Capacitance sensor and manufacturing method therefor

Abstract

To provide a capacitance sensor that features enhanced resistance uniformity of an entire sensor member, and a method of manufacturing the same.SOLUTION: A capacitance sensor 1 is provided, comprising: an insulative substrate 4; a conductive layer 5 formed on the insulative substrate 4, the conductive layer containing a conductive material; and an electronic control unit 3 electrically connected to one end 5a of the conductive layer 5 via wiring 2. Content of the conductive material in the conductive layer 5 is greater in the distal region far from the electronic control unit 3 than in the proximal region near the electronic control unit 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a capacitance sensor and a method for manufacturing the same.

Background Art

[0002] In recent years, there has been a demand for adding functions to the steering wheel of an automobile, that is, the steering wheel mounted on a vehicle. For example, a steering wheel including a capacitance sensor for detecting that a driver has grasped the rim portion of the steering wheel is known.

[0003] Patent Document 1 discloses a capacitance sensor for a steering wheel including two electrode layers and an insulating layer disposed between the electrode layers. A conductive polymer is used for the electrode portion, and carbon black or the like is used as the conductive material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since a conductive material such as carbon black has a higher resistance value compared to metal, in Patent Document 1, when used for a long sensor mat wound around the outer periphery of a steering wheel, the detection sensitivity decreases as the distance from the detector increases, and there is a problem that the detection time becomes long. The reason why the detection time of the capacitance sensor becomes long in this way is due to the increase in the resistance value according to the distance from the detector.

[0006] The present invention has been made in view of the problems of such prior art. An object of the present invention is to provide a capacitance sensor and a method for manufacturing the same, in which the uniformity of the resistance value of the entire sensor member is enhanced.

Means for Solving the Problems

[0007] The capacitance sensor according to the present embodiment includes an insulating substrate, a conductive layer formed on the insulating substrate and containing a conductive material, and an electronic control unit electrically connected to one end of the conductive layer via a wiring. The capacitance sensor is characterized in that the content of the conductive material contained in the conductive layer is larger in the far region away from the electronic control unit than in the near region close to the electronic control unit.

[0008] The method for manufacturing the capacitance sensor according to the present embodiment is the method for manufacturing the capacitance sensor described above, and includes a step of forming the conductive layer on the insulating substrate such that the conductive layer gradually becomes thicker from one end to the other end.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a capacitance sensor and a method for manufacturing the same, in which the uniformity of the resistance value of the entire sensor member is enhanced.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0011] Hereinafter, the capacitance sensor according to this embodiment and its manufacturing method will be described in detail with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may be different from the actual ratios.

[0012] [First Embodiment] The capacitance sensor 1 shown in FIG. 1 includes an insulating substrate 4, a conductive layer 5 formed on the insulating substrate 4, and an electronic control unit 3 electrically connected to one end 5a of the conductive layer 5 via a wiring 2.

[0013] The insulating substrate 4 is made of an insulating material and is formed in a sheet shape. The insulating substrate 4 is preferably formed of a resin having flexibility from the viewpoint of ease of winding around the rim portion of the steering wheel.

[0014] The conductive layer 5 is formed in a sheet shape on the insulating substrate 4 and contains a conductive material. The conductive material is not particularly limited, but is preferably at least one selected from the group consisting of graphite, graphene, carbon fiber, single-walled carbon nanotube (SWCNT), double-walled carbon nanotube (DWCNT), multi-walled carbon nanotube (MWCNT), carbon nanohorn, carbon nanofiber, carbon black, and fullerene.

[0015] The method for forming the conductive layer 5 on the insulating base material 4 is not particularly limited. For example, a general coating method or printing method as described below can be applied for formation. When a metal is used as the conductive material, methods such as metal plating or forming a metal foil can be mentioned. From the viewpoint that the capacitance sensor 1 has flexibility and is less likely to break when pulled, bent, or stretched, a method of forming the conductive layer 5 by coating or printing a conductive ink containing a conductive material on the insulating base material 4 is preferred.

[0016] The method for adjusting the conductive ink is not particularly limited. For example, a conductive ink in which a conductive material is dispersed in an organic solvent may be adjusted. In order to improve the dispersibility of the conductive material in the organic solvent, for example, it can be pulverized using a pulverizer such as a ball mill, a rotor speed mill, a cutting mill, a homogenizer, a vibration mill, or an attritor and then dispersed in the organic solvent.

[0017] The conductive layer 5 functions as a detection electrode of the capacitance sensor 1. The capacitance sensor 1 may be mounted on the rim portion of the steering wheel mounted on the vehicle, that is, the portion gripped by the driver. An electronic control unit 3 is electrically connected to the end portion 5a of the conductive layer 5 via the wiring 2. The electronic control unit 3, also called an ECU (Electronic Control Unit), can detect whether the driver has touched the steering wheel based on the change in capacitance in the conductive layer 5.

[0018] The content of the conductive material contained in the conductive layer 5 is greater in the far region away from the electronic control unit 3 than in the near region close to the electronic control unit 3. Specifically, as shown in FIG. 1, the content of the conductive material contained in the conductive layer 5 may gradually increase from one end portion 5a of the conductive layer 5, through the central portions 5b, 5c, 5d of the conductive layer 5, toward the other end portion 5e of the conductive layer 5. That is, in FIG. 1, the conductive layer 5 is arranged in the order of the conductive layer 5e, the conductive layer 5d, the conductive layer 5c, the conductive layer 5b, and the conductive layer 5a from far away from the electronic control unit 3, but it may be formed in the same order with the content of the conductive material contained in the conductive layer 5 increasing. As will be described later, generally, when the conductive layer 5 is uniformly formed on the insulating base material 4, the resistance value of the conductive layer 5 becomes higher in the region farther from the electronic control unit 3. In the capacitance sensor 1 according to the present embodiment, since the content of the conductive material contained in the conductive layer 5 is small in the near region close to the electronic control unit 3 and is greater in the far region than in the near region, a capacitance sensor with enhanced uniformity of the resistance value of the entire sensor member can be obtained.

[0019] The thickness of the conductive layer 5 may be formed thinner in the near region close to the electronic control unit 3 and may be formed thicker in the far region away from the electronic control unit 3 than in the near region. Specifically, as shown in FIG. 1, the thickness of the conductive layer 5 may be formed thinner at one end portion 5a of the conductive layer 5 to which the electronic control unit 3 is connected and may be formed thicker at the other end portion 5e of the conductive layer 5. Further, the thickness of the conductive layer 5 may be formed to gradually increase as it goes to the region farther from the electronic control unit 3. That is, in FIG. 1, the thickness of the conductive layer 5 may gradually increase from one end portion 5a of the conductive layer 5, through the central portions 5b, 5c, 5d of the conductive layer 5, toward the other end portion 5e of the conductive layer 5. In FIG. 1, the conductive layer 5 is arranged in the order of the conductive layer 5e, the conductive layer 5d, the conductive layer 5c, the conductive layer 5b, and the conductive layer 5a from far away from the electronic control unit 3, but it may be formed in the same order with the conductive layer 5 being thicker.

[0020] Furthermore, as shown in FIG. 5(f) described later, by forming the cross-section in the thickness direction of the conductive layer 5 in a stepped shape, it may be made to gradually thicken from one end portion 5f of the conductive layer 5, via the central portions 5g, 5h, 5i of the conductive layer 5, toward the other end portion 5j of the conductive layer 5.

[0021] Generally, the resistance value can be calculated from the following mathematical formula (1). R = ρ × L / S (1)

[0022] In the above mathematical formula (1), the resistance value R (Ω), resistivity ρ (Ω·m), length L (m), and cross-sectional area S (m 2 ) are represented. The resistivity ρ is a value specific to the material. For a conductor with a uniform cross-sectional area, the resistance value R is proportional to the length L. Therefore, when the conductive layer 5 is uniformly formed on the insulating base material 4, the farther the region is from the electronic control unit 3, the higher the resistance value of the conductive layer 5 becomes.

[0023] On the other hand, the time constant of an RC series circuit in which a resistor and a capacitor are connected in series can be calculated from the following mathematical formula (2). τ = R × C (2)

[0024] In the above mathematical formula (2), the time constant τ (seconds), the resistance value R (Ω), and the capacitance C (F) of the capacitor are represented. The time constant τ is related to the detection time of the capacitance sensor 1 and is proportional to the resistance value R. That is, when using the conductive layer 5 with a high resistance, the detection time becomes longer.

[0025] As shown in the above mathematical formulas (1) and (2), when the conductive layer 5 is uniformly formed on the insulating base material 4, in the vicinity region close to the electronic control unit 3, the resistance value of the conductive layer 5 is low and the detection time is short. On the other hand, in the far region far from the electronic control unit 3, the resistance value of the conductive layer 5 becomes high and the detection time becomes long. And the greater the difference in the resistance value of the conductive layer 5 within the capacitance sensor 1, the greater the difference in the detection time. In particular, in the case of the long-shaped capacitance sensor 1 mounted on the rim portion of the steering wheel, the difference in the resistance value of the conductive layer 5 between the vicinity region and the far region is likely to be large, and accordingly, the difference in the detection time is also likely to be large.

[0026] Figure 2 is a graph showing the influence of the type of conductive material and the coating film thickness used for the conductive layer 5 on the surface resistance. Specifically, conductive inks containing three types of conductive materials (MWCNT, graphene, or carbon black) were prepared respectively, and applied to the insulating substrate 4 so that the coating film thickness of the conductive layer 5 was 11 μm, 22 μm, or 44 μm, and the surface resistance was measured. As shown in Figure 2, in common for the three types of conductive materials, the surface resistance was the highest when the coating thin film was the thinnest at 11 μm, and the surface resistance was the lowest when the coating thick film was thick at 44 μm. That is, the thicker the coating film thickness of the conductive layer 5, the lower the resistance value of the conductive layer 5.

[0027] In the capacitance sensor 1 according to this embodiment, the content of the conductive material contained in the conductive layer 5 is less in the vicinity region close to the electronic control unit 3 and more in the distant region far from the electronic control unit 3 than in the vicinity region. Also, the thickness of the conductive layer 5 may be formed thinner in the vicinity region and thicker in the distant region than in the vicinity region. Therefore, in the vicinity region, the resistance becomes high and the detection time becomes long. On the other hand, in the distant region, the resistance becomes lower than in the vicinity region and the detection time becomes short. Thus, in such a capacitance sensor 1, the difference in detection time due to the difference in the resistance value of the conductive layer 5 can be canceled out, and a capacitance sensor with improved uniformity of the resistance value of the entire sensor member can be obtained.

[0028] The insulating substrate 4 and the conductive layer 5 may have a constricted portion 6. Specifically, as shown in Figure 1, by having constricted portions 6a, 6b, 6c, 6d that are constricted in the width direction of the insulating substrate 4 and the conductive layer 5, it becomes easier to wind around the rim portion of the steering wheel. In Figure 1, four constricted portions 6 are provided, but the number of constricted portions is not particularly limited and can be set to any number. Also, the formation method of the constricted portion 6 is not particularly limited. For example, it may be formed by punching the insulating substrate 4 in a constricted shape in advance before forming the conductive layer 5, or after forming the conductive layer 5 on the insulating substrate 4, it may be punched in a constricted shape after drying.

[0029] As described above, the capacitance sensor 1 according to this embodiment includes an insulating base material 4, a conductive layer 5 containing a conductive material formed on the insulating base material 4, and an electronic control unit 3 electrically connected to one end portion 5a of the conductive layer 5 via a wiring 2. And the content of the conductive material contained in the conductive layer 5 is larger in the distant region far from the electronic control unit 3 than in the vicinity region close to the electronic control unit 3. Therefore, according to the capacitance sensor 1 according to this embodiment, a capacitance sensor with improved uniformity of the resistance value of the entire sensor member can be obtained.

[0030] [Manufacturing Method of Capacitance Sensor] Next, the manufacturing method of the capacitance sensor 1 according to this embodiment will be described. The manufacturing method of the capacitance sensor 1 may include a step of forming the conductive layer 5 on the insulating base material 4 such that the conductive layer 5 gradually becomes thicker from one end portion 5a to the other end portion 5e. The method of forming the conductive layer 5 is not particularly limited, and it can be manufactured by applying a conductive ink on the insulating base material 4 by applying a general coating method or printing method. Examples of the coating method or printing method include die coating, gravure coating, wire bar coating, knife roll coating, bar coating, reverse coating, comma coating, blade coating, spray coating, offset printing, flexographic printing, gravure printing, screen printing, or inkjet printing.

[0031] As a method for forming the conductive layer 5, the kiss reverse gravure method may be used. The kiss reverse gravure method is a method in which, as shown in FIG. 3, the gravure roll 11 rotates in the reverse direction with respect to the conveyance direction (right direction) of the insulating base material 4 to apply the conductive ink 15. The kiss reverse gravure coater 10 includes a tank storing the conductive ink 15, a gravure roll 11 disposed above the tank, two rolls 12 disposed on the side opposite to the gravure roll 11 with respect to the insulating base material 4, and a doctor blade 13. The gravure roll 11 rotates in the counterclockwise direction, and the two rolls 12 are disposed on the upstream side and the downstream side of the gravure roll 11 along the conveyance direction of the insulating base material 4, respectively. The insulating base material 4 passes through the upstream roll 12, contacts the gravure roll 11, and is further conveyed through the downstream roll 12. Then, the portion where the insulating base material 4 contacts the gravure roll 11 becomes the transfer portion, the conductive ink 15 is transferred onto the insulating base material 4, and the conductive layer 5 is formed on the insulating base material 4. On the other hand, the doctor blade 13 is disposed at a position upstream of the transfer portion with respect to the rotation direction of the gravure roll 11. The doctor blade 13 scrapes off the excess conductive ink 15 on the outer peripheral surface of the gravure roll 11.

[0032] In the capacitance sensor 1 according to the present embodiment, the thickness of the conductive layer 5 may be formed thinner in the vicinity region close to the electronic control unit 3 and may be formed thicker than the vicinity region in the distant region far from the electronic control unit 3. When applying the conductive layer 5 onto the insulating base material 4 by the kiss reverse gravure method, the coating film thickness can be gradually increased by gradually retracting the doctor blade 13 in the direction of the arrow 16 in FIG. 3 (downward right direction) for coating. That is, in the manufacturing method of the capacitance sensor 1, when applying the conductive layer 5 onto the insulating base material 4, it may include a step of applying while gradually retracting the doctor blade 13 of the coater. Note that the step of applying while gradually retracting the doctor blade 13 may be applied to a method in which the gravure roll 11 rotates in the same direction (clockwise) with respect to the conveyance direction of the insulating base material 4 to apply the conductive ink 15, that is, the kiss gravure method. Further, it may be applied to the direct gravure method or the direct reverse gravure method in which a backup roll is disposed at the transfer portion between the insulating base material 4 and the conductive ink 15, and the insulating base material 4 and the gravure roll are brought into contact with each other for transfer by pressing the backup roll.

[0033] As a method for forming the conductive layer 5, a die method may be used. The die method is a method of coating the insulating base material 4 while discharging the conductive ink 25 from the die head 23 as shown in FIG. 4. The die coater 20 includes a die head 23 that discharges the conductive ink 25, a backup roll 21 disposed above the die head 23, and two rolls 22 disposed along the conveyance direction of the insulating base material 4. The backup roll 21 rotates in the counterclockwise direction, and the two rolls 22 are disposed on the upstream side and the downstream side of the backup roll 21 along the conveyance direction of the insulating base material 4, respectively. The insulating base material 4 passes through the upstream roll 22, contacts the backup roll 21 and the die head 23, and is further conveyed through the downstream roll 22. Then, the portion where the insulating base material 4 contacts the die head 23 becomes the transfer portion, and the conductive ink 25 discharged from the die head 23 is transferred onto the insulating base material 4, and the conductive layer 5 is formed on the insulating base material 4. The coating film thickness of the conductive layer 5 is determined by the discharge amount of the conductive ink 25 from the die head 23 and the conveyance speed of the insulating base material 4 that transfers it.

[0034] In the capacitance sensor 1 according to the present embodiment, the thickness of the conductive layer 5 may be formed thinner in the vicinity region close to the electronic control unit 3 and may be formed thicker than the vicinity region in the distant region far from the electronic control unit 3. When coating the conductive layer 5 on the insulating base material 4 by the die method, the coating film thickness can be gradually increased by gradually retracting the die head 23 in the direction of the arrow 26 (downward direction) in FIG. 4 during coating. That is, in the manufacturing method of the capacitance sensor 1, when coating the conductive layer 5 on the insulating base material 4, a step of gradually retracting the die head 23 of the coater during coating may be included.

[0035] As shown in Fig. 5(f), the method for manufacturing the capacitance sensor 1 may include a step of forming the conductive layer 5 on the insulating substrate 4 by performing overprinting so that the conductive layer 5 gradually becomes thicker from one end 5f to the other end 5j. For example, when screen printing is used as the method for forming the conductive layer 5, the insulating substrate 4 may be gradually moved to shift the printing area, and more overprinting may be performed in the area farther from the electronic control unit 3 so that the coating film thickness becomes thicker. The conductive layer 5 formed on the insulating substrate 4 by such a printing method has a stepped cross-section in the thickness direction.

[0036] Fig. 5(a) shows the insulating substrate 4 before the conductive layer 5 is formed. The vicinity area close to the electronic control unit 3 is arranged on the left side, and the distant area far from the electronic control unit 3 is arranged on the right side. From the state of Fig. 5(a), the conductive layer 5f is printed on the insulating substrate 4 and dried to obtain the state of Fig. 5(b). Then, from the state of Fig. 5(b), the insulating substrate 4 is moved in the longitudinal direction (left direction) by an arbitrary length to shift the printing area, and the conductive layer 5g is printed and dried, resulting in the state of Fig. 5(c). In the state of Fig. 5(c), the conductive layer 5g, which is an area farther from the electronic control unit 3 than the conductive layer 5f, is formed thicker than the conductive layer 5f.

[0037] From the state of Fig. 5(c), the insulating substrate 4 is moved in the longitudinal direction (left direction) by an arbitrary length to shift the printing area, and the conductive layer 5h is printed and dried, resulting in the state of Fig. 5(d). At this time, the conductive layer 5h, which is an area farther from the electronic control unit 3 than the conductive layer 5g, is formed even thicker than the conductive layer 5g. Also, from the state of Fig. 5(d), the insulating substrate 4 is moved in the longitudinal direction (left direction) by an arbitrary length to shift the printing area, and the conductive layer 5i is printed and dried, resulting in the state of Fig. 5(e). At this time, the conductive layer 5i, which is an area farther from the electronic control unit 3 than the conductive layer 5h, is formed even thicker than the conductive layer 5h.

[0038] Then, starting from the state of FIG. 5(e), if the insulating base material 4 is moved in the longitudinal direction (left direction) by an arbitrary length to shift the printing area, and the conductive layer 5j is printed and dried, the state of FIG. 5(f) is obtained. At this time, the conductive layer 5j, which is a region farther from the electronic control unit 3 than the conductive layer 5i, is formed thicker than the conductive layer 5i. Therefore, in FIG. 5(f), in the order from farther from the electronic control unit 3, there are the conductive layer 5j, the conductive layer 5i, the conductive layer 5h, the conductive layer 5g, and the conductive layer 5f arranged, and the thickness of the conductive layers is also formed in the same order.

[0039] In this way, by shifting the printing area with respect to the insulating base material 4 and applying the conductive layer 4 times by overcoating, the thickness of the conductive layer 5 is formed thinner in the vicinity region (left side) closer to the electronic control unit 3 and thicker in the distant region (right side) farther from the electronic control unit 3 than in the vicinity region. In this way, the cross-section of the conductive layer 5 in the thickness direction may be formed in a stepped shape. Note that the number of overcoating times is not particularly limited, and any number of 1 or more times can be arbitrarily set. In this way, in the method for manufacturing the capacitance sensor 1, when forming the conductive layer 5 on the insulating base material 4, a step of forming the conductive layer 5 to gradually become thicker from one end portion 5f to the other end portion 5j by performing overcoating may be included.

[0040] [Second Embodiment] Next, the capacitance sensor 1a according to the second embodiment will be described with reference to FIGS. 6 and 7. The capacitance sensor 1a corresponds to the capacitance sensor 1 according to the first embodiment. Also, the wiring 2, the electronic control unit 3, the insulating base material 4, the conductive layer 5, and the constricted portions 6e, 6f, 6g, 6h are the same as those of the capacitance sensor 1 according to the first embodiment, respectively, and thus the description thereof will be omitted.

[0041] As shown in FIGS. 6 and 7, the shape of the conductive layer in plan view may be composed of a plurality of dot shapes. And in order to ensure the electrical conductivity of the conductive layer 5, it is preferable that the plurality of dot shapes are connected to each other. Further, in the vicinity region (left side) close to the electronic control unit 3, the plurality of dot shapes may be large and the formation density of the plurality of dot shapes may be low. On the other hand, in the distant region (right side) far from the electronic control unit 3, the plurality of dot shapes may be smaller than those in the vicinity region and the formation density of the plurality of dot shapes may be higher. That is, in FIG. 6, in the order from far from the electronic control unit 3, the conductive layers 5о, 5n, 5m, 5l, 5k are arranged, and in the same order, they may be formed in the order of decreasing dot shape size and increasing dot shape formation density. Note that the formation density of the plurality of dot shapes means the number per unit area of the plurality of dot shapes formed on the surface of the insulating base material 4.

[0042] The capacitance sensor 1a has a high resistance and a long detection time when the plurality of dot shapes are large and the formation density of the plurality of dot shapes is low in the vicinity region close to the electronic control unit 3. On the other hand, in the distant region far from the electronic control unit 3, when the plurality of dot shapes are smaller than those in the vicinity region and the formation density of the plurality of dot shapes is higher, the resistance becomes low and the detection time becomes short. Therefore, in such a capacitance sensor 1a, it is possible to cancel out the difference in detection time due to the difference in the resistance value of the conductive layer 5, and a capacitance sensor with improved uniformity of the resistance value of the entire sensor member can be obtained.

[0043] The types of the plurality of dot shapes of the conductive layer 5 are not particularly limited, and may be, for example, circular, square, or triangular. However, as described above, in order to ensure the electrical conductivity of the conductive layer 5, it is preferable that the plurality of dot shapes are connected to each other.

[0044] The method for forming the conductive layer 5 of the capacitance sensor 1a is not particularly limited, and it can be manufactured by applying the general coating method or printing method in the capacitance sensor 1 described above to apply a conductive ink onto the insulating substrate 4. From the viewpoint of ease of forming a continuous dot shape, it is preferable to perform screen printing using a conductive ink. For example, it can be formed by creating a screen mask in which a plurality of dot shapes as shown in FIG. 6 are formed of a photosensitive resin, and then performing printing of the conductive ink onto the insulating substrate 4 using the screen mask. Thus, the manufacturing method of the capacitance sensor 1a may include a step of printing using a screen mask in which a plurality of dot shapes are formed of a photosensitive resin when forming the conductive layer 5 on the insulating substrate 4.

[0045] As described above, this embodiment has been explained, but this embodiment is not limited thereto, and various modifications are possible within the scope of the gist of this embodiment.

Description of Reference Numerals

[0046] 1 Capacitance sensor 2 Wiring 3 Electronic control unit 4 Insulating substrate 5 Conductive layer 5a One end portion of the conductive layer

Claims

1. An insulating substrate, A conductive layer formed on the insulating substrate and containing a conductive material, An electronic control unit electrically connected to one end of the conductive layer via a wiring, A capacitance sensor comprising: The capacitance sensor, wherein the content of the conductive material contained in the conductive layer is greater in a distant region far from the electronic control unit than in a nearby region close to the electronic control unit.

2. The capacitance sensor according to claim 1, wherein the conductive layer is formed thicker in the distant region than in the nearby region.

3. The capacitance sensor according to claim 1 or 2, wherein the cross-section of the conductive layer in the thickness direction is formed in a stepped shape.

4. The capacitance sensor according to claim 1, wherein the shape of the conductive layer in plan view is composed of a plurality of dot shapes, and the plurality of dot shapes are connected to each other.

5. A method for manufacturing the capacitance sensor according to claim 2, The method for manufacturing a capacitance sensor includes a step of forming the conductive layer on the insulating substrate such that the conductive layer gradually becomes thicker from one end to the other end.

6. A method for manufacturing the capacitance sensor according to claim 2, The method for manufacturing a capacitance sensor includes a step of forming the conductive layer on the insulating substrate such that the conductive layer gradually becomes thicker from one end to the other end by performing overcoating.

7. A method for manufacturing the capacitance sensor according to claim 4, The method for manufacturing a capacitance sensor includes a step of printing on the insulating substrate using a screen mask in which the plurality of dot shapes are formed of a photosensitive resin when forming the conductive layer.

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