Vibration power generation device, method of manufacturing vibration power generation device, and sensor module

Abstract

To provide a vibration power generation device that can enhance adhesion strength in connection of a connection wire and a substrate, a method of manufacturing the vibration power generation device and a sensor module.SOLUTION: A vibration power generation device comprises: a substrate (12) having a first plane and a second plane; a first piezoelectric part and a first connection part (19A) on the first plane; and a second piezoelectric part and a second connection part (19B) on the second plane. The second connection part is provided so as not to overlap with the first connection part in plan view. The first and second connection parts are each provided on the first plane or the second plane of the substrate, and each include: an electrode layer (31) that is electrically connected to the first or second piezoelectric part; a resin layer (32) that contains conductive resin and is electrically connected to the electrode layer; and a connection line layer (33) that contains a part of a connection line connected to a load and is electrically connected to the resin layer.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a vibration power generation device, a method for manufacturing a vibration power generation device, and a sensor module. [Background technology]

[0002] There are known vibration power generation devices that generate electric energy from vibration energy in the surrounding environment, and sensor modules that use vibration power generation devices. For example, Patent Document 1 discloses a power generation element having a structure in which multiple plate-like flexible bodies and a weight body are combined. In addition, for example, Patent Document 2 discloses a power generation device that includes multiple piezoelectric elements and a connecting member that connects the multiple piezoelectric elements, and can efficiently convert vibration energy into electric energy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-103170 A [Patent Document 2] JP 2020-061938 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a vibration power generation device, the substrate vibrates, so the adhesive strength of the connection wires for supplying power to an external load may not be sufficient if they are attached to the substrate using a metal paste.

[0005] In view of the above circumstances, an object of the present disclosure is to provide a vibration power generation device that can increase the adhesive strength between a connection wire and a substrate, a manufacturing method for a vibration power generation device, and a sensor module. [Means for solving the problem]

[0006] (1) A vibration power generation device according to an embodiment of the present disclosure, A substrate having a first plane and a second plane opposite to the first plane; A first piezoelectric portion provided on the first plane and including a piezoelectric body; A second piezoelectric portion provided on the second plane and including a piezoelectric body; a first connection portion in the first plane region, the first connection portion being electrically connected to supply power generated in the piezoelectric body of the first piezoelectric portion to a load outside the substrate; a second connection portion in the second plane area, where an electrical connection is made to supply power generated in the piezoelectric body of the second piezoelectric portion to the load, the second connection portion is provided so as not to overlap with the first connection portion in a plan view, Each of the first connection portion and the second connection portion is an electrode layer provided on the first plane or the second plane of the substrate and electrically connected to the first piezoelectric portion or the second piezoelectric portion; a resin layer containing a conductive resin and electrically connected to the electrode layer; a connection line layer including a portion of a connection line connected to the load and electrically connected to the resin layer.

[0007] (2) As an embodiment of the present disclosure, in (1), The resin layer is formed by pressing the conductive resin between the electrode layer and the connection line layer.

[0008] (3) As an embodiment of the present disclosure, in (1) or (2), The substrate is a metal substrate or a resin substrate.

[0009] (4) As an embodiment of the present disclosure, in any one of (1) to (3), the conductive resin is a resin containing conductive particles, the electrode layer includes a plurality of connection terminals; The distance between one of the plurality of connection terminals and an adjacent connection terminal is greater than the particle size of the conductive particles.

[0010] (5) As an embodiment of the present disclosure, in (4), The height of each of the plurality of connection terminals from the first plane or the second plane is greater than the particle size of the conductive particles.

[0011] (6) As an embodiment of the present disclosure, in any one of (1) to (5), The first connection portion and the second connection portion are symmetrical with respect to the substrate.

[0012] (7) A method for manufacturing a vibration power generation device according to an embodiment of the present disclosure includes: A method for manufacturing a vibration power generation device comprising: a substrate having a first plane and a second plane opposite to the first plane; a first piezoelectric portion provided on the first plane and having a piezoelectric body; a second piezoelectric portion provided on the second plane and having a piezoelectric body; a first connection portion in a region of the first plane that provides an electrical connection for supplying power generated in the piezoelectric body of the first piezoelectric portion to a load outside the substrate; and a second connection portion in a region of the second plane that provides an electrical connection for supplying power generated in the piezoelectric body of the second piezoelectric portion to the load, setting the second connection portion so as not to overlap the first connection portion in a plan view; The method includes a step of forming, by compression bonding, a resin layer containing a conductive resin between an electrode layer provided on the first plane or the second plane of the substrate and electrically connected to the first piezoelectric portion or the second piezoelectric portion, and a connection line layer including a portion of a connection line connected to the load, in each of the first connection portion and the second connection portion.

[0013] (8) A sensor module according to an embodiment of the present disclosure includes: A substrate having a first plane and a second plane opposite to the first plane; A first piezoelectric portion provided on the first plane and including a piezoelectric body; A second piezoelectric portion provided on the second plane and including a piezoelectric body; a first connection portion in the first plane region, the first connection portion being electrically connected to supply power generated in the piezoelectric body of the first piezoelectric portion to a load outside the substrate; a second connection portion in the second plane area, where an electrical connection is made to supply power generated in the piezoelectric body of the second piezoelectric portion to the load, the second connection portion is provided so as not to overlap with the first connection portion in a plan view, Each of the first connection portion and the second connection portion is an electrode layer provided on the first plane or the second plane of the substrate and electrically connected to the first piezoelectric portion or the second piezoelectric portion; a resin layer containing a conductive resin and electrically connected to the electrode layer; a connection line layer including a portion of a connection line connected to the load and electrically connected to the resin layer. Effect of the Invention

[0014] According to the present disclosure, it is possible to provide a vibration power generation device capable of increasing the adhesive strength in connecting a connection line and a substrate, a method for manufacturing a vibration power generation device, and a sensor module. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a functional block diagram showing a schematic configuration of a sensor module including a vibration power generation device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view taken along the vibration direction of a vibration power generation device according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is a top view for explaining the connection between the connection wire and the substrate. [Figure 4] FIG. 4 is a cross-sectional view for explaining the connection between the connection wire and the substrate. [Diagram 5] FIG. 5 is a diagram for explaining the crimping for forming the connection portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, a vibration power generation device, a manufacturing method for a vibration power generation device, and a sensor module according to an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are given the same reference numerals. In the description of this embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate. However, the drawings are schematic. For example, the relationship between thickness and width is different from the actual one. In addition, the embodiments shown below are examples of devices for embodying the technical ideas of the present disclosure, and do not limit the shape, structure, arrangement, etc. of the components to those described below.

[0017] 1 is a functional block diagram showing a schematic configuration of a sensor module 21 including a vibration power generation device 10 according to this embodiment. The sensor module 21 includes a sensor 22, a communication unit 23, a controller 24, and the vibration power generation device 10. The sensor module 21 may detect various conditions without receiving power from an external source and transmit the detection results to an external device. The sensor module 21 is used in, for example, bridges, trains, vehicles, power plants, outdoor machinery, factory equipment, etc.

[0018] The sensor 22 is, for example, a vibration sensor, a temperature sensor, a pressure sensor, etc., and detects an arbitrary state of an arbitrary object. The sensor 22 is driven by power supplied from the vibration power generation device 10.

[0019] The communication unit 23 is an interface that communicates with an external device via a network. The communication unit 23 may include, for example, a communication module that communicates with an external device via a network. The communication unit 23 transmits, for example, a detection value indicating an arbitrary state detected by the sensor 22 to the external device as a signal. Here, the detection value is a numerical representation of the detection result. The communication unit 23 may receive a command from the external device and transmit it to the controller 24. The communication unit 23 is driven by power supplied from the vibration power generation device 10.

[0020] The controller 24 controls the operation of the sensor 22 and the communication unit 23. For example, the controller 24 may be configured to include one or more processors and a memory. The processor may include a general-purpose processor that loads a specific program to execute a specific function and a dedicated processor specialized for a specific process. The dedicated processor may include an application specific integrated circuit (ASIC). The processor may include a programmable logic device (PLD). The PLD may include a field-programmable gate array (FPGA). The controller 24 may be either a system-on-a-chip (SoC) or a system in a package (SiP) in which one or more processors work together. The controller 24 is driven by power supplied from the vibration power generation device 10.

[0021] 2 is a cross-sectional view taken along the vibration direction of the vibration power generation device 10 according to this embodiment. The vibration power generation device 10 includes a weight section 11, a substrate 12, a piezoelectric section 17, and a fixed section 13. The vibration power generation device 10 may further include a housing 14.

[0022] Plummet 11 applies an inertial force to increase the vibration of substrate 12 supported by fixed portion 13. Plummet 11 may be provided on a surface of substrate 12 on the vibration direction side determined as the direction in which substrate 12 is vibrated.

[0023] Here, FIG. 2 shows orthogonal coordinates. These orthogonal coordinates are also used in FIG. 3 and FIG. 4, which will be referred to later. The z-axis direction is the direction in which the weight 11 vibrates during normal use, that is, the vibration direction. The z-axis direction is also the thickness direction (height direction) of the vibration power generation device 10. The x-axis direction corresponds to the width direction of the vibration power generation device 10. The y-axis direction corresponds to the depth direction of the vibration power generation device 10. In the following, the relative positional relationship may be described with the positive z-axis direction being the top and the negative z-axis direction being the bottom. For example, in FIG. 2, the fixing part 13 is located above and below the substrate 12 and supports the fixing part 13. In the following, the view of the xy plane from the front may be referred to as a planar view. For example, the view when the positional relationship on the main surface of the substrate 12 is described with a line of sight toward the negative z-axis direction, through the weight 11, the fixing part 13, and the housing 14, is a planar view. Here, the main surface is the surface with the largest area.

[0024] Each of the components of the vibration power generation device 10 will be described below. The weight portion 11 may have a main body portion 15 and a neck portion 16. The main body portion 15 is, for example, plate-shaped. The neck portion 16 may be columnar, such as a cylinder, and thinner than the main body portion 15. The axis of the neck portion 16 may pass through the center of the main body portion 15 and be perpendicular to the plate-shaped main body portion 15. The neck portion 16 may be fixed to the substrate 12 so that the axis is parallel to the vibration direction.

[0025] The substrate 12 may be a thin plate, and the plate surface may be perpendicular to the vibration direction. The substrate 12 may be a metal substrate or a resin substrate as long as it functions as a vibrating part. If the substrate 12 is a metal substrate, the substrate 12 may be made of, for example, SUS.

[0026] The piezoelectric portion 17 is provided on the substrate 12. The piezoelectric portion 17 may be disposed at a position where stress is generated by vibration of the substrate 12. The piezoelectric portion 17 may be provided on the surface of the substrate 12 on the vibration direction side. A plurality of piezoelectric portions 17 may be provided so as to be aligned along the extending direction of the substrate 12. A plurality of piezoelectric portions 17 may be provided on the surfaces on both sides of the vibration direction of the substrate 12. In other words, a plurality of piezoelectric portions 17 may be provided on the upper and lower surfaces (both main surfaces) of the substrate 12 in the z-axis direction.

[0027] The piezoelectric section 17 includes a piezoelectric body and an electrode. When the substrate 12 deforms due to vibration, the piezoelectric section 17 deforms together with the substrate 12. As a result, when the substrate 12 vibrates, stress is applied to the piezoelectric body in the piezoelectric section 17, and this stress is converted into electric power by the piezoelectric effect of the piezoelectric body. The electric power generated by the piezoelectric body is output to the outside of the vibration power generation device 10 via the electrode.

[0028] In this embodiment, the electric power generated by the piezoelectric body is further output to the outside of the vibration power generation device 10 via a connection part 19 (see FIG. 3). The connection part 19 will be described in detail later.

[0029] The fixing part 13 fixes the substrate 12 by an arbitrary method. The fixing part 13 is preferably formed of a member with high rigidity, and may be formed of, for example, a simple metal such as Fe, an alloy containing Fe, Ni, Cr, or the like, or a nonmetallic material such as SUS or resin.

[0030] The housing 14 may house the weight portion 11 and the substrate 12. The housing 14 may support the fixed portion 13.

[0031] Here, as shown in Fig. 2, the substrate 12 has two main surfaces, a first plane 12A and a second plane 12B. The second plane 12B is the opposite surface to the first plane 12A. The piezoelectric portions 17 can be distinguished by the surface on which they are provided. The piezoelectric portion 17 provided on the first plane 12A may be referred to as a first piezoelectric portion 17A. The piezoelectric portion 17 provided on the second plane 12B may be referred to as a second piezoelectric portion 17B.

[0032] As described above, when the substrate 12 is deformed by vibration, the piezoelectric portion 17 also deforms, and stress is applied to the piezoelectric body, generating electricity. However, as the substrate 12 deforms, force is also applied to the portion that performs electrical connection. Conventionally, a connection line 30 (see FIG. 3) for supplying power to an external load has been adhered to the substrate with a metal paste (silver paste as an example). However, the connection line 30 can peel off due to deformation of the substrate 12, and so an adhesion method with even higher adhesive strength has been desired.

[0033] 3 and 4 are a top view and a cross-sectional view for explaining the connection between the connection wire 30 and the substrate 12. The vibration power generation device 10 according to this embodiment includes the substrate 12, a first piezoelectric part 17A provided on the first plane 12A and including a piezoelectric body, a second piezoelectric part 17B provided on the second plane 12B and including a piezoelectric body, and a connection part 19. The connection part 19 includes a first connection part 19A which is an area of ​​the first plane 12A, and a second connection part 19B which is an area of ​​the second plane 12B. As shown in FIG. 3, the first connection part 19A provides an electrical connection for supplying the electric power generated in the piezoelectric body of the first piezoelectric part 17A to the load. The second connection part 19B provides an electrical connection for supplying the electric power generated in the piezoelectric body of the second piezoelectric part 17B to the load. Here, the load is an external device of the substrate 12, such as, but not limited to, the sensor 22, the communication part 23, or the controller 24. The connection line 30 is a wiring for supplying power to a load, and may be, for example, a flexible printed circuit (FPC).

[0034] As shown in FIG. 4, each of the first connection portion 19A and the second connection portion 19B includes an electrode layer 31, a resin layer 32, and a connection line layer 33. The electrode layer 31 is provided on the first plane 12A or the second plane 12B of the substrate 12, and is electrically connected to the first piezoelectric portion 17A or the second piezoelectric portion 17B. The resin layer 32 includes a conductive resin, and is electrically connected to the electrode layer 31. The connection line layer 33 includes a part of the connection line 30 connected to the load, and is electrically connected to the resin layer 32. As shown in FIG. 4, in this embodiment, the first connection portion 19A and the second connection portion 19B are symmetrical with respect to the substrate 12. That is, the first connection portion 19A and the second connection portion 19B have the same structure, but are arranged symmetrically with respect to both the x-axis direction and the z-axis direction. Such a symmetrical configuration can suppress deviation of the center of gravity of the vibration power generation device 10 from the design value.

[0035] Here, the conductive resin contained in the resin layer 32 may be a resin containing conductive particles 34. As an example of the conductive resin, an anisotropic conductive film (ACF) can be used. Here, the electrode layer 31 may be configured to include a plurality of connection terminals 35. As shown in FIG. 4, the plurality of connection terminals 35 are arranged at a predetermined interval. In this case, the distance (predetermined interval) between one of the plurality of connection terminals 35 and the adjacent connection terminal 35 is set to be larger than the particle diameter of the conductive particles 34. In addition, the height (length in the z-axis direction) of each of the plurality of connection terminals 35 from the first plane 12A or the second plane 12B is set to be larger than the particle diameter of the conductive particles 34. This is to prevent a short circuit caused by the conductive particles 34. Here, in FIG. 4 and FIG. 5, the conductive particles 34 are drawn large for ease of viewing, and are actually minute particles that are sufficiently smaller than the height of the connection terminals 35.

[0036] As shown in FIG. 5, the resin layer 32 is formed by compressing a conductive resin between the electrode layer 31 and the connection line layer 33. The conductive resin is pressurized and heated, and thus the adhesive strength can be increased compared to the method of adhering the connection line 30 to the substrate by a metal paste. However, when the conductive resin is pressure-bonded, the surface of the substrate 12 opposite to the resin layer 32 needs to be flat. For example, when the resin layer 32 of the first connection portion 19A is formed, the second plane 12B of the substrate 12 needs to be flat. Also, when the resin layer 32 of the second connection portion 19B is formed, the first plane 12A of the substrate 12 needs to be flat. Therefore, when the first connection portion 19A and the second connection portion 19B are set at positions where they overlap in the x-axis direction or the y-axis direction, the conductive resin cannot be pressure-bonded. In the vibration power generation device 10 according to this embodiment, the second connection portion 19B is provided so as not to overlap the first connection portion 19A in a plan view. Therefore, the resin layer 32 is formed by pressure-bonding the conductive resin, and the adhesive strength can be increased.

[0037] The manufacturing method of the vibration power generation device 10 includes at least a first step and a second step. The first step is a step of setting the second connection portion 19B so as not to overlap the first connection portion 19A in a plan view. The second step is a step of forming a resin layer 32 containing a conductive resin by compression bonding between the electrode layer 31 and the connection line layer 33 including a part of the connection line 30 connected to the load. The second step is performed for each of the first connection portion 19A and the second connection portion 19B.

[0038] As described above, the vibration power generation device 10, the manufacturing method for the vibration power generation device 10, and the sensor module 21 according to the present embodiment can increase the adhesive strength in the connection between the connection line 30 and the substrate 12 by using the above-mentioned configuration and process. Therefore, even if the substrate 12 continues to vibrate, problems such as the connection line 30 coming off the substrate 12 are unlikely to occur due to the high adhesive strength, and the reliability of the vibration power generation device 10 and the sensor module 21 can be increased.

[0039] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications or corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are included in the scope of the present disclosure.

[0040] In the above embodiment, the sensor module 21 has been described as having the configuration shown in Fig. 1, but it is not necessary to include all of the components. For example, the sensor module 21 may be configured not to include the sensor 22, and the vibration power generation device 10 may also function as the sensor 22. For example, the vibration power generation device 10 may output a signal indicating the strength of vibration together with the power generated by the piezoelectric body in the piezoelectric section 17. For example, the controller 24 may calculate the speed of a moving object on which the sensor module 21 is mounted based on the signal indicating the strength of vibration, thereby realizing the function of a speed sensor. [Explanation of symbols]

[0041] 10. Power-generating vibration device 11 Weight 12 Substrate 12A 1st plane 12B 2nd plane 13 Fixed part 14. Chassis 15 Main body 16 neck 17 Piezoelectric section 17A First Piezoelectric Part 17B Second piezoelectric part 19 Connection 19A 1st Connection 19B Second connection part 21 Sensor Module 22 Sensors 23 Communications Department 24 Controller 30 Connection Line 31 Electrode layer 32 Resin layer 33 Connection Line Layer 34 Conductive particles 35 Connection terminal

Claims

1. a substrate having a first plane and a second plane opposite to the first plane; A first piezoelectric portion provided on the first plane and including a piezoelectric body; A second piezoelectric portion provided on the second plane and including a piezoelectric body; a first connection portion in the first plane region, the first connection portion being electrically connected to supply power generated in the piezoelectric body of the first piezoelectric portion to a load outside the substrate; a second connection portion in the second plane region, where an electrical connection is made to supply power generated in the piezoelectric body of the second piezoelectric portion to the load, The second connection portion is provided so as not to overlap with the first connection portion in a plan view, Each of the first connection portion and the second connection portion is an electrode layer provided on the first plane or the second plane of the substrate, the electrode layer being electrically connected to the first piezoelectric portion or the second piezoelectric portion; a resin layer containing a conductive resin and electrically connected to the electrode layer; a connection line layer including a portion of a connection line connected to the load and electrically connected to the resin layer.

2. The vibration power generation device according to claim 1 , wherein the resin layer is formed by pressing the conductive resin between the electrode layer and the connection line layer.

3. The vibration power generation device according to claim 1 , wherein the substrate is a metal substrate or a resin substrate.

4. the conductive resin is a resin containing conductive particles, the electrode layer includes a plurality of connection terminals; The vibration power generation device according to claim 1 , wherein a distance between one of the plurality of connection terminals and an adjacent connection terminal is greater than a particle size of the conductive particles.

5. The vibration power generation device according to claim 4 , wherein a height of each of the plurality of connection terminals from the first plane or the second plane is greater than a particle size of the conductive particles.

6. The vibration power generation device according to claim 1 , wherein the first connection portion and the second connection portion are symmetrical with respect to the substrate.

7. A method for manufacturing a vibration power generation device comprising: a substrate having a first plane and a second plane opposite to the first plane; a first piezoelectric portion provided on the first plane and including a piezoelectric body; a second piezoelectric portion provided on the second plane and including a piezoelectric body; a first connection portion in a region of the first plane that provides electrical connection for supplying power generated in the piezoelectric body of the first piezoelectric portion to a load outside the substrate; and a second connection portion in a region of the second plane that provides electrical connection for supplying power generated in the piezoelectric body of the second piezoelectric portion to the load, setting the second connection portion so as not to overlap the first connection portion in a plan view; a step of forming, by compression, a resin layer containing a conductive resin between an electrode layer provided on the first plane or the second plane of the substrate and electrically connected to the first piezoelectric portion or the second piezoelectric portion, and a connection line layer including a part of a connection line connected to the load, in each of the first connection portion and the second connection portion.

8. a substrate having a first plane and a second plane opposite to the first plane; A first piezoelectric portion provided on the first plane and including a piezoelectric body; A second piezoelectric portion provided on the second plane and including a piezoelectric body; In the region of the first plane, the electric power generated in the piezoelectric body of the first piezoelectric portion is supplied to the outside of the substrate. a first connection portion for providing electrical connection to a load; a second connection portion in the second plane region, where an electrical connection is made to supply power generated in the piezoelectric body of the second piezoelectric portion to the load, The second connection portion is provided so as not to overlap with the first connection portion in a plan view, Each of the first connection portion and the second connection portion is an electrode layer provided on the first plane or the second plane of the substrate, the electrode layer being electrically connected to the first piezoelectric portion or the second piezoelectric portion; a resin layer containing a conductive resin and electrically connected to the electrode layer; a connection line layer including a portion of a connection line connected to the load and electrically connected to the resin layer.

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