Capacitive sensor and method for manufacturing the same

Abstract

This capacitance sensor (1) is provided with: a base material film (10) which has light-transmitting properties; a resist layer (20) which is provided on a part of one main surface (11) of the base material film (10) and exhibits higher adhesion to a specific conductive polymer than the base material film (10), while having light-transmitting properties; and electrodes (31-36) which are formed of a conductive material that contains the specific conductive polymer, while having light-transmitting properties, and which are at least partially provided on a surface of the resist layer (20) on the reverse side from the base material film (10). When viewed along the thickness direction of the base material film (10), a region (15) of the main surface (11) of the base material film (10) surrounds the electrodes (31-36), the region being not provided with the resist layer (20).

Description

[Technical field]

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

[0002] There is known a capacitance sensor that can be used for a touch panel display or the like. The following Patent Document 1 discloses a capacitance sensor in which a light-transmitting electrode made of a conductive polymer is provided on a light-transmitting base film. The following Patent Document 1 also discloses that a layer for increasing the adhesion between the base film and the conductive polymer may be provided between the base film and the electrode.

[0003] [Patent Document 1] Patent No. 6167103 Summary of the Invention

[0004] Generally, a layer for increasing adhesion tends to be provided on the entire surface of a base film. Therefore, when the above-mentioned layer is provided in the capacitance sensor of Patent Document 1, the thickness of the capacitance sensor as a whole increases and the flexibility of the capacitance sensor tends to decrease compared to when the layer is not provided. However, there are cases where the portion where the capacitance sensor is attached is a curved surface, and there is a demand for suppressing the decrease in flexibility from the viewpoint of attachment.

[0005] Therefore, an object of the present invention is to provide a capacitance sensor that can increase the adhesion of electrodes while suppressing a decrease in flexibility, and a method for manufacturing the capacitance sensor.

[0006] In order to achieve the above-mentioned object, the capacitance sensor of the present invention comprises a light-transmitting base film, a light-transmitting resist layer provided on a part of one main surface of the base film and having a higher adhesion to a predetermined conductive polymer than the base film, and a light-transmitting electrode made of a conductive material containing the predetermined conductive polymer, at least a part of which is provided on the surface of the resist layer opposite the base film side, and is characterized in that when viewed along the thickness direction of the base film, the area of ​​the one main surface of the base film where the resist layer is not formed surrounds the electrode.

[0007] In addition, the method for manufacturing a capacitance sensor of the present invention includes a resist layer formation process in which a resin material is applied to a portion of one main surface of a translucent base film to form a translucent resist layer having higher adhesion to a predetermined conductive polymer than the base film, and an electrode formation process in which a conductive material containing the predetermined conductive polymer is applied to at least a portion of the surface of the resist layer opposite the base film to form an electrode having translucency, wherein in the resist layer formation process, the resin material is applied so that the resist layer is surrounded by an area on the one main surface of the base film where the resist layer is not formed when viewed along the thickness direction of the base film, and in the electrode formation process, the conductive material is applied so that the electrode is surrounded by the area when viewed along the thickness direction of the base film.

[0008] In the capacitance sensor and the method for manufacturing the capacitance sensor, at least a part of the electrode having light transmission is attached to the base film via a resist layer. The adhesive strength between the predetermined conductive polymer contained in the conductive material constituting the electrode and the resist layer is higher than that between the predetermined conductive polymer and the base film. Therefore, the adhesive strength between the electrode and the base film can be increased compared to when the base film is not provided with a resist layer. In addition, in the capacitance sensor and the method for manufacturing the capacitance sensor, when viewed along the thickness direction of the base film, the region on one main surface of the base film where the resist layer is not formed surrounds the electrode. Therefore, according to the capacitance sensor, compared to when the resist layer is provided on the entire surface of one main surface of the base film, the decrease in flexibility at least around the electrode can be suppressed, and the attachment to a curved portion in an apparatus or the like can be improved. In addition, according to the method for manufacturing the capacitance sensor, a capacitance sensor that can suppress the decrease in flexibility while increasing the adhesive strength of the electrode can be manufactured.

[0009] The above-mentioned capacitance sensor may further include a shield layer provided in the region and spaced apart from the electrodes.

[0010] With this configuration, the influence of external electromagnetic fields and the like can be prevented from reaching the electrodes, compared to a case in which the capacitance sensor does not include a shield layer.

[0011] In this case, the shield layer may be thicker than the electrode.

[0012] With this configuration, the difference between the thickness of the shield layer and the sum of the thicknesses of the electrodes and the resist layer can be made smaller than when the shield layer is thinner than the electrodes, and therefore the amount of unevenness on the electrode side surface of the capacitance sensor relative to the base film can be made smaller than when the shield layer is thinner than the electrodes.

[0013] In this case, at least a portion of the electrode and a portion of the shielding layer may overlap with each other in a direction along the one main surface of the base film.

[0014] With this configuration, the influence of electromagnetic fields and the like from a direction along one of the main surfaces of the base film can be prevented from reaching the electrode, compared to a case in which the electrode and the shielding layer do not overlap each other in the direction along one of the main surfaces of the base film.

[0015] In the above-mentioned capacitance sensor, the base film has a main portion in which the resist layer is provided, and a tail portion connected to the main portion and in which a terminal electrically connected to the electrode is provided, and the one main surface of the tail portion of the base film may be included in the region.

[0016] With this configuration, no resist layer is provided on the tail portion of the base film, so that the decrease in flexibility of the portion of the capacitance sensor including the tail portion can be suppressed compared to a case in which a resist layer is provided on the tail portion, making it easier to position the terminal in the desired position.

[0017] The above-mentioned capacitance sensor may further include an over resist layer made of the same resin as that constituting the resist layer and covering the electrodes.

[0018] With this configuration, the difference between the amount of thermal expansion and contraction of the resist layer and the amount of thermal expansion and contraction of the over-resist layer can be made smaller than when the over-resist layer is made of a resin different from the resin that constitutes the resist layer, and cracks caused by thermal expansion and contraction can be suppressed.

[0019] As described above, according to the present invention, a capacitance sensor that can increase the adhesive force of electrodes while suppressing a decrease in flexibility, and a method for manufacturing a capacitance sensor are provided. [Brief description of the drawings]

[0020] [Figure 1] 1 is a plan view illustrating a capacitance sensor according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an exploded perspective view illustrating the capacitance sensor illustrated in FIG. [Diagram 3] 3 is a diagram illustrating a schematic cross section of the capacitance sensor taken along line III-III in FIG. 1. [Figure 4] 4 is a flowchart showing steps of a method for manufacturing the capacitance sensor according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, preferred embodiments of the capacitance sensor and the method for manufacturing the capacitance sensor according to the present invention will be described in detail with reference to the drawings. The embodiments exemplified below are intended to facilitate understanding of the present invention and are not intended to limit the interpretation of the present invention. The present invention can be modified or improved from the following embodiments without departing from the spirit of the present invention. In addition, in the drawings referred to below, the dimensions of each component may be changed to facilitate understanding.

[0022] Fig. 1 is a plan view that shows a schematic diagram of the capacitance sensor according to this embodiment, Fig. 2 is an exploded perspective view that shows a schematic diagram of the capacitance sensor shown in Fig. 1, and Fig. 3 is a view that shows a schematic diagram of a cross section of the capacitance sensor taken along line III-III in Fig. 1. As shown in Figs. 1 to 3, the capacitance sensor 1 of this embodiment includes a base film 10, a resist layer 20, electrodes 31 to 36, terminals 41 to 47, wirings 51 to 57, a shield layer 60, an over resist layer 70, and a back resist layer 80. In Fig. 1, the wirings 51 to 57 are indicated by thick lines.

[0023] The base film 10 is a resin film having translucency, insulation, and flexibility. Examples of the base film 10 include films made of resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polycarbonate (PC), and acrylic (PMMA), and the base film 10 may have a single-layer structure or a multi-layer structure. The thickness of the base film 10 is, for example, 10 μm or more and 200 μm or less. In this embodiment, the base film 10 is composed of a main portion 10M having a substantially rectangular shape and a strip-shaped tail portion 10T connected to the main portion 10M and elongated in a direction substantially parallel to the short direction of the main portion 10M. One short side of the main portion 10M and one long side of the tail portion 10T are located on the same straight line. The shape of the base film 10 is not particularly limited.

[0024] The resist layer 20 is a resin layer provided on a part of one of the main surfaces 11 of the base film 10, and has light transmission, insulation, and flexibility. In FIG. 2, the resist layer 20 is shown in a state of being provided on a part of the main surface 11. The adhesive strength between the resist layer 20 and a predetermined conductive polymer is higher than that between the base film 10 and the predetermined conductive polymer. Examples of the predetermined conductive polymer include PEDOT-PSS (poly 3-,4-ethylenedioxythiophene-polystyrene sulfonic acid). Examples of the resin constituting the resist layer 20 include, for example, thermosetting resins such as urethane, polyester, epoxy, and urethane acrylate, ultraviolet curing resins such as acrylate, and thermoplastic resins such as polyethylene, when the base film 10 is a single-layer PET film and the predetermined conductive polymer is PEDOT-PSS. The thickness of the resist layer 20 is, for example, 0.5 μm or more and 5 μm or less. The method for evaluating the adhesive strength is not particularly limited, but examples thereof include a cross-cut test and a scratch test. Moreover, the adhesive strength with respect to the predetermined conductive polymer can be considered to be approximately the same as the adhesive strength with respect to the conductive material that contains the predetermined conductive polymer and constitutes the electrodes 31 to , which will be described later.

[0025] In this embodiment, the resist layer 20 is composed of six regions 21-26 spaced apart from one another, and each of the regions 21-26 has a generally rectangular outer shape. These regions 21-26 are arranged in a matrix so as to be aligned along the short and long directions of the main portion 10M. Each of the regions 21-26 is spaced apart from the outer edge of the base film 10, and when viewed along the thickness direction of the base film 10, each of the regions 21-26 is surrounded by a region 15 on the main surface 11 of the base film 10 where the resist layer 20 is not formed. As long as the regions 21-26 are surrounded by the region 15, the shape, number, and arrangement of the regions 21-26 are not particularly limited.

[0026] The electrodes 31 to 36 are made of a conductive material containing the above-mentioned predetermined conductive polymer and have light-transmitting properties. At least a part of each of the electrodes 31 to 36 is provided on the surface of the resist layer 20 opposite to the base film 10 side. In this embodiment, the electrodes 31 to 36 correspond one-to-one to the portions 21 to 26, and when viewed along the thickness direction of the base film 10, the resist layer 20 and the electrodes 31 to 36 overlap each other, and each of the electrodes 31 to 36 is surrounded by a region 15. Similarly to the portions 21 to 26, the electrodes 31 to 36 are arranged in a matrix shape so as to be aligned along the short and long directions of the main portion 10M. The electrodes 31 to 36 have an approximately rectangular outer shape, and when viewed along the thickness direction of the base film 10, the entirety of each of the electrodes 31 to 36 is provided on the surface of the portions 21 to 26 corresponding to the electrodes 31 to 36 opposite to the base film 10 side. The conductive material constituting the electrodes 31-36 includes a predetermined conductive polymer and a resin that binds the predetermined conductive polymer, and the resin is not particularly limited, but may be, for example, epoxy, urethane, acrylic, polyimide, or other resin. The thickness of the electrodes 31-36 is, for example, 0.1 μm or more and 3 μm or less. The electrodes 31-36 may protrude from the corresponding portions 21-26, and a part of the electrodes 31-36 may be provided on the surface of the resist layer 20 opposite to the base film 10 side, and another part of the electrodes 31-36 may be provided on the main surface 11 of the base film 10. The shape, number, and arrangement of the electrodes 31-36 are not particularly limited, and the number of the electrodes 31-36 may be one, for example. In this case, for example, the number of portions constituting the resist layer 20 is one, and at least a part of the electrode is provided on the surface of the portion opposite to the base film 10 side.

[0027] Terminals 41 to 47 are provided on the tail portion 10T of the base film 10. The main surface of the base film 10 on which the terminals 41 to 47 are provided is the main surface 11 on which the resist layer 20 is provided. The terminal 41 and the electrode 31 are electrically connected by the wiring 51, the terminal 42 and the electrode 32 are electrically connected by the wiring 52, the terminal 43 and the electrode 33 are electrically connected by the wiring 53, the terminal 44 and the electrode 34 are electrically connected by the wiring 54, the terminal 45 and the electrode 35 are electrically connected by the wiring 55, and the terminal 46 and the electrode 36 are electrically connected by the wiring 56. The terminal 47 is also electrically connected to a shield layer 60, which will be described later, by the wiring 57. In this embodiment, as shown in FIG. 3, the wiring 51 covers the entire outer periphery of the electrode 31 to be connected and the entire outer periphery of the portion 21 where the electrode 31 overlaps. Like the wiring 51, each of the wirings 52-56 covers the outer periphery of the electrodes 32-36 to be connected and the outer periphery of the portions 22-26 with which the electrodes 32-36 overlap. Note that the wirings 51-56 do not have to cover at least one of the outer periphery of the electrodes 31-36 to be connected and the outer periphery of the portions 21-26 with which the electrodes 31-36 overlap.

[0028] The shield layer 60 is made of a conductive material and is provided in the region 15 on the main surface 11 of the base film 10, and is separated from the electrodes 31 to 36 and the wirings 51 to 56. The conductive material constituting the shield layer 60 is not particularly limited, and examples thereof include silver and copper. In this embodiment, the shield layer 60 surrounds most of the outer periphery of each of the electrodes 31 to 36 when viewed along the thickness direction of the base film 10. The shield layer 60 may be disposed on at least a part of the periphery of the electrodes 31 to 36. However, the shield layer 60 is preferably disposed on at least a part between the adjacent electrodes, and more preferably surrounds at least 1 / 4 of the outer periphery of each of the electrodes 31 to 36. The thickness of the shield layer 60 is, for example, 3 μm to 20 μm. In addition, in FIG. 1 to FIG. 3, the shield layer 60 is illustrated in a sheet shape for ease of understanding, but in this embodiment, the structure of the shield layer 60 when viewed along the thickness direction of the base film 10 is a mesh structure in which a plurality of lines overlap each other in a mesh shape. However, the structure of the shield layer 60 is not particularly limited, and may be in the form of a sheet.

[0029] The over resist layer 70 is a resin layer that covers the electrodes 31-36, the wirings 51-57, and the shield layer 60, and has optical transparency, insulation, and flexibility. In this embodiment, a part of the tail portion 10T is not covered by the over resist layer 70, and the terminals 41-47 are exposed. The resin constituting the over resist layer 70 is not particularly limited, and may be, for example, the same resin as that of the resist layer 20. The thickness of the over resist layer 70 is, for example, 5 μm or more and 20 μm or less. The resin constituting the over resist layer 70 is preferably the same as that constituting the resist layer 20. With this configuration, the difference between the amount of expansion and contraction due to heat of the resist layer 20 and the amount of expansion and contraction due to heat of the over resist layer 70 can be reduced, compared to when the over resist layer 70 is composed of a resin different from that of the resist layer 20, and cracks caused by expansion and contraction due to heat can be suppressed.

[0030] The rear resist layer 80 is a resin layer that covers at least a part of the main surface 12 of the base film 10 on the side opposite to the resist layer 20, and has optical transparency, insulation, and flexibility. In this embodiment, the rear resist layer 80 covers the entire main surface 12. The resin constituting the rear resist layer 80 is not particularly limited, but may be, for example, the same resin as that of the over resist layer 70. The thickness of the rear resist layer 80 is, for example, 5 μm or more and 20 μm or less. The resin constituting the rear resist layer 80 is preferably the same material as the resin constituting the resist layer 20. With this configuration, the difference between the amount of expansion and contraction due to heat of the resist layer 20 and the amount of expansion and contraction due to heat of the rear resist layer 80 can be reduced compared to when the rear resist layer 80 is composed of a material different from that of the resin constituting the resist layer 20, and cracks caused by expansion and contraction due to heat can be suppressed.

[0031] The capacitance sensor 1 having such a configuration is a so-called self-capacitance type capacitance sensor, and is used, for example, together with a detection device (not shown). Specifically, the terminals 41 to 47 are connected to the detection device, and the detection device applies a predetermined voltage to the terminals 41 to 46 and connects the terminal 47 to the ground. In this state, for example, when a finger approaches the electrode 31 from the over resist layer 70 side, a pseudo capacitor is formed between the electrode 31 and the finger. The capacitance of this capacitor changes depending on the distance between the electrode 31 and the finger. The detection device detects the change in capacitance of such a pseudo capacitor, for example, from the current value flowing through the terminals 41 to 46. Then, the detection device determines whether or not the finger has touched the portion of the over resist layer 70 that overlaps with the electrodes 31 to 36 based on whether or not the current value exceeds a threshold value, and outputs a signal indicating the determination result to another device. Such a detection device is composed of an integrated circuit such as a microcontroller, an integrated circuit (IC), a large-scale integrated circuit (LSI), or an application specific integrated circuit (ASIC), or an NC (Numerical Control) device.

[0032] Next, a method for manufacturing the capacitance sensor according to the embodiment of the present invention will be described.

[0033] Fig. 4 is a flow chart showing steps of the method for manufacturing the capacitance sensor according to this embodiment. As shown in Fig. 4, the method for manufacturing the capacitance sensor 1 of this embodiment mainly includes a resist layer forming step P1, an electrode forming step P2, a conductive member forming step P3, an over resist layer forming step P4, and a back resist layer forming step P5.

[0034] <Resist layer forming process P1> This step is a step of preparing a base film 10 having translucency, applying a resin material having fluidity to a part of one main surface 11 of the base film 10, and forming a translucent resist layer 20 having higher adhesion to a predetermined conductive polymer than the base film 10. The base film 10 may be purchased or manufactured as the preparation of the base film 10. In this step, the resin material is applied so that the resist layer 20 is surrounded by a region 15 on the main surface 11 of the base film 10 where the resist layer 20 is not formed when viewed along the thickness direction of the base film 10. The resin material is not particularly limited, but examples thereof include a molten resin in which a resin that becomes the resist layer 20 is melted, a solution containing a resin that becomes the resist layer 20 and an organic solvent, and a dispersion containing a resin that becomes the resist layer 20 and water. The organic solvent is not particularly limited, but examples thereof include isophorone, carbitol acetate, butyl carbitol acetate, terpineol, and the like. In this embodiment, the resin material is a solution containing a thermosetting resin and an organic solvent that will become the resist layer 20. After the prepared base film 10 is annealed, the resin material is applied to a part of one of the main surfaces 11 of the base film 10, and the base film 10 to which the resin material is applied is heated. In this manner, the thermosetting resin in the applied resin material is cured to form the resist layer 20. The method of applying the resin material is not particularly limited, and examples of the method include printing such as gravure printing, offset printing, flexographic printing, and screen printing. Note that most of the organic solvent contained in the resin material volatilizes over time and disappears from the resist layer 20. In addition, for example, when the resin material is a molten resin, heating of the base film 10 to which the resin material is applied is omitted. Note that, when the resist layer 20 is made of an ultraviolet curing resin, for example, a resin material that is a solution containing an ultraviolet curing resin and an organic solvent that will become the resist layer 20 is applied to a part of the main surface 11 of the base film 10 after the annealing treatment, and the resin material is irradiated with ultraviolet light. Furthermore, when the resist layer 20 is made of a thermoplastic resin, for example, a resin material which is a solution containing the thermoplastic resin that will become the resist layer 20 and an organic solvent is applied to a part of the main surface 11 of the base film 10 after the annealing treatment, and the base film 10 to which the resin material has been applied is cooled.

[0035] <Electrode formation process P2> This step is a step of forming electrodes 31-36 having light transmission by applying a conductive material containing a predetermined conductive polymer to at least a part of the surface of the resist layer 20 opposite to the substrate film 10 side. Here, the adhesion between the predetermined conductive polymer and the resist layer 20 is higher than the adhesion between the predetermined conductive polymer and the substrate film 10. In this step, the conductive material is applied so that the electrodes 31-36 are surrounded by the region 15 when viewed along the thickness direction of the substrate film 10. In this embodiment, the conductive material is applied by printing. The printing method is not particularly limited, and for example, the printing method listed in the resist layer formation step P1 can be used. In this embodiment, the conductive material is an ink containing a predetermined conductive polymer and an organic solvent. The organic solvent is not particularly limited, and for example, the organic solvent listed in the resist layer formation step P1 can be used. The conductive material is not particularly limited, and may be, for example, an ink in which a predetermined conductive polymer is dispersed in water.

[0036] Here, generally, when the base film 10 is annealed, oligomers tend to precipitate on the surface of the base film 10. The oligomers are dissolved by the organic solvent contained in the resist layer 20. If a conductive material is applied to the main surface 11 of the base film 10 without forming the resist layer 20, the oligomers are dissolved by the organic solvent contained in the conductive material, but due to the presence of the oligomers, unevenness is formed on the surface of the electrodes 31 to 36 on the side of the base film 10. If such unevenness is formed or oligomers remain, the unevenness scatters light or the oligomers scatter light, so that the haze value at the portion of the capacitance sensor overlapping with the electrodes 31 to 36 increases and the transparency of the portion decreases. Therefore, the presence of the resist layer 20 can suppress the decrease in transparency of the portion overlapping with the electrodes 31 to 36 compared to the case where the resist layer 20 is not present. From the viewpoint of suppressing such a decrease in transparency, it is preferable to adjust the ratio of the organic solvent contained in the resin material applied to the base film 10 in the resist layer forming step P1 and the ratio of the organic solvent contained in the conductive material so that the amount of the organic solvent contained per unit area of ​​the applied resin material is greater than the amount of the solvent contained per unit area of ​​the applied conductive material. By doing so, more oligomers can be dissolved compared to the case where the resist layer 20 is not provided.

[0037] <Conductive member formation process P3> This step is a step of forming terminals 41-47, wirings 51-57, and shield layer 60, which are conductive members, on the base film 10 on which the electrodes 31-36 have been formed. In this embodiment, the terminals 41-47, wirings 51-57, and shield layer 60 are formed by printing. The conductive ink used for printing is not particularly limited, and examples thereof include inks containing silver or copper as conductors. The printing method is not particularly limited, and examples thereof include printing methods similar to the printing method for applying the conductive material in the electrode formation step P2.

[0038] <Over resist layer forming process P4> This step is a step of forming the over resist layer 70 by applying a resin material having fluidity to the base film 10 on which the terminals 41-47, the wirings 51-57, and the shield layer 60, which are conductive members, are formed. The resin material is not particularly limited, but examples thereof include a molten resin in which the resin to be the over resist layer 70 is melted, a solution containing the resin to be the over resist layer 70 and an organic solvent, and a dispersion containing the resin to be the over resist layer 70 and water. The organic solvent is not particularly limited, but examples thereof include those listed in the resist layer forming step P1. In this embodiment, the resin material is a molten resin in which the thermosetting resin to be the over resist layer 70 is melted, and the resin material is applied so that the wirings 51-57 and the shield layer 60 are covered, and the base film 10 to which the resin material is applied is heated. In this way, the applied resin material is cured to form the over resist layer 70. The method of forming the over resist layer 70 is not particularly limited, and for example, the over resist layer 70 may be formed by using printing, similar to the resist layer forming step P1. Furthermore, when the over-resist layer 70 is made of an ultraviolet curing resin, for example, a resin material, which is a molten resin obtained by melting the ultraviolet curing resin that will become the over-resist layer 70, is applied to the base film 10 so as to cover the wirings 51-57 and the shield layer 60, and this resin material is irradiated with ultraviolet rays. When the over-resist layer 70 is made of a thermoplastic resin, for example, a resin material, which is a molten resin obtained by melting the thermoplastic resin that will become the over-resist layer 70, is applied to the base film 10 so as to cover the wirings 51-57 and the shield layer 60, and the base film 10 to which the resin material has been applied is cooled.

[0039] <Rear resist layer formation process P5> This step is a step of forming the back resist layer 80 by applying a resin material having fluidity to the base film 10 on which the over resist layer 70 has been formed. The resin material is not particularly limited, but examples thereof include a molten resin in which the resin to be the back resist layer 80 is melted, a solution containing the resin to be the back resist layer 80 and an organic solvent, and a dispersion containing the resin to be the back resist layer 80 and water. The organic solvent is not particularly limited, but examples thereof include those listed in the resist layer formation step P1. In this embodiment, the resin material is a molten resin in which the thermosetting resin to be the back resist layer 80 is melted, and the resin material is applied to the main surface 12 on the side opposite to the resist layer 20 side of the base film 10, and the base film 10 to which the resin material has been applied is heated. In this way, the applied resin material is cured to form the back resist layer 80. The method of forming the back resist layer 80 is not particularly limited, and for example, the back resist layer 80 may be formed by printing, as in the resist layer formation step P1. Furthermore, when the rear resist layer 80 is made of an ultraviolet curing resin, for example, a resin material, which is a molten resin obtained by melting the ultraviolet curing resin that will become the rear resist layer 80, is applied to the main surface 12 of the base film 10, and this resin material is irradiated with ultraviolet light. When the rear resist layer 80 is made of a thermoplastic resin, for example, a resin material, which is a molten resin obtained by melting the thermoplastic resin that will become the rear resist layer 80, is applied to the main surface 12 of the base film 10, and the base film 10 to which this resin material has been applied is cooled. Furthermore, the flow of the method for manufacturing the capacitance sensor 1 is not particularly limited. For example, the over resist layer forming step P4 may be performed after the rear resist layer forming step P5.

[0040] As described above, the capacitance sensor 1 of this embodiment includes a light-transmitting base film 10, a light-transmitting resist layer 20, and light-transmitting electrodes 31 to 36. The resist layer 20 is provided on a part of one main surface 11 of the base film 10, and the adhesion between a predetermined conductive polymer and the resist layer 20 is higher than the adhesion between the predetermined conductive polymer and the base film 10. The electrodes 31 to 36 are made of a conductive material containing a predetermined conductive polymer, and at least a part of each of the electrodes 31 to 36 is provided on the surface of the resist layer 20 opposite to the base film 10 side. When viewed along the thickness direction of the base film 10, the region 15 on the main surface 11 of the base film 10 where the resist layer 20 is not formed surrounds each of the electrodes 31 to 36.

[0041] The method for manufacturing the capacitance sensor 1 of this embodiment includes a resist layer forming step P1 and an electrode forming step P2. The resist layer forming step P1 is a step of applying a resin material to a part of the main surface 11 of the base film 10 having light-transmitting properties to form a light-transmitting resist layer 20 having higher adhesion to a predetermined conductive polymer than the base film 10. In the resist layer forming step P1, the resin material is applied so that the resist layer 20 is surrounded by a region 15 on the main surface 11 of the base film 10 where the resist layer 20 is not formed when viewed along the thickness direction of the base film 10. The electrode forming step P2 is a step of applying a conductive material containing a predetermined conductive polymer to at least a part of the surface of the resist layer 20 opposite to the base film 10 side to form electrodes 31 to 36 having light-transmitting properties. In the electrode forming step P2, the conductive material is applied so that the electrodes 31 to 36 are each surrounded by a region 15 when viewed along the thickness direction of the base film 10.

[0042] In the capacitance sensor 1 and the manufacturing method of the capacitance sensor 1 of the present embodiment, at least a part of each of the electrodes 31 to 36 having light transmission is attached to the base film 10 via the resist layer 20. The adhesion between the predetermined conductive polymer contained in the conductive material constituting the electrodes 31 to 36 and the resist layer 20 is higher than the adhesion between the predetermined conductive polymer and the base film 10. Therefore, the adhesion between the electrodes 31 to 36 and the base film 10 can be increased compared to when the resist layer 20 is not provided on the base film 10. Furthermore, in the capacitance sensor 1 and the manufacturing method of the capacitance sensor 1 of the present embodiment, when viewed along the thickness direction of the base film 10, the region 15 on the main surface 11 of the base film 10 where the resist layer 20 is not formed surrounds each of the electrodes 31 to 36. Therefore, according to the capacitance sensor 1 of the present embodiment, the decrease in flexibility at least around each of the electrodes 31 to 36 can be suppressed compared to when the resist layer 20 is provided on the entire main surface 11 of the base film 10, and the attachment to a curved portion of an apparatus or the like can be improved. Moreover, according to the method for manufacturing the capacitance sensor 1 of this embodiment, it is possible to manufacture the capacitance sensor 1 that can increase the adhesive force between the electrodes 31 to 36 while suppressing a decrease in flexibility.

[0043] Moreover, the capacitance sensor 1 of this embodiment further includes a shield layer 60 that is provided in the region 15 and is separated from the electrodes 31 to 36. Therefore, compared to a case in which the capacitance sensor 1 does not include the shield layer 60, the influence of an external electromagnetic field or the like can be suppressed from reaching the electrodes 31 to 36.

[0044] 3, in this embodiment, the shield layer 60 is thicker than the electrodes 31-36. Therefore, the difference between the thickness of the shield layer 60 and the total thickness of the electrodes 31-36 and the resist layer 20 can be made smaller than when the shield layer 60 is thinner than the electrodes 31-36. Therefore, the amount of unevenness on the surface of the capacitance sensor 1 on the side of the electrodes 31-36 with respect to the base film 10 can be made smaller than when the shield layer 60 is thinner than the electrodes 31-36.

[0045] In addition, in this embodiment, the entire electrodes 31 to 36 and a part of the shield layer 60 overlap each other in the direction along the main surface 11 of the base film 10. Therefore, compared with the case where the electrodes 31 to 36 and the shield layer 60 do not overlap in the direction along the main surface 11, the influence of the electromagnetic field or the like from the direction along the main surface 11 can be suppressed from reaching the electrodes 31 to 36. In addition, from the viewpoint of suppressing the influence of the electromagnetic field or the like from the direction along the main surface 11 from reaching the electrodes 31 to 36, it is sufficient that at least a part of each of the electrodes 31 to 36 and a part of the shield layer 60 overlap each other in this direction. In addition, in this embodiment, the thickness of the shield layer 60 is thicker than the sum of the thickness of the resist layer 20 and the thickness of the electrodes 31 to 36, and the surface SS of the shield layer 60 opposite the base film 10 side is located on the opposite side to the base film 10 side with respect to the surface ES of the electrodes 31 to 36 opposite the resist layer 20 side. Therefore, compared to the case where the surface SS of the shield layer 60 is located on the side of the base film 10 with respect to the surface ES of the electrodes 31 to 36 as a reference, it is possible to further prevent the influence of the electromagnetic fields and the like from reaching the electrodes 31 to 36. Furthermore, with this configuration, it is possible to prevent the portions of the surface of the capacitance sensor 1 on the side of the electrodes 31 to 36 with respect to the base film 10 as a reference, which overlap with the electrodes 31 to 36, from bulging outward in a convex shape, compared to the case described above, and thus it is possible to prevent a decrease in durability.

[0046] In the present embodiment, the base film 10 has a main portion 10M on which the resist layer 20 is provided, and a tail portion 10T on which the terminals 41-46 are provided, which are connected to the main portion 10M and electrically connected to the electrodes 31-36. One of the main surfaces of the tail portion 10T of the base film 10 is included in the region 15. Therefore, the resist layer 20 is not provided on the tail portion 10T. Therefore, according to the capacitance sensor 1 of the present embodiment, it is possible to suppress a decrease in flexibility of the portion of the capacitance sensor 1 including the tail portion 10T, compared to a case in which the resist layer 20 is provided on the tail portion 10T, and it is possible to easily arrange the terminals 41-46 at desired positions. The resist layer 20 may be provided on at least a part of the tail portion 10T of the base film 10.

[0047] Although the present invention has been described above using the above-mentioned embodiments as examples, the present invention is not limited to these.

[0048] For example, in the above embodiment, the capacitance sensor 1 including the shield layer 60 has been described as an example. However, the capacitance sensor 1 does not have to include the shield layer 60. The shield layer 60 may be provided on the main surface 12 of the base film 10 opposite the resist layer 20 side. In this case, the shield layer 60 is provided in a region of the main surface 12 that overlaps with the region 15 when viewed along the thickness direction of the base film 10, and is covered with the back resist layer 80. The shield layer 60 is separated from the electrodes 31 to 36 when viewed along the thickness direction of the base film 10.

[0049] In the above embodiment, the shield layer 60 is thicker than the electrodes 31 to 36. However, the shield layer 60 may be thinner than the electrodes 31 to 36, and the electrodes 31 to 36 and the shield layer 60 do not need to overlap each other in the direction along the main surface 11 of the base film 10.

[0050] In the above embodiment, the capacitance sensor 1 including the rear resist layer 80 has been described as an example. However, the capacitance sensor 1 does not necessarily need to include the rear resist layer 80.

[0051] In the above embodiment, the self-capacitance type capacitance sensor 1 has been described as an example. However, the capacitance sensor 1 may be a mutual capacitance type capacitance sensor. For example, such a capacitance sensor may have a configuration in which the electrode 31 is divided into two to form a first electrode and a second electrode arranged at a predetermined interval in a direction along the main surface 11 of the base film 10, and a terminal electrically connected to the first electrode instead of the terminal 41 and another terminal electrically connected to the second electrode.

[0052] As described above, according to the present invention, a capacitance sensor that can increase the adhesion of electrodes while suppressing a decrease in flexibility and a manufacturing method for a capacitance sensor are provided, and can be used in fields such as vehicle operation switches and touch panel displays.

Claims

1. A light-transmitting base film; a resist layer provided on a portion of one main surface of the base film, the resist layer having a light-transmitting property and a higher adhesiveness to a predetermined conductive polymer than the base film; an electrode made of a conductive material containing the predetermined conductive polymer and having light-transmitting properties, at least a portion of which is provided on a surface of the resist layer opposite to the base film side; an over resist layer made of the same resin as that constituting the resist layer, covering the electrodes, and having light transmitting properties; Equipped with When viewed along the thickness direction of the base film, a region on the one main surface of the base film where the resist layer is not formed surrounds the electrode.

1. A capacitance sensor comprising:

2. a shield layer provided in the region and spaced apart from the electrode; 2. The capacitance sensor according to claim 1.

3. The shield layer is thicker than the electrode.

3. The capacitance sensor according to claim 2.

4. At least a portion of the electrode and a portion of the shield layer overlap each other in a direction along the one main surface of the base film.

4. The capacitance sensor according to claim 3.

5. the base film has a main portion on which the resist layer is provided, and a tail portion connected to the main portion and on which a terminal electrically connected to the electrode is provided, The one main surface of the tail portion of the base film is included in the region.

5. The capacitance sensor according to claim 1, wherein the capacitance sensor is a capacitance sensor having a capacitance of 1 to 4.

6. a resist layer forming step of applying a resin material to a portion of one main surface of a light-transmitting base film to form a light-transmitting resist layer having a higher adhesiveness to a predetermined conductive polymer than the base film; an electrode forming step of forming a light-transmitting electrode by applying a conductive material containing the predetermined conductive polymer to at least a part of a surface of the resist layer opposite to the base film; an over-resist layer forming step of forming a light-transmitting over-resist layer by applying the same resin material as the resin material to the one main surface side of the base film on which the electrodes are formed so as to cover the electrodes; Equipped with In the resist layer forming step, the resin material is applied so that the resist layer is surrounded by a region on the one main surface of the base film where the resist layer is not formed, when viewed along a thickness direction of the base film; In the electrode forming step, the conductive material is applied so that the electrode is surrounded by the region when viewed along the thickness direction of the base film. A method for manufacturing a capacitance sensor comprising the steps of:

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