Load sensor

Abstract

This load sensor is provided with: an element unit configured so as to be applied with a load; a wiring pattern connected to the element unit; a first electrode connected to the wiring pattern; a base member having a surface on which the element unit, the wiring pattern, and the first electrode are formed; a circuit board installed on the base member so as to face the abovementioned surface of the base member so as to overlap the wiring pattern; a second electrode provided on the circuit board and joined to the first electrode at a joining position; a conductive member interposed between the first electrode and the second electrode to increase the electrical junction between the first electrode and the second electrode; and a fixing member for fixing the base member and the circuit board around the joining position.

Description

Load Sensor

[0001] The present disclosure relates to a load sensor that detects a load based on a change in capacitance.

[0002] Conventionally, capacitance-type load sensors have been used as HMIs (Human Machine Interfaces) in various devices such as keyboards and game controllers. This type of load sensor is further equipped with a circuit board for outputting an electrical signal corresponding to the load to an external circuit.

[0003] Japanese Patent Application Laid-Open No. 2006-101494 (Patent Document 1) describes a configuration for connecting a sensor element and a rigid substrate. In this configuration, a stretchable sheet made of PET (polyethylene terephthalate) is attached to the backside of the sensor element and the rigid substrate so as to straddle both of them. Furthermore, the wiring of the sensor element and the connection part of the rigid substrate are connected via a conductive adhesive.

[0004] Japanese Patent Application Laid-Open No. 2018-124179

[0005] In the sensor described above, the stretchable sheet is flexible rather than rigid. Therefore, when the stretchable sheet bends, stress tends to concentrate on the conductive adhesive that connects the wiring of the sensor element to the connection part of the rigid board. This can cause damage to the conductive adhesive.

[0006] A load sensor according to a main aspect of the present disclosure includes an element portion configured to receive a load, a wiring pattern connected to the element portion, a first electrode connected to the wiring pattern, a base member having a surface on which the element portion, the wiring pattern, and the first electrode are formed, a circuit board placed on the base member facing the surface of the base member so as to overlap the wiring pattern, a second electrode provided on the circuit board and joined to the first electrode at a joining position, a conductive member interposed between the first electrode and the second electrode to enhance the electrical connection between the first electrode and the second electrode, and a fixing member that fixes the base member and the circuit board around the joining position.

[0007] In the load sensor according to this aspect, the base member and the circuit board are fixed by the fixing member around the joint position, thereby reinforcing the joint between the first electrode arranged on the base member and the second electrode arranged on the circuit board at the joint position, thereby enabling a strong and stable joint between the electrode on the element portion and the electrode on the circuit board.

[0008] According to the present disclosure, it is possible to provide a load sensor in which the electrodes on the element section side and the electrodes on the circuit board side can be firmly and stably joined.

[0009] The effects and significance of the present disclosure will become more apparent from the following description of the embodiments, however, the embodiments described below are merely examples of how the present invention may be implemented, and the present invention is not limited to the embodiments described below.

[0010] FIG. 1 is a top view schematically showing the configuration of a wire and a circuit board according to the first embodiment. FIG. 2 is a top view schematically showing the configuration of a wire and a circuit board according to the first embodiment. FIG. 3 is a bottom view schematically showing the configuration of a first structure according to the first embodiment. FIG. 4 is a bottom view schematically showing the configuration of a second structure according to the first embodiment. FIGS. 5( a) and 5(b) are cross-sectional views each schematically showing two opposing electrodes joined with an adhesive according to the first embodiment. FIG. 6 is a bottom view schematically showing the configuration of a third structure according to the first embodiment. FIG. 7 is an enlarged view schematically showing a state in which the periphery of the joining position has been sewn according to the first embodiment. FIG. 8 is a bottom view schematically showing the configuration of a load sensor according to the first embodiment. FIG. 9 is a top view schematically showing the internal configuration of the load sensor according to the first embodiment. FIG. 10 is a top view schematically showing the configuration of a load sensor according to the first embodiment. 11(a) and 11(b) are diagrams each showing a cross section of a wire and a conductive elastic body in the vicinity of the intersection position when the wire and the conductive elastic body are cut along a plane parallel to the X-Z plane at the intersection position according to the first embodiment. FIG. 12 is a top view showing a configuration of a wire and a circuit board according to the second embodiment. FIG. 13 is a bottom view showing a configuration of a third structure according to the second embodiment. FIG. 14(a) is a diagram showing a cross section of the third structure cut along a plane parallel to the Y-Z plane passing through the position of the through-hole at the joining position according to the second embodiment. FIG. 14(b) is a diagram showing a cross section of the third structure cut along a plane parallel to the Y-Z plane passing through the position of the hole on the negative side of the Y-axis from the joining position according to the second embodiment. FIG. 15 is a bottom view showing a configuration of a load sensor according to the second embodiment. FIG. 16 is a top view showing a configuration of a load sensor according to the second embodiment. Fig. 17(a) is a bottom view schematically showing the configuration of a first structure according to embodiment 3. Fig. 17(b) is a bottom view schematically showing the configuration of a load sensor according to embodiment 3. Figs. 18(a) and 18(b) are cross-sectional views schematically showing two opposing electrodes joined with two types of adhesive according to embodiment 3. Figs. 19(a) and 19(b) are cross-sectional views schematically showing two opposing electrodes joined with an adhesive according to modification 1 of embodiment 3.FIG. 20( a) is a bottom view schematically showing the configuration of a load sensor according to Modification 2 of Embodiment 3. FIG. 20( b) is a cross-sectional view schematically showing two opposing electrodes joined with two types of adhesive and a fixing member according to Modification 2 of Embodiment 3. FIG. 21( a) is a top view schematically showing the configuration of a circuit board according to Embodiment 4. FIG. 21( b) is a bottom view schematically showing the configuration of a first structure according to Embodiment 4. FIG. 22 is a bottom view schematically showing the configuration of a load sensor according to Embodiment 4. FIG. 23 is a diagram schematically showing a cross section near the intersection position when cutting along a plane parallel to the X-Z plane at the intersection position of a wire and a conductive elastic body according to another modification.

[0011] The load sensor according to the present disclosure is applicable to a load sensor in a management system or electronic device that performs processing in response to an applied load.

[0012] Examples of management systems include inventory management systems, driver monitoring systems, coaching management systems, security management systems, and nursing care / childcare management systems.

[0013] In an inventory management system, for example, a load sensor installed on a stock shelf detects the weight of the stock piled up, and detects the type and number of products on the stock shelf. This allows for efficient inventory management and labor savings in stores, factories, warehouses, etc. Furthermore, a load sensor installed inside a refrigerator detects the weight of food in the refrigerator, and detects the type, number, and amount of food in the refrigerator. This allows for automatic menu suggestions using the food in the refrigerator.

[0014] In a driver monitoring system, for example, a load sensor provided in the steering device monitors the load distribution of the driver on the steering device (e.g., grip force, grip position, pedal force). Also, a load sensor provided in the vehicle seat monitors the load distribution of the driver on the vehicle seat while seated (e.g., center of gravity position). This makes it possible to provide feedback on the driver's driving state (drowsiness, psychological state, etc.).

[0015] In a coaching management system, for example, load sensors installed in the bottom of shoes monitor the load distribution on the soles of the feet, which can correct or guide the wearer to an appropriate walking or running state.

[0016] In a security management system, for example, load sensors installed on the floor detect the load distribution as a person passes through, and detect the person's weight, stride length, passing speed, shoe sole pattern, etc. By comparing this detected information with data, it becomes possible to identify the person who has passed through.

[0017] In a caregiving / childcare management system, for example, load sensors installed on bedding and toilet seats monitor the distribution of load on the human body relative to the bedding and toilet seat. This makes it possible to estimate what actions the person is about to take in relation to the position of the bedding and toilet seat and prevent falls.

[0018] Examples of electronic devices include in-vehicle devices (car navigation systems, audio equipment, etc.), home appliances (electric kettles, induction cooking heaters, etc.), smartphones, electronic paper, electronic book readers, PC keyboards, game controllers, smart watches, wireless earphones, touch panels, electronic pens, penlights, luminous clothing, musical instruments, etc. In electronic devices, a load sensor is provided in an input unit that receives input from a user.

[0019] The load sensor in the following embodiments is a capacitance-type load sensor that is typically provided in the load sensors of the management systems and electronic devices described above. Such load sensors are also sometimes referred to as "capacitive pressure-sensitive sensor elements," "capacitive pressure detection sensor elements," "pressure-sensitive switch elements," etc. The load sensors in the following embodiments are connected to a detection circuit, and the load sensor and the detection circuit constitute a load detection device. The following embodiments are one embodiment of the present disclosure, and the present invention is not limited to the following embodiments in any way.

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. For convenience, each drawing is labeled with X, Y, and Z axes that are orthogonal to each other. The Z-axis direction is the height direction of the load sensor 1. Each drawing is also labeled with a first direction and a second direction. The first direction is parallel to the Y-axis direction, and the second direction is parallel to the X-axis direction.

[0021] 1 to 8, the configuration of each part of a load sensor 1 according to embodiment 1 will be described, as well as the assembly of the load sensor 1. The load sensor 1 is configured to detect an applied load.

[0022] 1 and 2 are top views schematically illustrating the configuration of the wire 10 and the circuit board 20. Figures 1 and 2 are views of each part as viewed from above (in the negative Z-axis direction). Figure 2 shows the configuration of Figure 1 with the portion of the wire 10 on the negative Y-axis side removed.

[0023] 1, one wire 10 is bent at an end 10a opposite to the circuit board 20. The wire 10 is composed of a conductor wire 11, which will be described later with reference to FIGS.

[0024] 2, the circuit board 20 has a rectangular shape with its long sides extending in the X-axis direction in a plan view. The circuit board 20 has 11 electrodes 21, 11 electrodes 22, and two connectors 23 on its surface on the positive side of the Z-axis.

[0025] The eleven electrodes 21 are lined up in the X-axis direction near the end of the circuit board 20 on the positive side of the Y-axis. The eleven electrodes 22 are lined up in the X-axis direction near the end of the circuit board 20 on the negative side of the Y-axis. Each electrode 22 is overlapped at a joining position P1 with an electrode 33a of a wiring pattern 33, which will be described later with reference to FIG. 3. The two connectors 23 are lined up in the X-axis direction near the end of the circuit board 20. One connector 23 has terminals connected to each of the eleven electrodes 21, and the other connector 23 has terminals connected to each of the eleven electrodes 22. The two connectors 23 are connected to an external detection circuit.

[0026] The circuit board 20 is formed with 22 through holes 24, 12 holes 25, and 12 holes 26, each penetrating the circuit board 20 in the Z-axis direction. The through holes 24 are aligned in the X-axis direction and are provided within the electrodes 22. That is, each through hole 24 penetrates the main body of the circuit board 20 and the electrodes 22. Two through holes 24 are provided within one electrode 22.

[0027] The twelve holes 25 are located on the positive side of the Y-axis of the row in which the eleven electrodes 22 are lined up, and are aligned in the X-axis direction. The twelve holes 26 are located on the negative side of the Y-axis of the row in which the eleven electrodes 22 are lined up, and are aligned in the X-axis direction. In a plan view, the through-hole 24 has a circular shape, and the holes 25 and 26 have a rectangular shape that is long in the X-axis direction.

[0028] During assembly, a jig having grooves conforming to the shape of each wire 10 is used to arrange each wire 10 as shown in FIG. 1 . By arranging each wire 10 along the grooves in the jig, the wires 10 extend in the Y-axis direction and are spaced apart at predetermined intervals in the X-axis direction, as shown in FIG. 1 . Then, the circuit board 20 is positioned below each wire 10 held by the jig. At this time, 22 wires 10 are arranged so that two adjacent wires 10 pass over one electrode 21. The dielectric 12 formed on the wire 10 is removed from the wire 10 at a position overlapping the electrode 21, and the exposed conductor line 11 (see FIGS. 11( a) and 11(b)) is fixed to the electrode 21 by soldering. Thereafter, as shown in FIG. 2 , the end of each wire 10 located on the negative side of the electrode 21 on the Y-axis is removed.

[0029] Fig. 3 is a bottom view schematically showing the configuration of the first structure 1a, as viewed from below (in the positive direction of the Z axis).

[0030] The first structure 1 a includes a first base member 30 , eleven wires 31 , eleven conductive elastic bodies 32 , and eleven wiring patterns 33 .

[0031] The first base member 30 is an elastic, flat plate-like member. The first base member 30 has a rectangular shape in a plan view. The thickness of the first base member 30 is constant. If the thickness of the first base member 30 is small, the first base member 30 may be called a sheet member or a film member. The first base member 30 has insulating properties and is made of, for example, a non-conductive resin material or a non-conductive rubber material. The surface of the first base member 30 on the negative side of the Z axis is the opposing surface 30a. A notch 30b is formed at the end of the first base member 30.

[0032] The eleven wires 31 are formed on the opposing surface 30a of the first base member 30 so as to extend in the X-axis direction. The wires 31 are made of a material with lower resistance than the conductive elastic bodies 32. The wires 31 are made of a conductive material having elasticity, and the thickness of the wires 31 is smaller than the thickness of the conductive elastic bodies 32. The width in the Y-axis direction and the thickness in the Z-axis direction of each wire 31 are the same.

[0033] The conductive elastic bodies 32 are formed on the opposing surface 30a of the first base member 30 so as to cover the wiring 31 and extend in the X-axis direction. The conductive elastic bodies 32 are formed on the opposing surface 30a so that the wiring 31 is positioned at the intermediate position of the conductive elastic bodies 32 in the Y-axis direction, and both ends of the conductive elastic bodies 32 in the X-axis direction are located inside both ends of the wiring 31 in the X-axis direction. Each conductive elastic body 32 has the same width in the Y-axis direction, length in the X-axis direction, and thickness in the Z-axis direction. Each conductive elastic body 32 has a strip-like shape that is long in the X-axis direction, and is aligned in the Y-axis direction with a predetermined gap between them. In other words, the long sides of the conductive elastic bodies 32 are parallel to the X-axis, and the alignment direction of the conductive elastic bodies 32 is parallel to the Y-axis.

[0034] The conductive elastic body 32 is an elastic, conductive member. The wiring 31 and the conductive elastic body 32 formed to cover the wiring 31 are electrically connected. The wiring 31 and the conductive elastic body 32 are made of a resin material with a conductive filler dispersed therein, or a rubber material with a conductive filler dispersed therein.

[0035] The wiring 31 and the conductive elastic body 32 are formed on the facing surface 30a of the first base member 30 by a printing method such as screen printing, gravure printing, flexographic printing, offset printing, or gravure offset printing. The conductive elastic body 32 is formed so as to overlap the wiring 31 after the wiring 31 has been formed. These printing methods make it possible to form the wiring 31 and the conductive elastic body 32 with a thickness of approximately 0.001 mm to 0.5 mm on the facing surface 30a of the first base member 30. However, the method of forming the wiring 31 and the conductive elastic body 32 is not limited to the printing method.

[0036] The eleven wiring patterns 33 are respectively connected to the ends on the X-axis positive side of the eleven wires 31. Each wiring pattern 33 is disposed on the opposing surface 30a of the first base member 30, and is routed from the end on the X-axis positive side of the opposing surface 30a to the end on the Y-axis negative side.

[0037] An electrode 33a is formed at the end of each wiring pattern 33 on the negative side of the Y axis. The electrodes 33a are lined up in the X axis direction near the end of the opposing surface 30a on the negative side of the Y axis. The size of the electrodes 33a is approximately the same as that of the electrodes 22 (see FIG. 2), and when the circuit board 20 is placed on the first base member 30, the electrodes 33a and 22 face each other. The wiring patterns 33 and the electrodes 33a are formed integrally with the wiring 31. That is, the wiring 31, the wiring patterns 33, and the electrodes 33a are formed on the opposing surface 30a using the same material and method.

[0038] Fig. 4 is a bottom view schematically showing the configuration of the second structure 1b, as viewed from below (in the positive direction of the Z axis).

[0039] The wire 10 and circuit board 20 in Fig. 2 are placed upside down so that the Z-axis positive side surface of the circuit board 20 faces the Z-axis negative side surface (opposing surface 30a of first base member 30) of the first structure 1a in Fig. 3. As a result, the Y-axis negative side end of the first base member 30 is covered by the circuit board 20, as shown in Fig. 4. At this time, the wire 10 is in a state of extending linearly in the Y-axis direction by a jig that holds the wire 10, and the first base member 30 is held relative to this jig so that it extends without slack in the X-axis and Y-axis directions.

[0040] Furthermore, when the circuit board 20 is placed on the opposing surface 30a of the first base member 30, a conductive adhesive 41 is applied to a joining position P1 (the position where the electrode 33a and the electrode 22 face each other), and the electrode 33a and the electrode 22 are joined at the joining position P1. The adhesive 41 is formed, for example, by dispersing a conductive filler in an adhesive resin. The adhesive 41 may be flexible after solidifying.

[0041] 5(a) and 5(b) are cross-sectional views that schematically show how the electrode 33a and the electrode 22 are joined by the adhesive 41. The cross-sectional views of Figures 5(a) and 5(b) are cross-sections of the configuration of Figure 4 cut along a plane parallel to the YZ plane that passes through the center positions of the electrodes 33a and 22.

[0042] 5A , at joining position P1, electrode 33a is disposed on the opposing surface 30a (lower surface) of first base member 30, and electrode 22 is disposed on the upper surface of circuit board 20. Surface 22a (surface on the positive side of the Z axis) of electrode 22 is lower than the surface (surface on the positive side of the Z axis) of circuit board 20. That is, at the position where electrode 22 is disposed, recess 27 is formed in the surface of circuit board 20, and electrode 22 is formed on the bottom surface of recess 27. Furthermore, through-hole 24 penetrates circuit board 20 and electrode 22 in the thickness direction of circuit board 20.

[0043] From the state shown in FIG. 5( a), adhesive 41 is applied to the surface 22a of the electrode 22, and the first base member 30 and the circuit board 20 are aligned in the Z-axis direction. As a result, as shown in FIG. 5( b), the electrode 33a and the electrode 22 are electrically connected via the adhesive 41. At this time, because two through holes 24 are formed at the position of the electrode 22, excess adhesive 41 escapes into the through holes 24. This makes it difficult for the adhesive 41 to spill out from the joining position P1. Furthermore, because a recess 27 is formed at the position of the electrode 22, it is even more difficult for the adhesive 41 to spill out from the joining position P1. In this way, the second structure 1b is formed as shown in FIG. 4.

[0044] In the example shown in Figures 5(a) and (b), the electrode 22 is not formed to extend to the through hole 24, but this is not limited to this, and it may be formed on the inner surface of the through hole 24 in addition to the bottom surface of the recess 27.

[0045] FIG. 6 is a bottom view schematically showing the configuration of the third structure 1c.

[0046] With each wire 10 held by the jig and the first base member 30 stretched, as shown in Fig. 6, the fixing member 51 and the connecting members 61, 62 are fastened to the second structure 1b of Fig. 4. The fixing member 51 and the connecting members 61, 62 are made of insulating material, such as thread. This thread may be made of synthetic fiber, natural fiber, or a mixture of these fibers. The fixing member 51 and the connecting members 61, 62 are each formed by sewing together an upper thread positioned on the positive side of the Z axis of the object to be sewn and a lower thread positioned on the negative side of the Z axis of the object.

[0047] The fixing member 51 is sewn to the circuit board 20 and the first base member 30 via the holes 25 and 26. At this time, the fixing member 51 is sewn to the holes 25 and 26 so as to go around the two holes 25 and the two holes 26 arranged around one joining position P1. Then, after sewing the periphery of one joining position P1, the fixing member 51 is subsequently sewn to the holes 25 and 26 so as to go around the two holes 25 and the two holes 26 arranged around the adjacent joining position P1. In this way, the fixing member 51 is sewn to the holes 25 and 26 while going around each joining position P1 from the holes 25 and 26 at one end in the X-axis direction to the holes 25 and 26 at the other end in the X-axis direction.

[0048] FIG. 7 is an enlarged view schematically showing a state in which the periphery of one joining position P1 has been sewn.

[0049] The fixing members 51 are sewn together around each joining position P1, for example, by a sewing machine. When the periphery of each joining position P1 is sewn with the fixing members 51, for example, as shown in the central joining position P1 in FIG. 7 , the first base member 30 and the circuit board 20 are fixed at a pair of peripheral portions P11 that sandwich the joining position P1 in the Y-axis direction, and the first base member 30 and the circuit board 20 are fixed at a pair of peripheral portions P12 that sandwich the joining position P1 in the X-axis direction. As a result, the first base member 30 and the circuit board 20 are fixed by the fixing members 51 around the joining position P1, making it difficult for the electrodes 33 a and 22 to come apart at the joining position P1.

[0050] 6 , the connecting member 61 sews the wire 10 to the first base member 30 so that the end 10a straddles the wire 10 in the Y-axis direction. The connecting member 62 sews the wire 10 to the first base member 30 between two conductive elastic bodies 32 adjacent in the Y-axis direction so that a stitch row extends from the end of the first base member 30 on the positive side of the X-axis to the end on the negative side of the X-axis. The upper thread and lower thread of the connecting member 62 are sewn together while avoiding the wiring pattern 33.

[0051] In this way, as shown in FIG. 6, the fixing member 51 and the connecting members 61 and 62 are installed on the second structure 1b, and a third structure 1c is constructed.

[0052] Fig. 8 is a bottom view schematically showing the configuration of the load sensor 1. Fig. 8 is a view of the load sensor 1 as seen from below (in the positive direction of the Z axis).

[0053] The load sensor 1 includes the third structure 1c shown in FIG. 6, a second base member 70, and a connecting member 71.

[0054] The second base member 70 is an elastic, flat-plate-like member. The second base member 70 has a rectangular shape in a plan view. The thickness of the second base member 70 is constant. If the thickness of the second base member 70 is small, the second base member 70 may be called a sheet member or a film member. The length of the second base member 70 in the X-axis direction is the same as the length of the first base member 30 in the X-axis direction. The length of the second base member 70 in the Y-axis direction is the same as the length of the region of the first base member 30 that is not overlapped by the circuit board 20.

[0055] The second base member 70 has insulating properties and is made of, for example, a non-conductive resin material or a non-conductive rubber material. The second base member 70 is made of, for example, a material that can be used for the above-mentioned first base member 30. The second base member 70 may also be made of a hard material that is not easily elastically deformed.

[0056] The connecting member 71 is, for example, a thread. This thread is made of chemical fiber, natural fiber, or a mixture of these fibers, similar to the fixing member 51 and the connecting members 61 and 62. The connecting member 71 is formed by sewing together a thread arranged on the positive side of the Z axis of the first base member 30 and a thread arranged on the negative side of the Z axis of the second base member 70.

[0057] After the third structure 1c shown in Figure 6 is completed, the jig holding the wires 10 and first base member 30 is removed. Then, the second base member 70 is placed on the area of ​​the first base member 30 that does not overlap the circuit board 20, facing the opposing surface 30a from the negative side of the Z axis. In this state, each wire 10 is placed between the first base member 30 and the second base member 70. Thereafter, the first base member 30 and the second base member 70 are sewn together with connecting members 71 near the outer periphery of the second base member 70. In this manner, the load sensor 1 is completed.

[0058] Fig. 9 is a top view schematically showing the internal configuration of the load sensor 1. Fig. 9 is a view of the load sensor 1 as seen from above (in the negative direction of the Z axis). For convenience, Fig. 9 shows the circuit board 20 and the first base member 30 in a transparent state, and illustrates each part of the load sensor 1.

[0059] The 11 electrodes 33a installed on the opposing surface 30a (bottom surface) of the first base member 30 each face the 11 electrodes 22 of the circuit board 20, and at each joining position P1, the electrodes 33a and the electrodes 22 are electrically connected by adhesive 41.

[0060] Fig. 10 is a top view schematically showing the configuration of the load sensor 1. Unlike Fig. 9, Fig. 10 shows only the configuration of the top surface of the load sensor 1.

[0061] As shown by the solid lines, the upper thread of the fixing member 51 is arranged on the surface (top surface) on the positive side of the Z axis of the first base member 30, and as shown by the dashed lines, the upper threads of the connecting members 61, 62, and 71 are arranged. The two connectors 23 on the circuit board 20 are open in the positive direction of the Z axis (upward) through the notches 30b of the first base member 30.

[0062] The load sensor 1 is used with the first base member 30 facing the positive side of the Z axis and the second base member 70 facing the negative side of the Z axis. In this case, the upper surface of the first base member 30 is the surface to which the load is applied, and the lower surface of the second base member 70 is placed on the installation surface.

[0063] The load sensor 1 has a plurality of element units A1 arranged in a matrix in a plan view. The load sensor 1 shown in FIG. 10 has a total of 121 element units A1 arranged in the X-axis and Y-axis directions. Each element unit A1 corresponds to a region including an intersection between one conductive elastic body 32 and two wires 10 arranged below the conductive elastic body 32. That is, each element unit A1 includes the first base member 30, wiring 31, conductive elastic body 32, wire 10, and second base member 70 near the intersection. When the lower surface of the load sensor 1 (the lower surface of the second base member 70) is placed on a predetermined installation surface and a load is applied to the upper surface of the load sensor 1 (the upper surface of the first base member 30) that constitutes the element unit A1, the capacitance formed between the conductive elastic body 32 and the wire 10 changes, and the load is detected based on the capacitance. In this manner, the element unit A1 is configured to receive the load to be detected.

[0064] 11A and 11B are diagrams showing schematic cross sections of the wire 10 and the conductive elastic body 32 in the vicinity of the intersection when the wire 10 and the conductive elastic body 32 are cut along a plane parallel to the XZ plane at the intersection.

[0065] 11(a) and 11(b), the wire 10 is composed of a conductor wire 11 and a dielectric 12 formed on the conductor wire 11. The dielectric 12 is formed on the outer periphery of the conductor wire 11, and covers the entire surface of the conductor wire 11.

[0066] The conductor wire 11 is a conductive, linear member. The conductor wire 11 is made of, for example, a conductive metal material. Alternatively, the conductor wire 11 may be made of a glass core wire with a conductive layer formed on its surface, or a resin core wire with a conductive layer formed on its surface. The conductor wire 11 may be a twisted wire formed by twisting wires made of a conductive metal material. The dielectric 12 is electrically insulating and made of, for example, a resin material, a ceramic material, a metal oxide material, or the like.

[0067] The diameter of the conductor wire 11 may be, for example, 0.01 mm or more and 1.5 mm or less, or 0.05 mm or more and 0.8 mm or less. Such a configuration of the conductor wire 11 is preferable from the viewpoint of the strength and resistance of the conductor wire 11. The thickness of the dielectric 12 is preferably 5 nm or more and 100 μm or less, and can be appropriately selected depending on the design of the sensor sensitivity, etc.

[0068] 11(a) shows a state where no load is applied, and FIG. 11(b) shows a state where a load is applied. In FIG. 11(a) and (b), the lower surface of the second base member 70 on the negative side of the Z axis is placed on the installation surface.

[0069] As shown in Fig. 11(a), when no load is applied, the force acting between the conductive elastic body 32 and the wire 10 is almost zero. From this state, as shown in Fig. 11(b), when a load is applied downward to the upper surface of the first base member 30, the conductive elastic body 32 is deformed by the wire 10. At this time, the wire 10 is brought closer to the conductive elastic body 32 so as to be wrapped in the conductive elastic body 32, and the contact area between the wire 10 and the conductive elastic body 32 increases. This changes the capacitance between the conductor wire 11 and the conductive elastic body 32. The potential reflecting this change in capacitance is then measured in the detection circuit, and the load is calculated.

[0070] <Effects of First Embodiment> According to the first embodiment, the following effects are achieved.

[0071] A wiring pattern 33 connected to the element portion A1 is formed on the first base member 30 (base member). The circuit board 20 is placed on the first base member 30 (base member) so as to overlap the wiring pattern 33. An adhesive 41 (conductive member) is interposed between an electrode 33a (first electrode) on the wiring pattern 33 side and an electrode 22 (second electrode) on the circuit board 20 side to enhance the electrical connection between the electrode 33a (first electrode) and the electrode 22 (second electrode). A fixing member 51 fixes the first base member 30 (base member) and the circuit board 20 around a joining position P1 between the electrode 33a (first electrode) and the electrode 22 (second electrode).

[0072] That is, the load sensor 1 is configured to detect an applied load. The load sensor 1 includes an element portion A1 configured to receive a load, a wiring pattern 33 connected to the element portion A1, a first electrode 33a connected to the wiring pattern 33, a base member 30 having a surface (opposing surface 30a) on which the element portion A1, the wiring pattern 33, and the first electrode 33a are formed, a circuit board 20 installed on the base member 30 facing the surface (opposing surface 30a) of the base member 30 so as to overlap the wiring pattern 33, a second electrode 22 provided on the circuit board 20 and joined to the first electrode 33a at a joining position P1, an adhesive 41 (conductive member) interposed between the first electrode 33a and the second electrode 22 to enhance electrical bonding between the first electrode 33a and the second electrode 22, and a fixing member 51 that fixes the base member 30 and the circuit board 20 in the periphery of the joining position P1.

[0073] 7, the first base member 30 and the circuit board 20 are fixed by the fixing member 51 around the joining position P1. This reinforces the joining between the electrode 33a arranged on the first base member 30 and the electrode 22 arranged on the circuit board 20 at the joining position P1. This allows the electrode 33a on the element portion A1 side and the electrode 22 on the circuit board 20 side to be joined firmly and stably.

[0074] As described above, the fixing member 51 is a thread.

[0075] According to this configuration, the first base member 30 and the circuit board 20 can be fixed easily and smoothly around the joining position P1.

[0076] 2, holes 25 and 26 that penetrate the circuit board 20 are formed in the periphery of the joining position P1 in the circuit board 20. As shown in FIGS. 6 and 7, the fixing member 51 fixes the first base member 30 (base member) and the circuit board 20 via the holes 25 and 26.

[0077] According to this configuration, the first base member 30 and the circuit board 20 can be smoothly fixed together by the fixing member 51 through the holes 25, 26 formed in the circuit board 20 around the joining position P1.

[0078] As shown in FIG. 2, a plurality of holes 25 and 26 are formed in the circuit board 20 around the joining position P1.

[0079] According to this configuration, the first base member 30 and the circuit board 20 can be reliably fixed together at a plurality of locations around the joining position P1.

[0080] As described above, the fixing member 51 has insulating properties.

[0081] This configuration can prevent electrical leaks and short circuits from occurring through the fixing member 51. Therefore, the fixing member 51 can be prevented from affecting the detection performance of the load sensor 1.

[0082] As shown in FIG. 7, the fixing member 51 fixes the first base member 30 (base member) and the circuit board 20 at a pair of peripheral portions P11 that sandwich the joining position P1 in the Y-axis direction (first direction).

[0083] According to this configuration, the first base member 30 and the circuit board 20 can be firmly fixed together with a simple configuration.

[0084] Furthermore, the fixing member 51 fixes the first base member 30 (base member) and the circuit board 20 at another pair of peripheral portions P12 that sandwich the joining position P1 in the X-axis direction (second direction) that intersects the Y-axis direction (first direction).

[0085] According to this configuration, the fixing member 51 is arranged around the joining position P1, so that the first base member 30 and the circuit board 20 can be fixed more firmly than when the fixing member 51 is arranged only in the peripheral portion P11.

[0086] As shown in Figures 5(a) and (b), in the arrangement region R22 where the electrode 22 (second electrode) is arranged on the circuit board 20, a through hole 24 is formed that penetrates the circuit board 20 and the electrode 22 (second electrode) in the thickness direction of the circuit board 20.

[0087] According to this configuration, when the electrodes 33 a and 22 are joined, excess adhesive 41 escapes into the through-hole 24, making it less likely for the adhesive 41 to overflow from the joining position P1 of the electrodes 33 a and 22. This makes it possible to suppress leaks and short circuits caused by the overflow of adhesive 41.

[0088] As shown in FIGS. 5A and 5B, the surface 22 a of the electrode 22 (second electrode) is lower than the surface of the circuit board 20 .

[0089] With this configuration, the arrangement region R22 of the electrode 22 becomes the recess 27, which makes it even more difficult for the adhesive 41 to spill out from the joining position P1 of the electrodes 33 a, 22. Therefore, leaks and short circuits due to the spilling of the adhesive 41 can be more reliably suppressed.

[0090] As shown in FIG. 3, electrodes 33 a (first electrodes) of a plurality of wiring patterns 33 are arranged in a row on the first base member 30 (base member), and as shown in FIG. 2, a plurality of electrodes 22 (second electrodes) are arranged in a row on the circuit board 20 so as to correspond to the plurality of electrodes 33 a (first electrodes), respectively, and as shown in FIG. 6, the fixing member 51 is a thread that sews in a direction parallel to the row on both sides (P11 in FIG. 7) of the row in which a plurality of joining positions P1 between the plurality of electrodes 33 a (first electrodes) and the plurality of electrodes 22 (second electrodes) are arranged.

[0091] According to this configuration, the first base member 30 and the circuit board 20 can be smoothly fixed together around the plurality of joining positions P1. That is, the first base member 30 and the circuit board 20 can be easily sewn together using a sewing machine.

[0092] As shown in Fig. 6, the space between adjacent joining positions P1 is further sewn with a fixing member 51 (thread). That is, as shown in Fig. 7, the fixing member 51 is sewn to a peripheral portion P12 between adjacent joining positions P1.

[0093] According to this configuration, the electrode 33a and the electrode 22 can be joined more firmly and stably than when the fixing member 51 is not sewn to the peripheral portion P12.

[0094] 11(a) and 11(b), the element portion A1 (see FIG. 10) includes a conductive elastic body 32 formed on a first base member 30 (base member), a conductor wire 11 overlapping the conductive elastic body 32, and a dielectric 12 interposed between the conductive elastic body 32 and the conductor wire 11. As shown in FIG. 3, the wiring pattern 33 is connected to the conductive elastic body 32.

[0095] 11(a) and 11(b), according to this configuration, the contact area between the conductive elastic body 32 and the dielectric 12 changes in response to the load, and the capacitance between the conductive elastic body 32 and the conductor wire 11 changes. Therefore, the load can be detected by detecting this capacitance.

[0096] As shown in FIGS. 11( a ) and 11 ( b ), the dielectric 12 is disposed so as to cover the surface of the conductor wire 11 .

[0097] According to this configuration, the dielectric 12 can be disposed between the conductive elastic body 32 and the conductor wire 11 simply by covering the surface of the conductor wire 11 with the dielectric 12 .

[0098] 7, in the first embodiment, the periphery of the joining position P1 is fixed by the fixing member 51. In contrast, in the second embodiment, the joining position P1 and both sides of the row in which the joining positions P1 are arranged are fixed by the fixing member. The following describes the differences from the first embodiment.

[0099] FIG. 12 is a top view schematically illustrating the configuration of the wire 10 and the circuit board 20 according to the second embodiment.

[0100] In the second embodiment, compared to the first embodiment shown in Fig. 2, 33 holes 25 and 26 are formed in the circuit board 20. The holes 25 and 26 have a circular shape in a plan view. The 33 holes 25 are aligned in the X-axis direction on the positive side of the Y-axis of the joining position P1, and the 33 holes 26 are aligned in the X-axis direction on the negative side of the Y-axis of the joining position P1.

[0101] FIG. 13 is a bottom view schematically illustrating the configuration of a third structure 1c according to the second embodiment.

[0102] In the second embodiment, the wire 10 and the circuit board 20 shown in Fig. 12 are placed upside down so that the surface of the circuit board 20 on the positive side in the Z-axis direction faces the surface of the first structure 1a on the negative side in the Z-axis direction shown in Fig. 3. In this way, the first base member 30 and the circuit board 20 are stacked on top of each other, as shown in Fig. 13.

[0103] At this time, the fixing members 52 are sewn into the 22 through holes 24 aligned in the X-axis direction. As a result, the first base member 30 and the circuit board 20 are fixed at the positions of the through holes 24. Furthermore, the fixing members 53 are sewn into the 33 holes 25 aligned in the X-axis direction, and the fixing members 54 are sewn into the 33 holes 26 aligned in the X-axis direction. As a result, the first base member 30 and the circuit board 20 are fixed at the positions of the holes 25 and 26. The fixing members 52 to 54 are insulating and are made of thread similar to the fixing member 51 of the first embodiment.

[0104] Thereafter, adhesive 41 is introduced from the negative side of the Z axis of through-hole 24, and adhesive 41 is disposed between electrode 33a and electrode 22. As a result, electrode 33a and electrode 22 are joined together, similar to embodiment 1. In this way, third structure 1c is constructed.

[0105] As in the first embodiment, after the adhesive 41 is applied to the joining position P1, the fixing member 52 may be sewn into the through-hole 24 as shown in FIG.

[0106] Figure 14(a) is a schematic diagram showing a cross section of the third structure 1c shown in Figure 13 cut along a plane parallel to the YZ plane that passes through the position of the through hole 24 at the joining position P1.

[0107] The fixing members 52 are sewn together, for example, by a sewing machine, through each of the through holes 24 aligned in the X-axis direction. As a result, the first base member 30 and the circuit board 20 are fixed by the fixing members 52 at the positions of each of the through holes 24 aligned in the X-axis direction, and further the bond between the electrode 33a and the electrode 22 at the bonding position P1 is reinforced.

[0108] When the fixing member 52 is sewn into the through-hole 24 at the joining position P1 before the adhesive 41 hardens, a smaller amount of adhesive 41 is applied than in the first embodiment, for example, to prevent electrical conduction between adjacent joining positions P1 due to the adhesive 41 adhering to the sewing needle. From the viewpoint of avoiding such electrical conduction, the fixing member 52 may be sewn into the through-hole 24 after the adhesive 41 hardens.

[0109] Figure 14(b) is a schematic diagram showing a cross section of the third structure 1c shown in Figure 13 cut along a plane parallel to the Y-Z plane passing through the position of the hole 26 on the negative side of the Y axis of the joining position P1.

[0110] The fixing members 54 are sewn together, for example, by a sewing machine, through each of the holes 26 aligned in the X-axis direction, thereby fixing the first base member 30 and the circuit board 20 together by the fixing members 53 at the positions of each of the holes 26 aligned in the X-axis direction.

[0111] Similarly, at the position of the hole 25 on the positive side of the Y axis of the joining position P1, the fixing members 53 are sewn together, for example, by a sewing machine, through each of the holes 25 aligned in the X axis direction. As a result, the first base member 30 and the circuit board 20 are fixed by the fixing members 52 at the positions of the holes 25 aligned in the X axis direction.

[0112] 15 and 16 are bottom and top views, respectively, that schematically show the configuration of the load sensor 1 according to the second embodiment.

[0113] The load sensor 1 of embodiment 2 includes a third structure 1c shown in Fig. 13, and a second base member 70 and a connecting member 71 similar to those of embodiment 1. The second base member 70 is placed on the third structure 1c shown in Fig. 13, and the first base member 30 and the second base member 70 are sewn together near the outer periphery of the second base member 70 with the connecting member 71, similar to embodiment 1. In this way, the load sensor 1 is completed as shown in Figs. 15 and 16.

[0114] <Effects of Second Embodiment> According to the second embodiment, the following effects are achieved.

[0115] A plurality of pairs of element portion A1 and wiring pattern 33 are arranged on first base member 30 (base member). Electrodes 33a (first electrodes) of the plurality of wiring patterns 33 are arranged in a row on first base member 30. A plurality of electrodes 22 (second electrodes) are arranged in a row on circuit board 20 so as to correspond to the plurality of electrodes 33a, respectively. Fixing members 53 and 54 are threads that sew on both sides of a row of joining positions P1 between the plurality of electrodes 33a (first electrodes) and the plurality of electrodes 22 (second electrodes) in a direction parallel to the row (X-axis direction).

[0116] That is, a plurality of element portions A1, each of which is an element portion A1, a plurality of wiring patterns 33, each of which is a wiring pattern 33, and a plurality of first electrodes 33a, each of which is a first electrode 33a, are arranged on the surface (opposing surface 30a) of the base member 30. The plurality of first electrodes 33a are arranged in a row on the surface (opposing surface 30a) of the base member 30. A plurality of second electrodes 22, each of which is a second electrode 22, are arranged in a row on the circuit board 20 so as to correspond to the plurality of first electrodes 33a, respectively. The plurality of second electrodes 22 are respectively joined to the plurality of first electrodes 33a at a plurality of joining positions P1. The fixing members 53, 54 are threads that sew on both sides of the row of the plurality of joining positions P1 in a direction parallel to the row.

[0117] This configuration allows the first base member 30 and the circuit board 20 to be smoothly fixed together around the plurality of joining positions P1. Furthermore, because the fixing members 53 and 54 are threads, the fixing members 53 and 54 can be smoothly sewn together using a sewing machine.

[0118] In the second embodiment, the space between adjacent joining positions P1 may be further sewn with a fixing member having a configuration similar to that of the fixing members 53, 54. This allows the electrodes 33a, 22 to be joined together more firmly and stably.

[0119] As shown in Figure 13, at the joining position P1 between the electrode 33a (first electrode) and the electrode 22 (second electrode), the first base member 30 (base member) and the circuit board 20 are fixed by a fixing member 52 (another fixing member).

[0120] According to this configuration, the fixing member 52 reinforces the fixation between the first base member 30 and the circuit board 20 at the joining position P1, so that the electrodes 33a, 22 can be joined more firmly and stably.

[0121] Third Embodiment In a third embodiment, a through hole is formed at the position where the electrode 33a is disposed to check whether or not the adhesive is properly disposed at the joining position P1. The following describes the configuration different from the first embodiment.

[0122] Fig. 17A is a bottom view schematically illustrating the configuration of a first structure 1a according to embodiment 3. For convenience, Fig. 17A illustrates only the vicinity of the end of the first structure 1a on the negative side of the Y axis.

[0123] 3, in the third embodiment, two through holes 34a, 34b are formed at the positions of the electrodes 33a, penetrating the first base member 30 and the electrodes 33a in the thickness direction (Z-axis direction) of the first base member 30. At the positions of the electrodes 33a, the through holes 34a are located on the negative side of the through holes 34b on the X-axis.

[0124] Fig. 17(b) is a bottom view schematically illustrating the configuration of the load sensor 1 according to embodiment 3. For convenience, Fig. 17(b) illustrates only the vicinity of the end of the load sensor 1 on the negative side of the Y axis.

[0125] In the third embodiment, compared to the first embodiment shown in Fig. 8, an adhesive 41 similar to that in the first embodiment is disposed at the position of one of the through holes 24 provided at one joining position P1, and an adhesive 42 is disposed at the position of the other through hole 24. The adhesive 42 is formed, for example, from a resin having adhesive properties. Unlike the adhesive 41, the adhesive 42 does not contain a conductive filler and is therefore a non-conductive member, and has a higher adhesive ability than the adhesive 41.

[0126] 18A and 18B are cross-sectional views schematically showing that an electrode 33a and an electrode 22 are joined by adhesives 41 and 42 according to the third embodiment.

[0127] 18(a), the through holes 34a and 34b penetrate the first base member 30 and the electrode 33a at the joining position P1. The through holes 34a and 34b are positioned directly above the two through holes 24. The diameters of the through holes 34a and 34b are smaller than the diameters of the through holes 24. The recess 27 formed on the surface of the circuit board 20 is divided in the X-axis direction by a wall portion 27a that crosses the center of the recess 27 in the Y-axis direction. The electrode 22 is disposed on the surfaces of the two recesses 27 and the wall portion 27a.

[0128] Starting from the state shown in FIG. 18( a), adhesive 41 is applied to the electrode 22 around the through-hole 24 on the negative side of the X-axis, and adhesive 42 is applied to the electrode 22 around the through-hole 24 on the positive side of the X-axis, and the first base member 30 and the circuit board 20 are aligned in the Z-axis direction. As a result, as shown in FIG. 18( b), the electrode 33 a and the electrode 22 around the through-hole 34 a are electrically connected via the adhesive 41, and the electrode 33 a and the electrode 22 around the through-hole 34 b are connected via the adhesive 42. At this time, excess adhesive 41 and 42 escape not only into the through-hole 24 but also into the through-holes 34 a and 34 b, respectively. This prevents the adhesives 41 and 42 from spilling out from the joining position P1. Furthermore, the recess 27 prevents the adhesives 41 and 42 from spilling out from the joining position P1.

[0129] 18(a) and 18(b), the wall portions 27a are formed to provide recesses 27 corresponding to the two through holes 24, but similar to the first and second embodiments, the wall portions 27a may not be formed and one recess 27 may be formed for the two through holes 24. In this case, it is preferable that the adhesives 41 and 42 are arranged at one joining position P1 so as not to be mixed with each other.

[0130] After the electrodes 33a, 22 are joined at each joining position P1 in this way, the manufacturer of the load sensor 1 determines whether the adhesives 41, 42 are properly applied via the through holes 34a, 34b in the state shown in FIG. 18(b). If the manufacturer determines that the adhesives 41, 42 are not properly applied, the manufacturer introduces the adhesives 41, 42 from the negative side of the Z-axis of the through hole 24 to properly join the electrodes 33a, 22. Thereafter, assembly is performed in the same manner as in embodiment 1, and the load sensor 1 is completed as shown in FIG. 17(b).

[0131] After the fixing member 51 is sewn around the joining position P1, the adhesives 41 and 42 may be introduced from the negative side of the Z axis of the through-hole 24. In this case, when the adhesives 41 and 42 are introduced, air is sucked from the through-holes 34a and 34b, so that the adhesives 41 and 42 can be reliably disposed at the joining position P1 between the electrode 33a and the electrode 22.

[0132] <Effects of Third Embodiment> According to the third embodiment, the following effects are achieved.

[0133] As shown in Figures 18(a) and (b), in the arrangement region R33a where the electrode 33a (first electrode) is arranged on the first base member 30 (base member), through holes 34a and 34b are formed that penetrate the first base member 30 (base member) and the electrode 33a (first electrode) in the thickness direction of the first base member 30 (base member).

[0134] With this configuration, it is possible to check, via the through holes 34a, 34b, whether or not the adhesives 41, 42 are properly disposed between the electrodes 33a and 22. Furthermore, when the electrodes 33a, 22 are joined, excess adhesives 41, 42 escape into the through holes 34a, 34b, making it less likely that the adhesives 41, 42 will spill out from the joining position P1.

[0135] 18( a) and 18(b), a through hole 34a (first through hole) and a through hole 34b (second through hole) are formed in the arrangement region R33a of one electrode 33a (first electrode). An adhesive 41 (conductive member) is arranged at a position corresponding to the through hole 34a (first through hole), and an adhesive 42 that bonds the electrode 33a (first electrode) and the electrode 22 (second electrode) is arranged at a position corresponding to the through hole 34b (second through hole). In this embodiment, the adhesive 41 is arranged at and around the position where the through hole 34a of the electrodes 22 and 33a is provided, and the adhesive 42 is arranged at and around the position where the through hole 34b of the electrodes 22 and 33a is provided.

[0136] The general adhesive 42, which does not contain a conductive filler, can more firmly bond the electrode 33 a to the electrode 22 compared to the adhesive 41, which contains a conductive filler. Therefore, the above configuration can electrically bond the electrodes 33 a and 22 and further strongly bond them. Furthermore, it is possible to check whether the adhesives 41 and 42 are properly positioned via the through holes 34 a and 34 b, respectively.

[0137] <First Modification of Third Embodiment> In the third embodiment, two through holes 34 a, 34 b are formed at the position of one electrode 33 a, but one through hole 34 a may be formed at one position. In this case, for example, one type of adhesive 41 is used, as in the first embodiment.

[0138] 19(a) and 19(b) are cross-sectional views showing the electrode 33a and the electrode 22 bonded together by an adhesive 41 according to this modification.

[0139] In this modified example, one through-hole 34a is formed in the center of one joining position P1, as compared to embodiment 1. In this case, as in embodiment 3, it is possible to check whether the adhesive 41 is properly disposed between the electrode 33a and the electrode 22 via the through-hole 34a.

[0140] <Modification 2 of Embodiment 3> In Embodiment 3, the configuration in which through holes 34a, 34b are formed at one joining position P1 is applied to the load sensor 1 of Embodiment 1, but it may also be applied to the load sensor 1 of Embodiment 2.

[0141] Fig. 20(a) is a bottom view schematically illustrating the configuration of the load sensor 1 according to this modified example. For convenience, Fig. 20(a) illustrates only the vicinity of the end of the load sensor 1 on the negative side of the Y axis.

[0142] In this modification, similarly to the second embodiment shown in FIG. 15, the fixing member 52 is sewn to the through-hole 24, and the fixing members 53 and 54 are sewn to the holes 25 and 26.

[0143] FIG. 20B is a cross-sectional view showing a state in which the electrode 33a and the electrode 22 are joined by adhesives 41 and 42 according to this modification.

[0144] In this modified example, similar to the third embodiment shown in Figures 17(a) to 18(b), through holes 34a and 34b are formed at each joining position P1. The fixing member 52 in this modified example is sewn to the first base member 30 and the circuit board 20 via the through holes 24 and the through holes 34a and 34b. Thereafter, adhesive 41 is introduced through the through hole 24 located below the through hole 34a, and adhesive 42 is introduced through the through hole 24 located below the through hole 34b. At this time, air is sucked through the through holes 34a and 34b.

[0145] Here, if adhesives 41, 42 are introduced through through holes 24 after fixing member 52 is installed, there is a risk that adhesives 41, 42 introduced through through holes 24 will hit fixing member 52 and not reach bonding position P1 between electrode 33a and electrode 22. In contrast, air is sucked through through holes 34a, 34b when adhesives 41, 42 are introduced, so that adhesives 41, 42 can be reliably positioned at bonding position P1 with electrodes 33a, 22.

[0146] In this modified example, as in the third embodiment, it is possible to check, via the through holes 34a, 34b, whether or not the adhesives 41, 42 are properly disposed between the electrode 33a and the electrode 22. Furthermore, in this modified example, compared to the third embodiment, the first base member 30 and the circuit board 20 are sewn together by the fixing member 52 at the joining position P1, so that the electrode 33a and the electrode 22 can be joined even more firmly.

[0147] Fourth Embodiment In the first to third embodiments, the plurality of electrodes 22, 33a are elongated in the arrangement direction (X-axis direction). In contrast, in the fourth embodiment, the plurality of electrodes 22, 33a are elongated in the direction perpendicular to the arrangement direction (Y-axis direction). The following describes the configuration different from the second embodiment.

[0148] FIG. 21A is a top view schematically illustrating the configuration of a circuit board 20 according to the fourth embodiment.

[0149] In the fourth embodiment, each electrode 22 has a rectangular shape that is long in the Y-axis direction, compared to the second embodiment shown in Fig. 12. The center position of each electrode 22 in the fourth embodiment is the same as the center position of each electrode 22 in the second embodiment. However, in the fourth embodiment, each electrode 22 has a shape that is long in the Y-axis direction, and therefore the distance between two electrodes 22 aligned in the X-axis direction is longer than in the second embodiment.

[0150] Fig. 21(b) is a bottom view schematically illustrating the configuration of the first structure 1a according to embodiment 4. For convenience, Fig. 21(b) illustrates only the vicinity of the end portion of the first structure 1a on the negative side of the Y axis.

[0151] In the fourth embodiment, each electrode 33a has a rectangular shape that is elongated in the Y-axis direction, as compared with the second embodiment. Also, in the fourth embodiment, similar to the third embodiment, through holes 34a, 34b that penetrate the first base member 30 and the electrode 33a are formed in the arrangement region 33a where the electrode 33a is arranged. The center position of each electrode 33a in the fourth embodiment is the same as the center position of each electrode 33a in the second embodiment. However, in the fourth embodiment, since each electrode 33a has a shape that is elongated in the Y-axis direction, the distance between two electrodes 33a aligned in the X-axis direction is longer than in the second embodiment.

[0152] In the fourth embodiment, the same assembly as in the second and third embodiments is carried out, and the load sensor 1 is completed as shown in FIG.

[0153] FIG. 22 is a bottom view schematically illustrating the configuration of the load sensor 1 according to the fourth embodiment.

[0154] In the fourth embodiment, the through holes 24 located on the positive side of the Y axis at each joining position P1 are sewn closed by the fixing member 52a, and the through holes 24 located on the negative side of the Y axis at each joining position P1 are sewn closed by the fixing member 52b. As in the second modification of the third embodiment, adhesive 41 is introduced into each through hole 24 sewn closed by the fixing member 52a, and adhesive 42 is introduced into each through hole 24 sewn closed by the fixing member 52b. In this case as well, because the through holes 34a and 34b are formed at the positions where the electrodes 33a are disposed, as shown in FIG. 21(b), the manufacturer can determine whether the adhesives 41 and 42 are properly disposed via the through holes 34a and 34b.

[0155] <Effects of Fourth Embodiment> According to the fourth embodiment, the following effects are achieved.

[0156] As shown in FIG. 22, the electrode 33a (first electrode) and the electrode 22 (second electrode) at the joining position P1 have a shape that is elongated in a direction intersecting the arrangement direction of the electrode 33a (first electrode).

[0157] This configuration makes it easier to arrange multiple bonding positions P1 at intervals in the direction in which the electrodes 33a are aligned, thereby preventing the electrodes 33a and 22 at adjacent bonding positions P1 from shorting out with each other due to migration or the like.

[0158] <Other Modifications> In the above embodiment and modifications, the electrodes 33 a and 22 may be electrically connected by a conductive member (such as a conductive gel) that has almost no adhesive properties, instead of the adhesive 41. In this case, the first base member 30 and the circuit board 20 are fixed by a fixing member around and at the joining position P1, thereby firmly and stably joining the electrodes 33 a and 22. When the electrodes 33 a and 22 are joined by an adhesive or a conductive gel, it is possible to prevent the conduction between the electrodes 33 a and 22 from being lost due to deformation caused by heat.

[0159] In the above embodiment and modified examples, the fixing members 51, 53, 54 arranged around the joining position P1 are not limited to threads, but may be tapes, adhesives, wires, caulking members, or the like.

[0160] If the fixing members 51, 53, and 54 are tape, holes 25 and 26 are not formed in the circuit board 20, and the Z-axis negative side surface (opposing surface 30a) of the first base member 30 and the Z-axis positive side surface of the circuit board 20 are fixed together by tape around the joining position P1. In this case, double-sided tape is preferable. If the fixing members 51, 53, and 54 are adhesive, the first base member 30 and the circuit board 20 are fixed together by the adhesive around the joining position P1. If the fixing members 51, 53, and 54 are wire, the wire, like thread, sews the first base member 30 and the circuit board 20 together through the holes 25 and 26 formed in the circuit board 20. If the fixing members 51, 53, and 54 are crimping members, the crimping members fix the first base member 30 and the circuit board 20 together through the holes 25 and 26 formed in the circuit board 20.

[0161] Even when the fixing members 51, 53, and 54 are tape, adhesive, wire, or crimping members, the first base member 30 and the circuit board 20 can be easily and smoothly fixed in the vicinity of the joining position P1. In this case, too, the fixing members 51, 53, and 54 are preferably insulating. This can prevent electrical leaks and short circuits from occurring through the fixing members 51, 53, and 54.

[0162] In the above embodiment and modified examples, the fixing member 52 installed at the joining position P1 is not limited to thread, but may also be a wire, a crimping member, etc. When the fixing member 52 is a wire or a crimping member, the wire or the crimping member fixes the first base member 30 and the circuit board 20 via the through holes 24 formed at the joining position P1. Even when the fixing member 52 is a wire or a crimping member, the first base member 30 and the circuit board 20 are fixed at the positions of the through holes 24, and the joint between the electrode 33 a and the electrode 22 at the joining position P1 is further reinforced.

[0163] When the fixing member 52 is a wire and all the through holes 24 are sewn together with one wire, the wire is configured to have insulating properties. However, when the wire is fixed to two through holes 24 within one joining position P1, the wire may be conductive. Also, when the fixing member 52 is a crimping member and the crimping member is fixed so as not to protrude from the joining position P1, the crimping member may be conductive.

[0164] In the above embodiment and modified example, the connecting members 61, 62 that sew the wire 10 to the first base member 30 are made of thread to prevent the dielectric 12 from peeling off from the wire 10 due to contact between the connecting members 61, 62 and the wire 10. In this case, if the fixing members 51 to 54 are also made of thread like the connecting members 61, 62, the fixing members 51 to 54 and the connecting members 61, 62 can be smoothly installed using thread made of the same material.

[0165] In the above embodiment and modified examples, the fixing member 52 is not limited to sewing all of the through holes 24 aligned in the X-axis direction at once, but may be sewn to two through holes 24 for each joining position P1. Also, in the above-described fourth embodiment, instead of the fixing members 52a and 52b, the fixing member 52 may be sewn to two through holes 24 for each joining position P1. That is, two through holes 24 within one joining position P1 may be sewn by one fixing member 52. In this case, the fixing member 52 may be conductive. When a conductive fixing member 52 is provided for each joining position P1, the electrode 33a and the electrode 22 can be electrically connected more reliably.

[0166] In the above embodiment and modified example, two through holes 24 are formed in the arrangement region R22 of the electrode 22 corresponding to one joining position P1, but one through hole 24 may be formed, or three or more through holes 24 may be formed. Furthermore, in the first and third embodiments, instead of the through hole 24, a hole (recess) may be formed in the negative Z-axis direction from the arrangement region R22 of the electrode 22 and not penetrating the circuit board 20. In this case as well, excess adhesive 41 escapes into the hole (recess), making it less likely that the adhesive 41 will overflow from the joining position P1.

[0167] 7 , the fixing member 51 fixes the first base member 30 and the circuit board 20 at a pair of peripheral portions P11 that sandwich the joining position P1 in the Y-axis direction and a pair of peripheral portions P12 that sandwich the joining position P1 in the X-axis direction. However, this is not limited thereto, and the fixing member 51 may fix the first base member 30 and the circuit board 20 only at the pair of peripheral portions P11, or may fix the first base member 30 and the circuit board 20 only at the pair of peripheral portions P12. Furthermore, the pair of peripheral portions P11 may be regions that sandwich the joining position P1 in a direction slightly tilted in the X-Y plane with respect to the Y-axis direction, and the pair of peripheral portions P12 may be regions that sandwich the joining position P1 in a direction slightly tilted in the X-Y plane with respect to the X-axis direction.

[0168] In the above embodiment and modified examples, the fixing members are arranged linearly around the joining position P1, but the fixing members may also be arranged curvedly. In this case, for example, a plurality of holes may be provided around the joining position P1 at equal distances from the center of the joining position P1, and the fixing members may be sewn in an arc shape around the holes.

[0169] In the above embodiment and modified example, one or two through holes are formed in the first base member 30 and the electrode 33a corresponding to one joining position P1, but three or more through holes may be formed. If many such through holes are provided, it becomes easier to determine whether the adhesive is properly disposed at the joining position P1 through the through holes.

[0170] In the fourth embodiment, the electrodes 33 a, 22 at the joining position P1 have a shape that is elongated in the direction (Y-axis direction) perpendicular to the arrangement direction (X-axis direction) of the electrodes 33 a, 22, but the direction may be any direction that intersects with the arrangement direction of the electrodes 33 a, 22. For example, the longitudinal direction of the electrodes 33 a, 22 and the arrangement direction of the electrodes 33 a, 22 may intersect at an angle greater than 0° and less than 90°. In this case, it is also easy to arrange the multiple joining positions P1 at a distance from each other.

[0171] In the second modification of the third embodiment and the fourth embodiment, the fixing members 52, 52a, and 52b for fixing the joining position P1 may be omitted. Even in this case, the periphery of the joining position P1 is fixed by the fixing members 53 and 54, and the adhesive 42, which has stronger adhesive properties than the adhesive 41, is disposed, so that the electrodes 33a and 22 at the joining position P1 can be reliably electrically joined.

[0172] In the above embodiment and modified examples, the wiring pattern 33 is not limited to being formed on the facing surface 30a of the first base member 30 by a predetermined printing method, and may be a cable wire.

[0173] In the above embodiment and modified example, the fixing members 51 to 54, 52a, and 52b are sewn together by machine sewing, but they may also be sewn together by embroidery. However, machine sewing is preferable because it results in stronger stitches on the fixing members than embroidery.

[0174] In the above embodiment and modified example, the wiring 31 and the conductive elastic body 32 are arranged on the opposing surface 30a of the first base member 30, but this is not limiting, and they may also be arranged on the opposing surface (the surface on the positive side of the Z axis) of the second base member 70. In this case, for example, similar to the configuration on the first base member 30 side, a wiring pattern 33 is drawn out from the wiring 31 arranged on the second base member 70, and an electrode 33a of this wiring pattern 33 is connected to an electrode arranged on the underside of the circuit board 20 via an adhesive.

[0175] In the above embodiment and modified examples, the dielectric 12 is disposed so as to cover the entire circumference of the conductor wire 11, but the dielectric 12 may be disposed so as to cover at least the area of ​​the surface of the conductor wire 11 where the contact area changes depending on the load. Furthermore, the dielectric 12 is configured from one type of material in the thickness direction, but may have a structure in which two or more types of materials are laminated in the thickness direction.

[0176] In the above embodiment and modified example, the dielectric 12 is disposed on the surface of the conductor wire 11, but the dielectric 12 that determines the capacitance between the conductor wire 11 and the conductive elastic body 32 may be disposed between the conductor wire 11 and the conductive elastic body 32. For example, as shown in Fig. 23, the dielectric 12 may be disposed on the surface of the conductive elastic body 32. In this case, the dielectric 12 is made of an elastically deformable material so that the contact area with the conductor wire 11 changes in response to a load. For example, the dielectric 12 is made of a material having the same elastic modulus as the conductive elastic body 32.

[0177] In the above-described embodiment and modified example, the number of wires 10 arranged in one element portion A1 is two, but this is not limited to this. Also, the number of conductive elastic bodies 32 arranged in one element portion A1 is one, but this is not limited to this.

[0178] In the above embodiment and modified example, the number of wires 10 arranged in the load sensor 1 is 11, but this is not limited to this and may be, for example, 1. The number of conductive elastic bodies 32 arranged in the load sensor 1 is 11, but this is not limited to this and may be, for example, 1. In this case, there will also be one wiring pattern 33 drawn out from the conductive elastic body 32, and there will also be one joining position P1.

[0179] In the above embodiment and modified example, the number of element portions A1 in the X-axis direction is 11, but this is not limited to this and may be, for example, 1. Also, the number of element portions A1 in the Y-axis direction is 11, but this is not limited to this and may be, for example, 1.

[0180] In the above embodiment and modified example, the wiring 31 and the conductive elastic body 32 extend in the X-axis direction, but they may extend in a direction non-parallel to the X-axis direction. For example, the wiring 31 and the conductive elastic body 32 may cross the wire 10 in an oblique direction.

[0181] In the above embodiment and modified example, the wiring 31 is disposed between the opposing surface 30 a of the first base member 30 and the conductive elastic body 32, but the wiring 31 may be omitted. In this case, the wiring pattern 33 is drawn out from the end of the conductive elastic body 32 on the positive side of the X axis.

[0182] In the above-described embodiment and modified example, the element portion A1 is formed by the conductor wire 11 and the conductive elastic body 32 intersecting each other, but the configuration of the element portion A1 is not limited to this. For example, the element portion may be formed by a configuration in which a dielectric is sandwiched between a hemispherical conductive elastic body and a flat electrode. In this case, the dielectric may be formed on the surface of the electrode facing the conductive elastic body, or on the surface of the hemispherical conductive elastic body.

[0183] In addition, various modifications can be made to the embodiments of the present disclosure as appropriate within the scope of the technical ideas set forth in the claims.

[0184] <Supplementary Notes> The above description of the embodiments discloses the following techniques.

[0185] (Technology 1) A load sensor configured to detect an applied load, comprising: an element portion configured to receive the load; a wiring pattern connected to the element portion; a first electrode connected to the wiring pattern; a base member having a surface on which the element portion, the wiring pattern, and the first electrode are formed; a circuit board installed on the base member facing the surface of the base member so as to overlap the wiring pattern; a second electrode provided on the circuit board and joined to the first electrode at a joining position; a conductive member interposed between the first electrode and the second electrode to enhance electrical connection between the first electrode and the second electrode; and a fixing member that fixes the base member and the circuit board in the periphery of the joining position.

[0186] According to this technique, the base member and the circuit board are fixed by a fixing member around the joining position, thereby reinforcing the joining between the first electrode arranged on the base member and the second electrode arranged on the circuit board at the joining position, thereby enabling a strong and stable joining between the electrode on the element unit side and the electrode on the circuit board side.

[0187] (Technology 2) The load sensor according to Technology 1, wherein the fixing member is a thread, a tape, or a wire.

[0188] According to this technique, the base member and the circuit board can be easily and smoothly fixed in place around the joining position.

[0189] (Technology 3) The load sensor according to Technology 2, wherein the circuit board has a hole formed therethrough around the joining position, and the fixing member fixes the base member and the circuit board via the hole.

[0190] According to this technique, the base member and the circuit board can be smoothly fixed together by a fixing member such as a thread or wire through a hole formed in the circuit board around the joining position.

[0191] (Technology 4) In the load sensor described in Technology 2, the circuit board has a plurality of holes formed therethrough around the joining position, and the fixing member fixes the base member and the circuit board via the plurality of holes. According to this technology, the base member and the circuit board can be reliably fixed at a plurality of locations around the joining position.

[0192] (Technology 5) The load sensor according to any one of Technologies 1 to 4, wherein the fixing member has insulating properties.

[0193] This technique can prevent electrical leaks and short circuits from occurring through the fixing member, thereby preventing the fixing member from affecting the detection performance of the load sensor.

[0194] (Technology 6) The load sensor according to any one of Technologies 1 to 5, wherein the fixing member fixes the base member and the circuit board at a pair of peripheral portions sandwiching the joining position.

[0195] According to this technique, the base member and the circuit board can be firmly fixed together with a simple configuration.

[0196] (Technology 7) The load sensor according to Technology 6, wherein the pair of peripheral portions sandwich the joining position in a first direction, and the fixing member fixes the base member and the circuit board at another pair of peripheral portions that sandwich the joining position in a second direction that intersects the first direction.

[0197] According to this technique, the fixing member is disposed around the joining position, so that the base member and the circuit board can be fixed more firmly.

[0198] (Technology 8) A load sensor according to any one of technologies 1 to 7, characterized in that a through hole is formed in an arrangement area of ​​the circuit board where the second electrode is arranged, penetrating the circuit board and the second electrode in the thickness direction of the circuit board.

[0199] According to this technique, when the first electrode and the second electrode are joined, excess conductive material escapes into the through-hole, making it less likely for the conductive material to protrude from the joining position between the first electrode and the second electrode, thereby suppressing leaks and short circuits caused by the protruding conductive material.

[0200] (Technology 9) The load sensor according to Technology 8, wherein a surface of the second electrode is lower than a surface of the circuit board.

[0201] According to this technique, the region where the second electrode is disposed is recessed, which makes it even more difficult for the conductive material to protrude from the joint between the first electrode and the second electrode, thereby more reliably suppressing leaks and short circuits caused by the conductive material protruding.

[0202] (Technology 10) A load sensor according to any one of technologies 1 to 9, characterized in that: a plurality of element parts, each of which is the element part, a plurality of wiring patterns, each of which is the wiring pattern, and a plurality of first electrodes, each of which is the first electrode, are arranged on the surface of the base member; the plurality of first electrodes are arranged in a row on the surface of the base member; a plurality of second electrodes, each of which is the second electrode, are arranged in a row on the circuit board so as to correspond to the plurality of first electrodes, respectively; the plurality of second electrodes are respectively joined to the plurality of first electrodes at a plurality of joining positions; and the fixing member is a thread that sews on both sides of the row in a direction parallel to the row in which the plurality of joining positions are arranged.

[0203] According to this technique, the base member and the circuit board can be smoothly fixed together around the multiple joining positions.

[0204] (Technology 11) The load sensor according to Technology 10, wherein the space between adjacent joint positions among the plurality of joint positions is further sewn with thread as the fixing member.

[0205] This technique allows the electrodes on the element section side and the electrodes on the circuit board side to be joined more firmly and stably.

[0206] (Technology 12) The load sensor according to any one of technologies 1 to 11, further comprising another fixing member that fixes the base member and the circuit board at the joint position between the first electrode and the second electrode.

[0207] According to this technique, the fixing between the base member and the circuit board at the joining position is reinforced by the other fixing member, so that the electrodes on the element section side and the electrodes on the circuit board side can be joined more firmly and stably.

[0208] (Technology 13) A load sensor according to any one of technologies 1 to 12, characterized in that a first through hole is formed in the area on the base member where the first electrode is arranged, the first through hole penetrating the base member and the first electrode in the thickness direction of the base member.

[0209] This technology allows confirmation of whether the conductive member is properly positioned between the first and second electrodes via the through-hole. Furthermore, when joining the first and second electrodes, excess adhesive escapes into the through-hole, making it less likely for the adhesive to overflow from the joining position.

[0210] (Technology 14) A load sensor according to Technology 13, characterized in that a second through hole is formed in the placement area of ​​the base member, penetrating the base member and the first electrode in the thickness direction of the base member, the conductive member is placed at a position corresponding to the first through hole, and an adhesive that bonds the first electrode and the second electrode is placed at a position corresponding to the second through hole.

[0211] A general adhesive can bond the first electrode and the second electrode more firmly than a conductive member. Therefore, the above technology can electrically bond the first electrode and the second electrode and bond them more firmly. Furthermore, it is possible to check whether the conductive member and the adhesive are properly positioned through the first and second through holes, respectively.

[0212] (Technology 15) A load sensor described in any one of technologies 1 to 9, characterized in that: a plurality of element parts, each of which is the element part, a plurality of wiring patterns, each of which is the wiring pattern, and a plurality of first electrodes, each of which is the first electrode, are arranged on the surface of the base member; the plurality of first electrodes are arranged in a row on the base member; a plurality of second electrodes, each of which is the second electrode, are arranged in a row on the circuit board so as to correspond to the plurality of first electrodes, respectively; the plurality of second electrodes are respectively joined to the plurality of first electrodes at a plurality of joining positions; and the plurality of first electrodes and the plurality of second electrodes at the plurality of joining positions have a shape that is long in a direction intersecting the direction in which the first electrodes are arranged.

[0213] This technique makes it easier to arrange a plurality of bonding positions at intervals in the arrangement direction of the first electrodes, thereby preventing electrodes at adjacent bonding positions from shorting out due to migration or the like.

[0214] (Technology 16) A load sensor according to any one of technologies 1 to 15, characterized in that the element portion comprises a conductive elastic body formed on the base member, a conductor wire overlapping the conductive elastic body, and a dielectric interposed between the conductive elastic body and the conductor wire, and the wiring pattern is connected to the conductive elastic body.

[0215] According to this technology, the contact area between the conductive elastic body and the dielectric or the contact area between the dielectric and the conductor wire changes depending on the load, and the electrostatic capacitance between the conductive elastic body and the conductor wire changes.

[0216] Therefore, by detecting this capacitance, the load can be detected.

[0217] REFERENCE SIGNS LIST 1 Load sensor 11 Conductor wire 12 Dielectric 20 Circuit board 22 Electrode (second electrode) 24 Through hole 25, 26 Hole 30 First base member (base member) 32 Conductive elastic body 33 Wiring pattern 33a Electrode (first electrode) 34a Through hole (first through hole) 34b Through hole (second through hole) 41 Adhesive (conductive member) 42 Adhesive 51, 53, 54 Fixing member (thread) 52 Fixing member (other fixing member) 52a, 52b Fixing member (other fixing member) A1 Element portion P1 Bonding position P11 Peripheral portion (both sides) P12 Peripheral portion

Claims

1. A load sensor configured to detect an applied load, comprising: an element portion configured to receive the load; a wiring pattern connected to the element portion; a first electrode connected to the wiring pattern; a base member having a surface on which the element portion, the wiring pattern, and the first electrode are formed; a circuit board installed on the base member facing the surface of the base member so as to overlap the wiring pattern; a second electrode provided on the circuit board and joined to the first electrode at a joining position; a conductive member interposed between the first electrode and the second electrode to enhance the electrical connection between the first electrode and the second electrode; and a fixing member that fixes the base member and the circuit board in the vicinity of the joining position.

2. The load sensor according to claim 1, wherein the fixing member is a thread, a tape or a wire.

3. A load sensor as described in claim 2, wherein the circuit board is formed with a hole penetrating the circuit board around the joining position, and the fixing member fixes the base member and the circuit board via the hole.

4. A load sensor as described in claim 2, wherein the circuit board has a plurality of holes formed therethrough around the joining position, and the fixing member fixes the base member and the circuit board via the plurality of holes.

5. A load sensor according to any one of claims 1 to 4, characterized in that the fixing member has insulating properties.

6. A load sensor as claimed in any one of claims 1 to 5, characterized in that the fixing member fixes the base member and the circuit board at a pair of peripheral portions sandwiching the joining position.

7. A load sensor as described in claim 6, characterized in that the pair of peripheral portions sandwich the joining position in a first direction, and the fixing member fixes the base member and the circuit board at another pair of peripheral portions that sandwich the joining position in a second direction intersecting the first direction.

8. A load sensor as claimed in any one of claims 1 to 7, characterized in that a through hole is formed in the arrangement area of ​​the circuit board in which the second electrode is arranged, penetrating the circuit board and the second electrode in the thickness direction of the circuit board.

9. The load sensor according to claim 8, wherein a surface of the second electrode is lower than a surface of the circuit board.

10. A load sensor as claimed in any one of claims 1 to 9, characterized in that a plurality of element parts, each of which is the element part, a plurality of wiring patterns, each of which is the wiring pattern, and a plurality of first electrodes, each of which is the first electrode, are arranged on the surface of the base member, the plurality of first electrodes are arranged in a row on the surface of the base member, the circuit board has a plurality of second electrodes, each of which is the second electrode, arranged in a row corresponding to the plurality of first electrodes, the plurality of second electrodes are respectively joined to the plurality of first electrodes at a plurality of joining positions, and the fixing member is a thread that sews on both sides of the row in which the plurality of joining positions are arranged in a direction parallel to the row.

11. A load sensor according to claim 10, wherein adjacent joint positions among said plurality of joint positions are further sewn with thread as said fixing member.

12. A load sensor as claimed in any one of claims 1 to 11, further comprising another fixing member for fixing the base member and the circuit board at the joint position between the first electrode and the second electrode.

13. A load sensor as claimed in any one of claims 1 to 12, characterized in that a first through hole is formed in the arrangement area of ​​the base member in which the first electrode is arranged, penetrating the base member and the first electrode in the thickness direction of the base member.

14. A load sensor as described in claim 13, characterized in that a second through hole penetrating the base member and the first electrode in the thickness direction of the base member is formed in the placement area of ​​the base member, the conductive member is placed at a position corresponding to the first through hole, and an adhesive for joining the first electrode and the second electrode is placed at a position corresponding to the second through hole.

15. A load sensor as described in any one of claims 1 to 9, characterized in that a plurality of element parts, each of which is the element part, a plurality of wiring patterns, each of which is the wiring pattern, and a plurality of first electrodes, each of which is the first electrode, are arranged on the surface of the base member, the plurality of first electrodes are arranged in a row on the base member, a plurality of second electrodes, each of which is the second electrode, are arranged in a row on the circuit board so as to correspond respectively to the plurality of first electrodes, the plurality of second electrodes are respectively joined to the plurality of first electrodes at a plurality of joining positions, and the plurality of first electrodes and the plurality of second electrodes at the plurality of joining positions have a shape that is long in a direction intersecting the direction in which the first electrodes are arranged.

16. A load sensor as claimed in any one of claims 1 to 15, characterized in that the element portion comprises a conductive elastic body formed on the base member, a conductor wire overlapping the conductive elastic body, and a dielectric interposed between the conductive elastic body and the conductor wire, and the wiring pattern is connected to the conductive elastic body.

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