JP2015171295A - Power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generator that can enhance a power generation efficiency.SOLUTION: A power generator 1 has a base 2 and a power generating element 3. The base 2 has a frame-shaped support portion 21, a cantilever portion 22 which is disposed inside the support portion 21 and is freely swingably supported by the support portion 21, and a flow passage 23 constructed by a gap formed between the support portion 21 and the cantilever portion 22. The power generating element 3 has a substrate 30 which is smaller than the base 2 and has flexibility, and a piezoelectric conversion unit 36 formed on the surface 30a of the substrate 30. The power generating element 3 is stacked and joined onto the base 2. The power generating element 3 is away from the flow passage 23 and straddles over the support portion 21 and the cantilever portion 22. The cantilever portion 22 has a through-hole 24 penetrating in the thickness direction of the cantilever portion 22 within a vertical projection area of the power generating element 3.

Description

  The present invention relates to a power generation device, and more particularly to a fluid vibration power generation device that generates power using fluid excitation vibration.

  In recent years, power generation devices that convert vibration energy into electrical energy have attracted attention in fields such as energy harvesting.

  As this type of power generation device, for example, a power generation device 201 having a configuration shown in FIGS. 4A, 4B, and 4C is proposed (Patent Document 1).

  The power generation apparatus 201 includes a base 211 and a lead 213 to which the piezoelectric element 214 is fixed.

  The base 211 has a plate 215 on which a rectangular window 212 is formed. As shown in FIG. 4A, the size of the window 212 is slightly larger than the lead 213 facing the window 212, and a slight amount of gas F1 passes between the edge of the window 212 and the lead 213. A gap is formed.

  The lead 213 has flexibility that allows bending vibration in the plate thickness direction. For example, the lead 213 is a flexible printed board formed of FRP or the like. The lead 213 is positioned so that one end 231 is fixed to the upper surface of the plate 215 and the other end 232 faces the window 212 so that the window 212 can freely enter and exit.

  Further, as shown in FIG. 4B, the lead 213 is slightly inclined with respect to the upper surface of the plate 215 so that the end 232 is located outside the window 212 (the side into which the gas F1 flows). (Up)

  The piezoelectric element 214 is a bimorph piezoelectric element, and is fixed to both the front and back surfaces of the lead 213 as shown in FIGS. 4 (b) and 4 (c). Patent Document 1 describes that the piezoelectric element 214 may be a unimorph piezoelectric element fixed to one of the front surface and the back surface of the lead 213.

  In the technical field of the fluid vibration power generation device, not only the power generation device 201 but also further improvement in power generation efficiency is required.

JP 2012-97673 A

  This invention is made | formed in view of the said reason, The objective is to provide the electric power generating apparatus which can aim at the improvement of electric power generation efficiency.

  The power generation device of the present invention includes a base and a power generation element. The base includes a frame-shaped support portion, a cantilever portion that is disposed inside the support portion and is swingably supported by the support portion, and a gap formed between the support portion and the cantilever portion. A configured flow path. The power generating element includes a substrate that is smaller than the base and has flexibility, and a piezoelectric transducer formed on the surface of the substrate. The power generation element is overlapped and joined to the base. The power generation element is separated from the flow path and straddles the support part and the cantilever part in a plan view. In the cantilever portion, a hole penetrating in the thickness direction of the cantilever portion is formed in a vertical projection region of the power generation element.

  In this power generator, the base is preferably formed of a metal substrate.

  In this power generator, the base is preferably formed of a resin substrate.

  In this power generation device, the power generation element includes a first pad electrode and a second pad electrode, the base is formed of a printed circuit board, and the first pad electrode and the second pad electrode are electrically connected to each other. It is preferable to include a first conductor portion and a second conductor portion connected to each other.

  In this power generator, the minimum width of the flow path is preferably 20 μm or more and 100 μm or less.

  In this power generation device, the piezoelectric conversion unit has a piezoelectric conversion region, and the first end of the piezoelectric conversion region in a first direction along the length direction of the cantilever unit is the support unit and the cantilever unit. It is preferable that the first boundary is aligned with the first boundary.

  In the power generation device, the power generation element has a first end portion of the substrate in the first direction joined to the support portion, and a second end portion of the substrate in the first direction joined to the cantilever portion. It is preferable.

  In this power generation device, it is preferable that the support portion is thicker than the cantilever portion.

  In the power generation device, it is preferable that the power generation element has a thickness of each of the first end portion and the second end portion of the substrate that is greater than a thickness of a portion of the substrate immediately below the piezoelectric conversion portion.

  In this power generation device, the cantilever part includes a beam part and a weight part, a first end in the length direction of the beam part is fixed to the support part, and a second length in the length direction of the beam part. It is preferable that an end is fixed to the weight portion, and the power generation element has the second end portion of the substrate joined to the weight portion.

  In the power generation device of the present invention, the power generation element including the substrate and the piezoelectric conversion unit is overlapped and joined to the base including the support unit, the cantilever unit, and the flow path. It is separated from the flow path and straddles the support part and the cantilever part. As a result, the power generation device of the present invention shifts the position of the neutral surface of the power generation device from the neutral surface of the substrate toward the cantilever part, so that it is possible to improve the power generation efficiency. Further, the power generation device of the present invention can suppress the change in the area and shape of the flow path depending on the relative positional accuracy between the base and the power generation element, and can improve power generation efficiency. The cost can be reduced by downsizing the power generating element. Further, in the power generation device of the present invention, since a hole penetrating in the thickness direction of the cantilever part is formed in the vertical projection region of the power generation element in the cantilever part, the rigidity of the cantilever part can be lowered. This makes it possible to improve power generation efficiency.

FIG. 1A is a schematic plan view of the power generator according to the embodiment. FIG.1 (b) is XX schematic sectional drawing of Fig.1 (a). FIG. 2A is a schematic plan view of a base in the power generator according to the embodiment. FIG.2 (b) is XX schematic sectional drawing of Fig.2 (a). FIG. 3A is a schematic plan view of a power generation element in the power generation apparatus of the embodiment. FIG.3 (b) is XX schematic sectional drawing of Fig.3 (a). FIG. 4A is a schematic plan view of a conventional power generation device. FIG.4 (b) is XX schematic sectional drawing of Fig.4 (a). FIG.4 (c) is a YY schematic sectional drawing of Fig.4 (a).

  Below, the electric power generating apparatus 1 of this embodiment is demonstrated based on FIG. 1 (a), 1 (b), 2 (a), 2 (b), 3 (a), 3 (b).

  The power generation device 1 includes a base 2 and a power generation element 3. The base 2 is formed between a frame-shaped support portion 21, a cantilever portion 22 that is disposed inside the support portion 21 and is swingably supported by the support portion 21, and the support portion 21 and the cantilever portion 22. And a flow path 23 constituted by a gap. The power generating element 3 includes a substrate 30 that is smaller than the base 2 and has flexibility, and a piezoelectric conversion portion 36 formed on the surface 30 a of the substrate 30. The power generation element 3 is overlapped and joined to the base 2. The power generation element 3 is separated from the flow path 23 and straddles the support portion 21 and the cantilever portion 22 in a plan view. The cantilever portion 22 is formed with a hole 24 penetrating in the thickness direction of the cantilever portion 22 in the vertical projection region of the power generating element 3. Therefore, in the power generation device 1, the power generation element 3 including the substrate 30 and the piezoelectric conversion unit 36 is overlapped and joined to the base 2 including the support unit 21, the cantilever unit 22, and the flow path 23. It is separated from the flow path 23 and straddles the support portion 21 and the cantilever portion 22. As a result, the power generation device 1 shifts the position of the neutral surface of the power generation device 1 from the neutral surface of the substrate 30 to the cantilever portion 22 side, so that it is possible to improve the power generation efficiency. In addition, the power generation device 1 can suppress the change in the area, shape, and the like of the flow path 23 depending on the relative positional accuracy between the base 2 and the power generation element 3, and can improve power generation efficiency. The cost can be reduced by downsizing the element 3. Further, since the power generation device 1 has a hole 24 penetrating in the thickness direction of the cantilever portion 22 in the vertical projection region of the power generation element 3 in the cantilever portion 22, the rigidity of the cantilever portion 22 can be reduced. This makes it possible to improve power generation efficiency.

  Each component of the power generator 1 will be described in detail below.

  The base 2 can be formed by a metal substrate, for example. Accordingly, the power generation device 1 can suppress the vibration energy of the cantilever portion 22 from being attenuated in the base 2. As the material of the metal substrate, a material having a low logarithmic decay rate is preferable. For example, stainless steel can be adopted. As the stainless steel, for example, austenitic stainless steel is preferable, and examples thereof include SUS304 (18Cr-8Ni). Further, the material of the metal substrate is not limited to stainless steel, and for example, titanium, aluminum, brass, phosphor bronze, beryllium copper, or the like can be employed.

  The flow path 23 and the hole 24 of the base 2 can be formed, for example, by subjecting a metal substrate to wet etching. For the base 2, the support portion 21 and the cantilever portion 22 are formed by forming the flow path 23 with respect to the metal substrate.

  The support portion 21 preferably adopts a rectangular frame shape as the frame shape. That is, it is preferable that the support portion 21 has a rectangular outer peripheral shape. As a result, the power generation device 1 can reduce the cost by improving the material yield when the base 2 is cut out from the multi-piece metal substrate during manufacture.

  In the base 2, the cantilever portion 22 is disposed inside the support portion 21 in a plan view. The base 2 forms a U-shaped flow path 23 that surrounds the cantilever part 22, so that the part other than the connection part of the cantilever part 22 with the support part 21 is separated from the support part 21. Thereby, the cantilever part 22 is cantilevered by the support part 21.

  The base 2 preferably has a minimum width of the flow path 23 of 20 μm or more and 100 μm or less. As a result, the power generation device 1 can suppress the vibration of the cantilever portion 22 from occurring less easily regardless of the fluid flow velocity, flow rate, and the like. In addition, since the minimum width of the flow path 23 is 20 μm or more and 100 μm or less, the power generation device 1 can reduce the critical flow velocity of the fluid excitation vibration and can improve power generation efficiency. It becomes possible.

  The fluid excitation vibration is vibration of the cantilever portion 22 generated when the fluid flowing through the flow field passes through the flow path 23 in a state where the power generation device 1 is disposed in the flow field. This fluid excitation vibration is self-excited vibration. Examples of the fluid include air, gas, a mixed gas of air and gas, and liquid. When the fluid is a gas, examples of the flow field include the inside of an air supply duct of an air conditioner and the inside of an exhaust duct of an air conditioner, but are not particularly limited. The generation limit flow velocity of the fluid excitation vibration means a lower limit value of the flow velocity at which the self-excited vibration of the cantilever portion 22 can be generated.

  The generation limit flow velocity of the cantilever portion 22 that self-excites and receives fluid is proportional to the square root of the mass per unit length of the cantilever portion 22.

  The mechanism for estimating the operation of the power generation device 1 is self-excited due to the force acting on the cantilever portion 22 when the fluid passes through the flow path 23 and the restoring force due to the spring properties of the cantilever portion 22 and the substrate 30. It is estimated that vibration will occur. The power generation device 1 is arranged so that the direction in which the fluid flows coincides with the thickness direction of the base 2, the front surface 22 a side of the cantilever portion 22 is the upstream side of the fluid, and the back surface 22 b side of the cantilever portion 22 is the downstream side of the fluid. Are preferably used. In the power generation device 1, when the fluid flowing from the upstream side toward the power generation device 1 passes through the flow path 23, the flow velocity increases, so that the pressure on the back surface 22 b side of the cantilever portion 22 decreases and the cantilever portion 22 is displaced. In the power generation device 1, the cantilever portion 22 is displaced by the force of the fluid flowing from the upstream side toward the power generation device 1. And in the electric power generating apparatus 1, when the restoring force of the cantilever part 22 becomes larger than the force received from the fluid, it is estimated that the cantilever part 22 is displaced in a direction to return to the original position. In the power generation device 1, it is assumed that the cantilever part 22 self-excites and the piezoelectric conversion part 36 generates power by repeating such an operation. The resonance frequency of the power generation device 1 is determined by the mass and rigidity of the cantilever portion 22, the mass and rigidity of the substrate 30, and the like. Note that the power generation apparatus 1 of the present embodiment is within the scope of the present invention even if the estimation mechanism is different.

  The cantilever portion 22 includes a beam portion 25 and a weight portion 26, a first end 25 a in the length direction of the beam portion 25 is fixed to the support portion 21, and a second end 25 b in the length direction of the beam portion 25. Is preferably fixed to the weight portion 26. The length direction of the beam portion 25 is the same direction as the length direction of the cantilever portion 22. The beam portion 25 is formed in a cantilever shape. In the cantilever portion 22, the thickness of the beam portion 25 and the thickness of the weight portion 26 are the same, but this is not restrictive. For example, the cantilever part 22 may make the thickness of the beam part 25 thinner than the thicknesses of the support part 21 and the weight part 6. In the cantilever part 22, the thickness of the weight part 26 may be larger than the thickness of each of the support part 21 and the beam part 25.

  For example, the hole 24 may have a rectangular opening shape. The opening size of the hole 24 is smaller than that of the power generation element 3. Here, the hole 24 is preferably formed over the entire length of the beam portion 25 in the length direction. The base 2 is not limited to the case where the number of holes 24 is one, and may include a plurality of holes 24. Even when the base 2 includes a plurality of holes 24, all the holes 24 are formed in the vertical projection region of the power generation element 3 in the cantilever portion 22. The opening shape of the hole 24 is not limited to a rectangular shape, and may be, for example, a circular shape or a polygonal shape other than a rectangular shape.

  Regarding the manufacturing method of the power generation element 3, the power generation element 3 can be manufactured using, for example, a MEMS manufacturing technique.

  The outer peripheral shape of the substrate 30 is preferably rectangular. Thereby, in the manufacturing method of the electric power generating apparatus 1, after performing the pre-process which forms the several electric power generation element 3 in a silicon wafer, it becomes possible to improve workability | operativity at the time of performing a dicing by a post process. Further, in the method for manufacturing the power generation device 1, since the outer peripheral shape of the substrate 30 is rectangular, the power generation element 3 can be easily handled, the power generation element 3 can be positioned with respect to the base 2, and the like.

  The substrate 30 includes a silicon substrate 31 and an insulating film 32 formed on the surface of the silicon substrate 31. The insulating film 32 has electrical insulation. The insulating film 32 can be composed of, for example, a silicon oxide film. The insulating film 32 can be formed by, for example, a thermal oxidation method. The formation method of the insulating film 32 is not limited to the thermal oxidation method, and may be a CVD method, for example. The insulating film 32 is not limited to being composed of only a silicon oxide film, and may be composed of a laminated film of a silicon oxide film and a silicon nitride film, for example.

  In the power generating element 3, the silicon substrate 31 and the piezoelectric conversion unit 36 are electrically insulated by the insulating film 32.

  The thickness of the silicon substrate 30 is set to 50 μm. The thickness of the substrate 30 is not limited to 50 μm and is preferably set within a range of 20 μm to 100 μm, for example. The thickness of the insulating film 32 is set to 1 μm. The thickness of the insulating film 32 is not limited to 1 μm and is preferably set within a range of 0.5 μm to 3 μm, for example.

  The piezoelectric conversion unit 36 is formed on the surface 30 a of the substrate 30. The piezoelectric conversion unit 36 includes a first electrode 33 formed on the surface 30 a of the substrate 30, a piezoelectric layer 34 formed on the first electrode 33, and a second electrode 35 provided on the piezoelectric layer 34. And comprising. In short, the piezoelectric conversion unit 36 includes the piezoelectric layer 34 and the first electrode 33 and the second electrode 35 facing each other with the piezoelectric layer 34 sandwiched from both sides in the thickness direction.

As the piezoelectric material of the piezoelectric layer 34, PZT (Pb (Zr, Ti) O ₃ ) is adopted, but not limited to this, for example, PZT-PMN (Pb (Mn, Nb) O ₃ ), PZT added with impurities may also be used. Further, the piezoelectric material may be AlN, ZnO, KNN (K _0.5 Na _0.5 NbO ₃ ), KN (KNbO ₃ ), NN (NaNbO ₃ ), a material obtained by adding impurities to KNN, or the like. Examples of the impurity include Li, Nb, Ta, Sb, and Cu. The piezoelectric layer 34 is composed of a piezoelectric thin film.

  The material of the first electrode 33 is Pt, but is not limited to this, and may be Au, Al, Ir, or the like, for example. The material of the second electrode 35 is Au, but is not limited thereto. For example, Mo, Al, Pt, Ir, or the like may be used.

  In the power generating element 3, the thickness of the first electrode 33 is set to 500 nm, the thickness of the piezoelectric layer 34 is set to 3000 nm, and the thickness of the second electrode 35 is set to 500 nm. However, the power generation element 3 is not limited to these values. .

The power generating element 3 may have a structure in which a buffer layer is provided between the substrate 30 and the first electrode 33. The material of the buffer layer is preferably selected as appropriate according to the piezoelectric material of the piezoelectric layer 34. When the piezoelectric material of the piezoelectric layer 34 is PZT, for example, SrRuO ₃ , (Pb, La) TiO ₃ , PbTiO ₃ , MgO, LaNiO ₃ or the like is preferably used as the buffer layer material. Further, the buffer layer may be constituted by a laminated film of a Pt film and a SrRuO ₃ film, for example. By providing the buffer layer, the power generation element 3 can improve the crystallinity of the piezoelectric layer 34 and improve the power generation efficiency.

  The power generating element 3 includes a first pad electrode 38 and a second pad electrode 39. The first pad electrode 38 and the second pad electrode 39 are formed on the surface 30 a of the substrate 30. The first pad electrode 38 and the second pad electrode 39 are preferably arranged in the vertical projection region of the support portion 21 on the surface 30 a of the substrate 30.

  The first pad electrode 38 is electrically connected to the first electrode 33 via the first wiring 41. The second pad electrode 39 is electrically connected to the second electrode 35 via the second wiring 42. The material of the first wiring 41, the second wiring 42, the first pad electrode 38, and the second pad electrode 39 is Au, but is not limited to this. For example, Mo, Al, Pt, Ir, etc. may be used. Good. The materials of the first wiring 41, the second wiring 42, the first pad electrode 38, and the second pad electrode 39 are not limited to the same material, and different materials may be adopted. The first wiring 41, the second wiring 42, the first pad electrode 38, and the second pad electrode 39 are not limited to a single layer structure, and may have a multilayer structure of two or more layers.

  In the power generation device 1, an insulating layer 37 that prevents a short circuit between the second wiring 42 and the first electrode 33 is provided between the second wiring 42 and the peripheral portion of the first electrode 33. The insulating layer 37 is composed of a silicon oxide film, but is not limited to a silicon oxide film, and may be composed of, for example, a silicon nitride film.

  In the power generation device 1, the piezoelectric layer 34 of the piezoelectric conversion unit 36 receives stress due to the vibration of the cantilever unit 22, and a bias of electric charge occurs between the second electrode 35 and the first electrode 33, and an AC voltage is generated in the piezoelectric conversion unit 36. Occur. In short, in the power generation device 1, the piezoelectric conversion unit 36 generates power using the piezoelectric effect of the piezoelectric material. The AC voltage generated in the piezoelectric conversion unit 36 is a sinusoidal AC voltage corresponding to the vibration of the piezoelectric layer 34.

  The planar shape of the piezoelectric layer 34 is formed in a rectangular shape. In the piezoelectric conversion unit 36, it is preferable that the outer size of the piezoelectric layer 34 is slightly smaller than the outer size of the first electrode 33 and slightly larger than the outer size of the second electrode 35. Here, the piezoelectric transducer 36 has a piezoelectric transducer region 36a. The piezoelectric conversion region 36 a means a region where the first electrode 33, the piezoelectric layer 34, and the second electrode 35 overlap in the thickness direction of the substrate 30. In the piezoelectric conversion unit 36, the piezoelectric conversion region 36a contributes to generation of an AC voltage.

  An example of the method for manufacturing the power generating element 3 will be briefly described below.

  In manufacturing the power generating element 3, first, a silicon substrate 31 is prepared, and then a first step of forming the substrate 30 by forming an insulating film 32 on the silicon substrate 31 is performed. In the first step, an insulating film 32 is formed on the silicon substrate 31 using a thermal oxidation method or the like. In the first step, not limited to the thermal oxidation method, for example, a CVD method or the like may be employed.

  After the first step, a second step of forming a first conductive layer serving as a basis for the first electrode 33 and the first wiring 41 is performed on the entire surface of the substrate 30 on the surface 30a side, and then the piezoelectric layer 34 is formed. A third step of forming a piezoelectric material layer that is the basis of the above is performed. In the second step, the sputtering method is employed as a method for forming the first conductive layer, but the present invention is not limited thereto, and for example, a CVD method, a vapor deposition method, or the like may be employed. In the third step, the sputtering method is employed as a method for forming the piezoelectric material layer. However, the method is not limited thereto, and for example, a CVD method, a sol-gel method, or the like may be employed.

  After the third step, a fourth step of patterning the piezoelectric material layer into a predetermined shape of the piezoelectric layer 34 is performed, and then the first conductive layer is formed into a predetermined shape of the first electrode 33 and the first wiring 41. A fifth step of patterning is performed. In the fourth step, the piezoelectric material layer is patterned using a lithography technique and an etching technique. In the fifth step, the first conductive layer is patterned using a lithography technique and an etching technique.

  After the fifth step, a sixth step of forming the insulating layer 37 on the surface 30a side of the substrate 30 is performed. After the sixth step, a seventh step is performed in which a second conductive layer serving as a basis for the second electrode 35 and the second wiring 42 is formed on the entire surface of the substrate 30 on the surface 30a side. After the seventh step, an eighth step of patterning the second conductive layer into a predetermined shape of the second electrode 35 and the second wiring 42 is performed. In the sixth step, the insulating layer 37 is formed by using the lift-off method, but the insulating layer 37 may be formed by using, for example, a thin film forming technique, a lithography technique, and an etching technique. . In the seventh step, the sputtering method is employed as a method for forming the second conductive layer, but the present invention is not limited thereto, and for example, a CVD method, a vapor deposition method, or the like may be employed. In the eighth step, the second conductive layer is patterned using a lithography technique and an etching technique.

  After the eighth step, a ninth step is performed in which a third conductive layer serving as a basis for the first pad electrode 38 and the second pad electrode 39 is formed on the entire surface of the substrate 30 on the surface 30a side. After the ninth step, a tenth step of patterning the third conductive layer into a predetermined shape of the first pad electrode 38 and the second pad electrode 39 is performed.

  In manufacturing the power generation element 3, the process until the end of the tenth step is performed at the wafer level, and then the dicing process is performed to divide the power generation element 3 into individual power generation elements 3.

  In the power generating element 3, the piezoelectric conversion portion 36 has the piezoelectric conversion region 36 a described above, and the first end of the piezoelectric conversion region 36 a in the first direction along the length direction of the cantilever portion 22 has the support portion 21 and the cantilever. It is preferable that they are arranged so as to be aligned with the first boundary with the portion 22. Thus, the power generation device 1 can increase the area of the piezoelectric conversion region 36a and increase the power generation efficiency compared to the case where the first end of the piezoelectric conversion region 36a in the first direction is closer to the cantilever part 22 side than the first boundary. It becomes possible to improve. Further, the power generation device 1 does not contribute to power generation in the piezoelectric conversion region 36a as compared with the case where the first end of the piezoelectric conversion region 36a in the first direction is closer to the support portion 21 than the first boundary. The part which becomes can be reduced and it becomes possible to improve electric power generation efficiency. The hole 24 of the base 2 is preferably formed with an opening size that is aligned with the vertical projection region of the piezoelectric conversion region 36a.

  Since the power generation device 1 forms the support portion 21, the cantilever portion 22, and the flow path 23 on the base 2, which is a separate member from the power generation element 3, a silicon wafer is adopted as a wafer on which the substrate 30 of the power generation element 3 is based It becomes possible to do. Therefore, the power generation device 1 can achieve cost reduction compared to the case where an SOI wafer is used as a wafer on which the substrate 30 of the power generation element 3 is based.

  In the power generating element 3, it is preferable that the first end portion 301 of the substrate 30 in the first direction is bonded to the support portion 21 and the second end portion 302 of the substrate 30 in the first direction is bonded to the cantilever portion 22. Thereby, the power generation device 1 can improve the power generation efficiency. Here, in the power generating element 3, it is preferable that the piezoelectric conversion portion 36 is formed on a portion of the substrate 30 between the first end portion 301 and the second end portion 302. In the power generating element 3, the first end portion 301 of the substrate 30 is bonded to the support portion 21 of the base 2 via the first bonding portion 51, and the second end portion 302 of the substrate 30 is bonded to the second bonding portion 52. The base 2 can be joined to the cantilever portion 22. As a material for the first bonding portion 51 and the second bonding portion 52, for example, an organic resin-based die bonding material, AuSn solder, low melting point glass, or the like can be used. Examples of the organic resin die bonding material include acrylic adhesives and epoxy adhesives.

  The power generation device 1 may be configured such that the support portion 21 is thicker than the cantilever portion 22. Thereby, the power generation device 1 can further increase the rigidity of the support portion 21, and can suppress the vibration energy of the cantilever portion 22 from being dissipated from the support portion 21. Therefore, the power generation device 1 can improve the power generation efficiency.

  The power generating element 3 may be configured such that the thickness of each of the first end portion 301 and the second end portion 302 in the substrate 30 is thicker than the thickness of the portion immediately below the piezoelectric conversion portion 36 in the substrate 30. Thereby, the power generation device 1 can suppress the vibration energy of the portion of the substrate 30 immediately below the piezoelectric conversion unit 36 from being dissipated from the first end 301 and the second end 302 of the substrate 30. Therefore, the power generation device 1 can improve the power generation efficiency.

  As described above, the power generation device 1 can be configured such that the cantilever portion 22 includes the beam portion 25 and the weight portion 26. Here, in the power generation device 1, the first end 25a in the length direction of the beam portion 25 is fixed to the support portion 21, and the second end 25b in the length direction of the beam portion 25 is fixed to the weight portion 26. It is preferable that the second end portion 302 of the substrate 30 of the power generation element 3 is joined to the weight portion 26. In the power generation device 1, since the cantilever portion 22 includes the weight portion 26, the inertial force when the cantilever portion 22 vibrates can be increased and the amplitude of the cantilever portion 22 can be increased compared to the case where the weight portion 26 is not provided. It becomes possible to do. In addition, since the cantilever portion 22 includes the weight portion 26, the power generation device 1 can intensively generate distortion in the beam portion 25 and the power generation element 3 when the cantilever portion 22 vibrates, thereby reducing power generation efficiency. It is possible to improve.

  The base 2 is not limited to a configuration formed by a metal substrate. For example, the base 2 may be formed of a resin substrate. Thereby, the power generation device 1 can achieve cost reduction compared to the case where the base 2 is formed of a metal substrate. As the material of the resin substrate, for example, acrylic resin, polyimide, or the like can be employed.

  Incidentally, the power generating element 3 includes the first pad electrode 38 and the second pad electrode 39 as described above. Here, the base 2 is formed of a printed circuit board, and a first conductor portion (not shown) and a second conductor portion (not shown) to which the first pad electrode 38 and the second pad electrode 39 are electrically connected, respectively. ). As a result, the power generation apparatus 1 can be used by mounting the electronic component or the like to which the power generation element 3 is electrically connected to the base 2.

  The configuration of the present invention has been described above based on the embodiment and the like. However, the present invention is not limited to the configuration of the embodiment and the like, and for example, is a configuration in which partial configurations such as the embodiment are appropriately combined. May be. In addition, the materials, numerical values, and the like described in the embodiments and the like are merely preferable examples and are not limited thereto. Furthermore, the present invention can be appropriately modified in configuration without departing from the scope of its technical idea.

DESCRIPTION OF SYMBOLS 1 Power generator 2 Base 3 Power generating element 21 Support part 22 Cantilever part 23 Flow path 24 Hole 25 Beam part 25a 1st end 25b 2nd end 26 Weight part 30 Substrate 30a Surface 36 Piezoelectric conversion part 36a Piezoelectric conversion area 38 1st pad electrode 39 Second pad electrode 301 First end 302 Second end

Claims (10)

A base and a power generation element,
The base includes a frame-shaped support portion, a cantilever portion that is disposed inside the support portion and is swingably supported by the support portion, and a gap formed between the support portion and the cantilever portion. Comprising a flow path configured,
The power generating element includes a substrate that is smaller than the base and has flexibility, and a piezoelectric transducer formed on the surface of the substrate,
The power generating element is overlapped and joined to the base, and in plan view, is separated from the flow path and straddles the support portion and the cantilever portion,
The cantilever part is formed with a hole penetrating in the thickness direction of the cantilever part in the vertical projection region of the power generation element.
A power generator characterized by that. The base is formed of a metal substrate;
The power generator according to claim 1. The base is formed of a resin substrate;
The power generator according to claim 1. The power generating element includes a first pad electrode and a second pad electrode,
The base is formed of a printed circuit board and includes a first conductor portion and a second conductor portion to which the first pad electrode and the second pad electrode are electrically connected, respectively.
The power generator according to claim 1. The minimum width of the flow path is 20 μm or more and 100 μm or less.
The power generator according to any one of claims 1 to 4, wherein the power generator is provided. The piezoelectric conversion unit includes a piezoelectric conversion region, and a first end of the piezoelectric conversion region in a first direction along a length direction of the cantilever unit is a first boundary between the support unit and the cantilever unit. Arranged to align,
The power generation device according to claim 1, wherein the power generation device is a power generation device. In the power generating element, a first end of the substrate in the first direction is joined to the support portion, and a second end of the substrate in the first direction is joined to the cantilever portion.
The power generator according to claim 6. The thickness of the support part is thicker than the thickness of the cantilever part,
The power generator according to claim 7. In the power generation element, the thickness of each of the first end and the second end of the substrate is thicker than the thickness of the portion immediately below the piezoelectric conversion unit of the substrate.
The power generator according to claim 7 or 8, wherein The cantilever part includes a beam part and a weight part, a first end in the length direction of the beam part is fixed to the support part, and a second end in the length direction of the beam part is the weight part. Is fixed to
In the power generating element, the second end portion of the substrate is joined to the weight portion.
The power generation device according to any one of claims 7 to 9, characterized by the above.

Images