periphery of the rectangular element substrate 2 a, and is electrically connected to the element electrode pad 3. The surface acoustic wave element 2 is provided with an intermediate wiring for electrically connecting the functional bodies 2b to one main surface of the element substrate 2a. The intermediate wiring is included in the wiring pattern 7. To do.

  The element electrode pad 3 is provided along the outer periphery of the rectangular element substrate 2 a and is provided at the end of the wiring pattern 7 or in the middle of the wiring pattern 7. There is something. In addition, the element electrode pad 3 may be electrically connected to the wiring pattern 7 or may not be electrically connected.

As shown in FIG. 3, the wiring pattern 7 includes a first wiring pattern 7a and a second wiring pattern 7b. The first wiring pattern 7a is provided on the element substrate 2a.
The second wiring pattern 7b connected to the functional body 2b is provided on the first wiring pattern 7a and is directed from the end of the first wiring pattern 7a toward the element electrode pad 3, It extends below the pad 3 and is provided on the element substrate 2a.

  The element electrode pad 3 is electrically connected to the first wiring pattern 7a via the second wiring pattern 7b. Further, the second wiring pattern 7b has an outer periphery that is larger than the outer periphery of the element electrode pad 3 in a plan view, as shown in FIG. It is provided so that it may be located outside. As a result, the outer periphery of the element electrode pad 3 does not protrude from the second wiring pattern 7b. That is, the outer periphery of the element electrode pad 3 is located inside the outer periphery of the second wiring pattern 7b as seen in a plan view. By being provided in this manner, the occurrence of peeling of the element electrode pad 3 starting from the outer periphery is suppressed.

  Moreover, the 2nd wiring pattern 7b should just be provided on the 1st wiring pattern 7a, and may or may not be connected to the functional body 2b.

  As shown in FIG. 3, the element electrode pad 3 is provided on the second wiring pattern 7b so as not to overlap the first wiring pattern 7a in a plan view. That is, the first wiring pattern 7 a is not provided below the element electrode pad 3.

  The wiring pattern 7 is provided such that the thickness of the second wiring pattern 7b provided on the element substrate 2a is thicker than the thickness of the first wiring pattern 7a. As shown in FIG. 3, the wiring pattern 7 includes the first wiring pattern 7a and the second wiring pattern 7b such that the relationship between the thickness T1 of the first wiring pattern 7a and the thickness T2 of the second wiring pattern 7b is T1 <T2. Second wiring patterns 7b are respectively provided on the element substrate 2a.

  The first wiring pattern 7a has a thickness T1 of, for example, 100 (nm) to 500 (nm), and the second wiring pattern 7b has a thickness T2 of, for example, 300 (nm) to 3,000 (nm). ).

  Thus, the surface of the second wiring pattern 7b is likely to be roughened by increasing the thickness T2, while the first wiring pattern 7a is formed simultaneously with the functional body 2b, and the thickness T1 is thin. The surface is not easily roughened. For example, when the element electrode pad 3 is provided directly on the first wiring pattern 7a without providing the second wiring pattern 7b, the adhesion of the element electrode pad 3 is lowered and peeling is likely to occur. Become. However, in the surface acoustic wave device 10, the element electrode pad 3 is provided on the second wiring pattern 7b, and the adhesion with the second wiring pattern 7b is improved.

  The surface roughness (Ra) of the first wiring pattern 7a is, for example, 2 (nm) to 6 (nm), and the second wiring pattern 7b is formed by increasing the film thickness, thereby increasing the first wiring pattern. The surface roughness (Ra) is larger than the surface roughness (Ra) of 7a, and the surface roughness (Ra) of the second wiring pattern 7b is, for example, 30 (nm) to 80 (nm). The surface roughness (Ra) is the centerline average roughness (Ra), and can be measured using, for example, a surface roughness measuring instrument.

  In the surface acoustic wave element 2, for example, a signal is input via any one of a plurality of element electrode pads 3 on one main surface (lower surface), and the input signal is subjected to a predetermined process to be a plurality of element electrode pads 3. A signal is output from either of the above. The plurality of element electrode pads 3 are provided in an appropriate number on one main surface (lower surface) of the element substrate 2a. The shape, number, formation position, role, etc. of the element electrode pads 3 are the surface acoustic wave element. 2 is set as appropriate according to the internal configuration of 2.

  In the surface acoustic wave element 2, as shown in FIG. 1, a protective film 2c is provided on one main surface of the element substrate 2a so as to cover the functional body 2b. The protective film 2c is formed on the element substrate 2a so as to cover the functional body 2b and the first wiring pattern 7a, so that a region where the second wiring pattern 7b is formed on the first wiring pattern 7a is exposed. In addition, it is removed so that the region where the second wiring pattern 7b on the element substrate 2a is formed is exposed. The element electrode pad 3 is provided on the second wiring pattern 7b.

Specifically, the protective film 2c is formed on the element substrate 2a so as to cover the functional body 2b and the wiring pattern 7a by using, for example, a CVD (Chemical Vapor Deposition) method. Further, in order to provide the second wiring pattern 7b on the first wiring pattern 7a, the protective film 2c formed on the wiring pattern 7a is removed by using a known photolithography method or the like to remove the first wiring pattern 7a. In addition, in order to provide the second wiring pattern 7b on the element substrate 2a, the protection film 2c in the region where the second wiring pattern 7b is formed is removed to expose the element substrate 2a.

  The protective film 2c is made of an insulating material such as silicon oxide, aluminum oxide, or silicon nitride. The thickness of the protective film 2c is, for example, 5 (nm) to 30 (nm).

  In the surface acoustic wave element 2, the functional body 2b and the wiring pattern 7a connected to the functional body 2b are formed of a conductive layer. For example, the conductive material of the functional body 2b and the first wiring pattern 7a is made of the same conductive material. The layer can be simultaneously formed on the element substrate 2a. Any of the conductive layers is Al or Al alloy (for example, Al-Cu, Al-Si-Cu, or Al-Ti), Cu or Cu alloy (for example, Cu-Mg or Cu-Ti), A metal material such as Ag or an Ag alloy (for example, Ag—Mg or Ag—Ti) can be used. In addition, the conductive layer may be a single layer made of a single conductive material, or may be a laminate formed by stacking a plurality of conductive materials. The functional body 2b and the wiring pattern 7a may be formed of different conductive materials. The functional body 2b and the wiring pattern 7a have a thickness of, for example, 100 (nm) to 500 (nm).

  Further, the second wiring pattern 7b has a laminated structure, and is provided on the first wiring pattern 7a and on the element substrate 2a as shown in FIG. It consists of The second wiring pattern 7b has a first layer 7b1, a second layer 7b2, and a third layer 7b3, and a second layer provided on the first layer 7b1 and the first layer 7b1 from the element substrate 2a side. 7b2 and the third layer 7b3 provided on the second layer 7b2. Further, the second wiring pattern 7b may be composed of a laminate of three or more layers.

  The first layer 7b1 has a thickness of 2 (nm) to 30 (nm), for example, and the second layer 7b2 has a thickness of 0.8 (μm) to 3 (μm), for example. The layer 7b3 has a thickness of 2 (nm) to 30 (nm), for example. The surface roughness (Ra) of the second wiring pattern 7b is mainly reflected by the surface roughness of the second layer 7b2 because the thickness of the second layer 7b2 is large.

  The first layer 7b1 is, for example, a titanium (Ti) layer or a chromium (Cr) layer, and the second layer 7b2 is an Al layer or an Al alloy layer (for example, Al—Cu based, Al—Si—Cu based or Al -Ti type), Cu layer or Cu alloy layer (for example, Cu-Mg type or Cu-Ti type), Ag layer or Ag alloy layer (for example, Ag-Mg type or Ag-Ti type), etc. . The third layer 7b3 is, for example, a titanium (Ti) layer or a chromium (Cr) layer. For the Al layer, for example, Al having a purity of 99.9999% or more can be used.

  For the first layer 7b1, a titanium (Ti) layer or a chromium (Cr) layer can be used in order to improve the adhesion with the first wiring pattern 7a. The third layer 7b3 can be a titanium (Ti) layer or a chromium (Cr) layer in order to improve adhesion to the device electrode pad 3 and to prevent oxidation of the second layer 7b2. For the second layer 7b2, Al or an Al alloy can be used in order to make the second wiring pattern 7b have a low resistance.

  The element electrode pad 3 has a multilayer structure, and is provided on the second wiring pattern 7b as shown in FIG. 3, and is composed of a three-layered structure. The element electrode pad 3 includes a first layer 3a, a second layer 3b, and a third layer 3c, and a second layer provided on the first layer 3a and the first layer 3a from the second wiring pattern 7b side. The third layer 3c is provided on the layer 3b and the second layer 3b. The element electrode pad 3 may be composed of a laminate of three or more layers.

  The first layer 3a has a thickness of, for example, 5 (nm) to 15 (nm), and the second layer 3b has a thickness of, for example, 900 (nm) to 3500 (nm). The layer 3c has a thickness of 60 (nm) to 100 (nm), for example.

  The first layer 3a is, for example, a titanium (Ti) layer or a chromium (Cr) layer, and the second layer 3b is a nickel (Ni) layer or a metal material containing nickel (Ni) as a main component (for example, Ni-Ti alloy) layer. The third layer 3c is, for example, a gold (Au) layer.

  For the first layer 3a, a titanium (Ti) layer can be used to improve the adhesion with the second wiring pattern 7b. The second layer 3b is a nickel (Ni) layer or a metal material layer containing nickel (Ni) as a main component for the barrier layer of the solder bump 5, and the third layer 3c is a second layer 3c. A gold (Au) layer can be used to prevent oxidation of the nickel (Ni) layer of the layer 3b or the metal material layer mainly composed of nickel (Ni).

  The functional body 2b and the first wiring pattern 7a are provided on the element substrate 2a as follows. Specifically, first, using a thin film forming method such as a sputtering method or a vapor deposition method, a metal layer (conductive layer) that becomes the functional body 2b and the first wiring pattern 7a on one main surface (lower surface) of the element substrate 2a. ) Is formed. Next, the functional body 2b and the first wiring pattern 7a can be formed by patterning the formed metal layer using a known photolithography method or the like.

Further, as described above, the protective layer 2c is formed on the element substrate 2a so as to cover the functional body 2b and the first wiring pattern 7a by using, for example, a CVD (Chemical Vapor Deposition) method. Then, the protective film 2c in the region where the second wiring pattern 7b is to be formed is removed by using a known photolithography method or the like on the formed protective film 2c. That is, the protective film 2c on the first wiring pattern 7a in the region where the second wiring pattern 7b is formed is removed, and the protective film 2c on the element substrate 2a in the region where the second wiring pattern 7b is formed. remove.

  The second wiring pattern 7b is a metal layer that becomes the second wiring pattern 7b on the first wiring pattern 7a and the element substrate 2a from which the protective film 2c has been removed by using a thin film forming method such as vapor deposition. (Conductive layer) is formed. Note that, for example, three layers of the first layer 7b1, the second layer 7b2, and the third layer 7b3 are continuously formed as the metal layer. Next, the second wiring pattern 7b can be formed by patterning the formed metal layer using a known photolithography method or the like.

Furthermore, the element electrode pad 3 is formed with a metal layer (conductive layer) to be the element electrode pad 3 on the second wiring pattern 7b by using, for example, a sputtering method. For example, the metal layer is formed of three layers of a first layer 3a, a second layer 3b, and a third layer 3c in succession. Next, the element electrode pad 3 can be formed by patterning the formed metal layer using a known photolithography method or the like. Thereby, the element electrode pad 3 is provided on the second wiring pattern 7b.

  In the surface acoustic wave element 2, the element substrate 2a has a thickness of, for example, 50 (μm) to 400 (μm), and the length of the long side and the short side in plan view is, for example, 0.4. (Mm) to 3 (mm). The thickness of the element substrate 2a and the lengths of the long side and the short side in plan view can be set to appropriate thicknesses and lengths.

  In the surface acoustic wave device 10, the surface acoustic wave element 2 is mounted on the upper surface of the circuit wiring board 1 with one main surface of the element substrate 2 a (the lower surface of the element substrate 2 a) facing the surface. Further, the circuit wiring board 1 is provided with a plurality of substrate electrode pads 4 on a main surface (upper surface) opposite to one main surface of the element substrate 2a, and the substrate electrode pads 4 correspond to the corresponding element electrode pads. 3 is electrically connected via solder bumps 5.

  The surface acoustic wave element 2 is disposed so that the element substrate 2 a faces the upper surface side of the circuit wiring board 1 so as to form a space S between the upper surface of the circuit wiring board 1. Thus, the element electrode pad 3 and the substrate electrode pad 4 are electrically connected via the solder bumps 5 so as to have the space S between the element substrate 2 a and the circuit wiring board 1. The solder bump 5 is made of, for example, a solder material such as Sn—Ag, Sn—Ag—Cu, or Sn—Bi, or a high melting point solder material containing Pb. In the surface acoustic wave device 10, the thickness of the solder bump 5 is, for example, 10 (μm) to 100 (μm), and the distance between the circuit wiring board 1 and the element substrate 2 a (including the protective film 2 c) is, for example, 10 (μm) to 130 (μm).

  As described above, the surface acoustic wave element 2 is provided with the functional body 2b on one main surface of the element substrate 2a, and the surface acoustic wave device 10 includes the surface acoustic wave element 2 on one main surface (function) of the element substrate 2a. It is mounted on the printed circuit board 1 so as to have a space S for vibration between the body 2b) and the main surface of the circuit wiring board 1.

  The element substrate 2a is a piezoelectric substrate, and is formed in a generally thin rectangular parallelepiped shape as shown in FIGS. The element substrate 2a is composed of a single crystal substrate having piezoelectricity such as a lithium tantalate single crystal or a lithium niobate single crystal. The planar shape and various dimensions of the element substrate 2a may be set as appropriate. The element substrate 2a has, for example, a quadrangular shape in plan view, a thickness that is constant, for example, is set as appropriate, and is, for example, 50 (μm) to 300 (μm), and is long in plan view. The lengths of the side and the short side are, for example, 0.5 (mm) to 1.5 (mm). Further, the element substrate 2a may be formed of a so-called bonded substrate.

  As shown in FIGS. 1 and 2, the surface acoustic wave element 2 has a functional body 2b provided on one main surface (lower surface) of the element substrate 2a. The functional body 2b is, for example, a well-known IDT (Inter Digital). transducer) electrode 2b1 and two reflectors 2b2, which are so-called SAW resonators.

As shown in FIG. 2, the IDT electrode 2 b 1 has a pair of comb electrodes arranged so as to mesh with each other (a plurality of electrode fingers alternate with each other). Each comb electrode of the IDT electrode 2b1 includes a bus bar and a plurality of electrode fingers extending from the bus bar in a direction perpendicular to the longitudinal direction of the bus bar. The pitch of the plurality of electrode fingers is generally constant. Actually, the IDT electrode 2b1 may be provided to have more electrode fingers.

  As shown in FIG. 2, the reflector 2b2 is provided so as to sandwich the IDT electrode 2b1 from both sides, and has a pair of bus bars and a plurality of electrode fingers extending between the pair of bus bars. The pitch of the plurality of electrode fingers is substantially constant and is substantially the same as the pitch of the plurality of electrode fingers of the IDT electrode 2b1.

  As shown in FIG. 2, the surface acoustic wave element 2 has a wiring pattern 7 formed on the element substrate 2a, and the wiring pattern 7 is provided to extend from one bus bar of the IDT electrode 2b1. Thus, the wiring pattern 7 is formed so as to extend from the IDT electrode 2b1 toward the element electrode pad 3 around the functional body 2b. The wiring pattern 7 serves as an input / output path for electric signals to the IDT electrode 2 b 1, and the element electrode pad 3 is provided on the second wiring pattern 7 b of the wiring pattern 7 and is electrically connected to the wiring pattern 7. Has been. That is, the wiring pattern 7 electrically connects the functional body 2 b and the element electrode pad 3.

  As shown in FIG. 1, the circuit wiring board 1 is disposed so as to face one main surface (lower surface) of the element substrate 2a, the substrate electrode pad 4 is provided on the upper surface, and the lower surface conductor layer 1c is provided on the lower surface. The internal conductor layer 1b is provided inside. In the circuit wiring board 1, the substrate electrode pad 4 on the upper surface and the internal conductor layer 1b are electrically connected through the through conductor layer 1a, and the internal conductor layer 1b and the lower conductor layer 1c are in the through conductor layer. It is electrically connected via 1a. The substrate electrode pad 4 has a thickness of, for example, 5 (μm) to 15 (μm).

  As shown in FIG. 1, the circuit wiring board 1 is formed in, for example, a generally thin rectangular parallelepiped shape. The circuit wiring board 1 is made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon carbide sintered body, or a glass ceramic sintered body. Alternatively, the circuit wiring board 1 is made of an organic resin material such as polyimide resin, cyanate resin, epoxy resin, or polyphenylene ether resin. A composite material obtained by mixing an inorganic material such as ceramic or glass with an organic resin material such as an epoxy resin can also be used. The circuit wiring board 1 has a long side and a short side in a plan view having a length of, for example, 30 (mm) to 300 (mm).

  Further, the substrate electrode pad 4 is formed with a nickel (Ni) layer and a gold (Au) layer thereon by using, for example, a plating layer forming method for the purpose of improving the bonding property with the solder bump 5. Has been.

  The circuit wiring board 1 can be manufactured using a manufacturing method similar to a general wiring board manufacturing method. An example of a method for manufacturing the circuit wiring board 1 is shown below. In the present embodiment, the circuit wiring board 1 is shown as having a two-layer structure including a first wiring board and a second wiring board. For example, the upper wiring board 1 and the lower wiring board 1 are shown. The second wiring board can be laminated and manufactured.

  In the circuit wiring board 1, first, the lower surface conductor layer 1c is formed of a metal material such as copper on the lower surface of the lower second wiring board by using a known printing method or photolithography method. In the second wiring board, a through-hole penetrating the second wiring board is formed on the lower conductor layer 1c from the upper surface by using laser processing, drilling, die processing, or the like. Next, the second wiring board is formed by using a well-known printing method or photolithography method, for example, with a through conductor layer 1a formed in a through hole with a metal material such as copper, and an inner conductor layer 1b on the upper surface. It is formed. Then, the first wiring board is laminated on the upper surface of the second wiring board, and the circuit wiring board 1 having two layers is obtained through the above manufacturing process.

In the surface acoustic wave device 10, the sealing resin layer 6 covers the upper surface of the surface acoustic wave element 2 (the main surface opposite to the one main surface of the element substrate 2 a) and the side surface of the surface acoustic wave element 2. Is provided. Moreover, the thickness of the sealing resin layer 6 is 0.2 (mm)-0.8 (mm), for example, and the sealing resin layer 6 consists of resin materials, such as an epoxy resin, for example.

  The surface acoustic wave device 10 is provided on the second wiring pattern 7b so that the element electrode pad 3 does not overlap the first wiring pattern 7a in a plan view, and stress concentration is reduced. The adhesion between the second wiring pattern 7b and the element electrode pad 3 is improved, and the occurrence of peeling or the like is suppressed. For example, as shown in FIG. 3, the second wiring pattern 7b has a stepped portion due to the end of the first wiring pattern 7a. If the element electrode pad 3 is provided so as to overlap the pattern 7a, the element electrode pad 3 rides on the stepped portion, stress concentrates on the stepped portion on which the element electrode pad 3 rides, and the element electrode pad 3 is peeled off. It becomes easy.

  The present invention is not particularly limited to the above-described embodiments, and various changes and improvements can be made within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Circuit wiring board 1a Through-conductor layer 1b Internal conductor layer 1c Lower surface conductor layer 2 Surface acoustic wave element 2a Element board 2b Functional body 2c Protective film 3 Element electrode pad 4 Board electrode pad 5 Solder bump 6 Sealing resin layer 7 Wiring pattern 7a First wiring pattern 7b Second wiring pattern 10 Surface acoustic wave device S Space

Claims (4)

An element substrate;
A functional body provided on the element substrate;
Device electrode pads provided around the functional body;
A wiring pattern extending from the functional body toward the device electrode pad and electrically connected to the device electrode pad;
With
The wiring pattern is provided on the element substrate, and is provided on the first wiring pattern connected to the functional body and the first wiring pattern, and from an end of the first wiring pattern. Extending below the element electrode pad, including a second wiring pattern provided on the element substrate;
The element electrode pad is provided on the second wiring pattern so as not to overlap the first wiring pattern when seen in a plan view, and is formed on the first layer and the first layer from the second wiring pattern side. A second layer provided and a third layer provided on the second layer, wherein the first layer comprises a Ti layer or a Cr layer, the second layer comprises a Ni layer, the third layer, the surface acoustic wave device characterized Rukoto such an Au layer. 2. The surface acoustic wave device according to claim 1, wherein a thickness of the second wiring pattern provided on the element substrate is thicker than a thickness of the first wiring pattern. Said second wiring pattern, the first layer from the element substrate side, has a third layer provided on the second layer and the second layer on which is provided on said first layer, said first the first layer consists of Ti layer or a Cr layer, the second layer, made of Al layer or an Al alloy layer, the third layer, according to claim 1 or claim characterized by comprising a Ti layer or a Cr layer Item 3. The surface acoustic wave device according to Item 2. It claims 1 to surface acoustic wave device you characterized that you have mounted on the circuit wiring board surface acoustic wave device according to claim 3.

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