Mounting structure for a sensor device with a spacer having two passage sections

Abstract

Sensor device mounting structure (10, 30, 430), comprising: a component (20) comprising a thick section (20a) and a thin section (20b), wherein the thin section (20b) is thinner than the thick section (20a); a flexible plate (31, 131, 431); at least one sensor device (40, 140, 340) installed on the flexible plate (31, 131, 431); a spacer (50, 450), which is formed in the form of a film with a uniform thickness, which is sandwiched between the thin section (20b) and the flexible plate (31, 131, 431), and which includes a passage section (51, 451) which is formed at a position corresponding to the at least one sensor device (40, 140, 340) in a thickness direction of the spacer (50, 450) through the spacer (50, 450); and an adhesive (60) which is introduced into the passage section (51, 451), and connecting the thin section (20b) and the flexible plate (31, 131, 431) together, wherein The spacer (50, 450), in addition to the passage section (51, 451), includes another passage section (55) which is formed in the thickness direction of the spacer (50, 450) at a position that does not correspond to the at least one sensor device (40, 140, 340).

Description

Cross-reference to similar application

[0001] This application is based on and claims priority from prior Japanese Patent Application No. 2021-147920, filed on September 10, 2021. Background of the inventionTechnical field of the invention

[0002] The present disclosure relates to a mounting structure for a sensor device or a sensor device mounting structure in which a sensor device is mounted on a component. Related prior art

[0003] Until now, there has been a structure obtained by forming a protruding portion on a bottom surface of a recessed part formed in a casing, injecting an adhesive into the recessed part, placing a glass base coupled to a sensor device onto the protruding portion, pressing the glass base from above, and curing the adhesive to fix the glass base (see Japanese Patent Application Laid-Open No. JP H06-186104 A). According to Japanese Patent Application Laid-Open No. JP H06-186104 A, the glass base is supported in a horizontal posture.stored with its bottom surface partially overlapping with the protruding portion, and the adhesive is applied from the protruding portion into surface areas without any gap between the bottom surface of the glass base and the bottom surface of the recessed part.

[0004] JP H06-186104 A discloses the following: In a semiconductor pressure sensor, a resin package, a lid attached to the top of the package, a lead terminal row molded integrally with the resin package, a glass base housed in and fixed to a bottom recessed portion within the package, a semiconductor pressure sensing element mounted on the base, and lead wires connecting the pressure sensing element to the lead terminal row are assembled and formed as main parts. In the semiconductor pressure sensor, a protrusion that supports and holds the glass base is formed on the bottom of the recessed portion in the resin package. Then, using the protrusion as a reference plane, an adhesive (a pressure-sensitive silicone adhesive that exhibits rubber elasticity when cured) is filled into the recessed portion, and the glass base is bonded and fixed in a predetermined position. Summary

[0005] In this context, when attaching a sensor device installed on a flexible plate to a thin portion of a component, it is difficult to form the protruding portion on the flexible plate or the thin portion because the flexible plate and the thin portion are thin. Furthermore, even if the protruding portion can be formed, it is difficult to ensure dimensional accuracy of the protruding portion. Thus, the structure disclosed in Japanese Patent Application Laid-Open No. JP H06-186104 A cannot be employed, and consequently, it is difficult to ensure the thickness of an adhesive for attaching the sensor device due to the protruding portion.

[0006] The present disclosure has been made to solve problems as described above, and its main object is to ensure a thickness of an adhesive in a sensor device mounting structure in which a sensor device installed on a flexible board is mounted on a thin portion of a component.

[0007] This object is achieved by the sensor device mounting structure having the features of claim 1. Further advantageous embodiments and further developments are the subject of the subsequent claims.

[0008] According to one embodiment of the present disclosure, a sensor device mounting structure is provided, including: a component including a thick portion and a thin portion, the thin portion being thinner than the thick portion; a flexible plate; at least one sensor device installed on the flexible plate; a spacer that formed in a form of a film with a uniform thickness, sandwiched between the thin section and the flexible plate, and includes a through-portion formed through the spacer at a position corresponding to the at least one sensor device in a thickness direction of the spacer; and an adhesive that is introduced into the passage section, and connects the thin section and the flexible plate together, whereby the spacer includes, in addition to the through portion, another through portion formed through the spacer at a position other than the at least one sensor device in the thickness direction of the spacer.

[0009] In the above-described configuration, the at least one sensor device is installed on the flexible plate. The spacer is formed in the shape of a film having a uniform thickness and is sandwiched between the thin portion and the flexible plate. Thus, in a state where the flexible plate is pressed against the thin portion by interposing the spacer, a distance between the thin portion and the flexible plate is equal to the thickness of the spacer. Thus, this distance can be adjusted by adjusting the thickness of the spacer.

[0010] In addition, the through-passage portion is formed at the position corresponding to the at least one sensor device in the thickness direction of the spacer through the spacer. In this context, the adhesive injected into the through-passage portion bonds the thin portion and the flexible plate to each other. Thus, by injecting the adhesive into the through-passage portion and then pressing the flexible plate against the thin portion by interposing the spacer, a thickness of the adhesive is equal to the thickness of the spacer. In other words, the thickness of the adhesive can be ensured due to the thickness of the spacer. Thus, the thickness of the adhesive can be ensured even when the at least one sensor device installed on the flexible plate is attached to the thin portion of the component.

[0011] Furthermore, the spacer includes the other through-passage portion formed through the spacer at a position in the thickness direction of the spacer that does not correspond to the at least one sensor device. With such a configuration, the thickness of the adhesive can be ensured even at this non-corresponding portion if a portion of the flexible plate that does not correspond to the at least one sensor device is also bonded to the thin portion.

[0012] Furthermore, the thin portion may be formed in a crown-shaped form, and The flexible plate and the spacer can be formed in a ring shape along the thin portion. With such a configuration, the thickness of the adhesive on a composite part can be ensured when the flexible plate is bonded in conformity to the shape of the thin portion.

[0013] Furthermore, in the spacer, a shape and size of the through portion formed at the position corresponding to the at least one sensor device and a shape and size of the other through portion formed at the position not corresponding to the at least one sensor device can be the same. With such a configuration, in the spacer, the through portions are formed with the same shape and size both at the position corresponding to the at least one sensor device and at the position not corresponding to the at least one sensor device. Thus, the through portions can be easily formed (i.e., manufactured), and the shapes and sizes of the through portions can be easily controlled.

[0014] Furthermore, the at least one sensor device can be formed as an electronic circuit pattern on the flexible board. With such a configuration, bonding or soldering of the at least one sensor device to the flexible board can be omitted. Thus, the at least one sensor device can be easily installed on the flexible board.

[0015] Furthermore, the at least one sensor device may include a plurality of sensor devices, and The through-portion of the spacer may include a plurality of through-portions formed through the spacer at positions corresponding to the plurality of sensor devices, respectively, in the thickness direction of the spacer. With such a configuration, the thickness of the adhesive can be ensured at all corresponding ones of the plurality of through-portions when the plurality of sensor devices are attached to the thin portion.

[0016] Furthermore, the through-passage portion may be connected to an outer side of the spacer. In such a configuration, excess adhesive may be extruded from parts of the through-passage portion through a portion that is connected to the outer side of the spacer. Short description of the drawings

[0017] It shows / it shows: Fig. 1 is a cross-sectional view of a sensor device mounting structure, Fig. 2 is a bottom view of a flexible plate structure; Fig. 3 is a cross-sectional view as viewed from a direction indicated by arrows 3-3 in Fig. 2 is displayed; Fig. 4 is a bottom view illustrating a modification of the structure of a flexible plate; Fig. 5 is a bottom view illustrating another modification of the structure of a flexible plate; Fig. Fig. 6 is a bottom view illustrating still another modification of the structure of a flexible plate; Fig. Fig. 7 is a bottom view illustrating still another modification of the structure of a flexible plate; Fig. Fig. 8 is a bottom view illustrating still another modification of the structure of a flexible plate; Fig. 9 is a cross-sectional view illustrating a modification of the sensor device mounting structure; Fig. 10 is a cross-sectional view illustrating another modification of the sensor device mounting structure; Fig. 11 is a cross-sectional view illustrating still another modification of the sensor device mounting structure; and Fig. 12 is a bottom view illustrating yet another modification of the structure of a flexible plate. Detailed description of the preferred embodiments

[0018] A first embodiment in which a sensor device mounting structure for mounting a sensor device on a strain wave gearing provided on a joint of a robot is configured will be described below with reference to the drawings.

[0019] As in Fig. 1, a sensor device mounting structure 10 includes a component 20, a flexible plate assembly 30, and an adhesive 60.

[0020] The component 20 is, for example, a flexible gear, a clutch component, or a housing to be included in the strain wave gear (a speed reducer), and includes a thick portion 20a and a thin portion 20b.

[0021] As in Fig. 1 to Fig. 3, the flexible plate assembly 30 includes a flexible plate 31, a sensor device 40, and a spacer 50.

[0022] The flexible board 31 is a well-known FPC (Flexible Printed Circuit). The flexible board 31 is formed, for example, by forming an adhesive layer over a base film that is a thin-film insulator, applying a conductor pattern (such as a conductive foil) to the adhesive layer, and covering parts other than terminal portions and soldering portions with an insulating cover made of polyimide or the like. A thickness of the flexible board 31 is, for example, 0.1 [mm] to 0.5 [mm].

[0023] The sensor device 40 is a sensor device such as a torque sensor (more specifically, a strain gauge), a vibration sensor, a temperature sensor, a pressure sensor, or an optical sensor. The sensor device 40 includes a device portion and a lead wire (such as a conductive wire) extending from the device portion, and this lead wire is soldered (e.g., surface-mounted) to the soldering portion of the flexible board 31. In other words, the sensor device 40 is installed on the flexible board 31. Although a shape of the sensor device 40 is illustrated herein as a disk shape, the sensor device 40 may be formed into any desired shapes.

[0024] The spacer 50 is obtained by forming, for example, polyimide or an insulating resin such as fluororesin into a film form with a uniform thickness. The thickness of the spacer 50 ranges, for example, from 0.05 [mm] to 0.2 [mm] in accordance with a type of the sensor device 40 and a thickness of the adhesive 60 to be adjusted. The spacer 50 is applied to a surface on a side opposite to a side on which another surface to which the sensor device 40 is attached exists among surfaces of the flexible plate 31. In a state in which the flexible plate assembly 30 is attached to the thin portion 20b of the component 20, the spacer 50 is sandwiched between the thin portion 20b and the flexible plate 31.It should be noted that the spacer 50 can be formed integrally with the cover if the material of the cover of the flexible plate 31 and the material of the spacer 50 are the same.

[0025] A through-hole 51 is formed through the spacer 50 in its thickness direction. The through-hole 51 (i.e., a through-portion) is formed to be larger than the sensor device 40 and includes the sensor device 40 in a bottom view. In other words, the through-hole 51 is formed at a position corresponding to the sensor device 40 (i.e., at a position overlapping the sensor device 40). Although a shape of the through-hole 51 is illustrated as a square shape in its cross section, the through-hole 51 can be formed in any shape. When the through-hole 51 is formed to be larger than the sensor device 40, the sensor device 40 is enabled to sense the thin portion 20b only via the adhesive 60 for the spacer 50.Thus, uniformity in sensing can be increased to be higher than that when performing sensing across a plurality of components made of different materials for the spacer 50.

[0026] The adhesive 60 is, for example, a thermosetting adhesive. The adhesive 60 is applied to fill the through-hole 51 of the spacer 50. The adhesive 60 is cured by heating to bond the thin portion 20b of the component 20 and the flexible plate 31 together. Note that the adhesive 60 can be, for example, a temperature-curing adhesive or a two-component adhesive.

[0027] Next, a method for attaching the sensor device 40 to the thin portion 20b of the component 20 (a manufacturing method for the sensor device attachment structure) will be described. The following process may be performed by an operator, or it may be performed by a manufacturing machine such as a robot.

[0028] First, the flexible plate 31 is prepared on which a predetermined conductor pattern has been formed.

[0029] Subsequently, the lead wire of the sensor device 40 is soldered to the soldering portion of the flexible board 31. In other words, the sensor device 40 is mounted (i.e., attached) to an upper surface (also referred to as a "first surface") of the flexible board 31.

[0030] Next, the spacer 50 is applied (i.e., tightly fitted or bonded) to a lower surface of the flexible plate 31 (also referred to as a "second surface" on the side opposite the side where the first surface is present). At this time, the spacer 50 is positioned relative to the flexible plate 31 such that a center point of the through-hole 51 of the spacer 50 and a center point of the sensor device 40 are aligned with each other in the bottom view. In this way, the flexible plate assembly 30 is completed.

[0031] Thereafter, the adhesive 60 is injected into the through-hole 51. At this time, the through-hole 51 is filled with the adhesive 60 such that no voids are formed.

[0032] Subsequently, the spacer 50 is pressed against the thin portion 20b of the component 20, specifically at a position where the flexible plate assembly 30 is mounted. In other words, the flexible plate 31 is pressed against the thin portion 20b by interposing the spacer 50. In this state, the thickness of the adhesive 60 is equal to the thickness of the spacer 50. At this time, excess adhesive 60 can be extruded from the through-hole 51.

[0033] Next, the component 20 and the flexible plate assembly 30 are heated to cure the adhesive 60. In this way, the sensor device mounting structure 10 is completed (i.e., manufactured).

[0034] The embodiment described in detail above provides the following advantages.

[0035] The sensor device 40 is installed on the flexible plate 31. The spacer 50 is formed in the shape of a film with a uniform thickness and is sandwiched between the thin portion 20b and the flexible plate 31. Thus, in the state where the flexible plate 31 is pressed against the thin portion 20b by interposing the spacer 50, a distance between the thin portion 20b and the flexible plate 31 is equal to the thickness of the spacer 50. Thus, this distance can be adjusted by adjusting the thickness of the spacer 50.

[0036] The through-hole 51 is formed at the position overlapping with the sensor device 40 in the thickness direction thereof through the spacer 50. In addition, the adhesive 60 injected into the through-hole 51 bonds the thin portion 20b and the flexible plate 31 together. Thus, by injecting the adhesive 60 into the through-hole 51 and then pressing the flexible plate 31 against the thin portion 20b by interposing the spacer 50, the thickness of the adhesive 60 is equal to the thickness of the spacer 50. In other words, the thickness of the adhesive 60 can be ensured due to the thickness of the spacer 50. Thus, the thickness of the adhesive 60 can be ensured even when the sensor device 40 installed on the flexible plate 31 is attached to the thin portion 20b of the component 20.Furthermore, it is easy to adjust the thickness of the layered spacer 50, and consequently, the thickness of the adhesive 60 can also be stabilized during mass production. Furthermore, it is easy to appropriately control the bonding strength and distance between the thin portion 20b and the sensor device 40.

[0037] Note that the above-described embodiment may be modified as follows. Parts similar to those in the above-described embodiment are denoted by the same reference numerals to omit redundant description.

[0038] As in Fig. 4, a groove 52 communicating an outer side of the spacer 50 and the through-hole 51 may be formed in the spacer 50. With such a configuration, even if a large amount of the adhesive 60 is injected into the through-hole 51, the excess adhesive 60 can be extruded through the groove 52 when the spacer 50 is pressed against the thin portion 20b. Note that a width of the groove 52 is smaller than a width of the through-hole 51, and thus, the adhesive 60, which is viscous, remains unlikely to be extruded into the groove 52 until it fills an inside of the through-hole 51. Thus, the inside of the through-hole 51 is easily filled with the adhesive 60, and the adhesive 60 is unlikely to remain in a thickness direction of the spacer 50.As a result, the thickness of the adhesive 60 can be further stabilized.

[0039] As in Fig. 5, an adhesive pool 54, which is a through-hole not communicating with the outside, may be formed in the spacer 50, and the through-hole 51 and the adhesive pool 54 communicate with each other via a groove 53. Furthermore, with such a configuration, when the spacer 50 is pressed against the thin portion 20b, even if a large amount of the adhesive 60 is injected into the through-hole 51, the excess adhesive 60 can be extruded into the adhesive pool 54 through the groove 53. Thus, the inside of the through-hole 51 is easily filled with the adhesive 60, and the adhesive 60 is unlikely to remain in the thickness direction of the spacer 50. As a result, the thickness of the adhesive 60 can be further stabilized.Note that the groove 53 may be omitted to directly communicate the through-hole 51 and the adhesive pool 54. In this case, a width of the adhesive pool 54 is also smaller than the width of the through-hole 51, and consequently, the adhesive 60, which is viscous, remains unlikely to be extruded into the adhesive pool 54 until it fills the interior of the through-hole 51. Thus, functions and advantages similar to those in the case where the groove 53 is formed are provided.

[0040] As in Fig. As illustrated in Fig. 6, the flexible plate assembly 30 (i.e., the sensor device mounting structure 10) may include a plurality of sensor devices 40, and a plurality of through-holes 51 may be formed at positions corresponding to the plurality of sensor devices 40 in the thickness direction thereof through the spacer 50. With such a configuration, the thickness of the adhesive 60 can be ensured at each of the corresponding ones of the plurality of through-holes 51 when the plurality of sensor devices 40 are mounted to the thin portion 20b. In addition, the adhesive 60 is injected into the plurality of through-holes 51, and accordingly, it can be seen that the adhesive 60 is accurately positioned relative to each of the plurality of sensor devices 40 using the plurality of through-holes 51.In addition, it should be noted that wiring for the plurality of sensor devices 40 is performed collectively using the flexible plate 31 since the flexible plate structure 30 includes the plurality of sensor devices 40.

[0041] As in Fig. 7, other through-holes 55 (i.e., through-portions) may be formed through the spacer 50 at positions where the sensor devices 40 do not overlap in the thickness direction thereof. With such a configuration, if parts other than the sensor devices 40 among parts of the flexible plate 31 are also bonded to the thin portion 20b, the thickness of the adhesive 60 can be ensured even at these non-corresponding parts. In addition, if the parts other than the sensor devices 40 are not bonded to the thin portion 20b, a phenomenon may occur in which the flexible plate 31 peels off from the thin portion 20b. However, this phenomenon can be prevented by bonding the parts other than the sensor devices 40 to the thin portion 20b.This can prevent the detached flexible plate 31 from vibrating in a manner that would affect detection by the sensor devices 40. Additionally, in the spacer 50, the shape and size of each of the through-holes 51 formed at the positions overlapping with the sensor devices 40 and the shape and size of the other through-holes 55 formed at the positions not overlapping with the sensor devices 40 are the same. With such a configuration, in the spacer 50, the through-holes 51 and 55 are formed with the same shape and size at the position corresponding to the sensor devices 40 and the positions not corresponding to the sensor devices 40, respectively.Thus, unlike a case where through-holes of different shapes and sizes are formed at the positions corresponding to the sensor devices 40 and the positions not corresponding to the sensor devices 40, a common means for forming the through-holes can be adopted. As a result, the through-holes 51 and 55 can be easily formed, and the shapes and sizes of the through-holes 51 and 55 can be easily controlled. In addition, amounts of the adhesive 60 to be injected into the through-holes 51 and 55 can be equalized when the thicknesses of the through-holes 51 and 55 are equal to each other, and accordingly, the same amount of the adhesive 60 can be injected into each of the through-holes 51 and 55. In other words, productivity can be increased.It should be noted that the shape of the through holes 51 and the shape of the through holes 55 may differ from each other. In addition, the size of the through holes 51 and the size of the through holes 55 may differ from each other.

[0042] As in Fig. 8, a cutout 57 may be formed in the spacer 50 instead of the through-hole 51. The cutout 57 (i.e., a through-portion) is formed to open the spacer 50 in its thickness direction. The cutout 57 is formed from positions in the spacer 50 at the position overlapping with the sensor device 40 and communicates with the outside of the spacer 50. With such a configuration, functions and advantages similar to those of the configuration shown in Fig. 4 is illustrated.

[0043] As in Fig. As illustrated in Fig. 9, a flexible board structure 130 may include a flexible board 131 in which a sensor device 140 is formed as an electronic circuit pattern. The sensor device 140 is formed, for example, from a resistor pattern and a conductor pattern, and is covered with a cover of the flexible board 131. In other words, the sensor device 140 is installed in the flexible board 131. With such a configuration, bonding or soldering of the sensor device 140 to the flexible board 131 can be omitted. Thus, the sensor device 140 can be easily installed in the flexible board 131. Further, the sensor device 140 may be formed, for example, together with a wiring pattern (such as the conductor pattern) in the flexible board 131 as an electronic circuit pattern.Furthermore, the sensor device 140 can be handled while being installed in the flexible plate 131, and accordingly, the sensor device 140 can be handled easily.

[0044] As in Fig. As illustrated in Fig. 10, in a flexible plate structure 230, the sensor device 40 can be accommodated in the through-hole 51 of the spacer 50. Furthermore, in this case, the spacer 50 is sandwiched between the thin portion 20b and the flexible plate 31, and the through-hole 51 is formed at the position overlapping with the sensor device 40. In addition, the adhesive 60 is injected into the through-hole 51 to bond the thin portion 20b, the flexible plate 31, and the sensor device 40 together.

[0045] As in Fig. As illustrated in Figure 11, in a flexible plate structure 330, the spacer 50 may be sandwiched between the thin portion 20b and a sensor device 340. More specifically, a sensor device mounting structure may be provided, including: a thin section that is thinner than other parts of a component; a flexible plate; at least one sensor device installed under the flexible plate; a spacer, which is formed in a form of a film with a uniform thickness, which is sandwiched between the thin portion and the at least one sensor device, and which includes a through-portion formed through the spacer at a position corresponding to a part of the at least one sensor device in a thickness direction of the spacer; and an adhesive, which is introduced into the passage section, and which connects the thin section and the at least one sensor device.

[0046] In the spacer 50, the through-hole 51 is formed at a position overlapping a part of the sensor device 340. The adhesive 60 bonds the thin portion 20b and the sensor device 340 to each other. With such a configuration, in a state where the sensor device 340 is pressed against the thin portion 20b by interposing the spacer 50, a distance between the thin portion 20b and the sensor device 340 is equal to the thickness of the spacer 50. Thus, the thickness of the adhesive 60 is equal to the thickness of the spacer 50 by injecting the adhesive 60 into the through-hole 51 and then pressing the sensor device 340 against the thin portion 20b by interposing the spacer 50. In other words, the thickness of the adhesive 60 can be ensured due to the thickness of the spacer 50.Thus, the thickness of the adhesive 60 can be ensured even when the sensor device 340, which is installed under the flexible plate 31, is attached to the thin portion 20b of the component 20. Furthermore, it is easy to adjust the thickness of the layered spacer 50, and consequently, the thickness of the adhesive 60 can also be stabilized during mass production. Furthermore, it is easy to appropriately control the bonding strength and the distance between the thin portion 20b and the sensor device 340.

[0047] As in Fig.As illustrated in FIG. 12, the thin portion 20b may be formed in a ring-shaped manner, and a flexible plate 431 and a spacer 450 may be formed in a ring-shaped manner along the thin portion 20b. A flexible plate assembly 430 (i.e., the sensor device mounting structure 10) includes the plurality of sensor devices 40, and at positions corresponding to the plurality of sensor devices 40, a plurality of through-holes 451 (i.e., through-portions) are formed through the spacer 450 in its thickness direction, respectively. At positions not overlapping the plurality of sensor devices 40, a plurality of other through-holes 455 (i.e., through-portions) may be formed through the spacer 450 in its thickness direction.With such a configuration, the thickness of the adhesive 60 on the bonded parts can be ensured when the flexible plate 431 is bonded in conformity to the shape of the thin portion 20b. Additionally, grooves 452 that communicate between an outer side of the spacer 450 and the through holes 451 are formed in the spacer 450, and grooves 456 that communicate the outer side of the spacer 450 and the other through holes 455 are formed in the spacer 450.

[0048] The thin portion 20b of the component 20 does not necessarily have to be a flat plate part, but may also be a curved plate part.

Claims

[1] Sensor device mounting structure (10, 30, 430), comprising: a component (20) including a thick portion (20a) and a thin portion (20b), the thin portion (20b) being thinner than the thick portion (20a); a flexible plate (31, 131, 431); at least one sensor device (40, 140, 340) installed on the flexible plate (31, 131, 431); a spacer (50, 450), which is formed in a form of a film with a uniform thickness, which is sandwiched between the thin portion (20b) and the flexible plate (31, 131, 431), and which includes a through-portion (51, 451) formed at a position corresponding to the at least one sensor device (40, 140, 340) in a thickness direction of the spacer (50, 450) through the spacer (50, 450); and an adhesive (60) which is introduced into the passage section (51, 451), and connecting the thin section (20b) and the flexible plate (31, 131, 431) together, wherein the spacer (50, 450), in addition to the through-portion (51, 451), includes another through-portion (55) formed through the spacer (50, 450) at a position other than the at least one sensor device (40, 140, 340) in the thickness direction of the spacer (50, 450). [2] The sensor device mounting structure (10, 30, 430) according to claim 1, wherein the thin portion (20b) is formed in a ring-shaped shape, and wherein the flexible plate (31, 131, 431) and the spacer (50, 450) are formed in a ring shape along the thin portion (20b). [3] The sensor device mounting structure (10, 30, 430) according to claim 1, wherein, in the spacer (50, 450), a shape and a size of the through portion (51, 451) formed at the position corresponding to the at least one sensor device (40, 140, 340) and a shape and a size of the other through portion (55) provided in addition to the through portion (51, 451) and formed at the position not corresponding to the at least one sensor device (40, 140, 340) are the same as each other. [4] The sensor device mounting structure (10, 30, 430) according to claim 1, wherein the at least one sensor device (40, 140, 340) is formed as an electronic circuit pattern having a conductor pattern on the flexible board (31, 131, 431). [5] Sensor device mounting structure (10, 30, 430) according to claim 1, wherein the at least one sensor device (40, 140, 340) includes a plurality of sensor devices, and wherein the through portion (51, 451) of the spacer (50, 450) includes a plurality of through portions formed at positions corresponding to the plurality of sensor devices, respectively, in the thickness direction of the spacer (50, 450) through the spacer (50, 450). [6] The sensor device mounting structure (10, 30, 430) according to claim 1, wherein a groove (52) communicates an outer side of the spacer (50, 450) and the through portion (51, 451) with each other.

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