Strain gauge, method for manufacturing a strain gauge, and control device

Abstract

This sensor device enables the quick and efficient mounting of multiple strain-sensing elements onto a strain-generating element, and minimizes variations in the placement of the mounted strain-sensing elements. [Solution] The strain gauge (1) comprises a film (11), wiring (13a) formed on one main surface of the film (11), and a strain-sensing element (12a) connected to the wiring (13a), which is also formed on one main surface of the film (11).

Description

Technical Field

[0001] The present invention relates to a film-type strain gauge and a method for manufacturing such a strain gauge. The present invention also relates to a sensor device provided with such a strain gauge.

Background Art

[0002] Sensor devices that detect force and / or torque acting on a strain-generating body using a strain gauge bonded to the strain-generating body are widely used. As the strain gauge, a film-type strain gauge including a film and a pair of strain-sensitive bodies formed on one main surface of the film is often used. As a document disclosing a film-type strain gauge, for example, Patent Document 1 can be cited.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0004] In a sensor device, it is usually necessary to mount two or more pairs of strain-sensitive bodies on a strain-generating body. Therefore, in order to manufacture the sensor device, it was necessary to bond a plurality of film-type strain gauges each including one pair of strain-sensitive bodies to the strain-generating body one by one. For this reason, there are problems that the work of mounting two or more pairs of strain-sensitive bodies on the strain-generating body takes time, and variations tend to occur in the arrangement of the mounted two or more pairs of strain-sensitive bodies. In addition, in order to connect the two or more pairs of strain-sensitive bodies to an amplifier or the like, it was necessary to connect wiring (for example, by soldering) to each of the plurality of film-type strain gauges each including one pair of strain-sensitive bodies. For this reason, there are problems that the work of connecting the plurality of film-type strain gauges to an amplifier or the like takes time, and the routing of the plurality of connected wirings tends to be complicated.

[0005] One aspect of the present invention has been made in view of the above-mentioned problems, and one of its objectives is to realize a sensor device in which the process of mounting two or more strain-sensing elements onto a strain-generating element is not time-consuming, and in which variations in the arrangement of the mounted two or more strain-sensing elements are less likely to occur. [Means for solving the problem]

[0006] A strain gauge provided in a sensor device according to one aspect of the present invention comprises a film, wiring formed on one main surface of the film, and two or more pairs of strain-sensing elements connected to the wiring, the two or more pairs of strain-sensing elements formed on the one main surface of the film.

[0007] A method for manufacturing a strain gauge according to one aspect of the present invention includes the steps of forming wiring on one main surface of a film and forming two or more strain-sensing elements connected to the wiring on the one main surface of the film. [Effects of the Invention]

[0008] According to one aspect of the present invention, two or more strain-sensing elements can be mounted on a strain-generating body simply by bonding a single strain gauge, on which two or more strain-sensing elements are deposited, to the strain-generating body. Therefore, the process of mounting two or more strain-sensing elements to the strain-generating body is not time-consuming, and a sensor device can be realized in which variations in the arrangement of the mounted two or more strain-sensing elements are less likely to occur. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view showing the front side of a strain gauge according to the first embodiment of the present invention. [Figure 2] Figure 1 is a plan view showing the back side of the strain gauge. [Figure 3] Figure 1 is a cross-sectional view showing the cross-section of the straight gauge. [Figure 4] This is a plan view showing the front side of a strain gauge according to a second embodiment of the present invention. [Figure 5] Figure 4 is a plan view showing the back side of the strain gauge. [Figure 6]Figure 4 is a cross-sectional view showing the cross-section of the strain gauge. [Figure 7] Figures 1-3 are perspective views of a sensor device including strain gauges. [Modes for carrying out the invention]

[0010] [First Embodiment] (Stroke gauge configuration) The configuration of the strain gauge 1 according to the first embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a plan view showing the front side of the strain gauge 1. Figure 2 is a plan view showing the back side of the strain gauge 1. Figure 3 is a cross-sectional view showing the AA' section of the strain gauge 1.

[0011] The strain gauge 1 comprises a film 11, strain-sensitive elements 12a, 12b, wiring 13a, 13b, electrode pads 14a, 14b, and protective films 15a, 15b. Note that the protective films 15a, 15b are not shown in Figures 1 and 2.

[0012] Film 11 is a film-like insulator. While polyimide film is used as film 11, the invention is not limited to this. The material of film 11 can be any material.

[0013] In this embodiment, the film 11 is composed of an annular portion 111 and a strip-shaped portion 112 extending outward from the outer circumference of the annular portion 111. Hereinafter, when the strain gauge 1 is viewed from the front in a plan view, the direction in which the strip-shaped portion 112 extends, as seen from the center of the annular portion 111, will be referred to as the 12 o'clock direction. When the strain gauge 1 is viewed from the front in a plan view, the region located at the 12 o'clock direction in the annular portion 111 will be referred to as "region N", the region located at the 3 o'clock direction will be referred to as "region E", the region located at the 6 o'clock direction will be referred to as "region S", and the region located at the 9 o'clock direction will be referred to as "region W". Furthermore, the region located at the end of the strip-shaped portion 112 opposite to the annular portion 111 will be referred to as "region N'".

[0014] As shown in Figure 1, two or more pairs (four pairs, or eight in this embodiment) of strain-sensitive elements 12a, wiring 13a, electrode pads 14a, and electrode pads 14b are deposited on one main surface 11a of the film 11. One end of the wiring 13a is connected to the strain-sensitive element 12a, and the other end of the wiring 13a is connected to the electrode pad 14a. Since two wirings 13a are connected to each strain-sensitive element 12a, twice the number of wirings 13a and electrode pads 14a are deposited on the surface 11a of the film 11. The strain-sensitive element 12a is a strip-shaped conductor whose resistance changes easily in response to strain. Examples of materials for the strain-sensitive element 12a include, but are not limited to, chromium nitride. The wiring 13a is a strip-shaped conductor whose resistance does not change easily in response to strain. The electrode pads 14a and 14b are rectangular-shaped conductors whose resistance does not change easily in response to strain. Examples of materials for the wiring 13a and electrode pads 14a and 14b include, but are not limited to, copper.

[0015] In this embodiment, four strain-sensitive elements 12a are formed on the surface 11a of the film 11. Of these four strain-sensitive elements 12a, two are located in region E, and the remaining two are located in region W. Two wires 13a are connected to each strain-sensitive element 12a. Therefore, a total of four wires 13a are connected to the two strain-sensitive elements 12a located in region E. These four wires 13a travel from region E to region N via a quadrant arc-shaped path set in the annular portion 111, and then from region N to region N' via a linear path set in the strip-shaped portion 112. The ends of these four wires 13a are connected to electrode pads 14a located in region N'. Similarly, a total of four wires 13a are connected to the two strain-sensitive elements 12a located in region W. These four wires 13a travel from region W to region N via a quadrant arc-shaped path set in the annular portion 111, and then from region N to region N' via a straight path set in the strip-shaped portion 112. The ends of these four wires 13a are connected to electrode pads 14a located in region N'.

[0016] Note that, as shown in FIG. 3, a protective film 15a covering the strain-sensitive body 12a and the wiring 13a may be formed on the surface 11a of the film 11. Examples of the material of the protective film 15a include, but are not limited to, silicon dioxide. The protective film 15a is preferably formed so as not to cover the electrode pads 14a and 14b.

[0017] As shown in FIG. 2, on the back surface 11b which is the other main surface of the film 11, two or more pairs (four pairs, eight in total in the present embodiment) of other strain-sensitive bodies 12b and other wirings 13b are formed. One end of the wiring 13b is connected to the strain-sensitive body 12a, and the other end of the wiring 13b is connected to the electrode pad 14b formed on the surface 11a of the film 11 via a through hole formed in the film 11. Since two wirings 13b are connected to each strain-sensitive body 12b, twice as many wirings 13b as the number of the strain-sensitive bodies 12b are formed on the back surface 11b of the film 11, and twice as many electrode pads 14b as the number of the strain-sensitive bodies 12b are formed on the surface 11a of the film 11. The strain-sensitive body 12b is a strip-shaped conductor whose resistance easily changes in response to strain. Examples of the material of the strain-sensitive body 12b include, but are not limited to, chromium nitride. The wiring 13b is a strip-shaped conductor whose resistance hardly changes in response to strain. Examples of the material of the wiring 13b include, but are not limited to, copper.

[0018] In the present embodiment, four strain-sensitive bodies 12b are formed as a film on the back surface 11b of the film 11. Of these four strain-sensitive bodies 12b, two strain-sensitive bodies 12b are arranged in region E, and the remaining two strain-sensitive bodies 12b are arranged in region W of the annular portion 111. Two wirings 13b are connected to each of the strain-sensitive bodies 12b. Accordingly, a total of four wirings 13b are connected to the two strain-sensitive bodies 12b arranged in region E. These four wirings 13b extend from region E to region N via a quadrant arcuate path set in the annular portion 111, and further extend from region N to region N' via a linear path set in the strip portion 112. The distal ends of these four wirings 13b are connected to electrode pads 14b provided on the front surface 11a of the film 11 through through-holes formed in the film 11. Similarly, a total of four wirings 13b are connected to the two strain-sensitive bodies 12b arranged in region W. These four wirings 13b extend from region W to region N via a quadrant arcuate path set in the annular portion 111, and further extend from region N to region N' via a linear path set in the strip portion 112. The distal ends of these four wirings 13b are connected to electrode pads 14b provided on the front surface 11a of the film 11 through through-holes formed in the film 11.

[0019] Note that another protective film 15b covering the strain-sensitive bodies 12b and the wirings 13b may be formed as a film on the back surface 11b of the film 11, as shown in FIG. 3. Examples of the material for the protective film 15b include, but are not limited to, silicon dioxide.

[0020] When viewing the film 11 from above, the strain-sensitive element 12a deposited on the surface 11a of the film 11 and the other strain-sensitive element 12b deposited on the back surface 11b of the film 11 overlap each other (more specifically, they intersect and partially overlap each other). Similarly, when viewing the film 11 from above, the wiring 13a deposited on the surface 11a of the film 11 and the other wiring 13b deposited on the back surface 11b of the film 11 overlap each other (more specifically, they run parallel to each other and completely overlap each other). Therefore, the combination of the strain-sensitive element 12a and wiring 13a deposited on the surface 11a of the film 11 and the combination of the strain-sensitive element 12b and wiring 13b deposited on the back surface 11b of the film 11 have equivalent performance. In other words, in the strain gauge 1, the circuit for detecting the strain realized by the combination of the strain-sensitive element 12a and wiring 13a is duplicated.

[0021] In this embodiment, a configuration is adopted in which multiple strain-sensitive elements 12a and wiring 13a are filmed on the surface 11a of the film 11, but the present invention is not limited thereto. That is, a configuration in which the strain-sensitive elements 12a and wiring 13a are filmed on the surface 11a of the film 11 in a single composition may also be adopted.

[0022] (Method of manufacturing strain gauges) The strain gauge 1 described above can be manufactured, for example, by a manufacturing method that includes the following steps.

[0023] Step 1: A film 11 is produced by laser cutting a polyimide film into a predetermined shape.

[0024] Step 2: A copper film is formed on the surface 11a of the film 11, which functions as wiring 13a and electrode pads 14a and 14b.

[0025] Step 3: A chromium nitride film that functions as a strain sensor 12a is formed on the surface 11a of the film 11.

[0026] Step 4: A silicon dioxide film, which functions as a protective film 15a, is formed on the surface 11a of the film 11.

[0027] Step 5: A copper film that functions as wiring 13b is formed on the back surface 11b of the film 11.

[0028] Step 6: A chromium nitride film that functions as a strain sensor 12b is formed on the back surface 11b of the film 11.

[0029] Step 7: A silicon dioxide film, which functions as a protective film 15b, is formed on the back surface 11b of the film 11.

[0030] Step 8: A reinforcing plate that reinforces the tip of the strip-shaped portion 112 is attached to the back surface 11b of the film 11.

[0031] In addition, through-holes may be formed in step 1 to allow electrical connection between the electrode pads 14b formed on the surface 11a of the film 11 in step 2 and the wiring 13b formed on the back surface 11b of the film 11 in step 5. Alternatively, through-holes may be formed in advance, and step 1 may be carried out using a polyimide film.

[0032] [Second Embodiment] (Stroke gauge configuration) The configuration of the strain gauge 2 according to the second embodiment of the present invention will be described with reference to Figures 4 to 6. Figure 4 is a plan view showing the front side of the strain gauge 2. Figure 5 is a plan view showing the back side of the strain gauge 2. Figure 6 is a cross-sectional view showing the AA' section of the strain gauge 2.

[0033] The strain gauge 2 comprises films 21a, 21b, strain-sensing elements 22a, 22b, wiring 23a, 23b, electrode pads 24a, 24b, and protective films 25a, 25b. Note that the protective films 25a, 25b are not shown in Figures 4 and 5.

[0034] Films 21a and 21b are film-like insulators. While PET (Poly Ethylene Terephthalate) films are used as films 21a and 21b, the material is not limited to this. The material of films 21a and 21b is arbitrary. Films 21a and 21b are bonded together such that film 21a is positioned on the front side of the strain gauge 2, and film 21b is positioned on the back side of the strain gauge 2. That is, the back surface of film 21a and the front surface of film 21b are bonded together, so that the front surface of film 21a becomes the front surface of the strain gauge 2, and the back surface of film 21b becomes the back surface of the strain gauge 2.

[0035] In this embodiment, film 21a is composed of an annular portion 21a1 and a strip-shaped portion 21a2 extending outward from the outer circumference of the annular portion 21a1. Similarly, film 21b is composed of an annular portion 21b1 and a strip-shaped portion 21b2 extending outward from the outer circumference of the annular portion 21b1. The annular portion 21a1 of film 21a and the annular portion 21b1 of film 21b overlap each other in their entirety. The strip-shaped portion 21a2 of film 21a and the strip-shaped portion 21b2 of film 21b overlap each other in their portions other than the leading edge.

[0036] Hereinafter, when the strain gauge 2 is viewed from the front in a plan view, the direction in which the strip-shaped portions 21a2 and 21b2 extend from the center of the annular portions 21a1 and 21b1 is defined as the 12 o'clock direction. Furthermore, when the strain gauge 2 is viewed from the front in a plan view, the region located at the 12 o'clock direction in the annular portions 21a1 and 21b1 is called "region N", the region located at the 3 o'clock direction is called "region E", the region located at the 6 o'clock direction is called "region S", and the region located at the 9 o'clock direction is called "region W". In addition, the region located at the end of the strip-shaped portions 21a2 and 21b2 opposite to the annular portions 21a1 and 21b1 is called "region N'".

[0037] As shown in Figure 4, the surface of the film 21a has two or more pairs (four pairs, eight in this embodiment) of strain-sensitive elements 22a, wiring 23a, and electrode pads 24a deposited on it. One end of the wiring 23a is connected to the strain-sensitive element 22a, and the other end of the wiring 23a is connected to the electrode pad 24a. Since two wirings 23a are connected to each strain-sensitive element 22a, twice the number of wirings 23a and electrode pads 24a as the number of strain-sensitive elements 22a are deposited on the surface of the film 21a. The strain-sensitive element 22a is a strip-shaped conductor whose resistance changes easily in response to strain. Examples of materials for the strain-sensitive element 22a include, but are not limited to, chromium nitride. The wiring 23a is a strip-shaped conductor whose resistance does not change easily in response to strain. The electrode pads 24a are rectangular-shaped conductors whose resistance does not change easily in response to strain. Examples of materials for the wiring 23a and electrode pads 24a include, but are not limited to, copper.

[0038] In this embodiment, four strain-sensitive elements 22a are formed on the surface of the film 21a. Of these four strain-sensitive elements 22a, two are located in region E, and the remaining two are located in region W. Two wires 23a are connected to each strain-sensitive element 22a. Therefore, a total of four wires 23a are connected to the two strain-sensitive elements 22a located in region E. These four wires 23a travel from region E to region N via a quadrant arc-shaped path set in the annular portion 21a1, and then from region N to region N' via a linear path set in the strip-shaped portion 21a2. The ends of these four wires 23a are connected to electrode pads 24a located in region N'. Similarly, a total of four wires 23a are connected to the two strain-sensitive elements 22a located in region W. These four wires 23a travel from region W to region N via a quadrant arc-shaped path set in the annular portion 21a1, and then from region N to region N' via a straight path set in the strip-shaped portion 21a2. The ends of these four wires 23a are connected to electrode pads 24a located in region N'.

[0039] Furthermore, as shown in Figure 6, a protective film 25a may be formed on the surface of the film 21a to cover the strain-sensitive element 22a and the wiring 23a. The protective film 25a may be, for example, a cover film that is heat-laminated to the film 21a, but is not limited thereto. It is preferable that the protective film 25a is formed so as not to cover the electrode pad 24a.

[0040] As shown in Figure 5, two or more pairs (four pairs, or eight in this embodiment) of other strain-sensitive elements 22b, other wiring 23b, and electrode pads 24b are deposited on the back surface of the film 21b. One end of the wiring 23b is connected to the strain-sensitive element 22b, and the other end of the wiring 23b is connected to the electrode pad 24b. Since two wirings 23b are connected to each strain-sensitive element 22b, twice the number of wirings 23b and electrode pads 24b as the number of strain-sensitive elements 22b are deposited on the back surface of the film 21b. The strain-sensitive element 22b is a strip-shaped conductor whose resistance changes easily in response to strain. Examples of materials for the strain-sensitive element 22b include, but are not limited to, chromium nitride. The wiring 23b and electrode pads 24b are strip-shaped conductors whose resistance does not change easily in response to strain. Examples of materials for the wiring 23b and electrode pads 24b include, but are not limited to, copper.

[0041] In this embodiment, four strain-sensitive elements 22b are formed on the back surface of the film 21b. Of these four strain-sensitive elements 22b, two are located in region E, and the remaining two are located in region W of the annular portion 21b1. Two wires 23b are connected to each strain-sensitive element 22b. Therefore, a total of four wires 23b are connected to the two strain-sensitive elements 22b located in region E. These four wires 23b travel from region E to region N via a quadrant arc-shaped path set in the annular portion 21b1, and then from region N to region N' via a linear path set in the strip-shaped portion 21b2. The ends of these four wires 23b are connected to electrode pads 24a located in region N'. Similarly, a total of four wires 23b are connected to the two strain-sensitive elements 22b located in region W. These four wires 23b travel from region W to region N via a quadrant arc-shaped path set in the annular portion 21b1, and then from region N to region N' via a straight path set in the strip-shaped portion 21b2. The ends of these four wires 23b are connected to electrode pads 24a located in region N'.

[0042] Furthermore, as shown in Figure 6, another protective film 25b may be formed on the back surface of the film 21b to cover the strain-sensitive element 22b and the wiring 23b. Examples of the other protective film 25b include, but are not limited to, a cover film that is heat-laminated to the film 21b. It is preferable that the other protective film 25b is formed so as not to cover the electrode pad 24b.

[0043] The strain-sensitive element 22a deposited on the surface of film 21a and the other strain-sensitive element 22b deposited on the back surface of film 21b overlap each other when film 21 is viewed from above (more specifically, they intersect and partially overlap each other). Similarly, the wiring 23a deposited on the surface of film 21a and the other wiring 23b deposited on the back surface of film 21b overlap each other when film 21a is viewed from above (more specifically, they run parallel to each other and completely overlap each other). Therefore, the combination of the strain-sensitive element 22a and wiring 23a deposited on the surface of film 21a and the combination of the strain-sensitive element 22b and wiring 23b deposited on the back surface of film 21b have equivalent performance. In other words, in strain gauge 2, the circuit for detecting the strain realized by the combination of strain-sensitive element 22a and wiring 23a is duplicated.

[0044] In this embodiment, a configuration is adopted in which multiple layers of strain-sensitive elements 22a and wiring 23a are filmed on the surface of the film 21a, but the present invention is not limited thereto. That is, a configuration in which only one layer of strain-sensitive elements 22a and wiring 23a is filmed on the surface of the film 21a may also be adopted.

[0045] (Method of manufacturing strain gauges) The strain gauge 2 described above can be manufactured, for example, by a manufacturing method that includes the following steps.

[0046] Step 1: A PET film with its back side bonded to a glass substrate is laser-cut into a predetermined shape to produce a film 21a.

[0047] Step 2: A copper film that functions as wiring 23a and electrode pads 24a is formed on the surface of the film 21a.

[0048] Step 3: A chromium nitride film, which functions as a strain sensor 22a, is formed on the surface of the film 21a. The strain sensor 22a may also be formed by silk screen printing.

[0049] Step 4: A cover film that functions as a protective film 25a is heat-laminated onto the surface of the film 21a. The film 21a, on which the strain-sensitive element 22a, wiring 23a, electrode pad 24a, and protective film 25a are formed, is peeled off from the glass substrate.

[0050] Step 5: A PET film with its surface bonded to a glass substrate is laser-cut into a predetermined shape to produce a film 21b.

[0051] Step 6: A copper film that functions as wiring 23b and electrode pads 24b is formed on the back surface of film 21b.

[0052] Step 7: A chromium nitride film, which functions as a strain sensor 22b, is formed on the back surface of the film 21b. The strain sensor 22b may also be formed by silk screen printing.

[0053] Step 8: A cover film that functions as a protective film 25b is heat-laminated to the back surface of the film 21b. The film 21b, on which the strain-sensitive element 22b, wiring 23b, electrode pad 24b, and protective film 25b are formed, is peeled off from the glass substrate.

[0054] Step 9: The back surface of film 21a, which was peeled off the glass substrate in Step 4, and the front surface of film 21b, which was peeled off the glass substrate in Step 4, are bonded together.

[0055] [Examples of application] The strain gauges 1 and 2 described above can be applied to sensor devices such as force sensors for detecting force, torque sensors for detecting torque, and force sensing sensors for detecting both force and torque.

[0056] Figure 7 is a perspective view showing the configuration of the sensor device 100. The sensor device 100 includes a strain generating body 101 and a strain gauge 102 attached to the strain generating body 101. The strain gauges 1 and 2 described above can be used as the strain gauge 102 of the sensor device 100.

[0057] In conventional sensor devices, mounting multiple strain sensors onto a strain generator required attaching multiple strain gauges, each containing a pair of strain sensors, to the strain generator. This resulted in a time-consuming process for mounting two or more pairs of strain sensors onto the strain generator, and also made it easy for variations to occur in the placement of the mounted pairs of strain sensors. Furthermore, in conventional sensor devices, connecting two or more pairs of strain sensors to an amplifier or other device required connecting (for example, soldering) wires to each of the multiple strain gauges, each containing a pair of strain sensors. This resulted in a time-consuming process for connecting two or more pairs of strain sensors to an amplifier or other device, and also made it easy for the routing of the multiple connected wires to become complicated.

[0058] In contrast, in the sensor device 100, two or more pairs of strain-sensing elements can be mounted on the strain-generating element 101 simply by attaching a single strain gauge 102, on which two or more pairs of strain-sensing elements are deposited, to the strain-generating element 101. Therefore, the work of mounting two or more pairs of strain-sensing elements on the strain-generating element does not take much time, and variations in the arrangement of the mounted two or more pairs of strain-sensing elements are less likely to occur. Furthermore, in the sensor device 100, two or more pairs of strain-sensing elements can be connected to an amplifier, etc., simply by connecting a single strain gauge on which two or more pairs of wires are deposited (for example, by connecting a connector). Therefore, the work of connecting two or more pairs of strain-sensing elements to an amplifier, etc., does not take much time, and the routing of the multiple connected wires is less likely to become complicated.

[0059] (summary) A strain gauge according to embodiment 1 of the present invention comprises a film, wiring formed on one main surface of the film, and two or more pairs of strain-sensing elements connected to the wiring, the two or more pairs of strain-sensing elements formed on the one main surface of the film.

[0060] According to the above configuration, two or more strain-sensing elements can be mounted on a strain-generating body simply by bonding a single strain gauge, on which two or more strain-sensing elements are deposited, to the strain-generating body. Therefore, the process of mounting two or more strain-sensing elements to the strain-generating body is quick, and a sensor device can be realized in which variations in the arrangement of the mounted two or more strain-sensing elements are less likely to occur.

[0061] The strain gauge according to embodiment 2 of the present invention is the strain gauge according to embodiment 1, wherein an electrode pad connected to the wiring is further formed on one of the main surfaces.

[0062] The above configuration makes it easy to connect two or more distortion sensors to an amplifier or the like.

[0063] A strain gauge according to embodiment 3 of the present invention is a strain gauge according to embodiment 1 or 2, wherein a protective film covering the strain-sensing element and the wiring is formed on one of the main surfaces.

[0064] According to the above configuration, short circuits between wires that may occur due to contact with conductive objects can be made less likely. Furthermore, the durability of the strain-sensitive element and the wires can be increased. In addition, oxidation of the strain-sensitive element and the wires can be suppressed.

[0065] A strain gauge according to aspect 4 of the present invention is the strain gauge according to aspect 1, further comprising: other wiring formed on the other main surface of the film; and two or more pairs of other strain-sensing elements connected to the other wiring, the two or more pairs of other strain-sensing elements formed on the other main surface of the film.

[0066] According to the above configuration, the strain sensor and wiring can be duplicated. That is, if a strain sensor or wiring deposited on one main surface fails, another strain sensor or wiring deposited on the other main surface can be used, and if another strain sensor or wiring deposited on the other main surface fails, the strain sensor or wiring deposited on one main surface can be used. Alternatively, the strain sensor deposited on one main surface and the strain sensor deposited on the other main surface can be used as strain sensors with different biases.

[0067] A strain gauge according to embodiment 5 of the present invention is a strain gauge according to embodiment 1, further comprising: another film having one main surface bonded to the other main surface of the film; another wiring formed on the other main surface of the other film; and another strain-sensing element connected to the other wiring, the other strain-sensing element being formed on the other main surface of the other film.

[0068] According to the above configuration, the strain sensor and wiring can be duplicated. That is, if a strain sensor or wiring deposited on one film fails, another strain sensor or wiring deposited on the other film can be used, and if another strain sensor or wiring deposited on the other film fails, the strain sensor or wiring deposited on one film can be used. Alternatively, the strain sensor deposited on one film and the strain sensor deposited on the other film can be used as strain sensors with different biases.

[0069] A method for manufacturing a strain gauge according to embodiment 6 of the present invention includes the steps of forming wiring on one main surface of a film and forming two or more strain-sensing elements connected to the wiring on the one main surface of the film.

[0070] According to the above configuration, two or more strain-sensing elements can be mounted on a strain-generating body simply by bonding a single strain gauge, on which two or more strain-sensing elements are deposited, to the strain-generating body. Therefore, the process of mounting two or more strain-sensing elements to the strain-generating body is quick, and it is possible to manufacture a sensor device in which variations in the arrangement of the mounted two or more strain-sensing elements are less likely to occur.

[0071] A strain gauge according to embodiment 7 of the present invention is a method for manufacturing a strain gauge according to embodiment 6, further comprising the steps of: forming other wiring on the other main surface of the film; and forming other strain-sensing elements connected to the other wiring on the other main surface of the film.

[0072] According to the above configuration, it is possible to manufacture strain gauges in which the strain-sensing element and wiring are duplicated, or in which strain-sensing elements with different biases are formed.

[0073] A strain gauge according to embodiment 8 of the present invention is a method for manufacturing a strain gauge according to embodiment 6, further comprising the steps of: forming other wiring on the other main surface of another film; forming other strain-sensing elements connected to the other wiring on the other main surface of the other film; and bonding the other main surface of the film to one main surface of the other film.

[0074] According to the above configuration, it is possible to manufacture strain gauges in which the strain-sensing element and wiring are duplicated, or in which strain-sensing elements with different biases are formed.

[0075] A sensor device according to aspect 9 of the present invention comprises a strain gauge as described in aspects 1 to 5 and a strain-generating body to which the strain gauge is attached.

[0076] According to the above configuration, two or more strain-sensing elements can be mounted on a strain-generating body simply by bonding a single strain gauge, on which two or more strain-sensing elements are deposited, to the strain-generating body. Therefore, the process of mounting two or more strain-sensing elements to the strain-generating body is quick, and a sensor device can be realized in which variations in the arrangement of the mounted two or more strain-sensing elements are less likely to occur.

[0077] A strain gauge according to embodiment 10 of the present invention is a strain gauge according to embodiment 4 or 5, wherein the strain-sensing element and the other strain-sensing element are arranged such that they partially or completely overlap each other when the strain gauge is viewed from above, and the wiring and the other wiring are arranged such that they partially or completely overlap each other when the strain gauge is viewed from above.

[0078] According to the above configuration, the characteristics of the circuit including the distortion sensor and wiring can be matched with the characteristics of other circuits including other distortion sensors and other wiring. Therefore, the change in characteristics that may occur when switching the distortion sensor and wiring used can be kept to a minimum.

[0079] [Additional Notes] [Explanation of Symbols]

[0080] 1,2: Strain gauges, 11,21a,21b: Films, 12a,12b,22a,22b: Strain-sensing elements, 13a,13b,23a,23b: Wiring, 14a,14b,24a,24b: Electrode pads, 15a,15b,25a,25b: Protective films

Claims

1. Film and, Wiring formed on one main surface of the aforementioned film, The device comprises two or more pairs of strain-sensitive elements connected to the aforementioned wiring, wherein two or more pairs of strain-sensitive elements are formed on one of the main surfaces of the film. Strain gauge.

2. An electrode pad connected to the wiring is further formed on one of the main surfaces. The strain gauge according to claim 1.

3. A protective film covering the strain-sensitive element and the wiring is formed on one of the main surfaces. The strain gauge according to claim 1.

4. Other wiring formed on the other main surface of the aforementioned film, The present invention further comprises two or more pairs of other strain-sensitive elements connected to the other wiring, wherein two or more pairs of other strain-sensitive elements are formed on the other main surface of the film. The strain gauge according to claim 1.

5. One main surface of the film is bonded to the other main surface of the film, Other wiring formed on the other main surface of the aforementioned other film, The present invention further comprises two or more pairs of other strain-sensitive elements connected to the other wiring, wherein two or more pairs of other strain-sensitive elements are formed on the other main surface of the other film. The strain gauge according to claim 1.

6. A process of forming wiring on one main surface of the film, The process includes forming a film on one main surface of the film with two or more strain-sensitive elements connected to the wiring. A method for manufacturing strain gauges.

7. A step of forming other wiring on the other main surface of the aforementioned film, The process further includes the step of forming a film on the other main surface of the film, in which two or more pairs of other strain-sensitive elements connected to the other wiring are formed. The method for manufacturing a strain gauge according to claim 6.

8. A process of forming other wiring on the other main surface of another film, A step of forming a film on the other main surface of the other film, comprising two or more pairs of other strain-sensitive elements connected to the other wiring, The process further includes a step of bonding the other main surface of the aforementioned film to one main surface of the other film. The method for manufacturing a strain gauge according to claim 6.

9. A strain gauge according to any one of claims 1 to 5, The strain-generating body comprises the strain gauge to which the strain gauge is attached, Sensor device.

Images