Capacitance sensor

Abstract

Provided is a capacitance sensor that can be cut into an arbitrary shape. The capacitance sensor comprises: a flexible substrate; a plurality of electrodes arranged in a matrix in a first direction and a second direction; a plurality of terminals; and a plurality of wires connecting the electrodes and the terminals. When a section having one electrode is defined as a sensor section, in a plurality of such sensor sections that are arranged in a single row in the second direction, a plurality of lead-out wires that are connected to the respective electrodes in said row are bundled and arranged disproportionately on the side close to the terminals in the first direction while maintaining insulation between adjacent lead wires. The edge of the flexible substrate has a cutting line from which a portion of the lead-out wires or the electrodes is exposed.

Description

Capacitive Sensor

[0001] This disclosure relates to a capacitive sensor.

[0002] In Patent Document 1, as an example of a capacitive sensor, a detection device including a sensor substrate on which a plurality of detection electrodes are arranged and a flexible printed circuit board is disclosed. The sensor substrate and the flexible printed circuit board are electrically connected via terminals.

[0003] Japanese Patent Application Laid-Open No. 2023-084604

[0004] In the capacitive sensor described in Patent Document 1, the flexible printed circuit board (flexible substrate) has flexibility, but the sensor substrate does not have flexibility. Therefore, when a sensor substrate having a shape different from a rectangle is desired, a dedicated design must be made for each application. Also, in order to meet the demand for changing the size even if it is the same rectangle, a dedicated design must be made for each size.

[0005] An object of this disclosure is to provide a capacitive sensor that can be cut into an arbitrary shape.

[0006] The capacitive sensor of this disclosure has a plurality of electrodes arranged in a matrix in a first direction and a second direction, a plurality of terminals, and a plurality of wirings connecting the electrodes and the terminals. A section having one electrode is defined as one sensor section. In a plurality of sensor sections arranged in a single column in the second direction, a plurality of lead-out wirings each connected to one of the plurality of electrodes in a single column are biased and bundled on the side closer to the terminals in the first direction while maintaining insulation between adjacent lead-out wirings, and a cutting line where a part of the electrodes or the lead-out wirings is exposed is provided at the edge of the flexible substrate.

[0007] Figure 1 is a plan view of the detection surface side of a capacitance sensor according to Embodiment 1. Figure 2 is a plan view showing the position of the lead wires in the capacitance sensor according to Embodiment 1. Figure 3 is a partial cross-sectional view along the lead wires in the electrode portion of the capacitance sensor according to Embodiment 1. Figure 4 is a diagram showing an example of an equivalent circuit of a capacitance sensor and a detection circuit. Figure 5 is a plan view of the detection surface side of a capacitance sensor according to Embodiment 2. Figure 6 is a plan view showing the position of the lead wires in the capacitance sensor according to Embodiment 2. Figure 7 is a plan view of the detection surface side of a capacitance sensor according to Embodiment 3. Figure 8 is a cross-sectional view showing the VIII-VIII section of Figure 7. Figure 9 is a cross-sectional view showing the IX-IX section of Figure 7. Figure 10 is an enlarged view of the electrode portion of a capacitance sensor according to Embodiment 4. Figure 11 is an enlarged view of Figure 10. Figure 12 is a cross-sectional view showing the XII-XII section of Figure 11. Figure 13 is a plan view showing the position of the lead wires in a capacitance sensor according to Embodiment 5. Figure 14 is a partial cross-sectional view of the electrode portion of a capacitance sensor according to Embodiment 5.

[0008] The embodiments of this disclosure will be described below with reference to the drawings. This disclosure is not limited to the embodiments described below. Furthermore, the components described below include those that are readily conceivable to those skilled in the art, and those that are substantially the same. In addition, the components described below can be combined as appropriate.

[0009] Furthermore, the disclosure is merely an example, and modifications that a person skilled in the art could easily conceive of while maintaining the spirit of the invention are naturally included within the scope of this disclosure. In addition, the drawings may schematically represent the width, thickness, shape, etc. of each part in order to clarify the explanation, but these are merely examples and do not limit the interpretation of this disclosure. In addition, in this specification and each drawing, elements similar to those described above in previously shown drawings are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0010] (Embodiment 1) Figure 1 is a plan view of the detection surface side of the capacitance sensor according to Embodiment 1. Figure 2 is a plan view showing the position of the lead wires in the capacitance sensor according to Embodiment 1. Figure 3 is a partial cross-sectional view along the lead wires in the electrode portion of the capacitance sensor according to Embodiment 1. Figure 4 is a diagram showing an example of an equivalent circuit of the capacitance sensor and detection circuit. The first direction X and the second direction Y are orthogonal to each other. Also, the first direction X and the second direction Y are parallel to the detection surface.

[0011] The capacitance sensor 1 is a self-capacitive sensor. The capacitance sensor 1 is in the form of a film and detects an object located on the detection surface side. The object to be detected is, for example, the user's finger. However, the object to be detected may be a stylus pen or a part of the user other than a finger.

[0012] Capacitive sensor 1 detects an object when it is in contact with the detection surface. Capacitive sensor 1 can also perform hover detection, detecting an object even when it is not in contact with the detection surface.

[0013] The capacitance sensor 1 includes a plurality of sensor compartments 20 arranged in a matrix in a first direction X and a second direction Y on a flexible printed circuit board (FPC) 10.

[0014] The flexible substrate 10 is in the form of a film and is flexible. The insulating material of the flexible substrate 10 is, for example, polyethylene terephthalate and polyimide. The flexible substrate 10 has a main body portion 11 and a connecting portion 12 integrally.

[0015] The main body portion 11 has a side 11a that extends along a predetermined direction (corresponding to the first direction X in this embodiment) in a plan view. The main body portion 11 is rectangular in plan view, having the side 11a. One side of the main body portion 11 corresponds to the detection surface, which is the side that detects the object to be detected. The capacitance sensor 1 can change its shape from rectangular to irregular by cutting the outer shape of the main body portion 11. Also, even if the capacitance sensor 1 is still rectangular, it can be made smaller by cutting the outer shape of the main body portion 11 when changing its size.

[0016] The connecting portion 12 is a part that protrudes from the main body portion 11 in a plan view. The main body portion 11 and the connecting portion 12 are continuous without a break. The connecting portion 12 protrudes from the edge 11a of the main body portion 11. The connecting portion 12 is located off-center in the first direction X on the edge 11a of the main body portion 11. In this embodiment, the connecting portion 12 protrudes from one end of the edge 11a in the first direction X.

[0017] When the connecting portion 12 is located off-center from the first direction X of the side 11a, it is possible to suppress the connection portion 12 from hindering the bending of the main body portion 11 compared to when the connecting portion 12 is located at the first direction X of the side 11a.

[0018] The connecting portion 12 is strip-shaped. The connecting portion 12 extends along the second direction Y. The length of the connecting portion 12 in the protruding direction (length in the second direction Y) is shorter than the length of the connecting portion 12 in the width direction (length in the first direction X). Needless to say, the shape of the connecting portion 12 is not limited to the shape described above. For example, the length of the connecting portion 12 in the protruding direction (length in the second direction Y) may be longer than or equal to the length of the connecting portion 12 in the width direction (length in the first direction X).

[0019] As shown in Figure 2, at the protruding end 12a of the connection portion 12, multiple terminals 13 are exposed from the insulating material of the flexible substrate 10. Each of the terminals 13 is connected to a detection circuit 40 (see Figure 4) that drives the capacitance sensor 1.

[0020] As shown in Figure 1, the multiple sensor compartments 20 are arranged on the main body 11. Specifically, the multiple sensor compartments 20 are arranged in a matrix along the first direction X and the second direction Y on the detection surface of the main body 11.

[0021] As shown in Figure 2, one electrode 21 is placed in one sensor compartment 20. The electrode 21 is a solid rectangular film in plan view.

[0022] The electrode 21 is formed from one or more metals selected from aluminum (Al), copper (Cu), silver (Ag), molybdenum (Mo), chromium (Cr), and tungsten (W), or from an alloy containing one or more of these metal materials. The electrode 21 may also have a conductive layer of translucent conductive oxides such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGO (Indium Gallium Oxide), and IGZO (Indium Gallium Zinc Oxide) laminated on it. Alternatively, a blackened film, black organic film, or black conductive organic film combining the above-mentioned metal material and conductive oxide may be laminated on it. The metal material of the electrode 21 has lower resistance than conductive oxides such as ITO. The electrode 21 may also be formed solely from conductive oxides such as ITO.

[0023] As shown in Figure 3, the first insulating layer 201, the first conductive layer 202, the second insulating layer 203, the second conductive layer 204, the third insulating layer 205, the third conductive layer 206, and the fourth insulating layer 207 are stacked in order. In the sensor compartment 20 (see Figure 2), the first conductive layer 202, the second conductive layer 204, and the third conductive layer 206 are patterned. Specifically, the first conductive layer 202 has a rectangular shape that overlaps all of the multiple sensor compartments 20 shown in Figure 1. The second conductive layer 204 is the lead wire 31 (see Figure 2). The third conductive layer 206 is the electrode 21 (see Figure 2). Alternatively, the third conductive layer 206 may be the lead wire 31 (see Figure 2) and the second conductive layer 204 may be the electrode 21 (see Figure 2).

[0024] As shown in Figure 3, the second conductive layer 204 and the third conductive layer 206 are electrically connected by a connecting via 32. As shown in Figure 2, when the sensor section 20 is divided into two equal parts in the first direction X, such as the first section 20XL and the second section 20XR, the connecting via 32 is located in the first section 20XL, which is close to the lead wiring 31 to which the electrodes 21 of the sensor section 20 are connected.

[0025] The insulating material of the flexible substrate 10 covers multiple electrodes 21. Furthermore, the areas of the electrodes 21 that do not have metal material are larger than the line width of the electrodes 21. As a result, the presence of each sensor section 20 becomes less noticeable, and the electrodes 21 can be made invisible.

[0026] As shown in Figure 2, the lead wires 31 are arranged to connect the electrodes 21 and the terminals 13. The number of lead wires 31 is equal to the number of sensor compartments 20. Multiple lead wires 31 are arranged in a state where they are electrically insulated from each other by the insulating material of the flexible substrate 10.

[0027] As shown in Figure 2, the flexible substrate 10 is cut along the cutting line Lcut. At the edge of the flexible substrate 10 cut along the cutting line Lcut, the lead wires 31 and a portion of the electrodes 21 shown in Figure 2 are exposed. In the capacitance sensor 1, the lead wires 31 are visible from the detection surface side. This allows the cutting position to change the shape of the main body 11 to avoid the lead wires 31 as much as possible while still being able to see them.

[0028] Next, the operation of the capacitance sensor 1 will be described. The detection circuit 40 includes, for example, an analog front end (AFE) 41 and a power supply circuit 44. The analog front end 41 includes a signal detection circuit 42 and an A / D conversion circuit 43. The detection circuit 40 provides a drive signal VD supplied from the power supply circuit 44 to each electrode 21 and detects the component caused by the capacitance Cdet generated between the object to be detected F and the electrode 21 as a detection signal Det.

[0029] The signal detection circuit 42 generates analog detection values ​​for each electrode 21 based on the detection signal Det of each electrode 21.

[0030] The A / D conversion circuit 43 samples the analog detection values ​​from the signal detection circuit 42 and converts them into digital signals. The analog front end 41 outputs the detection value Rawdata of the object to be detected F present in the detection region or the space above the detection region, based on the detection value of each electrode 21.

[0031] The shield electrode 23 is a conductive layer having a rectangular shape that overlaps all of the sensor compartments 20 shown in Figure 1. The shield electrode 23 is covered with the insulating material of the flexible substrate 10. The shield electrode 23 and the electrode 21 are insulated from each other by the insulating material of the flexible substrate 10. Similarly, the shield electrode 23 and the lead wire 31 (see Figure 2) are insulated from each other by the insulating material of the flexible substrate 10.

[0032] As shown in Figure 4, the shield electrode 23 is supplied with a drive signal VD from the power supply circuit 44. As a result, the shield electrode 23 is supplied with a drive signal VD that is synchronized with the drive signal VD supplied to electrode 21. Consequently, the parasitic capacitance Cp component is reduced.

[0033] The detected value Rawdata is expressed by the following equation (1), where S(Cdet) is the component caused by the capacitance Cdet generated between the substance to be detected F and the electrode 21, and S(Cp) is the component caused by the parasitic capacitance Cp.

[0034] Rawdata=S(Cdet)+S(Cp)...(1)

[0035] In signal processing, the detection value obtained when no object to be detected F is present in the detectable space within the detection area is set as the baseline (= S(Cp)). Then, by subtracting the baseline from the Rawdata of each electrode 21 obtained during normal detection operation, the component (S(Cp)) caused by parasitic capacitance Cp is removed.

[0036] In the multiple sensor compartments 20 arranged in a single row in the second direction Y, as shown in Figure 1, the multiple lead wires 31 connected to each of the multiple electrodes 21 in the row are bundled together and biased towards the side closer to the terminal 13 (connection part 12) in the first direction X, as shown in Figure 2. The biased bundled adjacent lead wires 31 are insulated by the insulating material of the flexible substrate 10. This ensures that insulation is maintained between adjacent lead wires 31.

[0037] As shown in Figure 2, the flexible substrate 10 is cut from a rectangle as shown in Figure 1 to a desired irregular shape along the cutting line Lcut. At the cutting line Lcut, a portion of the lead wires 31 and a portion of the electrodes 21 shown in Figure 2 are exposed at the edge of the flexible substrate 10. The sensor section 20B that does not cross the lead wires 31 can detect capacitance, but the sensor section 20A that crosses the lead wires 31 cannot detect capacitance because the lead wires 31 have been cut.

[0038] In a row of multiple sensor compartments 20 aligned in the second direction Y, the multiple lead wires 31 have regions without lead wires 31 between adjacent rows of multiple sensor compartments 20. Along the first direction X, regions with a high density of multiple lead wires 31 per unit area and regions with a low density of multiple lead wires 31 alternate. This allows the cutting line Lcut to pass through regions with a low density of multiple lead wires 31 per unit area as much as possible.

[0039] Furthermore, since the connecting via 32 is located in the first section 20XL, which is close to the lead wire 31 to which the electrode 21 of the sensor section 20 is connected, the cutting line Lcut can be made to pass through as much of the area where the density per unit area of ​​the multiple lead wires 31 is sparse as possible.

[0040] As a result, in a row of multiple sensor compartments 20 with a cutting line Lcut, the number of sensor compartments 20A where the cutting line Lcut crosses the lead wiring 31 is less than the number of sensor compartments 20B where the cutting line Lcut does not cross the lead wiring 31. Furthermore, even in the sensor compartments 20 along the cutting line Lcut, the number of sensor compartments 20A that can detect capacitance can be increased.

[0041] In the main body 11, the number of sensor compartments 20 on one side of the first direction X is greater than the number of sensor compartments 20 on the other side of the first direction X compared to the connection section 12. As a result, regions with high density and regions with low density per unit area of ​​the multiple lead wires 31 are arranged alternately.

[0042] (Embodiment 2) FIG. 5 is a plan view of the detection surface side of the capacitance sensor according to Embodiment 2. FIG. 6 is a plan view showing the position of the lead wiring in the capacitance sensor according to Embodiment 2. Note that the same components as those described in the above-described Embodiment 1 are denoted by the same reference numerals, and redundant descriptions are omitted.

[0043] As shown in FIG. 5, the connection portion 12 protrudes from the side 11a of the main body portion 11. The connection portion 12 is located at the center in the first direction X on the side 11a of the main body portion 11. As a result, in the sensor section 20 in the main body section 11, the number of sensor sections 20 on one side in the first direction X is the same as the number of sensor sections 20 on the other side in the first direction X, compared to the connection portion 12.

[0044] The flexible substrate 10 is cut along a cutting line Lcut into a desired irregular shape such as a rectangle as shown in FIG. 5. As shown in FIG. 6, the plurality of lead wirings 31 connected to each of the plurality of electrodes 21 in one row are biased and bundled and arranged on the side closer to the terminal 13 (connection portion 12) in the first direction X. A part of the lead wiring 31 shown in FIG. 6 and a part of the electrode 21 shown in FIG. 3 are exposed at the edge of the flexible substrate 10 along the cutting line Lcut. The sensor section 20B that does not cross the lead wiring 31 can detect capacitance, but in the sensor section 20A that crosses the lead wiring 31, the lead wiring 31 is cut, so capacitance cannot be detected.

[0045] The plurality of lead wirings 31 in the rows of the plurality of sensor sections 20 arranged in the second direction Y have a region without lead wirings 31 between the plurality of lead wirings 31 in the rows of the adjacent plurality of sensor sections 20. As shown in FIG. 5, since the connection portion 12 is located at the center in the first direction X on the side 11a of the main body portion 11, as shown in FIG. 6, the plurality of lead wirings 31 are arranged symmetrically with respect to the first direction X with the connection portion 12 as a reference. As a result, it is possible to arrange the cutting lines Lcut on one side and the other side in the first direction X.

[0046] As shown in FIG. 6, the connection via 32 on one side in the first direction X is located in the first section 20XL close to the lead wiring 31 to which the electrode 21 of the sensor section 20 is connected. The connection via 32 on the other side in the first direction X is located in the second section 20XR close to the lead wiring 31 to which the electrode 21 of the sensor section 20 is connected. Thereby, the cut line Lcut can be made to pass through a region where the density per unit area of the plurality of lead wirings 31 is coarse as much as possible.

[0047] Also in Embodiment 2, in the plurality of sensor sections 20 in one row where the cut line Lcut exists, the number of sensor sections 20A where the cut line Lcut crosses the lead wiring 31 is less than the number of sensor sections 20B where the cut line Lcut does not cross the lead wiring 31. And even in the sensor section 20 along the cut line Lcut, the number of sensor sections 20A capable of detecting capacitance can be increased.

[0048] (Embodiment 3) FIG. 7 is a plan view of the detection surface side of the capacitance sensor according to Embodiment 3. FIG. 8 is a cross-sectional view showing the VIII-VIII cross-section of FIG. 7. FIG. 9 is a cross-sectional view showing the IX-IX cross-section of FIG. 7. Note that the same components as those described in Embodiment 1 described above are denoted by the same reference numerals and redundant descriptions are omitted.

[0049] The capacitance sensor 1 of Embodiment 3 shown in FIG. 7 and the capacitance sensor 1 of Embodiment 1 shown in FIG. 1 differ only in the shape of the shield electrode 23 (see FIG. 4).

[0050] As shown in Figure 8, in the sensor compartment 20 (see Figure 7), the first insulating layer 211, the first conductive layer 212, the second insulating layer 213, the second conductive layer 214, the third insulating layer 215, the third conductive layer 216, and the fourth insulating layer 217 are stacked in order. In the sensor compartment 20, the first conductive layer 212, the second conductive layer 214, and the third conductive layer 216 are patterned. Specifically, the first conductive layer 212 is a solid film shielding electrode 23 for each sensor compartment 20. One shielding electrode 23 is a rectangle the same size as the sensor compartment 20. The second conductive layer 214 is a lead wire 31 (see Figure 2). The third conductive layer 216 is an electrode 21 (see Figure 2). Alternatively, the third conductive layer 216 may be a lead wire 31 (see Figure 2) and the second conductive layer 214 may be an electrode 21 (see Figure 2).

[0051] As shown in Figure 9, the first insulating layer 211, the first conductive layer 212, the second insulating layer 213, the third insulating layer 215, and the fourth insulating layer 217 are stacked in order between adjacent sensor compartments 20 (see Figure 7). The second conductive layer 214 shown in Figure 8 is an empty layer 214N shown in Figure 9, and in reality, the second insulating layer 213 and the third insulating layer 215 are directly stacked. The third conductive layer 216 shown in Figure 8 is an empty layer 216N shown in Figure 9, and in reality, the third insulating layer 215 and the fourth insulating layer 217 are directly stacked.

[0052] As shown in Figure 9, the connecting portion of the shield electrode 23 (see Figure 4) is linear and electrically connects the first conductive layers 212 of the sensor compartment 20 shown in Figure 8. In this way, the first conductive layer 212, which has a narrower cross-section than the first conductive layer 212 in the sensor compartment 20, connects the respective shield electrodes 23 of adjacent sensor compartments 20.

[0053] The cross-sections shown in Figures 8 and 9 can also be said to show the state of the cross-section when the cutting line Lcut (see Figure 2) becomes the edge of the flexible substrate 10. As described above, along the cutting line Lcut (see Figure 2), the second conductive layer 214 of a part of the lead wiring 31, the third conductive layer 216 of a part of the electrode 21, or the first conductive layer 212 of a part of the shield electrode 23 is exposed at the edge of the flexible substrate 10. In that case, there is a possibility that the first conductive layer 212 of a part of the lead wiring 31, a part of the electrode 21, or a part of the shield electrode 23 may corrode.

[0054] In the capacitance sensor 1 of Embodiment 3, as shown in Figure 9, the second conductive layer 214 and the third conductive layer 216 are absent at the boundary between adjacent sensor compartments 20. Therefore, even if the second conductive layer 214 or the third conductive layer 216 corrodes at the cutting line Lcut (see Figure 2), it does not affect the second conductive layer 214 and the third conductive layer 216 of other sensor compartments 20 that are different from the sensor compartment 20 where the corrosion occurred.

[0055] Furthermore, as shown in Figure 9, at the boundary between adjacent sensor compartments 20, the area of ​​the first conductive layer 212 is smaller than that of the sensor compartment 20. Therefore, even if the first conductive layer 212 corrodes at the cutting line Lcut (see Figure 2), it is less likely to affect the first conductive layer 212 of other sensor compartments 20 that are different from the one where the corrosion occurred.

[0056] (Embodiment 4) Figure 10 is an enlarged view of the electrode portion of the capacitance sensor according to Embodiment 4. Figure 11 is an enlarged view of Figure 10. Figure 12 is a cross-sectional view showing the section XII-XII in Figure 11. Note that the same reference numerals are used for the same components as those described in Embodiment 1 above, and redundant explanations are omitted.

[0057] Embodiment 4 differs from Embodiment 1 in that the lead wiring 31 of the capacitance sensor 1 is formed in the same layer as the electrode 21A.

[0058] As shown in Figures 10 and 11, the electrode 21A is composed of metallic conductive wires extending in a third direction Dx and a fourth direction Dy, which are different directions from the first direction X and the second direction Y. In this way, the electrode 21A is formed in a mesh-like manner in plan view. The electrode 21A can be formed from the same material as the electrode 21 described above. The conductive wires constituting the electrode 21A may be arranged in a zigzag or wavy pattern in plan view.

[0059] The electrode 21A is formed from one or more metals selected from aluminum (Al), copper (Cu), silver (Ag), molybdenum (Mo), chromium (Cr), and tungsten (W), or from an alloy containing one or more of these metal materials. The conductive bridge portion 22 is formed from a translucent conductive oxide such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IGO (Indium Gallium Oxide), and IGZO (Indium Gallium Zinc Oxide).

[0060] As shown in Figure 11, the metal conductive wire extending in the third direction Dx and the metal conductive wire extending in the fourth direction Dy are connected in a mesh-like manner to the entire electrode via the conductive bridge portion 22.

[0061] As shown in Figure 12, in the sensor compartment 20 (see Figure 10), the first insulating layer 221, the first conductive layer 222, the second insulating layer 223, the second conductive layer 224, the third insulating layer 225, the third conductive layer 226, and the fourth insulating layer 227 are stacked in that order. The first conductive layer 222 is the shield electrode 23 (see Figure 4) and is a rectangle the same size as the sensor compartment 20. The second conductive layer 224 consists of a metal conductive wire extending in the third direction Dx and a metal conductive wire extending in the fourth direction Dy, as shown in Figure 11. The metal material of the second conductive layer 224 has lower resistance than the conductive oxide such as ITO of the third conductive layer 226. The third conductive layer 226 is a conductive bridge portion 22 (see Figure 11). As shown in Figure 12, there is a conductive bridge portion 22, which is a conductive oxide, between the metal conductive wire extending in the third direction Dx and the metal conductive wire extending in the fourth direction Dy.

[0062] Similarly, metal conductive wires extending in the third direction Dx are electrically connected via the conductive bridge portion 22, thereby extending in the third direction Dx as lead wires 31.

[0063] The cross-section shown in Figure 12 can also be said to show the state of the cross-section when the cutting line Lcut (see Figure 2) becomes the edge of the flexible substrate 10. As described above, along the cutting line Lcut (see Figure 2), the second conductive layer 224 of a part of the lead wiring 31 or a part of the electrode 21A, or the first conductive layer 222 of a part of the shield electrode 23, is exposed at the edge of the flexible substrate 10.

[0064] Conductive oxides such as ITO are less susceptible to corrosion than the metal material of electrode 21A. Therefore, even if the second conductive layer 224 corrodes in the cutting line Lcut (see Figure 2), the corrosion is suppressed by the third conductive layer 226, making the other second conductive layers 224 less susceptible to corrosion. This effect is the same not only for electrode 21A but also for the lead wiring 31.

[0065] While preferred embodiments of this disclosure have been described above, this disclosure is not limited to such embodiments. The content disclosed in the embodiments is merely an example, and various modifications are possible without departing from the spirit of this disclosure. Any modifications made without departing from the spirit of this disclosure will naturally fall within the technical scope of this disclosure.

[0066] For example, the multiple electrodes 21A may be planar transparent conductive layers. In this case, the material of the electrodes 21A is a light-transmitting conductive material such as ITO, IZO, IGO, and IGZO, partitioned for each sensor compartment 20.

[0067] (Embodiment 5) Figure 13 is a plan view showing the position of the lead wiring in the capacitance sensor according to Embodiment 5. Figure 14 is a partial cross-sectional view of the electrode portion of the capacitance sensor according to Embodiment 5. The same reference numerals are used for the same components as those described in Embodiment 1 above, and redundant explanations are omitted.

[0068] Embodiment 5 differs from Embodiment 1 in that the lead wire 31 of the capacitance sensor is formed in the same layer as the electrode 21B. As shown in Figure 13, the electrode 21B is rectangular, and the lead wire 31 is connected to the electrode 21B at its corner.

[0069] As shown in Figure 14, in the sensor compartment 20 (see Figure 13), the first insulating layer 231, the first conductive layer 232, the second insulating layer 233, the second conductive layer 234, and the third insulating layer 235 are stacked in that order. The first conductive layer 232 is the shield electrode 23 (see Figure 4) and is a rectangle the same size as the sensor compartment 20. The second conductive layer 234 is the electrode 21B and the lead wire 31. Thus, the electrode 21B and the lead wire 31 are formed from the same layer.

[0070] The shield electrode 23 is formed in a mesh pattern when viewed from above. The conductors constituting the shield electrode 23 may be arranged in a zigzag or wavy pattern when viewed from above. The shield electrode 23 is not limited to a mesh pattern when viewed from above, but may also be a solid film.

[0071] The flexible substrate 10 is cut along the cutting line Lcut to form a desired irregular shape from a rectangle as shown in Figure 13. A portion of the electrode 21B is exposed at the edge of the flexible substrate 10 along the cutting line Lcut. In Embodiment 5, the number of sensor sections 20 that can detect capacitance can be increased along the sensor section Lcut.

[0072] Furthermore, any other effects and advantages brought about by the embodiments described herein that are obvious from this specification or that can be appropriately conceived by those skilled in the art are naturally provided by this disclosure.

[0073] 1 Capacitive sensor 10 Flexible substrate 11 Main body 12 Connection part 13 Terminals 20, 20A, 20B Sensor section 21, 21A, 21B Electrode 22 Conductive bridge section 23 Shield electrode 31 Outlet wiring 32 Connection via 40 Detection circuit 41 Analog front end 42 Signal detection circuit 43 A / D conversion circuit 44 Power supply circuit 201, 211, 221, 231 First insulating layer 202, 212, 222, 232 First conductive layer 203, 213, 223, 233 Second insulating layer 204, 214, 224, 234 Second conductive layer 205, 215, 225, 235 Third insulating layer 206, 216, 226 Third conductive layer 207, 217, 227 Fourth insulating layer F Detected object Lcut Cutting line X First direction Y Second direction

Claims

1. A capacitive sensor comprising a flexible substrate, a plurality of electrodes arranged in a matrix in a first and second direction, a plurality of terminals, and a plurality of wires connecting the electrodes and the terminals, wherein each section containing one electrode is defined as a sensor section, and in the plurality of sensor sections arranged in a row in the second direction, the plurality of lead wires connected to each of the plurality of electrodes in a row are arranged in a biased bundle on the side closer to the terminals in the first direction, while maintaining insulation between adjacent lead wires, and the edge of the flexible substrate has a cut line in which a part of the electrodes or the lead wires is exposed.

2. In a row of multiple sensor compartments having the cutting line, the number of sensor compartments where the cutting line crosses the lead wire is less than the number of sensor compartments where the cutting line does not cross the lead wire, according to claim 1.

3. The capacitive sensor according to claim 1, wherein the flexible substrate has a main body and a connecting portion, the main body has the plurality of electrodes arranged thereon, the connecting portion has the plurality of terminals arranged thereon, and the number of sensor compartments on one side of the connecting portion in the first direction is greater than the number of sensor compartments on the other side of the connecting portion in the first direction.

4. The capacitive sensor according to claim 1, wherein the flexible substrate has a main body and a connecting portion, the main body has the plurality of electrodes arranged thereon, the connecting portion has the plurality of terminals arranged thereon, and the number of sensor compartments on one side of the connecting portion in the first direction is the same as the number of sensor compartments on the other side of the connecting portion in the first direction.

5. The capacitive sensor according to any one of claims 1 to 4, wherein the flexible substrate is laminated in order a first insulating layer, a first conductive layer, a second insulating layer, a second conductive layer, a third insulating layer, a third conductive layer, and a fourth insulating layer, the first conductive layer being a shield electrode, one of the second conductive layer and the third conductive layer being at least a part of the electrode, the first conductive layer, the second conductive layer and the third conductive layer being patterned in the sensor compartment, the second conductive layer and the third conductive layer being absent at the boundary between adjacent sensor compartments, and the first conductive layer being thinner than the first conductive layer in the sensor compartment connecting the respective shield electrodes of the adjacent sensor compartments.

6. The capacitance sensor according to any one of claims 1 to 4, wherein the electrode includes a plurality of linear metal conductive wires spaced apart from each other and a conductive bridge portion of a conductive oxide, the conductive bridge portion electrically connecting adjacent metal conductive wires.

Images