Strain Sensor

Abstract

Provided is a strain sensor capable of increasing the accuracy of detecting strain in a measurement region of an object to be measured. The strain sensor comprises a substrate including a main face and having elasticity, and a first wiring and a second wiring provided on the main face. The substrate includes a sensing region capable of expanding and contracting in a first direction if viewed in planar view from the normal direction of the main face, and a first region and second region positioned facing each other with the sensing region interposed therebetween. Each of the first wiring and the second wiring extends to the first region, the sensing region, and the second region. The first wiring and the second wiring are electrically separated from each other and disposed spaced apart in a second direction orthogonal to the first direction in the sensing region. At least one of the first wiring and the second wiring includes a first wiring concentrated portion in which the wiring is disposed in greater concentration than in the sensing region, and at least one of the first wiring and the second wiring includes a second wiring concentration portion in which the wiring is disposed in greater concentration than in the sensing region.

Description

[Technical Field]

[0001] The present invention relates to a strain sensor. [Background technology]

[0002] In recent years, strain sensors have been used to detect and control the movements of bodies and robots. Patent Document 1 by the present applicant discloses a strain sensor that can be attached to, for example, the human body to detect the movements of joints or cartilage.

[0003] The strain sensor disclosed in Patent Document 1 includes a sensor sheet having a stretchable substrate and detection conductors (hereinafter referred to as "detection wiring" or simply "wiring") provided on the substrate and made of a material whose resistance value changes greatly with expansion and contraction. The detection wiring expands and contracts in a predetermined direction in response to strain in the object to be measured, and detects strain in the expansion and contraction direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 166122 Summary of the Invention [Problem to be solved by the invention]

[0005] In the strain sensor of Patent Document 1, the detection accuracy may decrease due to deformation of the portions of the sensor sheet located on both ends of the sensing portion.

[0006] SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a strain sensor that can improve the accuracy of detecting strain in a measurement target area of ​​an object to be measured. [Means for solving the problem]

[0007] In order to achieve the above object, a strain sensor according to one aspect of the present invention includes a substrate having a main surface and having flexibility, a first wiring provided on the main surface and extending in a first direction, and a second wiring provided on the main surface and extending in the first direction, wherein the substrate has a sensing region that can expand and contract in the first direction when viewed in a plan view from a normal direction of the main surface, and a first region and a second region that are positioned opposite each other across the sensing region in the first direction, and the first wiring and the second wiring are respectively connected to the first region, the The first wiring and the second wiring extend into a sensing region and the second region, and are electrically isolated from each other and arranged at a distance from each other in a second direction in the sensing region that is perpendicular to the first direction, and at least one of the first wiring and the second wiring has a first wiring-dense portion in the first region that is arranged more densely than in the sensing region, and at least one of the first wiring and the second wiring has a second wiring-dense portion in the second region that is arranged more densely than in the sensing region. [Effects of the Invention]

[0008] The strain sensor according to the present invention can improve the accuracy of detecting strain in the measurement target region of the object to be measured. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view of a strain sensor according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged plan view showing a part of the strain sensor of FIG. 1. [Figure 3] FIG. 2 is an enlarged plan view for explaining the wiring density in the strain sensor of FIG. [Figure 4] FIG. 2 is an enlarged plan view of a densely packed wiring portion of the strain sensor of FIG. 1. [Figure 5A] FIG. 2 is a plan view for explaining a measurement example using the strain sensor of FIG. 1. [Figure 5B] 2 is a diagram illustrating a measurement result using the strain sensor of FIG. 1. FIG. [Figure 5C]FIG. 10 is a plan view for explaining a measurement example when the distance between wirings is changed. [Figure 6] FIG. 10 is a plan view showing a strain sensor of a first modified example. [Figure 7] FIG. 10 is a plan view showing a strain sensor according to a second modification. [Figure 8] FIG. 10 is a plan view showing a strain sensor according to a third modification. [Figure 9] 9 is an enlarged plan view of a densely packed wiring portion of the strain sensor of FIG. 8. FIG. [Figure 10] FIG. 10 is a plan view showing a strain sensor of a fourth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Findings that form the basis of the present invention) The present inventors have conducted extensive research to further improve the accuracy of detecting strain in a measurement target region of an object to be measured, and have come to the following findings.

[0011] In the substrate constituting the strain sensor, the region located in the sensing section is called the "sensing region," and the region located around the sensing section is called the "peripheral region." For example, the detection wiring may be arranged so that it extends not only in the sensing region of the substrate but also in the peripheral region of the substrate. In order to further improve detection accuracy, a strain sensor with such a configuration is required that suppresses deformation of the peripheral region of the substrate without interfering with the expansion and contraction of the substrate and detection wiring in a predetermined direction in response to the strain of the object to be measured in the measurement target region.

[0012] Therefore, the inventors discovered that by extending two or more detection wirings to a sensing region of a substrate and two peripheral regions (hereinafter referred to as the "first region" and the "second region") that are positioned opposite each other across the sensing region of the substrate in the direction of expansion and contraction of the detection wirings (hereinafter referred to as the "first direction"), and by arranging a densely packed portion of any of the detection wirings in each of the first and second regions, it is possible to suppress deformation of the peripheral regions without interfering with expansion and contraction of the sensing region in a predetermined direction. Based on this novel finding, the inventors arrived at the present invention.

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment. In addition, substantially the same components in the drawings are designated by the same reference numerals.

[0014] Furthermore, for the sake of convenience, the following uses terms indicating directions such as "up," "down," "right," "left," and "side," assuming a state of normal use, but this does not mean to limit the state of use of the strain sensor according to the present invention.

[0015] <<Embodiment>> Fig. 1 is a plan view of a strain sensor according to an embodiment of the present invention, and Fig. 2 is an enlarged plan view showing a part of the strain sensor of Fig. 1 in an enlarged scale.

[0016] 1 and 2, the strain sensor 100 according to this embodiment includes a stretchable substrate 10 and a plurality of wirings 20a-20e (hereinafter sometimes collectively referred to as "wirings 20") provided on the main surface of the substrate 10. The strain sensor 100 may further include a plurality of terminal portions 40 and a fixing member 50 that supports at least a portion of the substrate 10. In this specification, in the plan views shown in FIGS. 1 and 2, the horizontal direction is defined as the x direction, the direction perpendicular to the x direction (the up-down direction) is defined as the y direction, and the thickness direction of the substrate 10 is defined as the z direction.

[0017] The substrate 10 has a main surface and a back surface opposite the main surface. When the strain sensor 100 is in use, the back surface of the substrate 10 is located, for example, on the side of the object to be measured. In a plan view, the substrate 10 has a sensing region 10s, a first region 11, and a second region 12. The sensing region 10s is a region that can expand and contract in a first direction (the x direction in this example). The first region 11 and the second region 12 are positioned opposite each other in the first direction (x direction) with the sensing region 10s sandwiched therebetween. The sensing region 10s can expand and contract in the x direction in response to, for example, deformation of the object to be measured. Note that "plan view" refers to a plan view from the normal direction of the main surface of the substrate 10, in other words, a plan view from above the main surface of the substrate 10 in the thickness direction (z direction) of the substrate 10.

[0018] The sensing region 10s has a bottom end 10L and a top end 10U that face each other in the y direction, and a right end and a left end that face each other in the x direction. In this example, the left end of the sensing region 10s contacts the first region 11, and the right end of the sensing region 10s contacts the second region 12. The substrate 10 may be a continuous sheet member that includes the sensing region 10s, the first region 11, and the second region 12.

[0019] In a plan view, the substrate 10 may further have a connection region 13 and a terminal region 14 in which the terminal portion 40 is arranged. The connection region 13 is a region that connects the first region 11 and / or the second region 12 (here, the first region 11) to the terminal region 14. In the example shown, in a plan view, the connection region 13 extends downward from the lower end of the first region 11.

[0020] Each of the multiple wirings 20 is, for example, a detection wiring whose resistance value can change due to expansion and contraction. The multiple wirings 20 are electrically isolated from one another. Each wiring 20 extends to the first region 11, the sensing region 10s, and the second region 12. As described below, each wiring 20 may have a folded structure. As shown in the figure, each wiring 20 may also extend to the connection region 13 and the terminal region 14. Each end of each wiring 20 is electrically connected to a corresponding terminal portion 40. In this specification, the portion of each wiring 20 located in the sensing region 10s may be referred to as a "detection portion," the portion located in the first region 11 and the second region 12 as a "lead-out portion," and the portion located in the connection region 13 and the terminal region 14 as a "connection portion." The detection portion of each wiring 20 may be, for example, linear and extending in the x-direction. Note that the detection portion may extend in the first direction (x-direction) and may include a linear portion, a curved portion, or both, and may have a bent portion (or curved portion).

[0021] In the example shown in FIG. 1, the five wirings 20a-20e are arranged in this order in the sensing area 10s from the lower end 10L to the upper end 10U, spaced apart from one another in a second direction (here, the y direction) perpendicular to the first direction. In the sensing area 10s, the detection sections of the wirings 20a-20e may be arranged parallel to one another. Within the sensing area 10s, the regions rs1-rs4 located between two wirings 20 adjacent to one another in the y direction are referred to as "inter-wiring regions." The distances (maximum distances) d1 in the y direction between the respective inter-wiring regions rs1-rs4 may be equal to one another. This allows for more accurate measurement of the displacement of the object under test in the y direction.

[0022] The wiring 20a has a first wiring dense portion 21a in the first region 11 and a second wiring dense portion 22a in the second region 12. In this specification, the "wiring dense portion" refers to a portion where the wiring is arranged more densely than in the sensing region 10s. The wiring dense portion may have, for example, a meandering shape. Similarly, the wirings 20b to 20d have first wiring dense portions 21b to 21d in the first region 11 and second wiring dense portions 22b to 22d in the second region 12, respectively. Some of the wirings (here, wiring 20e) may not have a wiring dense portion.

[0023] The first wiring dense portions 21a to 21d (sometimes collectively referred to as "first wiring dense portions 21") of the wirings 20a to 20d may be arranged at a distance from each other in the y direction in the first region 11. Similarly, the second wiring dense portions 22a to 22d (sometimes collectively referred to as "second wiring dense portions 22") of the wirings 20a to 20d may be arranged at a distance from each other in the y direction in the second region 12.

[0024] The number of wirings 20 in the strain sensor 100 is not particularly limited. The strain sensor 100 only needs to have at least two wirings (sometimes referred to as "first wirings" and "second wirings") as the multiple wirings 20. In this embodiment, at least one of the first wirings and the second wirings only needs to have a first wiring-dense portion 21 in the first region 11, and at least one of the first wirings and the second wirings only needs to have a second wiring-dense portion 22 in the second region 12.

[0025] Hereinafter, a more detailed wiring structure will be described with reference to Fig. 2, taking as an example a case where the "first wiring" is wiring 20a and the "second wiring" is wiring 20b. Note that the first wiring and the second wiring may each be other wirings.

[0026] The wiring 20a and the wiring 20b are arranged at a distance from each other in the y direction in the sensing region 10s. In a plan view, the wiring 20b is arranged between the wiring 20a and the upper end portion 10U (i.e., above the wiring 20a).

[0027] In a plan view, at least a portion (here, the entirety) of the first wiring dense portion 21a of the wiring 20a is located in a first adjacent region r1 adjacent to the inter-wire region rs1 in the first region 11. At least a portion (here, the entirety) of the second wiring dense portion 22a of the wiring 20a is located in a second adjacent region r2 adjacent to the inter-wire region rs1 in the second region 12. That is, in a plan view, the first wiring dense portion 21a and the second wiring dense portion 22a are positioned opposite each other with the inter-wire region rs1 in between. Similarly, at least a portion of the first wiring dense portion 21b of the wiring 20b is located in a region adjacent to the inter-wire region rs2 in the first region 11, and at least a portion of the second wiring dense portion 22b of the wiring 20b is located in a region adjacent to the inter-wire region rs2 in the second region 12.

[0028] 2, in a plan view, the wiring 20a has an extending portion (also referred to as a "first extending portion") a1, an extending portion (also referred to as a "second extending portion") a2, and a folded portion (also referred to as a "first folded portion") a3 that connects one end (here, the right end) of each of the extending portions a1 and a2. The extending portions a1 and a2 each extend to the first region 11, the sensing region 10s, and the second region 12. The folded portion a3 is disposed in the first region 11 or the second region 12 (here, the second region 12). In this specification, such a wiring structure is referred to as a "folded structure."

[0029] The folded portion a3 may have a structure that reverses the extending direction of the wiring 20a. The first wiring dense portion 21 (or the second wiring dense portion 22) may include a portion that functions as the folded portion. As shown in the figure, a part of the second wiring dense portion 22 having a meandering shape may function as the folded portion a3.

[0030] In the sensing region 10s, the extensions a1 and a2 are arranged at a distance ("first distance") d2 from each other in the y direction. In the sensing region 10s, the extensions a1 and a2 may be parallel to each other. The first distance d2 between the extensions a1 and a2 is smaller than the distance d1 between the two wirings 20a and 20b adjacent to each other in the y direction (here, the distance in the y direction of the inter-wiring region rs1). The distance d1 is, for example, 5 mm, and the first distance d2 is, for example, 0.5 mm.

[0031] In a plan view, of the two extending portions a1, a2 of the wiring 20a, the extending portion a1 located on the lower end portion 10L side is sometimes referred to as the "lower extending portion," and the extending portion a2 located on the upper end portion 10U side (the wiring 20b side) is sometimes referred to as the "upper extending portion." In this example, the first wiring dense portion 21a and the second wiring dense portion 22a are formed in the upper extending portion a2 of the wiring 20a. This allows the first wiring dense portion 21a and the second wiring dense portion 22a to be disposed in the regions r1, r2 adjacent to the first inter-wiring region rs1. The lower extending portion a1 of the wiring 20a does not need to have a wiring dense portion.

[0032] Like the wiring 20a, the wiring 20b also has a lower extending portion (also referred to as a "third extending portion") b1, an upper extending portion (also referred to as a "fourth extending portion") b2, and a folded portion (also referred to as a "second folded portion") b3 (folded structure). The extending portions b1 and b2 extend to the first region 11, the sensing region 10s, and the second region 12, respectively. The folded portion b3 is disposed in the first region 11 or the second region 12 (here, the second region 12). In the sensing region 10s, the extending portion b1 and the extending portion b2 are disposed with a distance ("second distance") d3 between them in the y direction. The second distance d3 is smaller than the distance d1 between the wirings 20a and 20b in the y direction. The second distance d3 may be the same as the first distance d2. The first wiring dense portion of the wiring 20b 21 b and the second wiring density area 22 b may be formed in the upper extending portion b2, which allows the first wiring dense portion 21b and the second wiring dense portion 22b to be disposed in regions adjacent to the inter-wiring region rs2.

[0033] Although the above description has been given taking the wirings 20a and 20b as an example, the other wirings 20c to 20e may also have a folded structure, as shown in FIG. 1. Furthermore, the first wiring dense portion 21c and the second wiring dense portion 22c of the wiring 20c (sometimes referred to as the "third wiring") may each be disposed in a region adjacent to the inter-wiring region rs3. Similarly, the first wiring dense portion 21d and the second wiring dense portion 22d of the wiring 20d (sometimes referred to as the "fourth wiring") may each be disposed in a region adjacent to the inter-wiring region rs4. The wiring dense portions of the wirings 20c and 20d may be provided in upper extending portions of the wirings.

[0034] 1, a wire-dense portion is provided in the upper extending portion of each wire 20, but instead, a wire-dense portion may be provided in the lower extending portion of each wire 20. In this case, a first wire-dense portion and a second wire-dense portion of wire 20b may be arranged in a first adjacent region r1 and a second adjacent region r2 adjacent to inter-wire region rs1. Furthermore, a first wire-dense portion and a second wire-dense portion of wire 20c may be arranged in a region adjacent to inter-wire region rs2.

[0035] According to this embodiment, at least one densely-packed wiring portion 21, 22 is formed in each of the first region 11 and the second region 12 located on both sides of the sensing region 10s of the substrate 10. This suppresses deformation (expansion / contraction) of the first region 11 and the second region 12, thereby reducing the effect of deformation of the first region 11 and the second region 12 on the strain detection results in the sensing region 10s. Therefore, by installing the strain sensor 100 so that the measurement target region and the sensing region 10s face each other, strain occurring in the measurement target region can be detected with higher accuracy. For example, measurement errors caused by expansion / contraction of the wiring 20 (e.g., the lead-out portions of each wiring 20) due to deformation of the first region 11 and the second region 12 can be suppressed. Furthermore, suppressing deformation (expansion / contraction) of the sensing region 10s in the y direction due to deformation of the first region 11 and the second region 12 can suppress distortion of the wiring 20 in the sensing region 10s and fluctuations in the distance d1 between the wirings 20. As a result, it is possible to reduce measurement errors (for example, measurement errors of the amount of displacement of the object to be measured) caused by distortion of wiring 20, fluctuations in distance d1, etc., and therefore improve detection accuracy. The influence of fluctuations in distance d1 on the detection results will be described later with reference to FIG. 5C.

[0036] In the strain sensor of Patent Document 1, the wiring is folded back near the center of the sensing region and does not extend to both sides of the sensing region. In contrast, in this embodiment, the wiring 20 is intentionally extended to both sides of the sensing region 10s and is used to suppress deformation of the first region 11 and the second region 12. By forming dense wiring sections in both the first region 11 and the second region 12, deformation of the first region 11 and the second region 12 can be suppressed in a balanced manner, thereby further reducing the impact on detection accuracy. Furthermore, because deformation of the sensing region 10s in the y direction is suppressed more than when the wiring 20 extends to only one side of the sensing region 10s, fluctuations in the distance d1 between the wiring 20a and the wiring 20b are less likely to occur.

[0037] Furthermore, according to this embodiment, at least one of the wires (here, wires 20a to 20d) has both the first wire-dense portion 21 and the second wire-dense portion 22. This configuration makes it possible to more efficiently suppress deformation of the substrate 10 on both sides of the portion (detection portion) of the wire located in the sensing region 10s. Therefore, it is possible to further improve the accuracy of detection using the wire.

[0038] Furthermore, in this embodiment, the first and second densely-spaced wire portions 21a and 22a of one of the wires (here, the wire 20a) are located in the first and second adjacent regions r1 and r2, respectively, adjacent to the inter-wire region rs1. This configuration makes it possible to more effectively suppress fluctuations in the distance d1 in the y-direction of the inter-wire region rs1, even if tension is applied to the first and second regions 11 and 12 of the substrate 10 when the strain sensor 100 is installed in the measurement target region. In plan view, the densely-spaced wire portions of one of the wires 20 may be located on both sides of each of the inter-wire regions rs1 to rs4 in the sensing region 10s. This makes it possible to suppress fluctuations in the distance d1 between two adjacent wires 20 throughout the entire sensing region 10s.

[0039] Furthermore, according to this embodiment, each wiring 20 has a folded structure, and thus two extending portions electrically connected to each other can be used to measure the strain of the device under test located at the position of that wiring 20. This improves measurement accuracy. Furthermore, by forming a wiring-dense portion in either the upper extending portion or the lower extending portion of each wiring 20, the wiring-dense portion can be positioned adjacent to a desired inter-wiring region.

[0040] Each component of the strain sensor 100 will be described in more detail below.

[0041] (Substrate 10) The material of the substrate 10 is preferably a stretchable material with a low elastic modulus, such as polyurethane, acrylic, styrene, silicone resin, etc. The thickness of the substrate 10 is not particularly limited, but is preferably 10 μm to 200 μm, more preferably 20 μm to 100 μm, and even more preferably 30 μm to 50 μm.

[0042] The size of the sensing region 10s in plan view can be set taking into account the size of the measurement target region of the object to be measured. In this example, the outer edge of the sensing region 10s is a rectangle with sides extending in the x and y directions. The size of each of the first region 11 and the second region 12 in plan view is not particularly limited as long as it is possible to arrange multiple wirings 20, including a wiring-dense portion. The width of each of the first region 11 and the second region 12 in the x direction may be smaller than the width of the sensing region 10s. The width of each of the first region 11 and the second region 12 in the y direction may be approximately the same as the width of the sensing region 10s.

[0043] It is preferable that the sensing region 10s is more easily deformed in the first direction (x direction) than the first region 11 and the second region 12. In other words, it is preferable that the sensing region 10s is configured to have higher followability in response to strain of the object to be measured than the first region 11 and the second region 12. The followability of the sensing region 10s can be set taking into consideration the flexibility of the object to be measured. In this example, the sensing region 10s includes a plurality of slits s1 extending in a direction (e.g., y direction) intersecting the x direction, which is the direction in which the wiring 20 expands and contracts. The slits s1 may be arranged at intervals in the x direction in each of the inter-wiring regions rs1 to rs4. The slits s1 are formed between the wiring 20a and the lower end 10L and between the wiring 20e and the upper end 10L. 0U. The sensing region 10s may further have a plurality of slits s2 extending in the x-direction. Each of the slits s2 may be located between two adjacent wirings 20. On the other hand, it is preferable that no slits are formed in the first region 11 and the second region 12. This makes it easier for the sensing region 10s to deform in the x-direction than the first region 11 and the second region 12.

[0044] The size, number, arrangement, etc. of the slits provided in the substrate 10 are not particularly limited and can be set appropriately to ensure the desired tracking ability. In addition, the position, shape, etc. of each region of the substrate 10 (sensing region 10s, first region 11, second region 12, connection region 13, terminal region 14) are not limited to the example shown in the figures.

[0045] (Wiring 20) Each wiring 20 has a detection portion located in the sensing region 10s and lead-out portions located in the first region 11 and the second region 12. Each wiring 20 may further have connection portions 61, 62 located in the connection region 13 and the terminal region 14 for connecting the wiring to the terminal portion 40.

[0046] It is preferable that at least the detection portion of the wiring 20 be made of a material that exhibits a large change in resistance value with respect to expansion and contraction. The material of the detection portion of the wiring 20 may be, for example, a mixture containing metal powder such as silver (Ag) or copper (Cu) and an elastomer resin such as silicone. When the wiring 20 (or at least the detection portion of the wiring 20) is made of a mixture of metal powder and resin, expansion and contraction of the sensing region 10s increases the distance between the metal powder particles as well as the number of contact points between the metal powder particles, thereby increasing the rate of increase or decrease in resistance value with respect to displacement. Furthermore, the elasticity of the resin can prevent breakage due to deformation.

[0047] The material of the detection portion of the wiring 20 may be the same as the material of the lead-out portion. In this embodiment, the dense wiring portions 21 and 22 can suppress expansion and contraction of the lead-out portion of the wiring 20. Therefore, even if the material of the lead-out portion is the same as that of the detection portion, the effect of expansion and contraction of the lead-out portion on the detection result (changes in the resistance value of the wiring 20) can be reduced. The material of the connection portions 61 and 62 may also be the same as that of the detection portion. If the entire wiring 20 is made of the same material, they can be formed collectively in a single process (for example, a printing method), allowing for inexpensive manufacturing.

[0048] Note that the portions of each wiring 20 other than the detection portion (such as the lead-out portion, connection portions 61 and 62) may be made of a material different from that of the detection portion. In this case, by selecting a material with lower resistance than the material of the detection portion as the material of the portions other than the detection portion, it becomes possible to detect strain with higher accuracy.

[0049] The width (line width) of the detection portion of the wiring 20 is not particularly limited, but may be, for example, 0.3 mm. The width and film thickness of the lead-out portion may be the same as the width and film thickness of the detection portion. It is also preferable that the overall length (wiring length) of each wiring 20 is equal to one another. In this embodiment, the wiring lengths of the multiple wirings 20 can be made equal by adjusting the length of the portion of each wiring 20 that constitutes the wiring dense portion.

[0050] (Dense wiring area) 3, in this embodiment, in a plan view, the first wiring dense portion 21a of the wiring 20a is preferably configured so that the wiring density in a unit region U1 including the first wiring dense portion 21a in the first region 11 is higher than the wiring density in a unit region Us including the wiring 20a in the sensing region 10s. Similarly, the second wiring dense portion 22a of the wiring 20a is preferably configured so that the wiring density in a unit region U2 including the second wiring dense portion 22a in the second region 12 is higher than the wiring density in the unit region Us in the sensing region 10s. Here, a "unit region" is a square region in a plan view, with one side being the distance d1 in the y direction between two adjacent wirings 20a and 20b. Furthermore, "wiring density" refers to the proportion of the area of ​​the wiring (here, wiring 20a) that occupies the unit region.

[0051] 4 is an enlarged plan view illustrating the first dense wiring portion 21 in the strain sensor 100. Here, the first dense wiring portion 21 will be described as an example, but the second dense wiring portion 22 may also have a similar shape.

[0052] 4 has a meandering shape. In plan view, the meandering shape may include, for example, two or more (preferably four or more) straight line portions m1 extending in a direction intersecting the x direction (preferably the y direction) and at least one (preferably multiple) bent portion m2 bent so as to be convex in the y direction.

[0053] The wiring spacing d4, d5 (here, the spacing between two adjacent straight line portions m1) in the first wiring dense portion 21 may be smaller than the spacing between the extending portions of the wiring 20 (in this example, the first spacing d2). The minimum value of the spacing d4, d5 may be equal to or smaller than the wiring width dw or the width obtained by adding the length of the tolerance to the wiring width dw. The wiring width dw is, for example, 0.3 mm±0.1 mm (0.1 mm is the tolerance), and the minimum value of the spacing d4, d5 is, for example, 0.2 mm.

[0054] According to this embodiment, the first wiring dense section 21 and the second wiring dense section 22 have a meandering shape including the above-mentioned straight section m1, so that deformation of the first region 11 and the second region 12 in the y direction can be more effectively suppressed without preventing the sensing region 10s and the detection portion of the wiring 20 from expanding and contracting in the x direction in response to the strain of the object to be measured.

[0055] The specific configuration of the dense wiring portion is not limited to the example shown in FIG. 4. The size (area) of the dense wiring portion, the extension direction of the straight line portions m1 in the dense wiring portion, the number of straight line portions m1, the wiring spacings d4 and d5, the area ratio of the wiring portions to the non-wiring portions in the dense wiring portion, and the like can be set as appropriate. Furthermore, the meandering shape of the dense wiring portion may not have the straight line portions m1, but may be a serpentine shape made up of curved lines. As will be described later, the dense wiring portion may have other planar shapes, such as a double-winding shape.

[0056] (area of ​​densely packed wiring) The area of ​​the dense wiring portion can be set appropriately depending on, for example, the position in the y direction. The "area of ​​the dense wiring portion" is the area of ​​a region including densely arranged wiring portions and non-wiring portions surrounded or defined by the wiring portions in a plan view. In the example shown in Fig. 4, the area of ​​the first dense wiring portion 21 is the area of ​​a virtual rectangle 210 drawn so as to contact the outermost portion of the meandering shape of the wiring 20.

[0057] 1 may include at least two first dense wiring portions 21 that are different in area from each other. Similarly, the second dense wiring portions 22 that are arranged in the second region 12 may include at least two second dense wiring portions that are different in area from each other.

[0058] In this embodiment, the area of ​​each of the multiple first wiring-dense portions 21 and / or the multiple second wiring-dense portions 22 may be varied depending on the position in the y direction in a plan view. This allows the area of ​​the wiring-dense portions provided in positions that are particularly susceptible to deformation in the first region 11 and the second region 12 to be made larger than the areas in the other regions, taking into consideration the use of the strain sensor and structures other than the wiring of the strain sensor. This allows deformation of the first region 11 and the second region 12 to be more efficiently suppressed.

[0059] As an example, when the strain sensor 100 is used to detect throat movement due to swallowing, since the amount of movement of the shoulder is greater than the amount of movement of the neck, the wirings 20 may be configured so that the area of ​​the wire-dense portion at the bottom closest to the shoulder is the largest and the area of ​​the wire-dense portion decreases as it becomes farther from the shoulder (moving away from the bottom in the y direction). Specifically, as shown in Fig. 1, the wirings 20a to 20e may be configured so that the areas of the first wire-dense portions 21a to 21d decrease in order, and the areas of the second wire-dense portions 22a to 22d decrease in order.

[0060] The size relationship of the areas of the dense wiring portions is not limited to the above example. For example, if the areas near the centers in the y direction of the first region 11 and the second region 12 are particularly susceptible to deformation depending on the application of the strain sensor 100, the areas of the dense wiring portions located near the centers may be made the largest.

[0061] Furthermore, in a plan view, the areas of the first wiring dense portion 21a and the second wiring dense portion 22a arranged on both sides of the inter-wiring region rs1 may be different from each other. Similarly, the areas of the first wiring dense portion 21 and the second wiring dense portion 22 arranged on both sides of each of the other inter-wiring regions rs2 to rs4 may be different from each other. This makes it possible to control the ease of deformation of the first region 11 and the second region 12 by the areas of the wiring dense portions.

[0062] 1, the connection portions 61, 62 of each wiring 20 extend in the y direction in the first region 11 but do not extend in the second region 12. Therefore, if the first wiring dense portion 21 and the second wiring dense portion 22 have the same area, the first region 11 may be less likely to deform in the y direction than the second region 12. In contrast, by making the area of ​​the second wiring dense portion 22 arranged in the second region 12 larger than the area of ​​the first wiring dense portion 21, the difference in hardness (resistance to deformation) between the first region 11 and the second region 12 can be reduced.

[0063] The area of ​​the wiring dense portions is not limited to the above example. The areas of the multiple first wiring dense portions 21 may all be the same. Similarly, the areas of the multiple second wiring dense portions 22 may all be the same. Furthermore, the areas of the two wiring dense portions 21, 22 located on both sides of each of the inter-wiring regions rs1 to rs4 may be the same.

[0064] (Measurement example using strain sensor 100) The strain sensor 100 is used by being attached to an object to be measured (e.g., a human body) so that the sensing area 10s faces the measurement target area of ​​the object to be measured. Here, an example will be described in which the strain sensor 100 is used to detect throat movement due to swallowing.

[0065] The strain sensor 100 is attached to the skin of the anterior neck of the subject so as to cover the range of movement of the thyroid cartilage (measurement target area). The strain sensor 100 is positioned, for example, so that the lower end 10L of the sensing area 10s is located below the measurement target area (shoulder side) and the upper end 10U is located on the neck side. The strain sensor 100 is preferably attached so that the vertical movement direction of the thyroid cartilage intersects (preferably orthogonal to) the x-direction, which is the direction in which the multiple wirings 20 expand and contract. The sensing area 10s of the substrate 10 deforms due to displacement of the thyroid cartilage as the subject swallows, and as a result, some of the wirings 20 expand and contract. If the thyroid cartilage is located below a certain wiring 20, the wiring 20 will expand due to the protrusion caused by the thyroid cartilage, and the resistance value of the wiring 20 will increase. The strain sensor 100 generates an output signal based on, for example, the change in resistance value of each wiring 20 due to the expansion and contraction of the wiring 20.

[0066] As shown in Fig. 5A, in the sensing area 10s, when the wires 20a and 20b are arranged parallel to each other at a predetermined interval d1 (e.g., 5 mm) and the thyroid cartilage 90 moves up and down across two or more wires 20, the direction and speed of movement of the thyroid cartilage 90 can be estimated from the change over time in the resistance of the wires 20a and 20b. Fig. 5B is a diagram showing an example of the output signals Sa and Sb of the wires 20a and 20b when the thyroid cartilage 90 moves downward across the wires 20a and 20b. From the results shown in Fig. 5B, it can be estimated that the thyroid cartilage 90 moved downward by 0.5 mm in 0.1 seconds.

[0067] Even when the thyroid cartilage moves back and forth (deforms in the z direction), the wires 20a and 20b expand and contract according to the position and amount of the forward and backward movement, and the resistance value change do. Specifically, when the wires 20a and 20b stretch, the resistance increases, and when they contract, the resistance decreases. In other words, when the thyroid cartilage moves forward, the wires 20a and 20b act in the stretching direction, so the resistance increases. Also, when the thyroid cartilage moves backward and then returns to its original position after having moved forward once, the wires 20a and 20b act in the contracting direction, so the resistance decreases. Therefore, the amount of forward and backward movement of the thyroid cartilage can be estimated. According to this embodiment, since each wire 20 is fixed by a wire-dense section on both sides of the sensing area 10s, not only the up and down movement of the thyroid cartilage but also the forward and backward movement can be detected more accurately.

[0068] As mentioned above, if the sensing area of ​​the substrate 10 expands or contracts in the y direction during attachment of the strain sensor 100, causing the distance d1 between the wirings 20a and 20b to fluctuate, a measurement error may occur. FIG. 5C is a comparative example showing a state in which the distance d1 between the wirings 20a and 20b is increased by Δd (e.g., 2 mm) from d1 (e.g., 5 mm). In this state, if downward movement of the thyroid cartilage 90 is detected and output signals Sa and Sb similar to those shown in FIG. 5B are obtained, the thyroid cartilage 90 will be mistakenly perceived as having only moved 5 mm (= d1) in 0.1 seconds, even though it actually moved 7 mm (= d1 + Δd). In contrast, with the strain sensor 100 of this embodiment, the dense wiring area suppresses fluctuations in the distance d1 between the wirings, allowing for more accurate measurement of the displacement of the measurement target.

[0069] (upper layer) The strain sensor 100 may further include a first upper layer 31 disposed on at least a portion of the first region 11 of the substrate 10. The strain sensor 100 may also include a second upper layer 32 disposed on at least a portion of the second region 12 of the substrate 10. In the example shown in FIG. 1 , the first upper layer 31 is disposed so as to cover the plurality of wirings 20, and the second upper layer 32 is disposed so as to cover the plurality of wirings 20.

[0070] The first upper layer 31 and the second upper layer 32 are resin layers formed of, for example, a UV-curable urethane-modified acrylic resin. The first upper layer 31 may extend to the connection region 13 and the terminal region 14 so as to cover the connection portions 61, 62 of each wiring 20. As shown in the figure, it is preferable that the first upper layer 31 and the second upper layer 32 do not extend to the sensing region 10s and do not cover the detection portions of each wiring 20.

[0071] By providing the first upper layer 31, the thickness of the portion of the strain sensor 100 where the first region 11 is arranged (hereinafter referred to as the "first peripheral portion") can be made larger than the thickness of the portion of the strain sensor 100 where the sensing region 10s is arranged (hereinafter referred to as the "sensing portion"). Similarly, by providing the second upper layer 32, the thickness of the portion of the strain sensor 100 where the second region 12 is arranged (hereinafter referred to as the "second peripheral portion") can be made larger than the thickness of the sensing portion. Note that the "thickness of the first peripheral portion" is the thickness in the z direction passing through the first region 11 of the strain sensor 100, and the "thickness of the second peripheral portion" is the thickness in the z direction passing through the second region 12 of the strain sensor 100. The "thickness of the sensing portion" is the thickness in the z direction passing through the sensing region 10s of the strain sensor 100.

[0072] The strain sensor 100 may further include a protective layer (sometimes referred to as a "third upper layer") disposed on the sensing region 10s of the substrate 10 so as to cover the plurality of wirings 20. The material of the protective layer may be the same as or different from the material of the first upper layer 31 and the second upper layer 32. The protective layer may be disposed only on the sensing region 10s, or may extend across the substrate 10. For example, the protective layer may cover the first upper layer 31, the second upper layer 32, and the sensing region 10s.

[0073] When the protective layer, the first upper layer 31 and the second upper layer 32 are made of the same material, the thickness of the protective layer is preferably thinner than the thickness of the first upper layer 31 and the second upper layer 32 .

[0074] When the protective layer and the first and second upper layers 31 and 32 are made of different materials, the materials of the first and second upper layers 31 and 32 are preferably harder (i.e., have a larger Young's modulus) than the material of the protective layer. A known resin material can be used as the material of the protective layer. This makes it possible to make the first and second peripheral portions harder, i.e., less susceptible to deformation, than the sensing portion.

[0075] By making the first peripheral portion and the second peripheral portion thicker or harder than the sensing portion, the first region 11 and the second region 12 can be made even less susceptible to deformation than the sensing region 10s. This further reduces the effect of deformation of the first region 11 and the second region 12 on strain measurement in the sensing region 10s.

[0076] (fixing member) The strain sensor 100 may further include a fixing member 50 that supports at least a portion of the substrate 10. The fixing member 50 is disposed, for example, on the back surface side of the substrate 10. In a plan view, the entire substrate 10 may be disposed so as to overlap the main surface of the fixing member 50. Alternatively, the fixing member 50 may have an opening or a cutout portion at a position corresponding to the sensing region 10s. In this case, in a plan view, at least a portion of the sensing region 10s may overlap the opening or the cutout portion of the fixing member 50. The fixing member 50 may be made of a material such as rubber, urethane rubber, or silicone rubber, or a sponge, such as chloroprene rubber sponge.

[0077] <Variation 1> Fig. 6 is a plan view showing a strain sensor 101 of Modification 1. The strain sensor 101 differs from the strain sensor 100 shown in Fig. 1 in that, in plan view, first wiring dense portions 21a-21d of the wirings 20a-20d are formed above the detection portions of the wirings, and second wiring dense portions 22a-22d are formed below the detection portions of the wirings.

[0078] In this modification, wire-dense portions of different wires (two wires 20a, 20b defining the inter-wire region rs1) are arranged on both sides of the inter-wire region rs1. Specifically, a first wire-dense portion 21a of the wire 20a is arranged in a first adjacent region r1 adjacent to the inter-wire region rs1, and a second wire-dense portion 22b of the wire 20b is arranged in a second adjacent region r2 adjacent to the inter-wire region rs1. With this configuration, the first wire-dense portion 21a located on the left side of the inter-wire region rs1 and the second wire-dense portion 22b located on the right side can be arranged to be shifted from each other in the y direction. This makes it possible to more efficiently suppress deformation of the inter-wire region rs1. Similarly, wire-dense portions of different wires may be arranged on both sides of the inter-wire regions rs2 and rs3.

[0079] In the illustrated example, the first wiring dense portion 21a is formed in the upper extending portion a2 of the wiring 20a, and the second wiring dense portion 22a is formed in the lower extending portion a1 of the wiring 20a. In this way, when the wiring 20 has a folded structure, one of the first wiring dense portion 21 and the second wiring dense portion 22 may be formed in the upper extending portion of the wiring 20, and the other may be formed in the lower extending portion.

[0080] <Variation 2> 7 is a plan view showing a strain sensor 102 of Modification 2. In the strain sensor 102, the wires 20a to 20d have a wire-dense portion only in one of the first region 11 and the second region 12.

[0081] In this modification, at least one of the wirings 20 (here, wirings 20a and 20c) has a first wiring dense portion 21, and at least one of the wirings 20 (here, wirings 20b and 20d) has a second wiring dense portion 22. This makes it possible to suppress deformation of the first region 11 and the second region 12. Furthermore, by reducing the number of wiring dense portions, it is possible to suppress an increase in the wiring length.

[0082] 7, either the first wiring dense portion 21 or the second wiring dense portion 22 is located in a region adjacent to each of the inter-wiring regions rs1 to rs4, thereby making it possible to suppress fluctuations in the distance d1 in the y direction of the inter-wiring region rs1.

[0083] In the sensing region 10s, the wirings 20a and 20c having the first wiring dense portion 21 and the wirings 20b and 20d having the second wiring dense portion 22 may be arranged alternately in the y direction, thereby making it possible to suppress deformation of the first region 11 and the second region 12 in a balanced manner.

[0084] In this modification, the first region 11 is provided with a first wiring dense portion (sometimes referred to as a “first lower wiring dense portion”) 21a arranged in at least one of the wirings 20a and 20b, and a first wiring dense portion (sometimes referred to as a “first upper wiring dense portion” or a “third wiring dense portion”) 21c arranged in at least one of the wirings 20c and 20d. The first upper wiring dense portion 21c is located above (closer to the upper end 10U than) the first lower wiring dense portion 21a. Similarly, the second region 12 is provided with a second wiring dense portion (sometimes referred to as a “second lower wiring dense portion”) 22b arranged in at least one of the wirings 20a and 20b, and a second wiring dense portion (sometimes referred to as a “second upper wiring dense portion” or a “fourth wiring dense portion”) 22d arranged in at least one of the wirings 20c and 20d. The second upper wiring dense portion 22d is located above (closer to the upper end portion 10U) than the second lower wiring dense portion 22b.

[0085] The area of ​​the first upper wiring dense portion 21c and the area of ​​the first lower wiring dense portion 21a may be different from each other. Also, the area of ​​the second upper wiring dense portion 22d and the area of ​​the second lower wiring dense portion 22b may be different from each other. For example, as shown in FIG. 7, the area of ​​the first wiring dense portion 21c is larger than the area of ​​the first wiring dense portion 21a. Small The area of ​​the second wiring dense portion 22d is larger than the area of ​​the second wiring dense portion 22b. Small By making the areas of the first wiring dense portion 21 and the second wiring dense portion 22 different depending on the position in the y direction, deformation of the first region 11 and the second region 12 can be more efficiently suppressed.

[0086] <Variation 3> 8 is a plan view showing a strain sensor 103 of Modification 3. In the strain sensor 103, the first dense wiring portion 21 and the second dense wiring portion 22 have a double-winding shape in plan view.

[0087] In the example shown in FIG. 8, the first wiring dense portions 21a-21d are formed in the upper extending portions of the wirings 20a-20d. Meanwhile, the second wiring dense portions 22a-22d are composed of two extending portions of each of the wirings 20a-20d. The first wiring dense portions 21a-21d may be formed in the lower extending portions of each of the wirings 20a-20d. The second wiring dense portions 22a-22d may be formed only in the upper extending portions or the lower extending portions of each of the wirings 20a-20d. In this example, the areas of the wiring dense portions are all the same, but may be different from each other.

[0088] 9 is an enlarged plan view illustrating the first dense wiring portion 21 having a double-winding shape. Here, the first dense wiring portion 21 will be described as an example, but the second dense wiring portion 22 may also have a similar shape.

[0089] In plan view, the double-winding shape may include multiple straight line portions m1 extending in a direction intersecting the x-direction (preferably the y-direction). This allows deformation of the first region 11 in the y-direction to be more effectively suppressed without preventing the sensing region 10s and the detection portion of the wiring 20 from expanding and contracting in the x-direction in response to strain in the object under test. The wiring spacing d6, d7 constituting the double-winding shape may be smaller than the spacing between the two extending portions of the wiring 20, for example. The minimum value of the spacing d6, d7 may be equal to or less than the wiring width dw or the width obtained by adding the length of the wiring width dw to the tolerance. The area of ​​the first wiring-dense portion 21 is the area of ​​a rectangle 210 that is in contact with the outermost portion of the wiring portion constituting the double-winding shape. The area, number of turns, number of straight line portions m1, and other factors of the double-winding shape are not particularly limited. The double-winding shape may also be formed by curves without including the straight line portion m1.

[0090] <Variation 4> 10 is a plan view showing a strain sensor 104 of Modification 4. In the strain sensor 104, each of the wires 20 does not have a folded structure.

[0091] The wiring 20a has one extending portion a1 that extends from the first region 11 through the sensing region 10s to the second region 12, and connection portions 61 and 62. The left end of the extending portion a1 is electrically connected to one corresponding terminal portion 40 through the connection portion 61, and the right end of the extending portion a1 is electrically connected to one corresponding terminal portion 40 through the connection portion 62. This type of wiring structure is called a "single-wire structure."

[0092] The wiring 20a has a first wiring dense portion 21a in the first adjacent region r1 and a second wiring dense portion 22a in the second adjacent region r2. In this example, the area of ​​the first wiring dense portion 21a is the same as the area of ​​the second wiring dense portion 22a. The other wirings 20b to 20e may also have a single-wire structure similar to that of the wiring 20a.

[0093] According to this modification, the connection portions 61 and 62 of each wiring 20 can be arranged separately in the first region 11 and the second region 12, so that there is little difference in the ease of deformation between these regions 11 and 12. 1 Even if the area of ​​the first wiring dense portion 21 and the area of ​​the second wiring dense portion 22 formed on both sides of ~rs4 are the same, deformation of the first region 11 and the second region 12 can be suppressed in a well-balanced manner.

[0094] The present invention is not limited to the above-described embodiment and modified examples, and can be implemented in various other forms. For example, the distances in the y direction of the inter-wire regions rs1 to rs4 may be set to predetermined distances depending on the application, and may be different from each other. Furthermore, the illustrated strain sensor has five wires 20a to 20e, but it is sufficient to have at least two wires.

[0095] Any of the various embodiments and modifications may be combined as appropriate to achieve the effects of each of them.

[0096] Although the present invention has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes and modifications will become apparent to those skilled in the art, and it is to be understood that such changes and modifications are included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

[0097] The above description can also be expressed as follows.

[0098] The strain sensor of the first aspect comprises: a substrate having a main surface and having elasticity; a first wiring and a second wiring provided on the main surface; the substrate has a sensing region that is expandable and contractible in the first direction when viewed in a plan view from a normal direction of the main surface, and a first region and a second region that are positioned opposite each other in the first direction with the sensing region interposed therebetween; the first wiring and the second wiring extend in the first region, the sensing region, and the second region, respectively; the first wiring and the second wiring are electrically isolated from each other and are arranged in the sensing region at a distance from each other in a second direction perpendicular to the first direction; At least one of the first wiring and the second wiring has a first wiring dense portion in the first region that is arranged more densely than the sensing region, At least one of the first wiring and the second wiring has a second wiring dense portion in the second region that is arranged more densely than the sensing region.

[0099] The strain sensor of the second aspect comprises: In the strain sensor of the first aspect, In the first region, at least a portion of the first densely-packed wiring portion is located in a region of the sensing region adjacent to an inter-wiring region located between the first wiring and the second wiring, In the second region, at least a portion of the second densely-spaced wiring portion is located in a region adjacent to the inter-wiring region.

[0100] The strain sensor of the third aspect comprises: In the strain sensor of the second aspect, The first wiring has the first wiring dense portion and the second wiring dense portion.

[0101] In a fourth aspect, the strain sensor is In the strain sensor of the second aspect, The first wiring has the first wiring dense portion, and the second wiring has the second wiring dense portion.

[0102] The strain sensor of the fifth aspect includes: In the strain sensor according to any one of the first to fourth aspects, the first wiring has a first extending portion, a second extending portion, and a first folded portion connecting end portions of the first extending portion and the second extending portion, the first extending portion and the second extending portion extending to the first region, the sensing region, and the second region, respectively, and the first folded portion is disposed in the first region or the second region; the second wiring has a third extending portion, a fourth extending portion, and a second folded portion connecting end portions of the third extending portion and the fourth extending portion, the third extending portion and the fourth extending portion extending to the first region, the sensing region, and the second region, respectively, and the second folded portion is disposed in the first region or the second region; In the sensing region, the first extension portion and the second extension portion are arranged at a first interval in the second direction, the third extension portion and the fourth extension portion are arranged at a second interval in the second direction, and the first interval and the second interval are smaller than the distance in the second direction between the first wiring and the second wiring.

[0103] The strain sensor of the sixth aspect includes: In the strain sensor of the fifth aspect, The extending portion located on the second wiring side of the first extending portion and the second extending portion has the first wiring dense portion and the second wiring dense portion.

[0104] The strain sensor of the seventh aspect includes: In the strain sensor of the fifth aspect, the first extending portion and the second extending portion, the extending portion located on the second wiring side has the first wiring dense portion; The third extending portion and the fourth extending portion, whichever is located closer to the first wiring, has the second wiring dense portion.

[0105] The strain sensor of the eighth aspect includes: In the strain sensor according to any one of the second to fourth aspects, When viewed in a plan view from the normal direction of the main surface, the area of ​​the first wiring dense portion and the area of ​​the second wiring dense portion are different from each other.

[0106] The strain sensor of the ninth aspect includes: In the strain sensor according to any one of the first to eighth aspects, When viewed from above in a normal direction to the main surface, at least one of the first wiring dense portion and the second wiring dense portion has a meander shape or a double-winding shape.

[0107] The strain sensor of the tenth aspect includes: In the strain sensor according to any one of the first to ninth aspects, The thickness of the strain sensor in the normal direction of the main surface passing through the first region and the thickness of the strain sensor in the normal direction of the main surface passing through the second region are greater than the thickness of the strain sensor in the normal direction of the main surface passing through the sensing region.

[0108] The strain sensor of the eleventh aspect includes: In the strain sensor according to any one of the first to tenth aspects, a first upper layer disposed on the first region of the substrate so as to cover the first wiring and the second wiring; The semiconductor device further includes a second upper layer disposed on the second region of the substrate so as to cover the first wiring and the second wiring.

[0109] The strain sensor of the twelfth aspect includes: In the strain sensor of the eleventh aspect, a third upper layer disposed on the sensing region of the substrate so as to cover the first wiring and the second wiring; The material of the first and second top layers is harder than the material of the third top layer.

[0110] The strain sensor of the thirteenth aspect includes: In the strain sensor according to any one of the first to twelfth aspects, each of the first wiring and the second wiring has the first wiring dense portion and the second wiring dense portion; When viewed in a plane from the normal direction of the main surface, the area of ​​the first wiring dense portion of the first wiring is larger than the area of ​​the first wiring dense portion of the second wiring, and the area of ​​the second wiring dense portion of the first wiring is larger than the area of ​​the second wiring dense portion of the second wiring.

[0111] The strain sensor of the fourteenth aspect includes: In the strain sensor according to any one of the first to thirteenth aspects, further comprising a third wiring and a fourth wiring provided on the main surface of the substrate; the third wiring and the fourth wiring extend to the first region, the sensing region, and the second region; the first wiring, the second wiring, the third wiring, and the fourth wiring are electrically isolated from one another; When viewed in a plan view from a normal direction of the main surface, the sensing region has an upper end and a lower end that face each other in the second direction, and in the sensing region, the first wiring, the second wiring, the third wiring, and the fourth wiring are arranged in this order from the lower end toward the upper end, At least one of the third wiring and the fourth wiring has a third wiring dense portion in the first region that is arranged more densely than the sensing region, When viewed in a plan view from the normal direction of the main surface, the third wiring dense portion is located closer to the upper end than the first wiring dense portion, and the area of ​​the first wiring dense portion and the area of ​​the third wiring dense portion are different from each other.

[0112] The strain sensor of the fifteenth aspect includes: In the strain sensor of the fourteenth aspect, At least one of the third wiring and the fourth wiring has a fourth wiring dense portion in the second region that is arranged more densely than in the sensing region, When viewed in a plan view from the normal direction of the main surface, the fourth wiring dense portion is located closer to the upper end portion than the second wiring dense portion, The area of ​​the first wiring dense portion is larger than the area of ​​the third wiring dense portion, and the area of ​​the second wiring dense portion is larger than the area of ​​the fourth wiring dense portion.

[0113] The strain sensor of the sixteenth aspect includes: In the strain sensor according to any one of the first to fifteenth aspects, The first wiring and the second wiring each extend in the first direction in the sensing region. [Industrial Applicability]

[0114] The strain sensor according to the present invention can be applied to applications requiring detection of strain in various regions, such as detecting deformation such as local swelling of the skin of the human body. [Explanation of symbols]

[0115] 10 Substrate 10s sensing area 10L bottom end 10U top end 11 First area 12 Second area 13 Connection Area 14 Terminal area 20, 20a~20e wiring 21, 21a~21d 1st wiring dense area 22, 22a~22d Second wiring dense area 31 1st upper layer 32 2nd upper layer 40 Terminals 50 fixed parts 100~104 センサ a1 (lower side) extends to the a2 (upper side) extends to the d1 The distance in the second direction of the wiring room area d2 1st interval d3 2nd interval r1 First adjacent domain r2 Second adjacent domain rs1~rs4 wiring room area

Claims

1. a substrate having a main surface and having elasticity; a first wiring and a second wiring provided on the main surface; the substrate has a sensing region that can expand and contract in a first direction when viewed in a plan view from a normal direction of the main surface, and a first region and a second region that are positioned opposite each other in the first direction with the sensing region therebetween; the first wiring and the second wiring extend in the first region, the sensing region, and the second region, respectively; the first wiring and the second wiring are electrically isolated from each other and are arranged in the sensing region at a distance from each other in a second direction perpendicular to the first direction; At least one of the first wiring and the second wiring has a first wiring dense portion in the first region that is arranged more densely than the sensing region, At least one of the first wiring and the second wiring has a second wiring dense portion in the second region that is arranged more densely than the sensing region.

2. In the first region, at least a portion of the first densely-spaced wiring portion is located in a region of the sensing region adjacent to an inter-wiring region located between the first wiring and the second wiring, The strain sensor according to claim 1 , wherein in the second region, at least a part of the second densely-packed wiring portion is located in a region adjacent to the inter-wiring region.

3. The strain sensor according to claim 2 , wherein the first wiring has the first dense wiring portion and the second dense wiring portion.

4. The strain sensor according to claim 2 , wherein the first wiring has the first dense wiring portion, and the second wiring has the second dense wiring portion.

5. the first wiring has a first extending portion, a second extending portion, and a first folded portion connecting end portions of the first extending portion and the second extending portion, the first extending portion and the second extending portion extending to the first region, the sensing region, and the second region, respectively, and the first folded portion is disposed in the first region or the second region; the second wiring has a third extending portion, a fourth extending portion, and a second folded portion connecting end portions of the third extending portion and the fourth extending portion, the third extending portion and the fourth extending portion extending to the first region, the sensing region, and the second region, respectively, and the second folded portion is disposed in the first region or the second region; 5. A strain sensor as described in any one of claims 1 to 4, wherein in the sensing region, the first extension portion and the second extension portion are arranged at a first interval from each other in the second direction, the third extension portion and the fourth extension portion are arranged at a second interval from each other in the second direction, and the first interval and the second interval are smaller than the distance in the second direction between the first wiring and the second wiring.

6. 6. The strain sensor according to claim 5, wherein, when viewed in a plane from a normal direction of the main surface, the extension portion of the first extension portion and the second extension portion that is located on the second wiring side has the first wiring dense portion and the second wiring dense portion.

7. When viewed in a plan view from the normal direction of the main surface, the first extending portion and the second extending portion, the extending portion located on the second wiring side, has the first wiring dense portion; The strain sensor according to claim 5 , wherein one of the third extension portion and the fourth extension portion that is located closer to the first wiring has the second wiring dense portion.

8. The strain sensor according to claim 2 , wherein an area of ​​the first dense wiring portion and an area of ​​the second dense wiring portion are different from each other when viewed in a plan view from a normal direction of the main surface.

9. 5. The strain sensor according to claim 1, wherein at least one of the first wiring dense portion and the second wiring dense portion has a meander shape or a double-winding shape when viewed in a planar view from a normal direction of the main surface.

10. 5. A strain sensor according to claim 1, wherein a thickness of the strain sensor in the normal direction of the main surface passing through the first region and a thickness of the strain sensor in the normal direction of the main surface passing through the second region are greater than a thickness of the strain sensor in the normal direction of the main surface passing through the sensing region.

11. a first upper layer disposed on the first region of the substrate so as to cover the first wiring and the second wiring; The strain sensor according to claim 1 , further comprising: a second upper layer disposed on the second region of the substrate so as to cover the first wiring and the second wiring.

12. a third upper layer disposed on the sensing region of the substrate so as to cover the first wiring and the second wiring; The strain sensor of claim 11 , wherein the material of the first and second top layers is harder than the material of the third top layer.

13. each of the first wiring and the second wiring has the first wiring dense portion and the second wiring dense portion; 5. The strain sensor according to claim 1, wherein, when viewed in a plane from a normal direction of the main surface, an area of ​​the first wiring dense portion of the first wiring is larger than an area of ​​the first wiring dense portion of the second wiring, and an area of ​​the second wiring dense portion of the first wiring is larger than an area of ​​the second wiring dense portion of the second wiring.

14. further comprising third wiring and fourth wiring provided on the main surface of the substrate; the third wiring and the fourth wiring extend to the first region, the sensing region, and the second region; the first wiring, the second wiring, the third wiring, and the fourth wiring are electrically isolated from one another; When viewed in a plan view from a normal direction of the main surface, the sensing region has an upper end and a lower end that face each other in the second direction, and in the sensing region, the first wiring, the second wiring, the third wiring, and the fourth wiring are arranged in this order from the lower end toward the upper end, At least one of the third wiring and the fourth wiring has a third wiring dense portion in the first region that is arranged more densely than the sensing region, 5. The strain sensor according to claim 1, wherein, when viewed in a plane from a normal direction of the main surface, the third wiring dense portion is located closer to the upper end portion than the first wiring dense portion, and an area of ​​the first wiring dense portion and an area of ​​the third wiring dense portion are different from each other.

15. At least one of the third wiring and the fourth wiring has a fourth wiring dense portion in the second region that is arranged more densely than in the sensing region, When viewed in a plan view from the normal direction of the main surface, the fourth wiring dense portion is located closer to the upper end portion than the second wiring dense portion, The strain sensor according to claim 14 , wherein an area of ​​the first dense wiring portion is larger than an area of ​​the third dense wiring portion, and an area of ​​the second dense wiring portion is larger than an area of ​​the fourth dense wiring portion.

16. The strain sensor according to claim 1 , wherein the first wiring and the second wiring each extend in the first direction in the sensing region.

Images