Vibration power generation element

Abstract

The objective is to provide a vibration power generation element that can improve reliability by simultaneously solving conventional problems 1 (damage due to compressive force load on the stopper) and 2 (increased manufacturing difficulty due to extremely narrow slits) by devising the arrangement of the deformation limiting means for the stopper. [Solution] The vibration power generation element (100A) comprises a base (7), a movable part (20), a fixed part (10), a fixed support part (30) fixed to the base (7) and having a stopper part (31) that can contact the end face (22a) of the movable part (20), an elastic support part (40), and a stopper part deformation limiting means (25). The stopper part deformation limiting means (25) is provided on the movable part (20) which is positioned opposite the fixed support part (30) and is located on a central axis Lc parallel to the vibration direction of the movable part (20) passing through the stopper contact part (31c), and away from the end face (22a) of the movable part (20).

Description

Technical Field

[0001] The present invention relates to a vibration power generation element provided with a stopper portion deformation restricting means provided on a movable portion that is separated from an end surface of the movable portion and disposed opposite to a fixed support portion on a central axis passing through a stopper contact portion.

Background Art

[0002] Some vibration power generation elements are provided with stopper portions on both sides of the vibration range of the movable portion in order to limit the vibration range of the movable portion. This stopper portion functions when the vibration range of the movable portion becomes larger than a predetermined value. When the end portion of the movable portion abuts against the stopper portion, a restoring force is generated in a direction in which the vibration range of the movable portion becomes smaller due to the deformation of the stopper portion.

[0003] Here, the stopper portion has an elongated shape extending along the end surface of the movable portion. Therefore, when the vibration range of the movable portion becomes relatively large, a shear stress larger than the allowable displacement amount, that is, a relatively large shear stress is generated in the stopper portion that abuts against the movable portion, and there is a risk of cracks or breakage.

[0004] On the other hand, for example, in Patent Document 1, as shown in FIG. 8, there is a vibration power generation device 801 in which a vibration power generation element (hereinafter referred to as “conventional vibration power generation element”) 800 is enclosed in a vacuum package, which has a base 807, a movable electrode 821, and a movable portion 820 that can vibrate in a predetermined direction, a fixed portion 810 that is fixed to the base 807 and provided with a fixed electrode 811 facing the movable electrode 821, a fixed support portion 830 that is fixed to the base 807 and has a stopper portion 831 that can abut against an end surface 822a (see FIG. 9) of the movable portion 820, and an elastic support portion 840 that is interposed between the fixed support portion 830 and the movable portion 820 and supports the movable portion 820.

[0005] Furthermore, Patent Document 1 describes a device in which, as shown in Figure 9, a convex portion 833, which is a means for limiting the deformation of the stopper portion, is positioned between the central band portion 822, which is a movable portion 820, and the stopper portion 831 via a slit 832 on the central axis Lc of the band portion 822. The movable portion 820 moves in the direction of the white arrow in Figure 9, causing one end surface 822a of the central band portion 822 to come into contact with the stopper portion 831, and the stopper portion 831 further comes into contact with the convex portion 833, thereby limiting the deformation of the stopper portion 831.

[0006] Thus, when the stopper portion 831 further contacts the protrusion 833, the stopper portion 831 is subjected to a pulsed compressive force generated by being sandwiched between the central band portion 822 and the protrusion 833, which could cause it to break (hereinafter referred to as "Conventional Problem 1 (Damage due to compressive force applied to the stopper portion)").

[0007] Furthermore, the width Cr0'' of the slit 832 defines the maximum displacement of the stopper portion 831 in the X-axis direction, and since it needs to be set to be less than or equal to the allowable displacement of the stopper portion 831 (for example, 10 μm), it is made extremely narrow.

[0008] Therefore, creating these extremely narrow slits 832 with a uniform width would be extremely difficult in the MEMS manufacturing process and could become a bottleneck in the manufacturing process (hereinafter referred to as "Conventional Problem 2 (Increased Manufacturing Difficulty Due to Extremely Narrow Slits)"). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2021-62428 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The object of the present invention is to provide a vibration power generation element that can improve reliability by simultaneously solving conventional problems 1 (damage due to compressive force load on the stopper portion) and 2 (increased manufacturing difficulty due to extremely narrow slits) by devising the arrangement of the stopper portion deformation limiting means. [Means for solving the problem]

[0011] To solve the above problems, a base is provided; a movable part having a movable electrode and capable of vibrating in a predetermined direction; a fixed part fixed to the base and provided opposite the movable electrode and having a fixed electrode; a fixed support part fixed to the base and having a stopper part that can contact the end face of the movable part; an elastic support part interposed between the fixed support part and the movable part and supporting the movable part; and when the end face of the movable part is in contact with the stopper part, the deformation of the stopper part is controlled by the movable part contacting the fixed support part. A vibration power generation element comprising a means for limiting the deformation of a stopper portion, wherein the stopper portion extends in a direction perpendicular to the vibration direction of the movable portion and has both ends connected to the fixed support portion, and a stopper contact portion that can contact the end face of the movable portion, and the stopper portion deformation limiting means is provided on the movable portion which is positioned opposite to the fixed support portion, and is spaced apart from the end face of the movable portion when viewed from a direction perpendicular to the vibration plane of the movable portion, on a central axis parallel to the vibration direction of the movable portion passing through the stopper contact portion, and on the movable portion.

[0012] The stopper deformation limiting means may be provided on both the one-direction side and the other-direction side in the vibration direction of the movable part, with the stopper deformation limiting means on the one-direction side restricting the displacement of the movable part in either the one-direction side or the other-direction side, and the stopper deformation limiting means on the other-direction side restricting the displacement of the movable part in either the one-direction side or the other-direction side.

[0013] Furthermore, in the above-described vibration power generation element, the stopper portion deformation limiting means is interposed between the movable portion and the elastic support portion and is provided to protrude from the movable portion to the elastic support portion, and the protruding portion may have a larger cross-sectional area than the elastic support portion.

[0014] Furthermore, in the above-described vibration power generation element, the stopper portion deformation limiting means may be one side of the protruding portion in the direction of vibration and the other side of the protruding portion in the direction of vibration.

[0015] Furthermore, in the above-mentioned vibration power generation element, the stopper portion deformation limiting means may be an overhang portion that, when viewed from a direction perpendicular to the vibration surface of the movable portion, extends outward in a direction away from the central axis compared to both ends of the movable portion.

[0016] Furthermore, in the above-described vibration power generation element, the stopper portion deformation limiting means may be one side in the vibration direction of at least one of the protruding portions, and the other side in the vibration direction of at least one of the protruding portions.

[0017] Furthermore, in the above-described vibration power generation element, the stopper deformation limiting means may be arranged symmetrically with respect to the central axis passing through the stopper contact portion, when viewed from a direction perpendicular to the vibration plane of the movable portion. [Effects of the Invention]

[0018] According to the present invention, by devising the arrangement of the stopper deformation limiting means, it is possible to provide a vibration power generation element that can simultaneously solve conventional problems 1 (damage due to compressive force load on the stopper) and 2 (increased difficulty of manufacturing due to extremely narrow slits) and improve reliability. [Brief explanation of the drawing]

[0019] [Figure 1] This is a plan view of a vibration power generation element in a vibration power generation device according to the first embodiment of the present invention (vacuum package omitted). [Figure 2] A cross-sectional view taken along line II-II shown in FIG. 1, showing a vibration power generation device in which a vibration power generation element is enclosed in a vacuum package. [Figure 3] A partially enlarged view of the region surrounded by the broken line III of the vibration power generation element shown in FIG. 1. [Figure 4] A schematic diagram of a pseudo-equal beam that has a substantially uniform stress over the entire surface length of the side surface in the stopper portion shown in FIG. 1. (a) represents a pseudo-equal beam with parabolic side surfaces, and (b) represents a pseudo-equal beam with one parabolic side surface and one straight side surface. [Figure 5] A partially enlarged view of the region surrounded by the broken lines Va to d shown in FIG. 1. (a) represents the initial state, (b) represents the state of contact with the stopper portion, (c) represents the state of pushing in the stopper portion, and (d) represents the final state of contact with the stopper portion. [Figure 6] An explanatory diagram of another form of the stopper portion deformation restricting means (protrusion) (corresponding to FIG. 5(a)). [Figure 7] A partially enlarged view of the vibration power generation element according to the second embodiment of the present invention. (a) represents the initial state (corresponding to FIG. 5(a)), (b) represents the state of contact with the stopper portion (corresponding to FIG. 5(b)), (c) represents the state of pushing in the stopper portion (corresponding to FIG. 5(c)), and (d) represents the final state of contact with the stopper portion (corresponding to FIG. 5(d)). [Figure 8] A plan view of a vibration power generation device in which a vibration power generation element is enclosed in a vacuum package according to the prior art. [Figure 9] A partially enlarged view of the region surrounded by the broken line IX of the vibration power generation element shown in FIG. 8.

Modes for Carrying Out the Invention

[0020] Embodiments of the present invention will be described in detail with reference to FIGS. 1 to 7. However, the present invention is not limited to the aspects of this embodiment. Note that the gaps in each figure are exaggerated for the purpose of explanation.

[0021] <Regarding Terms> In this specification and the claims, “left,” “right,” “up,” and “down” refer to the directions shown in Figures 1, 3 to 9. In this specification and the claims, “X-axis direction,” “Y-axis direction,” and “Z-axis direction” refer to the directions shown in Figures 1 to 9. In this specification and the claims, “parabolic” refers to “a parabola, as well as a shape that approximates a parabola.” In this specification and the claims, “one side in the direction of vibration” and “the other side in the direction of vibration” refer to “the positive X-axis direction side” and “the negative X-axis direction side.” In this specification and the claims, “central axis” refers to “a line parallel to the vibration direction of the movable part passing through the stopper contact portion.”

[0022] (First embodiment) <About the configuration of the vibration power generation element> A vibration power generation element 100A according to the first embodiment of the present invention will be described with reference to Figures 1 and 2. This vibration power generation element 100A can be used as a vibration power generation device 1, for example, by being enclosed in a vacuum package as shown in Figure 2. Note that in Figure 1, the vacuum package is omitted, and only the vibration power generation element 100A is shown.

[0023] The vibration power generation element 100A is typically formed using a Silicon On Insulator (SOI) substrate and general MEMS processing technology. As shown in Figure 2, it consists of a three-layer structure in which a base 7 made of Si, a bonding layer 8 made of an inorganic insulating material such as SiO2, and a device layer 9 made of a Si active layer are stacked in the Z direction. The vacuum package consists of a case 2 made of an electrically insulating material (e.g., ceramics) and a top cover 3 that is seam-welded to the upper end of the case 2. The base 7 is fixed to the case 2 by die bonding. The vibration power generation element 100A also includes four fixed parts 10, a movable part 20, two fixed support parts 30, and four elastic support parts 40 in the device layer 9, and each of these configurations will be described in order below.

[0024] Herein, although the details will be described later, in the first embodiment, the stopper deformation limiting means is positioned on the central axis Lc passing through the stopper contact portion 31c and on one end face (end face) 22a of the movable portion 20, and is provided on the movable portion facing the fixed support portion 30. This solves both the conventional problem 1 (damage due to compressive force load on the stopper portion) and the conventional problem 2 (increased difficulty of manufacturing due to extremely narrow slits), thereby improving reliability.

[0025] <Regarding the fixing part> Each fixing portion 10 has a plurality of fixed comb teeth 11, a fixed comb tooth connecting portion 12 that connects the plurality of fixed comb teeth 11, and a lead portion 13. The fixed comb teeth 11 extend in the X-axis direction and are arranged at predetermined intervals in the Y-axis direction. The fixed comb tooth connecting portion 12 extends in the Y-axis direction and connects the plurality of fixed comb teeth 11 arranged in the Y-axis direction. Furthermore, the lead portion 13 extends in a direction perpendicular to the fixed comb tooth connecting portion 12, i.e., in the X-axis direction. A rectangular terminal portion is formed at the tip of this lead portion 13, and an electrode pad 14 is formed on the upper surface of this terminal portion. Each of these electrode pads 14 is connected by a wire (not shown) to an electrode (not shown) provided in the case 2.

[0026] The lead portion 13 and fixed comb tooth connecting portion 12 of each fixed portion 10 are supported by the base 7 via the bonding layer 8. The fixed comb teeth 11 of each fixed portion 10 extend over the region corresponding to the rectangular opening 7a (see Figure 2) provided in the base 7.

[0027] The two fixing parts 10 located on the positive X-axis side of the central band 22, which will be described later, are arranged symmetrically with respect to the central axis Lc of the central band 22, while the other two fixing parts 10 located on the negative X-axis side of the central band 22 are arranged symmetrically with respect to the central axis Lc of the central band 22.

[0028] <Regarding movable parts> The movable part 20 has a plurality of movable comb teeth 21, a central band 22, and a movable comb tooth connecting part 23 that connects the plurality of movable comb teeth 21. The movable comb tooth connecting part 23 extends from the center of the central band 22 in the X-axis direction in the positive Y-axis direction and the negative Y-axis direction, respectively. The movable comb teeth 21 extend from each movable comb tooth connecting part 23 that extends in the positive Y-axis direction and the negative Y-axis direction in the positive X-axis direction or the negative X-axis direction, and are arranged at predetermined intervals in the Y-axis direction. The movable comb teeth 21 that extend in the X-axis direction from each movable comb tooth connecting part 23 and the plurality of fixed comb teeth 11 that extend in the X-axis direction from each fixed comb tooth connecting part 12 are arranged to mesh with each other in the Y-axis direction with a gap in between.

[0029] As shown in Figure 2, weights 24a and 24b are fixed to the upper surface, which is the positive Z-axis side, and the lower surface, which is the negative Z-axis side, of the central band 22 of the movable part 20, respectively, by adhesive or the like. The centers of gravity of weights 24a and 24b are coaxial with the Z-axis, passing through the centers of the X-axis and Y-axis directions of the central band 22. The movable part 20 is positioned in the area corresponding to the opening 7a (see Figure 2) provided in the base 7.

[0030] In the first embodiment, an electret is formed on only one of the fixed part 10 and the movable part 20. In this case, a charge of opposite polarity is generated on the other part. As a result, in the first embodiment, when the movable part 20 vibrates in the X-axis direction, the insertion amount of the movable comb teeth 21 of the movable part 20 with respect to the fixed comb teeth 11 of the fixed part 10 changes, causing a transfer of charge and generating electricity.

[0031] In the first embodiment, electrets are formed on only one of the fixed part 10 and the movable part 20, but the invention is not limited to this, and electrets may be formed on both the fixed part 10 and the movable part 20, for example. Also, in the first embodiment, the capacitance is changed by changing the insertion amount of the movable comb teeth 21 relative to the fixed comb teeth 11, but the invention is not limited to this, and for example, the insertion amount of the movable comb teeth relative to the fixed comb teeth remains constant, while the capacitance is changed by changing the distance (the gap dimension in the Y-axis direction between the movable comb teeth 21 and the fixed comb teeth 11) (for example, U.S. Patent Application Publication No. 2011 / 0314924), or the capacitance is changed by the movement of the movable comb teeth over the fixed comb teeth (for example, Japanese Patent Application Publication No. 2020-137337).

[0032] <Regarding the fixed support section> The fixed support parts 30 are provided one each in the positive and negative X-axis directions of the central band 22, i.e., a pair. The pair of fixed support parts 30 are arranged symmetrically with respect to the central axis Lc of the central band 22 and are formed to be the same shape. The center line in the Y-axis direction of each fixed support part 30 is coaxial with the center line in the Y-axis direction of the central band 22. A rectangular terminal part is integrally formed on the fixed support part 30, and a conductive metal such as aluminum is provided on the upper surface of this terminal part to form an electrode pad 15. Each of these electrode pads 15 is connected by a wire (not shown) to an electrode (not shown) provided on the case 2.

[0033] The fixed support portion 30 is physically separated from each fixed portion 10 by a gap formed between it and the lead portion 13 and the fixed comb tooth connecting portion 12. As a result, the fixed support portion 30 is electrically insulated from each fixed portion 10. The fixed support portion 30 is also fixed to the base 7 via the bonding layer 8.

[0034] <About the elastic support section> Each elastic support section 40 is equipped with three elastically deformable beams 40a, 40b, and 40c. These three beams 40a, 40b, and 40c each extend in the Y-axis direction, with one end of each beam connected to the other, while the other ends of beams 40a and 40c are connected to the fixed support section 30, and the other end of beam 40b is connected to the movable section 20.

[0035] Two elastic support parts 40 located on the positive X-axis side of the central band 22 are arranged symmetrically with respect to the central axis Lc of the central band 22, while two other elastic support parts 40 located on the negative X-axis side of the central band 22 are also arranged symmetrically with respect to the central axis Lc of the central band 22. The movable part 20 is mechanically and electrically connected to the fixed support part 30 via beams 40a, 40b, and 40c in these four elastic support parts 40.

[0036] In the first embodiment, the elastic support section 40 has one beam 40b directly connected to the movable section 20. However, it is not limited to this, and for example, there may be two or more beams to increase the spring constant. Also, the elastic support section 40 in the first embodiment is in the form of a beam. However, it is not limited to this, and any other form such as a coil spring may be used as long as it can elastically support the movable section 20.

[0037] <Detailed configuration of the fixed support section> The fixed support portion 30 also functions as a limiting portion that restricts the range of vibration of the movable portion 20 in the X-axis direction. Each fixed support portion 30 has a stopper portion 31 and a first slit 32a and a second slit 32b extending along the stopper portion 31 on the negative X-axis and positive X-axis sides of the stopper portion 31, respectively.

[0038] <Detailed configuration of the stopper section> The stopper section 31 constitutes a pseudo-equal beam in which a nearly uniform stress distribution can be obtained along the entire length of the cantilevered beam. Here, first, the principle of the pseudo-equal beam will be explained using the stopper section 31' with parabolic shapes on both sides, as shown in Figure 4(a), and then the principle of the pseudo-equal beam will be explained using the stopper section 31 with linear and parabolic shapes on both sides, as shown in Figure 4(b).

[0039] As shown in Figure 4(a), the stopper section 31' consists of a parabolic beam 31A', which is a cantilevered beam formed by four beam components 31A1' to 31A4', and constitutes a pseudo-equal beam in which a nearly uniform stress distribution can be obtained along the entire length of the cantilevered beam. The vertex of the parabola of beam component 31A1' is connected to the vertex of the parabola of beam component 31A2' by beam component connecting section 31B1', and the vertex of the parabola of beam component 31A3' is connected to the vertex of the parabola of beam component 31A4' by beam component connecting section 31B2'.

[0040] Here, in the parabolic beam 31A', the width of the cross-section (the dimension in the axial direction perpendicular to both the X and Y axes) is constant at any position along the beam length, but the thickness W is a function of y, and the thickness at position y along the beam length is denoted as W(y). Both ends of the beam are fixed and a concentrated load is applied at the center of the beam length, with the point of application of the concentrated load being the origin 0, and the length from the origin being y. The beam length is L. The thickness of the beam at the fixed ends of the parabolic beam 31A' is denoted as W0.

[0041] Although the specific derivation process is omitted, by setting the function W(y) = W0√|1-4|y| / L|, the absolute value of the bending stress on the lower surface in the X-axis direction is constant regardless of the position y, and has a uniform distribution (see Patent Document 1).

[0042] Next, the pseudo-equal beam of the stopper section 31 will be explained using Figure 4(b). Here, the parabolic beam 31A' in the stopper section 31' in Figure 4(a) has a structure in which the four beam components 31A1' to 31A4' have contours that are symmetrical with respect to an axis parallel to the Y-axis direction passing through the vertex, whereas the stopper section 31 in Figure 4(b) has a parabolic beam structure in which one side extends in a straight shape, and only the side opposite to that side has a curved surface.

[0043] The stopper section 31 consists of a cantilevered beam formed by four beam components 31A1 to 31A4, forming a pseudo-equal beam that provides a nearly uniform stress distribution along the entire length of the cantilevered beam. The vertex of the parabola of beam component 31A1 is connected to the vertex of the parabola of beam component 31A2 by a beam component connecting section 31B1, and the vertex of the parabola of beam component 31A3 is connected to the vertex of the parabola of beam component 31A4 by a beam component connecting section 31B2.

[0044] Furthermore, the thickness in the X-axis direction of each beam component 31A1 to 31A4 at a position along the length of the beam is the same as the thickness W(y) of each beam component 31A1' to 31A4' shown in Figure 4(a). Note that since the stopper section 31 has a structure in which only one side is curved, the thickness of each beam component 31A1 to 31A4 is twice the thickness from the axis parallel to the Y-axis passing through the vertex of the parabolic beam 31A' shown in Figure 4(a). Therefore, even in the stopper section 31, the thickness of each beam component 31A1 to 31A4 is the same as the thickness at the corresponding y position in the stopper section 31' shown in Figure 4(a), so a nearly uniform stress distribution can be obtained along the entire length of the cantilevered beam.

[0045] In the first embodiment, the stopper portion 31 is a member having a parabolic or parabolic contour, but it is not limited to this, and it is not necessary to have an exact parabolic or parabolic contour. Also, in the first embodiment, the stopper portion 31 employs a pseudo-equal beam, but it is not limited to this, and may be a rectangular beam, for example, having regions where stress concentration occurs between the central part and the fixed parts of the beam at one end and the other end.

[0046] Returning to Figure 3, the explanation continues. The surfaces of the stopper portion 31 facing the central band portion 22 each have a parabolic contour similar to the beam components 31A1 to 31A4 in Figure 4(b). The stopper portion 31 also has end portions 31a and 31b that are integrally fixed to the fixed support portion 30 as a double-supported beam, a stopper contact portion 31c that can contact one end surface 22a of the central band portion 22, and a stopper back portion 31d on one straight side that is not in contact with the fixed support portion 30 at all times.

[0047] The vibration of the movable part 20 in the X-axis direction is limited by the movable part 20 colliding with each stopper part 31, causing the stopper parts 31 to deform. Although the force of the movable part 20 acts on these stopper parts 31, the stopper parts 31 have sufficient strength to withstand the force due to the acceleration of the movable part 20 without being damaged.

[0048] <Regarding the deformation limiting means (protruding part) of the stopper section> Using Figure 3, the stopper deformation limiting means (protrusion) in the first embodiment will be described. This stopper deformation limiting means (protrusion) is positioned on the central axis Lc parallel to the vibration direction (X-axis direction) of the movable part 20, passing through the stopper contact portion 31c, when viewed from a direction perpendicular to the vibration plane (XY plane) of the movable part 20, and is separated from one end face 22a of the central band portion 22. The protrusion 25 is provided on the movable part 20, which is positioned opposite the fixed support portion 30. Specifically, the protrusion 25 is interposed between the central band portion 22 of the movable part 20 and the beam 40b of the elastic support portion 40, and is provided to protrude from the central band portion 22 to the beam 40b. This protrusion 25 has a larger cross-sectional area in the XZ plane than the beam 40b. The fixed support portion 30 also has a final stopper portion 30A that is positioned opposite to the protrusion 25 so as to be able to contact it. As will be explained in more detail later, as shown in Figure 5(d), when one end face 22a of the central band portion 22 is in contact with the stopper contact portion 31c of the stopper portion 31, the protruding portion 25 comes into contact with the final stopper portion 30A, thereby limiting the deformation of the stopper portion 31, that is, defining the maximum displacement of the stopper portion 31 in the X-axis direction.

[0049] Thus, in the first embodiment, by employing a protruding portion 25 that extends from the central band portion 22 to the beam 40b as a means for limiting the deformation of the stopper portion, it is possible to manufacture the vibration power generation element 100A relatively easily by adding only the step of forming the protruding portion 25 to the MEMS manufacturing process.

[0050] In the first embodiment of the stopper portion deformation limiting means (protrusion), as shown in Figure 1, four protrusions 25 are provided to connect the central band portion 22 and the four elastic support portions 40, respectively. However, for the sake of simplicity, the following explanation will focus on one protrusion 25 (see upper right in Figure 1).

[0051] <Regarding operation when vibration of movable parts increases> From here, using Figures 5(a) to (d), the operation of the vibration power generation element 100A during vibration increase (initial state, state immediately after contact with the stopper part, state where the stopper part is pressed in, and final state where the stopper part is in contact) will be explained in order. Here, the gaps shown in Figures 5(a) to (d) are exaggerated to enhance understanding. Note that the operation during vibration decrease is the opposite of the operation during vibration increase, so only the operation during vibration increase will be explained here. In addition, although the vibration operation is a reciprocating motion in the positive and negative directions of the X axis, the vibration power generation element 100A has a vertically symmetrical and horizontally symmetrical structure (see Figure 1), that is, it has a pair of left and right stopper parts 31 and four protrusions 25 arranged vertically and horizontally symmetrically, so only the movement in the positive direction of the X axis will be explained here. Furthermore, when the vibration power generation element 100A is subjected to a relatively large external impact, although not much vibration is generated, its operation follows a similar pattern to when vibration increases: initial state, state immediately after contact with the stopper, state where the stopper is pushed in, and final state where the stopper is in contact. However, this explanation will be omitted here.

[0052] In the vibration power generation element 100A, the movable part 20 is supported on the base 7 via four elastic support parts 40 and a fixed support part 30, as shown in Figure 1. The movable part 20 supported by the elastic support parts 40 can vibrate in the X-axis direction due to external vibrations.

[0053] <Initial state> First, the initial state will be described using Fig. 5(a). In this initial state, the vibration power generation element 100A is not receiving external vibration, and the movable part 20 is not vibrating. At this time, a gap along the X-axis direction is formed between the movable part 20 and the fixed support part 30, etc. Specifically, there are gaps Br0 (for example, 30 μm) between one end face 22a of the central strip part 22 and the stopper contact part 31c of the stopper part 31, a gap Aru0 (for example, 40 μm) between the protruding part 25 of the movable part 20 and the final stopper part 30A of the fixed support part 30, and a gap Cr0 (for example, 50 μm) between the stopper back face part 31d of the stopper part 31 and the fixed support part 30. Note that the respective gaps Aru0 and Ard0 between the pair of upper and lower protruding parts 25 and the final stopper part 30A shown in Fig. 5(a) are line-symmetric with respect to the central axis line Lc of the central strip part 22 and are the same (Aru0 = Ard0). Hereinafter, for the sake of explanation, the gap Aru0 between the upper protruding part 25 and the final stopper part 30A will be focused on for explanation.

[0054] Here, the gap Aru0 between the protruding part 25 and the final stopper part 30A is set to be larger than the gap Br0 between one end face 22a of the central strip part 22 and the stopper contact part 31c (Br0 < Aru0). Also, the sum of the gap Br0 between one end face 22a of the central strip part 22 and the stopper contact part 31c and the gap Cr0 between the stopper back face part 31d and the fixed support part 30 is set to be larger than the gap Aru0 between the protruding part 25 and the final stopper part 30A (Aru0 < Br0 + Cr0). Therefore, the relationship of each gap in the initial state is 0 < Br0 < Aru0 < Br0 + Cr0, and the central strip part 22 and the stopper part 31, the protruding part 25 and the final stopper part 30A, and the stopper back face part 31d and the fixed support part 30 are in a non-contact state, respectively.

[0055] <State immediately after contact with the stopper part> Next, the state immediately after contact with the stopper portion will be explained using Figure 5(b). First, when external vibration is applied to the vibration power generation element 100A, the movable portion 20 supported by the elastic support portion 40 vibrates in the X-axis direction. As the acceleration of this external vibration increases, the vibration range of the movable portion 20 expands in the X-axis direction. As a result, one end surface 22a of the central band portion 22 moves to the stopper contact portion 31c of the stopper portion 31 (see M1 in Figure 5(b)) and collides with it. At this time, the gap Aru1 (Aru0-Br0) between the protruding portion 25 and the final stopper portion 30A decreases but does not become zero, and the gap Cr0 between the stopper back surface portion 31d and the fixed support portion 30 does not change. The gap Aru1 between the protruding portion 25 and the final stopper portion 30A corresponds to the maximum displacement amount in the X-axis direction of the stopper portion 31 from the state immediately after contact with the stopper portion to the state where the stopper portion is pushed in, and is set to be less than or equal to the allowable displacement amount of the stopper portion 31 (for example, 10 μm).

[0056] <Stopper part pressed in> Furthermore, the state in which the stopper portion is pressed in will be explained using Figure 5(c). As the acceleration of the external vibration increases further, the vibration range of the movable portion 20 expands further in the X-axis direction. As a result, one end face 22a of the central band portion 22 moves further toward the stopper contact portion 31c of the stopper portion 31 (see M2 in Figure 5(c)) and presses against it. Therefore, a restoring force is generated in the deformed stopper portion 31 in the direction that reduces the vibration range of the movable portion 20. At this time, since the stopper portion 31 constitutes a pseudo-equal beam, the stress distribution is almost uniform over the entire length of the cantilevered beam. In addition, the gap Aru2 between the protruding portion 25 and the final stopper portion 30A, and the gap Cr2 between the stopper back portion 31d and the fixed support portion 30 decrease compared to the state immediately after contact with the stopper portion, but do not become zero.

[0057] <Contact state of the final stopper part> Furthermore, the final stopper contact state will be explained using Figure 5(d). When the acceleration of external vibrations increases further from the state shown in Figure 5(c), the vibration range of the movable part 20 expands even more in the X-axis direction, and one end face 22a of the central band 22 moves further toward the stopper contact portion 31c of the stopper portion 31 (see M3 in Figure 5(d)) and presses against it. As a result, when one end face 22a of the central band 22 is in contact with the stopper contact portion 31c, the protruding portion 25, which is a stopper deformation limiting means, comes into contact with the final stopper portion 30A, and at this position, the movement of the central band 22 in the positive X-axis direction stops. This final stopper portion 30A is a limiting portion that limits the vibration range of the central band 22, i.e., the movable part 20. Furthermore, the protruding portion 25 is integrally formed with the movable portion 20 and has a larger cross-sectional area in the XZ plane than the beam 40b of the connected elastic support portion 40, i.e., a larger second moment of area. Its rigidity is increased so that it can withstand the force due to the acceleration of the central band portion 22, thus reliably defining the vibration range of the movable portion 20.

[0058] This stopper deformation limiting means (protrusion) limits the deformation of the stopper portion 31, that is, it defines the maximum displacement of the stopper portion 31 in the X-axis direction, and reliably prevents cracks or fractures from occurring in the stopper portion 31. In this case, the gap Cr3 between the stopper back portion 31d and the fixed support portion 30 decreases compared to the state in which the stopper portion is pressed in, but does not become zero (for example, 20 μm). Therefore, the stopper back portion 31d is in a non-contact state with the fixed support portion 30 under any circumstances, thus solving the conventional problem 1 (damage due to compressive force load on the stopper portion).

[0059] Furthermore, in the conventional vibration power generation element 800, as shown in Figure 9, the maximum displacement amount of the stopper portion 31 in the X-axis direction was defined by the width Cr0'' (for example, 10 μm) of the slit 832, so it was necessary to set the width Cr0'' of the slit 832 to be extremely narrow. In contrast, in the vibration power generation element 100A of the first embodiment, the stopper portion deformation limiting means (protrusion) is positioned such that, when viewed from a direction perpendicular to the vibration plane (XY plane) of the movable portion 20, the protrusion 25 is spaced apart from one end face 22a of the central band portion 22 and is positioned opposite the fixed support portion 30 of the movable portion 20. Therefore, in the first embodiment, as shown in Figure 5(a), there is no need to set the gap Cr0 between the stopper back portion 31d and the fixed support portion 30 in the initial state, that is, the width of the second slit 32b (for example, 50 μm), to be narrow, and there is no need to set the gap Aru0 (for example, 40 μm) between the protruding portion 25 and the final stopper portion 30A to be narrow, thus solving the conventional problem 2 (increased difficulty of manufacturing due to extremely narrow slits).

[0060] Although not explained in detail, when limiting the range of vibration of the central band 22 in the negative X-axis direction, the vibration power generation element 100A has a vertically symmetrical and horizontally symmetrical structure. Therefore, the state is the same as when limiting the range of vibration of the central band 22 in the positive X-axis direction, but with the stopper contact state immediately after contact (see Figure 5(b)), the stopper pressing state (see Figure 5(c)), and the final stopper contact state (see Figure 5(d)) reversed horizontally.

[0061] Furthermore, in the first embodiment, as shown in Figure 1, the protrusions 25, which are stopper deformation limiting means, are arranged in four symmetrical configurations, both vertically and horizontally. In the final stopper contact state, these upper and lower pairs of protrusions 25 simultaneously contact the final stopper 30A (see Figure 5(d)). This reliably prevents the central axis Lc of the central band 22 from tilting with respect to the X-axis direction, that is, it prevents the generation of a rotational moment in the vibration plane (XY plane), thereby suppressing the generation of unexpected stresses in the beams 40a, 40b, and 40c of the elastic support 40.

[0062] In the first embodiment, the stopper portion 31 has a parabolic shape and employs a pseudo-equal beam that provides a nearly uniform stress distribution over the entire length of the double-supported beam. However, it is not limited to this, and for example, a rectangular beam with a straight shape may also be used. When a rectangular beam is used for the stopper portion 31, there are regions where stress concentration occurs between the central part and the fixed parts of the beam at one end and the other end. Therefore, compared to the pseudo-equal beam, it is necessary to make the allowable displacement relatively small, that is, the gap Aru1 (see Figure 5(b)) between the protruding portion 25 and the final stopper portion 30A immediately after contact with the stopper portion must be extremely small (for example, 5 μm). However, the gap Aru0 (see Figure 5(a)) between the protruding portion 25 and the final stopper portion 30A in the initial state can be set relatively large (for example, 35 μm). Therefore, when a rectangular beam is used for the stopper portion 31 instead of a pseudo-equal beam, the conventional problem 2 (increased difficulty in manufacturing due to extremely narrow slits) can be solved, and a greater effect can be achieved.

[0063] As described above, in the first embodiment, by positioning the stopper deformation limiting means on the central axis Lc passing through the stopper contact portion 31c and on one end surface 22a of the movable portion 20, and by providing it on the movable portion 20 which is positioned opposite the fixed support portion 30, the conventional problem 1 (damage due to compressive force load on the stopper portion) and the conventional problem 2 (increased difficulty of manufacturing due to extremely narrow slits) can be solved simultaneously, and reliability can be improved. Furthermore, in the first embodiment, by employing a protruding portion 25 that protrudes from the central band portion 22 to the beam 40b as the stopper deformation limiting means, it is possible to handle this in the MEMS manufacturing process of the vibration power generation element 100A by adding only the process of forming the protruding portion 25, thus making it relatively easy to manufacture. Furthermore, in the first embodiment, the pair of upper and lower protrusions 25, which are stopper deformation limiting means, simultaneously come into contact with the final stopper portion 30A, thereby preventing the central axis Lc of the central band portion 22 from tilting with respect to the X-axis direction, and suppressing the occurrence of unexpected stresses in the beams 40a, 40b, and 40c of the elastic support portion 40.

[0064] (Another form of the stopper deformation limiting mechanism) Here, using Figure 6, we will describe another form of the stopper deformation limiting means in the first embodiment. The vibration power generation element 100A' in this other form of the stopper deformation limiting means differs from the vibration power generation element 100A in the first embodiment in that, although not shown in Figure 1, the pair of upper and lower beams 40b on the left side are directly connected to the central band 22, and the pair of upper and lower protrusions 25 on the left side are not formed. However, the other basic configurations are the same as those in the first embodiment. Here, identical components are denoted by the same reference numerals, and redundant explanations are omitted.

[0065] <Regarding concerns (difficulty in controlling the dimensions of protruding parts)> In the vibration power generation element 100A of the first embodiment, as shown in Figure 5, the protruding portions 25, which are stopper portion deformation limiting means, are arranged in four symmetrical positions both vertically and horizontally. Therefore, it was necessary to control the dimensions of the four protruding portions 25 in the X-axis direction to make the gaps Aru0 and Ard0 between the four protruding portions 25 and the final stopper portion 30A (the same applies to the two gaps on the left side) the same. This raised concerns that controlling the dimensions of the protruding portions 25 would be complicated (hereinafter referred to as "concern (complexity in controlling the dimensions of the protruding portions)").

[0066] As mentioned above, in the first embodiment, the pair of upper and lower protrusions 25 on the right or left side simultaneously contact the final stopper portion 30A, thereby preventing the central axis Lc of the central band portion 22 from tilting with respect to the X-axis direction, and suppressing the occurrence of unexpected stresses in the beams 40a, 40b, and 40c of the elastic support portion 40. However, in reality, the gap Aru0 between the protrusions 25 and the final stopper portion 30A is minimal (for example, 40 μm), and the tilt of the central band portion 22 is also minimal, so it is not essential that the four protrusions 25 be arranged symmetrically both vertically and horizontally.

[0067] Therefore, as an example of another form of the stopper deformation limiting means, we show a case in which the left side does not have a pair of upper and lower protrusions 25, while the right side does have a pair of upper and lower protrusions 25. Here, in Figure 6, in order to match the gaps Aru0, Ard0 between the pair of upper and lower protrusions 25 and the pair of upper and lower right-side final stopper portions 30RA, and the gaps Alu0, Ald0 between the pair of upper and lower protrusions 25 and the pair of upper and lower left-side final stopper portions 30LA, only the dimensions of the protrusions 25 in the X-axis direction at two locations are required, thus resolving the concern (the complexity of dimensional control of the protrusions).

[0068] Therefore, an alternative form of the stopper deformation limiting means may be one protrusion 25, specifically, the positive X-axis side (one side in the vibration direction) and the negative X-axis side (the other side in the vibration direction) of at least one protrusion 25 may contact the right final stopper portion 30RA and the left final stopper portion 30LA, respectively. This reduces the number of protrusions 25 that require dimensional control, thus resolving the concern (the complexity of dimensional control of the protrusions). Another alternative form of this stopper deformation limiting means may be one in which the protrusion 25, which is the stopper deformation limiting means, is provided on both the positive X-axis side and the negative X-axis side in the vibration direction of the movable portion 20. As shown in Figure 6, the X-axis negative side of the protrusion 25 provided on the X-axis positive side abuts against the left final stopper portion 30LA, restricting the displacement of the movable portion 20 in the X-axis negative direction. On the other hand, the X-axis positive side of the protrusion 25 provided on the X-axis negative side abuts against the right final stopper portion 30RA (not shown), also including cases where the displacement of the movable portion 20 in the X-axis positive direction is restricted.

[0069] As described above, in this alternative form of the stopper deformation limiting means, in addition to achieving the same effects as the first embodiment, the positive X-axis side surface of at least one protrusion 25 and the negative X-axis side surface of at least one protrusion 25 can come into contact with the right final stopper portion 30RA and the left final stopper portion 30LA, respectively. This makes it possible to reduce the number of protrusions 25 that require dimensional control, thereby resolving the concern (the complexity of dimensional control of the protrusions).

[0070] (Second embodiment) The vibration power generation element 100B according to the second embodiment will be described with reference to Figure 7. The vibration power generation element 100B according to the second embodiment differs from the vibration power generation element 100A of the first embodiment in that, as a means for limiting the deformation of the stopper portion, it employs an overhang portion 26 that is provided to protrude in a direction away from the central axis Lc compared to both ends of the central band portion 22', but the other basic configurations are the same as those of the first embodiment. Here, the same reference numerals are used for the same components, and redundant explanations are omitted.

[0071] <Regarding concerns (low design freedom in increasing the rigidity of the stopper deformation limiting mechanism)> In the first embodiment, as shown in Figure 5(a), a protruding portion 25 that extends from the central band 22 to the beam 40b is used as a stopper portion deformation limiting means. This protruding portion 25 needs to have sufficient rigidity to withstand the force due to the acceleration of the central band 22. Therefore, in order to increase the rigidity of the protruding portion 25, it is necessary to increase the second moment of area of ​​the protruding portion 25, that is, the cross-sectional area of ​​the protruding portion 25 (in the XZ plane). However, the dimension of the protruding portion 25 in the X-axis direction is limited by the gap Aru0 between the protruding portion 25 and the final stopper portion 30A, and the dimension of the protruding portion 25 in the Z-axis direction is limited by the thickness of the device layer 9, as shown in Figure 2. Therefore, there was a concern that the design freedom for increasing the rigidity of the protruding portion 25 would be low (hereinafter referred to as "concern (low design freedom in increasing the rigidity of the stopper portion deformation limiting means)").

[0072] <Regarding the deformation limiting means (protruding portion) of the stopper section> In contrast, the stopper deformation limiting means in the second embodiment, as shown in Figure 7, is an overhang 26 provided so as to extend from both ends of the central band 22' towards the center when viewed from a direction perpendicular to the vibration plane (XY plane) of the movable part 20', and two of these overhangs symmetrically arranged vertically. Compared to the protruding part 25 in the first embodiment, this overhang 26 has an extremely large dimension in the X-axis direction, that is, a cross-sectional area (in the XZ plane), and has extremely high rigidity (second moment of area), thus solving the concern (low design freedom in increasing the rigidity of the stopper deformation limiting means).

[0073] <Regarding operation when vibration of movable parts increases> From here, using Figures 7(a) to (d), the operation of the vibration power generation element 100B when vibration increases (initial state, state immediately after contact with the stopper part, state where the stopper part is pressed in, and final state where the stopper part is in contact) will be explained in order. Here, the gaps shown in Figures 7(a) to (d) are exaggerated to enhance understanding. Note that the operation when vibration decreases is the opposite of the operation when vibration increases, so only the operation when vibration increases will be explained here. In addition, although the vibration operation is a reciprocating motion in the positive and negative directions of the X axis, the vibration power generation element 100B has a vertically symmetrical and horizontally symmetrical structure (see Figure 1), that is, it has a pair of left and right stopper parts 31 and two vertically symmetrically arranged protruding parts 26, so only the movement in the positive direction of the X axis will be explained here.

[0074] <Initial state> First, the initial state will be described using FIG. 7(a). In this initial state, there are a gap Br0' (e.g., 30 μm) between one end face 22a of the central band portion 22' and the stopper contact portion 31c of the stopper portion 31, a gap Aru0' (e.g., 40 μm) between the overhanging portion 26 of the movable portion 20' and the final stopper portion 30B of the fixed support portion 30, and a gap Cr0' (e.g., 50 μm) between the stopper back face portion 31d of the stopper portion 31 and the fixed support portion 30. Note that the respective gaps Aru0', Ard0' between the pair of upper and lower overhanging portions 26 and the final stopper portion 30B shown in FIG. 7(a) are the same (Aru0' = Ard0'). Hereinafter, for the sake of explanation, attention will be paid to the gap Aru0' between the upper overhanging portion 26 and the final stopper portion 30B for explanation.

[0075] In addition, the relationship between the respective gaps in the initial state is the same as that in the first embodiment, and 0 < Br0' < Aru0' < Br0' + Cr0', and the central band portion 22', the stopper portion 31, the overhanging portion 26 and the final stopper portion 30B, and the stopper back face portion 31d and the fixed support portion 30 are in a non-contact state, respectively.

[0076] <State immediately after contact of the stopper portion> Next, the state immediately after contact of the stopper portion will be described using FIG. 7(b). In the state immediately after contact of the stopper portion, one end face 22a of the central band portion 22' moves (see M1' in FIG. 7(b)) and collides with the stopper contact portion 31c of the stopper portion 31. At this time, the gap Aru1' (Aru0' - Br0') between the overhanging portion 26 and the final stopper portion 30B decreases but does not become zero, and the gap Cr0' between the stopper back face portion 31d and the fixed support portion 30 does not change. Note that the gap Aru1' between the overhanging portion 26 and the final stopper portion 30B corresponds to the maximum displacement amount in the X-axis direction in the stopper portion 31 from the state immediately after contact of the stopper portion until the state where the stopper portion is pushed in, and is set to be not more than the allowable displacement amount (e.g., 10 μm) of the stopper portion 31.

[0077] <State where the stopper portion is pushed in> Furthermore, the state in which the stopper portion is pressed in will be explained using Figure 7(c). In the state in which the stopper portion is pressed in, one end surface 22a of the central band portion 22' moves further toward the stopper contact portion 31c of the stopper portion 31 (see M2' in Figure 7(c)) and presses against it. Also, the gap Aru2' between the protruding portion 26 and the final stopper portion 30B, and the gap Cr2' between the back surface portion 31d of the stopper and the fixed support portion 30 decrease compared to the state immediately after contact with the stopper portion, but they do not become zero.

[0078] <Contact state of the final stopper part> Furthermore, the final stopper contact state will be explained using Figure 7(d). In the final stopper contact state, one end face 22a of the central band 22' moves further toward the stopper contact portion 31c of the stopper portion 31 (see M3' in Figure 7(d)) ​​and presses against it. As a result, when one end face 22a of the central band 22' is in contact with the stopper contact portion 31c, the protruding portion 26, which is a stopper deformation limiting means, comes into contact with the final stopper portion 30B, and at this position, the movement of the central band 22' in the positive X-axis direction stops.

[0079] This stopper deformation limiting means (protruding portion) limits the deformation of the stopper portion 31, that is, it defines the maximum displacement of the stopper portion 31 in the X-axis direction, and reliably prevents cracks or fractures from occurring in the stopper portion 31. In this case, the gap Cr3' between the stopper back portion 31d and the fixed support portion 30 decreases compared to the state in which the stopper portion is pressed in, but does not become zero (for example, 20 μm). Therefore, the stopper back portion 31d is in a non-contact state with the fixed support portion 30 under any circumstances, thus solving the conventional problem 1 (damage due to compressive force load on the stopper portion).

[0080] Furthermore, in the vibration power generation element 100B of the second embodiment, the stopper deformation limiting means (protruding portion) is positioned such that, when viewed from a direction perpendicular to the vibration plane (XY plane) of the movable portion 20', it is spaced apart from one end face 22a of the central band portion 22' on the central axis Lc parallel to the vibration direction (X-axis direction) of the movable portion 20' passing through the stopper contact portion 31c, and the protruding portion 26 is positioned at the location of the movable portion 20' facing the fixed support portion 30. For this reason, in the second embodiment, as shown in Figure 7(a), it is not necessary to set the gap Cr0' between the stopper back portion 31d and the fixed support portion 30 in the initial state, that is, the width of the second slit 32b (for example, 50 μm), to be narrow, and it is also not necessary to set the gap Aru0' (for example, 40 μm) between the protruding portion 26 and the final stopper portion 30B to be narrow, thus solving the conventional problem 2 (increased difficulty of manufacturing due to extremely narrow slits).

[0081] Although not explained in detail, when limiting the range of vibration of the central band 22' in the negative X-axis direction, the vibration power generation element 100B has a vertically symmetrical and horizontally symmetrical structure. Therefore, the state is the same as when limiting the range of vibration of the central band 22' in the positive X-axis direction, but with the stopper contact state immediately after contact (see Figure 7(b)), the stopper pressing state (see Figure 7(c)), and the final stopper contact state (see Figure 7(d)) ​​reversed horizontally.

[0082] Furthermore, in the first embodiment, as shown in Figures 7(a) to (d), the protruding portions 26, which are stopper portion deformation limiting means, are arranged symmetrically in the upper and lower halves, and in the final stopper portion contact state, this pair of upper and lower protruding portions 26 simultaneously come into contact with the final stopper portion 30B (see Figure 7(d)). This reliably prevents the central axis Lc of the central band portion 22' from tilting with respect to the X-axis direction, that is, it prevents the generation of a rotational moment in the vibration plane (XY plane), and suppresses the generation of unexpected stresses in the beams 40a, 40b, and 40c of the elastic support portion 40.

[0083] In this second embodiment, the stopper portion 31 employs a pseudo-equal beam, similar to the first embodiment, but it is not limited to this; for example, a rectangular beam may also be used.

[0084] As described above, in the second embodiment, similar to the first embodiment, the stopper deformation limiting means is spaced apart from the central axis Lc passing through the stopper contact portion 31c and from one end face 22a of the movable portion 20', and is provided on the movable portion 20' which is positioned opposite the fixed support portion 30. This solves both conventional problem 1 (damage due to compressive force load on the stopper portion) and conventional problem 2 (increased manufacturing difficulty due to extremely narrow slits), thereby improving reliability. Furthermore, in the second embodiment, similar to the first embodiment, the pair of upper and lower protruding portions 26, which are stopper deformation limiting means, simultaneously contact the final stopper portion 30B, preventing the central axis Lc of the central band portion 22' from tilting with respect to the X-axis direction, and suppressing the occurrence of unexpected stresses in the beams 40a, 40b, and 40c of the elastic support portion 40. Furthermore, in the second embodiment, by employing protruding portions 26 that extend from both ends of the movable portion 20' toward the center as a means for limiting the deformation of the stopper portion, the concern (low design freedom in increasing the rigidity of the stopper portion deformation limiting means) can be resolved.

[0085] (Another form of the stopper deformation limiting mechanism) Here, although not shown in the figures, another form of the stopper deformation limiting means in the second embodiment will be described. In this other form of the stopper deformation limiting means, although not shown in the figures, the vibration power generation element differs from the vibration power generation element 100B of the second embodiment in that, in Figure 7, only the protruding portion 26 located on the positive Y-axis side of the central band 22' is used as the stopper deformation limiting means, and the protruding portion 26 located on the negative Y-axis side of the central band 22' is always in a non-contact state with the fixed support portion 30. However, the other basic configurations are the same as in the second embodiment. Here, identical components are denoted by the same reference numerals, and redundant explanations are omitted.

[0086] <Regarding concerns (the difficulty of managing the dimensions of the protruding section)> In the vibration power generation element 100B of the second embodiment, the protruding portions 26, which are stopper portion deformation limiting means, are arranged in pairs symmetrically vertically. Therefore, by controlling the dimensions of the protruding portions 26 in the X-axis direction at two locations, it was necessary to make the gaps Aru0', Ard0' between the four protruding portions 26 and the final stopper portion 30B (the same applies to the two gaps on the left side) match. This raised concerns that controlling the dimensions of the protruding portions 26 would be complicated (hereinafter referred to as "concern (complexity in controlling the dimensions of the protruding portions)").

[0087] As mentioned above, in the second embodiment, the upper and lower pair of overhangs 26 simultaneously contact the final stopper portion 30B, thereby preventing the central axis Lc of the central band portion 22' from tilting with respect to the X-axis direction, and suppressing the generation of unexpected stresses in the beams 40a, 40b, and 40c of the elastic support portion 40. However, in reality, the gap Aru0' between the overhangs 26 and the final stopper portion 30B is minimal (for example, 40 μm), and the tilt of the central band portion 22' is also minimal. Therefore, it is not essential to use the two vertically symmetrically arranged overhangs 26 as stopper portion deformation limiting means. It is sufficient that the positive X-axis side surface of at least one overhang 26 and the negative X-axis side surface of at least one protrusion 25 can contact the final stopper portion 30B.

[0088] Therefore, in another embodiment of the stopper deformation limiting means, the stopper deformation limiting means only needs to consist of one protruding portion 26. Specifically, the positive X-axis side (one side in the vibration direction) and the negative X-axis side (the other side in the vibration direction) of the one protruding portion 26 should be able to contact the final stopper portion 30B. This makes it possible to reduce the number of protruding portions 26 that require dimensional control, thereby resolving the concern (the complexity of dimensional control of the protruding portions).

[0089] As described above, in this alternative form of the stopper deformation limiting means, in addition to achieving the same effects as the second embodiment, by allowing the positive X-axis side surface and the negative X-axis side surface of one protruding portion 26 to come into contact with the final stopper portion 30B, it is possible to reduce the number of protruding portions 26 that require dimensional control, thereby resolving the concern (the complexity of dimensional control of the protruding portions).

[0090] <Other> Although the present invention has described the embodiments and alternative forms described above, the present invention is not limited to these, and various embodiments and alternative forms can be combined, or modified as appropriate without departing from the technical idea of ​​the present invention. [Explanation of Symbols]

[0091] 1. Vibration power generation device 2 cases 3 Top lid 7 Base 7a opening 8 Bonding layer 9. Device Layer 10 Fixed part 11 fixed comb teeth 12 Fixed comb tooth connection part 13 Lead section 14,15 Electrode pads 20,20' Moving part 21 Movable comb teeth 22,22' Central band 22a One end face (end face) 23 Movable comb tooth connection part 24a,24b weight 25 Protrusion 26 Overhang 30 Fixed support part 30A, 30B Final stopper section 30LA Left side final stopper section 30RA Right side final stopper section 31,31' Stopper part 31a,31b end 31A' Parabolic beam 31A1~31A4,31A1'~31A4' Beam component 31B1,31B2,31B1',31B2' Beam component connection part 31c Stopper contact area 31d Stopper rear section 32a First Slit 32b Second Slit 40 Elastic support section 40a~40c beam 100A, 100A', 100B vibration power generation element Ald0, Alu0, Ard0, Aru0: Gap between the protruding part and the final stopper part (initial state) Ard0', Aru0': Gap between the protruding part and the final stopper part (initial state) Aru1: Gap between the protruding part and the final stopper part (state immediately after contact with the stopper part) Aru1' Gap between the protruding part and the final stopper part (state immediately after contact with the stopper part) Aru2: Gap between the protruding part and the final stopper part (with the stopper part pushed in) Aru2' Gap between the protruding part and the final stopper part (stopper part in the pushed-in state) Br0, Br0' Gap between one end face of the central band and the stopper contact area (initial state) Cr0, Cr0' Gap between the back of the stopper and the fixed support part (initial state, state immediately after contact with the stopper part) Cr2, Cr2' Gap between the back of the stopper and the fixed support part (when the stopper is pushed in) Cr3, Cr3' Gap between the back of the stopper and the fixed support part (final stopper contact state) Lc center axis

Claims

1. Bass and, A movable part having a movable electrode and capable of vibrating in a predetermined direction, A fixed portion having a fixed electrode, which is fixed to the base and provided opposite the movable electrode, A fixed support portion having a stopper portion that is fixed to the base and can contact the end face of the movable portion, An elastic support portion interposed between the fixed support portion and the movable portion, which supports the movable portion, A stopper portion deformation limiting means is provided, which limits the deformation of the stopper portion by having the movable portion come into contact with the fixed support portion when the end face of the movable portion is in contact with the stopper portion, Equipped with, The stopper portion extends in a direction perpendicular to the vibration direction of the movable portion and has both ends connected to the fixed support portion, and a stopper contact portion that can contact the end face of the movable portion. The stopper deformation limiting means is a vibration power generation element provided on the movable part, which is positioned opposite the fixed support part, and is located on a central axis parallel to the vibration direction of the movable part that passes through the stopper contact portion, and away from the end face of the movable part, when viewed from a direction perpendicular to the vibration surface of the movable part.

2. The stopper deformation limiting means is provided on both the one-way and the other-way side in the vibration direction of the movable part, The deformation limiting means of the stopper portion on one side restricts the displacement of the movable portion to either the one side or the other side. The vibration power generation element according to claim 1, wherein the stopper deformation limiting means on the other side restricts the displacement of the movable part to either one direction or the other.

3. The stopper deformation limiting means is interposed between the movable part and the elastic support part, and is provided to protrude from the movable part to the elastic support part, wherein the protruding part has a larger cross-sectional area than the elastic support part, as described in claim 1.

4. The vibration power generation element according to claim 3, wherein the stopper portion deformation limiting means is one side in the vibration direction of at least one of the protruding portions and the other side in the vibration direction of at least one of the protruding portions.

5. The vibration power generation element according to claim 1, wherein the stopper deformation limiting means is a protruding portion that, when viewed from a direction perpendicular to the vibration plane of the movable portion, protrudes in a direction away from the central axis compared to both ends of the movable portion.

6. The vibration power generation element according to claim 5, wherein the stopper portion deformation limiting means is one side in the vibration direction of at least one of the protruding portions and the other side in the vibration direction of at least one of the protruding portions.

7. The vibration power generation element according to any one of claims 1 to 6, wherein the stopper deformation limiting means is arranged symmetrically with respect to the central axis passing through the stopper contact portion when viewed from a direction perpendicular to the vibration surface of the movable portion.

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