Touch panel, touch panel module, and method for inspecting touch panel

Abstract

A touch panel includes a substrate having insulating properties and including a sensing region and a non-sensing region, a plurality of sensor electrodes formed in the sensing region, a plurality of external connection terminals formed in the non-sensing region, and a lead-out wiring line electrically connecting one end of each of the plurality of sensor electrodes to each of the plurality of external connection terminals. The external connection terminal and the lead-out wiring line are continuously divided by a single slit along an extension direction of the external connection terminal and the lead-out wiring line in an entire length, or in a portion of the entire length from which an end portion in a sensor electrode side of the lead-out wiring line is excluded.

Claims

1. A touch panel comprising: a substrate having insulating properties and including a sensing region and a non-sensing region around the sensing region; a plurality of sensor electrodes formed in the sensing region; a plurality of external connection terminals formed in the non-sensing region; and a lead-out wiring line electrically connecting one end of each of the plurality of sensor electrodes to each external connection terminal of the plurality of external connection terminals, wherein the external connection terminal and the lead-out wiring line are continuously divided by a single slit along an extension direction of the external connection terminal and the lead-out wiring line in an entire length, or in a portion of the entire length from which an end portion in a sensor electrode side of the lead-out wiring line is excluded.

2. The touch panel according to claim 1, wherein the plurality of sensor electrodes include a plurality of first electrodes extending in a first direction and arranged in a second direction intersecting the first direction, and a plurality of second electrodes extending in the second direction and arranged in the first direction, and each electrode of the plurality of first electrodes is connected to the external connection terminal and the lead-out wiring line, and each electrode of the plurality of second electrodes is connected to the external connection terminal and the lead-out wiring line.

3. The touch panel according to claim 2, wherein the plurality of external connection terminals is formed in only one surface of the substrate.

4. The touch panel according to claim 2, wherein the slit extends into the plurality of sensor electrodes in a range where the slit does not completely divide the plurality of sensor electrodes.

5. A method for inspecting the touch panel according to claim 2, the method comprising: bringing a probe of a continuity inspection device into contact with each of a pair of split terminals including one of the plurality of external connection terminals divided; and inspecting continuity between the pair of split terminals via a pair of split wiring lines including the lead-out wiring line divided, and via one of the plurality of sensor electrodes.

6. The touch panel according to claim 1, wherein the plurality of external connection terminals are formed in only one surface of the substrate.

7. The touch panel according to claim 6, wherein the slit extends into the plurality of sensor electrodes in a range where the slit does not completely divide the plurality of sensor electrodes.

8. A method for inspecting the touch panel according to claim 6, the method comprising: bringing a probe of a continuity inspection device into contact with each of a pair of split terminals including one of the plurality of external connection terminals divided; and inspecting continuity between the pair of split terminals via a pair of split wiring lines including the lead-out wiring line divided, and via one of the plurality of sensor electrodes.

9. The touch panel according to claim 1, wherein the slit extends into the plurality of sensor electrodes in a range where the slit does not completely divide the plurality of sensor electrodes.

10. A method for inspecting the touch panel according to claim 9, the method comprising: bringing a probe of a continuity inspection device into contact with each of a pair of split terminals including one of the plurality of external connection terminals divided; and inspecting continuity between the pair of split terminals via a pair of split wiring lines including the lead-out wiring line divided, and via one of the plurality of sensor electrodes.

11. A method for inspecting the touch panel according to claim 1, the method comprising: bringing a probe of a continuity inspection device into contact with each of a pair of split terminals including one of the plurality of external connection terminals divided; and inspecting continuity between the pair of split terminals via a pair of split wiring lines including the lead-out wiring line divided, and via one of the plurality of sensor electrodes.

12. The touch panel according to claim 1, wherein the plurality of external connection terminals are formed in both surfaces of the substrate.

13. A touch panel module comprising: a substrate having insulating properties and including a sensing region and a non-sensing region around the sensing region; a plurality of sensor electrodes formed in the sensing region; a plurality of external connection terminals formed in the non-sensing region; a lead-out wiring line electrically connecting one end of each of the plurality of sensor electrodes to each external connection terminal of the plurality of external connection terminals; and a flexible printed circuit (FPC) crimped with the plurality of external connection terminals and including a plurality of FPC wiring lines, wherein the external connection terminal and the lead-out wiring line are continuously divided by a single slit along an extension direction of the external connection terminal and the lead-out wiring line in an entire length, or in a portion of the entire length from which an end portion in a sensor electrode side of the lead-out wiring line is excluded, and the plurality of FPC wiring lines of the FPC are connected to the plurality of external connection terminals while extending across both sides of the slit.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is an explanatory view illustrating an example of a typical capacitive touch panel and an FPC for external connection.

(2) FIG. 2 is a schematic view illustrating an example of a connection state of a lead-out wiring line and an external connection terminal for each sensor electrode in a touch panel according to the present disclosure.

(3) FIG. 3 is a schematic view illustrating an example of a method for inspecting a touch panel according to the present disclosure.

(4) FIG. 4 is a schematic view illustrating an example of a crimped state of an FPC wiring line in a touch panel module according to the present disclosure.

(5) FIG. 5 is a schematic view illustrating another example of a connection state of a lead-out wiring line and an external connection terminal for each sensor electrode in a touch panel according to the present disclosure.

(6) FIG. 6 is a schematic view illustrating another example of a connection state of a lead-out wiring line and an external connection terminal for each sensor electrode in a touch panel according to the present disclosure.

(7) FIG. 7 is a schematic view illustrating a connection state of a lead-out wiring line and an external connection terminal for each sensor electrode in a touch panel 4 according to the related art.

(8) FIG. 8 is a schematic view illustrating an example of a method for inspecting a touch panel according to the related art.

DETAILED DESCRIPTION

(9) Embodiments will be described below with reference to the drawings. To facilitate understanding of the present disclosure, in each of the figures referred to herein, some of components are schematically represented in such a way that the components are illustrated in an exaggerated manner. Accordingly, dimensions, ratios, and the like between components may be different from those of real objects. Additionally, dimensions, materials, shapes, relative positions, and the like of members and portions described in examples of the present disclosure are not intended to limit the scope of the invention to only those dimensions, materials, shapes, relative positions, and the like unless otherwise specified, and are merely an example for explanation.

1. First Embodiment

(10) Touch Panel

(11) FIG. 1 is an explanatory view illustrating an example of a typical capacitive touch panel and an FPC for external connection. In the present embodiment, a basic configuration as a capacitive touch panel is also the same. Since a constituent that is a feature of the present disclosure has a fine pattern, the constituent is not illustrated in FIG. 1. A touch panel 4 according to the present embodiment includes a substrate 8 having insulation properties and including a sensing region S and a non-sensing region P around the sensing region S, a plurality of sensor electrodes 1 formed in the sensing region S, a plurality of external connection terminals 3 formed in the non-sensing region P, and a lead-out wiring line 2 that electrically connects one end of each of the sensor electrodes 1 to each of the external connection terminals 3.

(12) For example, a resin film or a glass plate can be used as the substrate 8. When a resin film is used, examples of a material of the resin film can include acrylic, polycarbonate, polyethylene terephthalate, and a cycloolefin polymer.

(13) The plurality of sensor electrodes 1 includes a plurality of first electrodes 11 extending in a first direction and arranged in a second direction intersecting the first direction, and a plurality of second electrodes 12 extending in the second direction and arranged in the first direction. In FIG. 1, the plurality of sensor electrodes includes a plurality of X electrodes 11 extending in a Y direction and arranged in an X direction, and a plurality of Y electrodes 12 extending in the X direction and arranged in the Y direction.

(14) In the present embodiment, the X electrodes 11 are formed in a front surface side of the substrate 8 and are illustrated by solid lines. Additionally, the Y electrodes 12 are formed in a back surface side of the substrate 8 and are illustrated by dashed lines. All of the sensor electrodes 1 (the X electrodes 11 and the Y electrodes 12) include a plurality of island-shaped electrodes disposed along one direction, and connecting portions connecting the adjacent island-shaped electrodes. The island electrodes and the connecting portions are continuously and integrally formed.

(15) The sensor electrodes 1 can be made of a material having conductivity and may be transparent or opaque. A transparent conductive oxide such as indium tin oxide (ITO) and tin zinc oxide (TZO), a conductive polymer such as polyethylenedioxythiophene (PEDOT), or the like can be used as the material having conductivity. In this case, the above-described electrodes can be formed by using vapor deposition, screen printing, or the like. Additionally, a conductive metal such as copper or silver may be used as the material having conductivity. In this case, the above-described electrodes may be formed by vapor deposition, or may be formed by using metallic paste such as copper paste and silver paste. Further, a conductive material such as carbon nanotube, metallic particles, or metallic nanofiber dispersed in a binder may be used as the material having conductivity.

(16) The sensing region S is a region to be detected when a finger or a pen comes into contact with the touch panel 1. That is, a region where the sensor electrodes 1 (the X electrodes 11 and the Y electrodes 12) are formed is the sensing region. In FIG. 1, a rectangular region surrounding the X electrodes 11 and the Y electrodes 12 is defined as the sensing region S. The sensing region S is not limited to a rectangular region, and can be formed in any shape. Additionally, the sensing region may be a discontinuous region.

(17) In FIG. 1, the non-sensing region P is disposed in contact with three sides of the sensing region S. However, the non-sensing region P may be disposed in any manner. For example, the non-sensing region P may be disposed around four sides of the sensing region S. The non-sensing region P may be disposed in contact with one side or two sides of the sensing region S.

(18) FIG. 2 is a schematic view illustrating an example of a connection state of a lead-out wiring line and an external connection terminal for each sensor electrode in the touch panel according to the present disclosure.

(19) The single sensor electrode 1 (the X electrode 11 and the Y electrode 12) is extracted, and a connection relationship between the lead-out wiring line 2 and the external connection terminal 3 is the same in all of the sensor electrodes 1.

(20) A conductive metal such as copper or silver can be used as a material of the lead-out wiring line 2 and the external connection terminal 3. In this case, the lead-out wiring line 2 and the external connection terminal 3 may be formed by vapor deposition, or may be formed by using metal paste such as copper paste and silver paste. Further, a conductive material such as carbon nanotube, metallic particles, or metallic nanofiber dispersed in a binder may be used as a material of the lead-out wiring line 2 and the external connection terminal 3.

(21) The lead-out wiring line 2 and the external connection terminal 3 may each include a two-layer structure. In this case, the same material as the material of the sensor electrode 1 is used for a material of a lower layer, and the lower layers of the lead-out wiring line 2 and the external connection terminal 3, and the sensor electrode 1 may be formed at the same time.

(22) As illustrated in FIG. 2, the external connection terminal 3 and the lead-out wiring line 2 are continuously divided by a single slit 20, 30 along the extension direction of the external connection terminal 3 and the lead-out wiring line 2 in the entire length.

(23) That is, the lead-out wiring line 2 is completely divided, and a pair of split wiring lines 2a, 2b that is independent is configured. Additionally, the external connection terminal 3 is divided, and a pair of split terminals 3a, 3b is configured. Further, a slit 10 extends into the sensor electrode 1 in a range where the slit 10 does not completely divide the sensor electrode 1.

(24) Method for Inspecting Touch Panel

(25) A schematic view illustrating an example of a method for inspecting a touch panel according to the present disclosure is presented.

(26) For the above-described touch panel 4, a probe 5 of a continuity inspection device (not illustrated) is brought into contact with each of the pair of split terminals 3a, 3b dividing the external connection terminal 3, and continuity between the split terminals 3a, 3b via the pair of split wiring lines 2a, 2b dividing the lead-out wiring line 2, and via the sensor electrode 1 is inspected.

(27) At this time, in a case where only the split wiring line 2b of the pair of split wiring lines 2a, 2b is completely disconnected as in an enlarged portion indicated by a circle in FIG. 3, the lead-out wiring line 2 as a whole is not completely disconnected but is not in a conducting state in the continuity inspection. Thus, the touch panel can be detected as a progressive defective product having a possibility of a partial disconnection changing to a complete disconnection in the step subsequent to inspection.

(28) Note that the above-described touch panel 4 used in the inspection method does not need a wiring line dedicated to inspection, and thus an extra space is not required, and downsizing can be achieved. Additionally, the step of removing a wiring line dedicated to inspection after inspection is also unnecessary.

(29) Touch Panel Module

(30) After the above-described inspection of the touch panel is performed to remove a defective product, an FPC 6 is crimped with the external connection terminals 3 of the touch panel 4, and thus a touch panel module is obtained. An anisotropic conductive film (not illustrated) is used for connecting the FPC 6 to the external connection terminals 3 of the touch panel 4.

(31) The FPC 6 includes a plurality of FPC wiring lines 7 (see FIG. 1). The FPC 6 is a highly reliable and highly flexible printed circuit board in which the plurality of FPC wiring lines 7 made of copper or the like is formed on a flexible film base material 9 such as a polyimide film or a polyester film. The FPC 6 has characteristics of, for example, being freely bendable, having high crease performance, being foldable and windable, having a high tear resistance and wiring density, and having a light weight and a small thickness.

(32) In the anisotropic conductive film (not illustrated), conductive particles are dispersed in an adhesive (resin) that is cured by heat or light. The connection wiring lines 3 and the FPC wiring lines 7 of the FPC 6 are electrically connected by conductive particles.

(33) In FIG. 1, the flexible film base material 9 of the FPC 6 is divided into two sections. The FPC wiring lines 7 are formed in a front surface of one of the two sections. The FPC wiring lines 7 are formed in a back surface of the other of the two sections. Note that the FPC 6 may be prepared as two FPCs 6 one of which includes the FPC wiring lines 7 formed in a front surface of the flexible film base material 9 and the other of which includes the FPC wiring lines 7 formed in a back surface of the flexible film base material 9.

(34) FIG. 4 is a schematic view illustrating an example of a crimped state of the FPC wiring line in the touch panel module according to the present disclosure.

(35) Only one line including one of the sensor electrodes 1, one of the lead-out wiring lines 2, and one of the external connection terminals 3 of the touch panel 4, and one of the FPC wiring lines 7 of the FPC 6 are extracted, and the connection relationship between the external connection terminal 3 and the FPC wiring line 7 is the same in all lines.

(36) In the present embodiment, as illustrated in FIG. 4, the FPC wiring line 7 is connected to the external connection terminal 3 while extending across both sides of the slit 30. Accordingly, the external connection terminal 3 and the lead-out wiring line 2 function in the same manner as in a case where the external connection terminal 3 and the lead-out wiring line 2 are not divided.

(37) Additionally, as in an enlarged portion indicated by a circle in FIG. 4, even in a case where the touch sensor 4 where both of the pair of slit wiring lines 2a, 2b are barely conductive, that is, the touch sensor 4 (product) is determined as a good product in continuity inspection, and after the inspection, the partial disconnection of only the split wiring line 2b of the pair of split wiring lines 2a, 2b changes to the complete disconnection, the split wiring line 2a of the pair of split wiring lines 2a, 2b still remains, and thus a touch panel function can be maintained.

2. Second Embodiment

(38) In the first embodiment, as illustrated in FIG. 2, the slit 10 extends into the sensor electrode 1 in a range where the slit 10 does not completely divide the sensor electrode 1; however, the touch panel of the present disclosure is not limited to this. For example, a slit 10 need not be present in a sensor electrode 1 (see FIG. 5).

(39) At this time, as illustrated in FIG. 5, an external connection terminal 3 and a lead-out wiring line 2 are more preferably divided continuously by a single slit 20, 30 along the extension direction of the external connection terminal 3 and the lead-out wiring line 2 in a portion of the entire length from which an end portion 2E in a side of the sensor electrode 1 of the lead-out wiring line 2 is excluded. That is, the lead-out wiring line 2 is not completely divided, and is a pair of split wiring lines 2a, 2b connected at the end portion 2E in a side of the sensor electrode 1.

(40) In this way, a difference in a resistance value between the lead-out wiring line 2 having a standard design value and the lead-out wiring line 2 including a mouse bite (a defect of a wiring line chipped along a line as if a mouse bit), that is, the presence or absence of a mouse bite can be detected. Note that the pair of split wiring lines 2a, 2b is connected by the end portion 2E made of the same low resistance material as a material of the split wiring lines 2a, 2b, and thus a resistance value is stable and a mouse bite can be detected. That is, due to the presence of the end portion 2E, detection of a mouse bite is unaffected even when the sensor electrode 1 includes a high resistance material such as ITO.

3. Other Embodiments

(41) Although the first and second embodiments of the present disclosure are described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. In particular, the plurality of embodiments and modifications described herein can be combined arbitrarily with one another as necessary.

(42) For example, in the above-described embodiments, as illustrated in FIG. 1, the first electrodes (X electrodes) 11 are formed in the front surface side of the substrate 8, and the second electrodes (Y electrodes) 12 are formed in the back surface side of the substrate 8, but the first electrodes and the second electrodes are not limited to this. The first electrodes (X electrodes) 11 and the second electrodes (Y electrodes) 12 may be formed in only one surface of the substrate 8. In this case, an insulating ink film may be formed only at an intersection location of each of the first electrodes (X electrode) 11 and each of the second electrodes (Y electrode) 12, or an insulating ink film may be formed over the entire surface.

(43) Additionally, the first electrode 11 and the second electrode 12 may intersect each other and may not be orthogonal to the X and Y axes.

(44) Additionally, in the above-described embodiments, as illustrated in FIG. 1, the sensor electrodes 1 include the plurality of island-shaped electrodes disposed along one direction and the connecting portions connecting the adjacent island-shaped electrodes, but are not limited to this. For example, the sensor electrodes may each be formed in a strip shape. Additionally, as illustrated in FIG. 6, a sensor electrode 1 may be formed in a loop shape, and both ends of the loop may be connected to a pair of split wiring lines 2a, 2b that is independent.

(45) Additionally, in the above-described embodiments, as illustrated in FIG. 1, the external connection terminals 3 are formed in both the surfaces of the substrate 8, but are not limited to this. For example, the external connection terminals 3 may be aggregated in one surface of the substrate 8. In a case where the sensor electrodes 1 are formed in only one surface of the substrate 8, the lead-out wiring lines 2 and the external connection terminals 3 may be formed in the same surface as the sensor electrodes 1. Additionally, in a case where the sensor electrodes 1 are formed in both the surfaces of the substrate 8, through holes for the lead-out wiring lines 2 may be provided in the substrate.

(46) Further, the sensor electrodes 1 need not be formed to intersect each other. For example, the touch panel may be a switch type touch panel that detects only on and off. In this case, the lead-out wiring lines 2 may also be formed in the sensing region S.

(47) Additionally, the touch panel may be a resistive film touch panel.

INDUSTRIAL APPLICABILITY

(48) A touch panel of the present disclosure is useful for an electronic device such as an office automation device, a smart phone, a portable gaming device, an electronic dictionary, a car navigation system, a small PC, or various home appliances.

BRIEF DESCRIPTION OF THE REFERENCE CHARACTERS

(49) 1: Sensor electrode 2: Lead-out wiring line 2a, 2b: Split wiring line 2E: End portion 3: External connection terminal 3a, 3b: Split terminal 4: Touch panel 5: Probe 6: FPC 7: FPC wiring line 8: Substrate 9: Flexible film base material 10, 20, 30: Slit 11: First electrode (X electrode) 12: Second electrode (Y electrode)