JP4377500B2 - Surface acoustic wave device and method of manufacturing surface acoustic wave device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface acoustic wave device used in a wireless communication circuit such as a mobile communication device, and more particularly to a surface acoustic wave device capable of surface mounting.
[0002]
[Prior art and its problems]
Conventionally, various surface acoustic wave devices have been used as elements such as filters, delay lines, oscillators and the like of electronic devices using radio waves.
[0003]
2. Description of the Related Art In recent years, surface acoustic wave filters that are particularly small and light and have high steep cut-off performance as filters have been widely used as RF stage and IF stage filters for mobile terminal devices in the field of mobile communication.
[0004]
This mobile terminal device has been reduced in size and weight, and the number of built-in circuits has been increasing for the purpose of multiband compatibility with a plurality of communication systems. In order to increase the density, there is a strong demand for small parts that can be surface-mounted. A surface acoustic wave filter which is a key part of a portable terminal device is also required to have a small surface acoustic wave filter which can be surface-mounted with low loss and a cutoff characteristic outside the passband.
[0005]
At present, a can package type and a ceramic package type are put into practical use as surface acoustic wave devices, and the ceramic package type is widely used as a surface mountable device that can be downsized as compared with the can package type.
[0006]
In the first generation ceramic package type surface acoustic wave device, the surface acoustic wave element bonded and fixed in the package and the internal electrode of the package are electrically connected by wire-bonding. The outer shape is increased, and the surface acoustic wave device has an occupied area 5 to 6 times that of the built-in surface acoustic wave element.
[0007]
In order to solve this problem and reduce the size, as a second generation ceramic package type surface acoustic wave filter device, for example, as shown in FIG. 15, comb-like electrodes 2 and wiring electrodes which are excitation electrodes on a piezoelectric substrate 1 The surface acoustic wave device J1 in which the surface acoustic wave element having the surface 3 is face-down bonded to the inside of the package is put into practical use.
[0008]
In this way, wire bonding is used to make an electrical connection by connecting the metal bump 12 formed on the surface of the surface acoustic wave element and connected to the wiring electrode 3 and the internal electrode 11a formed on the package base 15. Therefore, as compared with the first generation ceramic package type surface acoustic wave device, the size is reduced by about a half. In the drawing, 13 is a package lid, 14 is a package frame, 11 is an electrode formed on the package substrate 15, 11b is a side electrode, and 11c is a bottom electrode.
[0009]
However, even in the second generation face-down mounting type ceramic package type surface acoustic wave device, the size of the package is about three times that of the built-in surface acoustic wave filter element, and it is not sufficiently miniaturized. .
[0010]
Further, the method for mounting the surface acoustic wave element on the package has a problem that it lacks mass productivity because it is assembled using individual packages after the device chip is cut from the wafer.
[0011]
Therefore, the present invention has been made to cope with such problems, and can be downsized to the extent that the occupied area of the outer shape is substantially equal to that of the built-in surface acoustic wave device, and is reliable. It is an object of the present invention to provide a surface acoustic wave device capable of high surface mounting and to provide a surface acoustic wave device excellent in mass productivity that can be packaged in a wafer state.
[0012]
[Means for Solving the Problems]
In order to solve the above problems, a surface acoustic wave device according to the present invention forms an excitation electrode for generating a surface acoustic wave and a wiring electrode connected to the excitation electrode on a piezoelectric substrate, and insulates the excitation electrode and the wiring electrode from each other. The conductor is covered with an insulating protector, and a conductor that penetrates the insulating protector and has a bent portion is disposed in the insulating protector. The conductor is formed on the surface of the wiring electrode and the insulating protector. It is characterized by being connected to both external electrodes.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a surface acoustic wave device according to the present invention will be described in detail with reference to the drawings.
[0014]
FIG. 1 and FIG. 2 are main part sectional views schematically showing surface acoustic wave devices S1 and S2 according to the present invention.
[0015]
The surface acoustic wave devices S1 and S2 include, for example, a lithium tantalate single crystal, a lithium niobate single crystal, a lithium tetraborate single crystal, a single crystal having a langasite-type crystal structure, or piezoelectric ceramics such as PZT and ZnO. On a piezoelectric substrate 1 made of a material, an excitation electrode 2 made of at least a pair of comb-like electrodes and generating a surface acoustic wave, and a wiring electrode connected to the excitation electrode 2 are arranged. The excitation electrode 2 and the wiring electrode 3 Is covered with an insulating protective body 6.
[0016]
Here, the excitation electrode 2 is made of a metal such as aluminum or an alloy thereof, and reflector electrodes may be disposed at both ends thereof, or a plurality of these may be connected in series and / or in parallel. The wiring electrode 3 is connected to the excitation electrode 2 and is made of the same metal material as the excitation electrode 2. The insulating protective body 6 is made of a thermosetting resin (epoxy, silicone, phenol, polyimide, polyurethane, etc.), a thermoplastic resin (polyphenylene sulfide, etc.), or a low melting point glass.
[0017]
A columnar shape made of metal (single or alloy of copper, gold, nickel, etc.) or conductive resin having a plurality of bent portions (5z, 5y) penetrating the insulating protective body 6 is provided in the insulating protective body 6. A conductor 5 is provided. The columnar conductor 5 includes a wiring electrode 3 made of the same material as the excitation electrode 2 and an external electrode 7 made of a metal material such as a solder bump formed on the surface of the insulating protective body 6. And connected to both sides.
[0018]
In order to secure the vibration space 11 of the excitation electrode 2, a cover body 4 made of metal, resin, glass or the like is disposed between the insulating protective body 6 and the excitation electrode 2.
[0019]
For example, as shown in FIGS. 1 and 3A, the columnar conductor 5 has the simplest structure in which two columnar portions 5a and 5b are connected by a single flat plate portion 5c. Further, as shown in FIGS. 3B, 3D, and 3E, one flat plate portion 5c can be bent or formed so that the planar outer shape includes a free curve such as an arc shape. is there. In addition, each figure of Fig.3 (a)-(e) illustrates the top view and side view of the columnar conductor 5. FIG. 4 to 6 to be described later, a plan view and a side view of the conductor are illustrated.
[0020]
Further, as shown in FIG. 2 and FIG. 3C, it is also possible to configure with three columnar portions 5a, 5b, 5d and two flat plate portions 5c, 5e. By increasing the number of bent portions in this way, the stress relaxation effect is further increased.
[0021]
Further, as shown in FIGS. 3A, 3B, and 3E, the central axis of the second columnar portion 5b may be shifted with respect to the central axis of the first columnar portion 5a. Therefore, the degree of freedom can be given to the arrangement of the external electrodes 7 and the arrangement of the electrodes on the piezoelectric substrate 1, and the optimum position design of the electrode pattern can be performed.
[0022]
In the above example, the columnar portion has a cylindrical shape, but may have a polygonal column shape such as a triangular column shape or a quadrangular column shape. Further, it is a matter of course that the present invention also includes a structure in which a plurality of bent portions are increased by combining a plurality of FIGS. 3A to 3E, that is, for example, as shown in FIG. Thus, by providing a large number of bent portions, the stress acting on the external electrode 7 is relaxed and transmitted to the columnar conductor, so that the influence on the piezoelectric substrate 1 can be suppressed as much as possible. As a result, when the surface acoustic wave device is mounted on a circuit board with solder or the like, the stress due to thermal strain or temperature change during the transmission is transmitted to the piezoelectric substrate 1 via the columnar electrode 5 and the characteristics are remarkably deteriorated. In some cases, the problem that cracks occur in the piezoelectric substrate can be prevented as much as possible, and a highly reliable surface acoustic wave device can be obtained.
[0023]
Further, as shown in FIGS. 5 (a) and 5 (b), the number of columnar portions may be different between the upper and lower portions of the flat plate-like portion 5c, and as shown in FIG. 5 (c), the flat plate-like portion. 5c may be narrowed so that the columnar portions overlap each other.
[0024]
Further, as shown in FIG. 6, the lower conductor 5 (5a, 5c, 5b) and the upper conductor 5 ′ (5′a, 5′b, 5′c) may be arranged so as to be separated. Well, for example, when the lower conductor is used for signal, the upper conductor can be used for signal or ground, and when the lower conductor is used for ground, the upper conductor is used for signal or ground. Can be used for.
[0025]
In any case, by providing a plurality of bent portions, damage can be prevented as much as possible by a relaxation effect caused by external stress applied to the external electrode 7 connected to the printed circuit board or the like by solder or the like acting on the piezoelectric substrate 1 through the columnar conductor. Can do.
[0026]
Further, as shown in FIG. 7B, even if the position of the external electrode 7 is on the end portion side of the surface acoustic wave device, as shown in FIG. It is possible to increase the degree of freedom of (wiring position, mode). As described above, it is possible to arrange the positions of the external electrodes 7 formed outside the protector 6 with the electrodes (wirings) at irregular positions on the piezoelectric substrate 1. The position of the electrode (wiring) is not limited to the position and mode of the external electrode 7 limited by the wiring of the external circuit board.
[0027]
Next, an example of a method for manufacturing the surface acoustic wave device will be described.
[0028]
First, a method for manufacturing a cover body of a surface acoustic wave device according to the present invention will be described. Although FIG. 9 shows a case where one cover body 4 is formed, in actuality, a large number of cover bodies A are formed on the wafer W as shown in FIG. In this way, first, a large number of cover bodies A are formed on the wafer W, and then a large number of surface acoustic wave element regions are formed on a separately prepared piezoelectric wafer, and the two wafers are stacked and bonded together. After removing W by polishing or the like, sealing is performed with an insulating protective body, and further, external electrodes are formed on the insulating protective body, and finally separated into individual chips to complete the surface acoustic wave device.
[0029]
First, as shown in FIG. 9A, an electrode film 4a for plating is formed on a region 10 of a wafer having the same size as the piezoelectric wafer forming the surface acoustic wave element. As this wafer, a piezoelectric substrate, a silicon substrate, or a glass substrate can be used, and a material that can be easily removed in a later process is used. The electrode film 4a is formed to a thickness of about 0.2 μm to 1 μm by sputtering using a metal material such as copper.
[0030]
Next, as shown in FIG. 9B, a plating guide corresponding to the upper portion of the cover body 4 is formed by photolithography. The thickness of the photoresist 9a is 50 μm to 100 μm.
[0031]
Next, as shown in FIG. 9C, a portion 4b corresponding to the upper portion of the cover body is formed by electrolytic plating of copper. For this electrolyte, copper sulfate 0.5-1.0 × 10 ³ mol / m ³ and sulfuric acid 1.5-2 × 10 ³ mol / m ³ are used, and potassium chloride / silver chloride standard is used for the reference electrode. Use electrodes.
[0032]
Next, as shown in FIG. 9D, a plating guide corresponding to the wall portion of the cover body is formed by photolithography. The thickness of the photoresist 9b is 50 μm to 100 μm, and the width of the groove corresponding to the wall thickness is about 50 μm to 100 μm.
[0033]
Next, as shown in FIG. 9 (e), a portion 4c corresponding to the wall of the cover body is formed by electrolytic plating of copper, and then the low melting point glass 8 is thickened by screen printing on the cover body 4c. Formed at 5-10 μm. Finally, the photoresist is removed to complete the substrate on which the cover bodies are arranged.
[0034]
Next, a method for manufacturing the surface acoustic wave device according to the present invention will be described. 10 to 12 are views showing a manufacturing process of the surface acoustic wave device. In these drawings, only a cross-sectional view of a certain region of the wafer which is a piezoelectric substrate is schematically shown as in FIG.
[0035]
First, as shown in FIG. 10A, the comb-like excitation electrode 2 and the first wiring electrode 3 a are formed on the piezoelectric substrate 1. As the piezoelectric substrate 1, a piezoelectric substrate such as a lithium niobate crystal substrate, a lithium tantalate crystal substrate, a crystal crystal substrate, a lithium tetraborate crystal substrate, a langasite crystal substrate, or a PZT substrate is used. The excitation electrode 2 and the first wiring electrode 3a are made of aluminum or aluminum alloy to which copper or the like is added. The excitation electrode 2 is for exciting and receiving surface acoustic waves. In this example, the excitation electrode 2 is a single layer, but may be a multilayer electrode for improving the power durability of the electrode. These films are formed by vapor deposition or sputtering and have a thickness of 0.2 μm to 1 μm.
[0036]
Next, as shown in FIG. 10B, the second wiring electrode 3b is selectively formed by photolithography. Nickel, chromium, titanium, etc. and copper are used as the electrode material of the second wiring electrode 3b. The thickness of the second wiring electrode 3b is 0.2 μm to 0.5 μm.
[0037]
Next, as shown in FIG. 10C, the cover body formed on the wafer described in FIG. 9 is placed on the piezoelectric wafer so that the low melting point glass is used as an adhesive in an inert gas atmosphere. Glue. The adhesion temperature of the low-melting glass is 350 ° C. to 450 ° C.
[0038]
Next, as shown in FIG. 10D, a part of the substrate (wafer) used for forming the cover body and the plating electrode 4a is removed by polishing. Polishing is performed in two stages: rough polishing by mechanical polishing using only an abrasive and mechanochemical polishing.
[0039]
Next, as shown in FIG. 10E, a plating guide for forming the columnar portion by plating is formed by photolithography. The thickness of the photoresist 9 is about 100 μm to 400 μm, and the diameter of the hole for the columnar conductor is about 50 μm to 200 μm.
[0040]
Next, as shown in FIG. 11A, the first columnar portion 5a is formed by electrolytic plating of copper. The electrolyte uses copper sulfate 0.5-1.0 × 10 ³ mol / m ³ and sulfuric acid 1.5-2 × 10 ³ mol / m ³ , and the reference electrode is a standard electrode of potassium chloride / silver chloride. Is used.
[0041]
Next, as shown in FIG. 11B, the photoresist 9 is removed. Thereafter, a part of the second wiring electrode 3b for forming the columnar conductor is removed by etching using the first columnar portion 5a and the cover body 4 as a mask. For the etching, wet etching or dry etching such as RIE is used.
[0042]
Next, as shown in FIG. 11C, a resin layer 6a is formed by transfer molding of a thermosetting resin. At this time, an upper part of the columnar conductor can be exposed from the resin layer by mounting a resin film having a thickness of about 100 μm on the surface of the die for pressing the resin from the upper part. The thickness of the resin layer 6a is about 100 μm to 400 μm.
[0043]
Next, as shown in FIG. 11D, after the first flat plate portion 5f is selectively formed by photolithography, the second flat plate portion 5g is formed, and then the third columnar portion is formed. For the plating guide, a photoresist 9 is used. Gold, copper or the like is used for the first flat plate portion, and nickel, chromium, titanium or the like and copper are used for the second flat plate portion. The thickness of the first flat plate portion is 0.5 μm to 10 μm, and the thickness of the second flat plate portion is 0.2 μm to 0.5 μm. The thickness of the photoresist 9 is 10 μm to 200 μm.
[0044]
Next, as shown in FIG. 12A, a third columnar body 5d is formed by electrolytic plating of copper by the same method as in FIG.
[0045]
Next, as shown in FIG. 12B, the photoresist 9 is removed, and then a part of the second flat plate-like portion 5g is removed by etching using the third columnar portion 5d as a mask. For this etching, wet etching or dry etching such as RIE is used.
[0046]
Next, as shown in FIG. 12C, a resin layer 6a is formed by transfer molding of a thermosetting resin. At this time, an upper part of the columnar conductor can be exposed from the resin layer by mounting a resin film having a thickness of about 100 μm on the surface of the die for pressing the resin from the upper part. The thickness of the resin layer 6b is 10 μm to 200 μm.
[0047]
Next, as shown in FIG. 12D, the planar electrode 5, the second columnar conductor 5b, and the third resin layer 6c are formed by repeating the steps of FIGS. 12A to 12D. To do.
[0048]
Finally, as shown in FIG. 2, cream solder is screen-printed on the top of the columnar conductor 5 and reflowed to form external electrodes 7 made of solder bumps, and a wafer including a large number of surface acoustic wave devices. Is completed. A desired surface acoustic wave device can be obtained by cutting and separating the wafer by dicing or the like.
[0049]
Thus, a small elastic surface device having high reliability and a size equivalent to the chip size can be manufactured by a manufacturing method which is rich in mass productivity and greatly simplified in process.
[0050]
As shown in FIGS. 1 and 2, a resin layer 66 may be formed on the back surface of the piezoelectric substrate 1. Since the wear level packaging surface acoustic wave device of the present invention manufactured through the dicing process is held on the circuit board by the collet of the mounter device, the substrate may be damaged. Thus, by providing the resin layer on the back surface of the piezoelectric substrate, this substrate damage can be prevented.
[0051]
FIGS. 13A and 13B and FIGS. 14A and 14B are plan views for explaining an example of the cover body 4 of the present invention in a ladder type filter and a dual mode resonator type filter, respectively. It is a figure to do. Each figure (a) shows a pattern of comb-like electrodes and wiring electrodes on the piezoelectric substrate 1, and each figure (b) shows a schematic cross-sectional view of the wall surface (concave part) of the cover body 4. In each figure (b), by providing the recessed part of the cover body 4 only in the part corresponding to the upper part of the excitation electrode 2, the mechanical reliability of the cover body 4 can be improved greatly.
[0052]
In particular, when the area occupied by the excitation electrode 2 and the wiring electrode 3 is large, it is effective to further improve the mechanical reliability by dividing the concave portion of the cover body 4 made of metal for each excitation electrode 2. . It goes without saying that the plurality of recesses formed in the cover body 4 are effective if they are independent recesses, but the same effect can be obtained even if the recesses are connected so as not to impair the mechanical strength. Is obtained. As a result, it is possible to provide a highly reliable surface acoustic wave device that can be miniaturized.
[0053]
【Example】
Next, specific examples of the present invention will be described.
[0054]
First, as shown in FIG. 10A, the excitation electrode 2 and the first wiring electrode 3 a were formed on the piezoelectric substrate 1. A 36 ° Y-cut lithium tantalate substrate having a thickness of 350 μm was used as the piezoelectric substrate 1, and an aluminum alloy (copper content 1%) was used for the excitation electrode 2 and the wiring electrode 3 a of the first layer of the wiring electrode 3. The electrode thickness was 2000 to 4000 mm. As the second wiring electrode 3b, a two-layer electrode of nickel and copper was used, and the thicknesses thereof were 1000 mm and 2000 mm, respectively, and were selectively formed using photolithography.
[0055]
Next, as shown in FIG. 10C, the cover body 4a formed on the silicon substrate 10 is bonded with the low melting point glass 8, and then the silicon substrate 10 and a part of the cover body 4a are attached using a polishing machine. Removed. The polishing liquid at this time was performed by using colloidal silica mixed in an aqueous alkali solution such as an aqueous sodium hydroxide solution.
[0056]
Next, as shown in FIGS. 10 (e) and 11 (a), a guide for forming the first columnar portion 5a by plating is formed of a photoresist, and the first electrolytic plating of copper is used for the first. Columnar portion 5a was formed. The diameter of the first columnar part 5a at this time was 100 μm, and the height was 200 μm.
[0057]
Next, as shown in FIGS. 11C and 11D, after removing the photoresist for plating guide, sealing was performed by transfer molding using a thermosetting molding resin. By attaching a heat-resistant resin film having a thickness of 100 μm to a die for pressing the resin from the upper part, the upper part of the first columnar part 5a was exposed from the first resin layer 6a. The thickness of the 1st resin layer 6a was about 200 micrometers.
[0058]
Next, as shown in FIGS. 12A to 12D, the flat plate-like portion 5c, the third columnar portion 5d, the second resin layer 6b, the flat plate-like portion 5e, the second columnar portion 5b, and the first 3 resin layers 6c were sequentially formed.
[0059]
As the flat plate portion, a single-layer electrode of copper and a double-layer electrode of nickel and copper were used, and the thicknesses thereof were 1 μm, 1000 mm, and 2000 mm, respectively. Copper plating was used for the columnar portion, and the thickness was 100 μm.
[0060]
Next, cream solder was screen-printed on the top of the columnar conductor 5 with a thickness of 10 μm, and then reflowed at 270 ° C. to form solder bumps to be the external electrodes 7.
[0061]
Finally, the surface acoustic wave devices (chips) were separated into one by one by dicing the substrate to complete the surface acoustic wave device. In the obtained surface acoustic wave device, the comb-like electrode is protected by the sealing resin that is the cover body and the insulating protective body, and the columnar conductor is provided with a bending portion for stress relaxation. Also in the temperature cycle test of −40 ° C. to 85 ° C., the piezoelectric substrate was not damaged, and no characteristic deterioration was observed. Further, it was possible to realize a reduction in size and a reduction in height of 0.8 mm, almost the same occupied area as the surface acoustic wave filter element (1 mm × 1.5 mm).
[0062]
【The invention's effect】
As described above in detail, according to the surface acoustic wave device of the present invention, the stress applied to the external electrode by providing a plurality of bent portions on the conductor connecting the wiring electrode and the external electrode of the surface acoustic wave element. Therefore, it is possible to provide a highly reliable surface acoustic wave device that does not deteriorate due to a temperature change or the like.
[0063]
Further, by providing the conductor with a bent portion, the wiring electrode position and the external electrode position of the surface acoustic wave element can be made different in the plane direction of the piezoelectric substrate. As a result, the degree of freedom of arrangement of the external electrodes and the wiring pattern can be given, and the optimum design of the electrodes can be performed.
[0064]
In addition, the piezoelectric substrate can be used as the lower housing and sealed with resin mold, which can be used as the upper housing, eliminating the need for a conventional ceramic package, etc. Thus, it is possible to provide a surface-mountable surface wave device that can be mounted on the surface and is ultimately miniaturized in that the size of the surface-wave device is substantially the same as that of a built-in surface acoustic wave device.
[0065]
In addition, all manufacturing processes can be performed in a wafer process, and a large number of surface acoustic wave devices can be formed simultaneously by processing in units of wafers. That is, individual surface acoustic wave devices can be formed in a dicing process on a wafer that has been completely sealed with resin Since a finished product can be obtained by cutting to a die bonder, wire bonder, seam welder, etc., which do not require individual surface acoustic wave elements to be assembled as in the processes after the conventional dicing process and have a small processing capacity. Therefore, it is possible to provide a surface acoustic wave device with a high mass productivity.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view illustrating an embodiment of a surface acoustic wave device according to the present invention.
FIG. 2 is a schematic cross-sectional view illustrating another embodiment of a surface acoustic wave device according to the present invention.
FIGS. 3A to 3E are a plan view and a side view, respectively, schematically illustrating structural examples of conductors according to the present invention.
FIGS. 4A and 4B are a plan view and a side view schematically illustrating a structure example of another conductor according to the present invention. FIGS.
FIGS. 5A to 5C are a plan view and a side view, respectively, schematically illustrating structural examples of other conductors according to the present invention.
FIGS. 6A and 6B are a plan view and a side view schematically illustrating a structure example of another conductor according to the present invention. FIGS.
FIGS. 7A and 7B are a plan view and a side view schematically illustrating a structure example of another conductor according to the present invention. FIGS.
FIG. 8 is a perspective view illustrating a state of a wafer for producing a cover body according to the present invention.
9 (a) to 9 (f) are cross-sectional views schematically illustrating a manufacturing process of a cover body of a surface acoustic wave device according to the present invention.
FIGS. 10A to 10E are cross-sectional views schematically illustrating a production process of a surface acoustic wave device according to the present invention.
FIGS. 11A to 11D are cross-sectional views schematically illustrating manufacturing steps of the surface acoustic wave device according to the present invention.
12 (a) to 12 (d) are cross-sectional views schematically illustrating manufacturing steps of the surface acoustic wave device according to the present invention.
13A is a schematic plan view showing an electrode pattern of a ladder-type surface acoustic wave filter element, and FIG. 13B is a schematic cross-sectional view for explaining a cover body.
14A is a schematic plan view showing an electrode pattern of a dual-mode resonator type surface acoustic wave filter element, and FIG. 14B is a schematic cross-sectional view for explaining a cover body.
FIG. 15 is a schematic cross-sectional view illustrating a conventional surface acoustic wave device.
[Explanation of symbols]
1: Piezoelectric substrate 2: Excitation electrode (a pair of comb-shaped electrodes)
3: Wiring electrode 3a: 1st wiring electrode 3b: 2nd wiring electrode 4: Cover body 4a: Metal film 4b for cover body formation: Cover body upper part 4c: Cover body wall part 5 and 5 ': Columnar conductor (conductor) )
5a: first columnar portion 5b: second columnar portion 5c: flat plate portion 5d: third columnar portion 5e: flat plate portion 5f: first flat plate portion 5g: second flat plate portion 6: resin Layer (insulating protective body)
6a: 1st resin layer 6b: 2nd resin layer 6c: 3rd resin layer 7: External electrode 8: Low melting glass 9: Photoresist 9a: Photoresist 9b: Photoresist 10: Substrate 66: Resin layer S1 , S2: surface acoustic wave device

Claims (7)

A piezoelectric substrate ;
And excitation electrodes that will be disposed on the piezoelectric substrate,
A wiring electrode disposed on the piezoelectric substrate and connected to the excitation electrode ;
A cover body that has a recess that constitutes a vibration space of the excitation electrode and is bonded to the piezoelectric substrate such that an outer peripheral edge is located in a region immediately above the piezoelectric substrate;
An insulating protective body covering the cover body ;
An external electrode disposed on the insulating protective body;
While being disposed on the insulating protective body, and the wiring electrodes are connected to both of the front Kigai portion electrode, and a columnar conductor having a bent portion at the connection path from the wiring electrode to the external electrode surface acoustic wave device provided. The columnar conductor includes a first columnar portion connected to the wiring electrode, a second columnar portion connected to the external electrode, and a plate-shaped portion connected to the first and second columnar portions. Become
2. The surface acoustic wave device according to claim 1, wherein the central axis of the second columnar part is located on the center side of the piezoelectric substrate with respect to the central axis of the first columnar part. The surface acoustic wave device according to claim 1, wherein the insulating protective body is made of a resin. The surface acoustic wave device according to claim 1, wherein the cover body is formed of any one of metal, resin, and glass. The surface acoustic wave device according to any one of claims 1 to 4, wherein the columnar conductor has a columnar portion formed by plating. The surface acoustic wave device according to claim 1, wherein the external electrode is located in a region immediately above the piezoelectric substrate. Forming an excitation electrode and a wiring electrode on a piezoelectric wafer having a plurality of surface acoustic wave element regions;
Forming a cover body having a recess that forms a vibration space of the excitation electrode on the piezoelectric wafer;
A step of forming a columnar conductor formed by plating, and a plate-shaped portion connected to the columnar portion and formed by photolithography, and connected to the wiring electrode;
Forming an insulating protective body covering the cover body;
Forming an external electrode connected to the columnar conductor on the insulating protective body;
Cutting the piezoelectric wafer for each surface acoustic wave element region.

Images