JP2015011568A - Touch detection module, display device with touch function, and touch panel sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch detection module in which the occurrence of a step and a gap is prevented.SOLUTION: The overcoat layer of a touch panel sensor is provided on a terminal part, so as to exist as an exposed part where a part of the terminal part is not covered with the overcoat layer. The thickness of the part in contact with the exposed part of the terminal part, of the overcoat layer is smaller than the average thickness of the overcoat layer. A flexible printed board is joined to the exposed part of the terminal part, so that the end of the flexible printed board is located on the part in contact with the exposed part of the terminal part, of the overcoat layer.

Description

  The present invention relates to a touch detection module including a touch panel sensor and a flexible printed board joined to the touch panel sensor. The present invention also relates to a display device with a touch function obtained by combining a touch detection module and a display device. The present invention also relates to a touch panel sensor used by being bonded to a flexible printed circuit board.

  Today, touch panel devices are widely used as input means. The touch panel device includes a touch panel sensor, a detection control unit that processes a signal from the touch panel sensor, and the like. In many cases, the touch panel device is used together with the display device as an input means for various devices including a display device such as a liquid crystal display or a plasma display (for example, a ticket vending machine, an ATM device, a mobile phone, a game machine). ing. In such a device, the touch panel sensor is disposed on the display surface of the display device, thereby enabling extremely direct input to the display device. The area | region which faces the display area of a display apparatus among touch panel sensors is transparent, and this area | region of a touch panel sensor comprises the active area which can detect a contact position (approach position).

  Touch panel devices are classified into various types based on the principle of detecting a contact position (approach position) on a touch panel sensor. In recent years, capacitive touch panel devices have attracted attention because they are optically bright, have good design properties, have a simple structure, and are superior in function. In a capacitively coupled touch panel device, when an external conductor (typically a finger) whose position is to be detected contacts (approaches) the touch panel sensor via a dielectric, a new strange capacitance is generated. The position of the object on the touch panel sensor is detected based on the change in capacitance caused by this strange capacity. The capacitive coupling method includes a surface type and a projection type, but the projection type is attracting attention because it is suitable for multi-touch recognition (multi-point recognition).

  The projected capacitively coupled touch panel sensor includes a dielectric, a transparent conductive pattern formed in the above active area of the dielectric, and an inactive area (so-called frame region) outside the active area of the dielectric. And a terminal portion electrically connected to the transparent conductive pattern through the extraction conductive pattern. A flexible printed circuit board is bonded to the terminal portion, and a signal from the transparent conductive pattern is transmitted to the detection control unit via the flexible printed circuit board (see, for example, Patent Document 1).

JP 2011-248810 A

  As described above, the terminal portion of the touch panel sensor is disposed in the inactive area, and therefore, the terminal portion is not required to have translucency. Therefore, in general, a metal material having high conductivity is used as a material constituting the terminal portion. In this case, in order to prevent the metal material of the terminal portion from corroding or causing an electromigration phenomenon, it is known to provide an insulating overcoat layer on the terminal portion. The overcoat layer does not cover the entire area of the terminal portion, but is partially provided on the terminal portion so that the portion of the terminal portion to which the flexible printed board is bonded is exposed.

  When the flexible printed circuit board is joined to the terminal portion exposed from the overcoat layer, the following two forms are considered as the positional relationship between the overcoat layer and the flexible printed circuit board. One is a form in which the flexible printed board runs on the overcoat layer, and the other is a form in which the flexible printed board does not run on the overcoat layer. In consideration of manufacturing tolerances, it is difficult to completely match the position of the end portion of the overcoat layer with the position of the end portion of the flexible printed circuit board. Therefore, the fact that the flexible printed circuit board does not run on the overcoat layer means that a gap is formed between the end part of the flexible printed circuit board and the end part of the overcoat layer.

Each of the problems that can occur in the above two forms will be discussed.
When the flexible printed circuit board runs on the overcoat layer, a large step based on the thickness of the flexible printed circuit board occurs between the touch panel sensor and the flexible printed circuit board. If such a large level difference exists, it is conceivable that productivity and workability in subsequent manufacturing processes such as a transport process and a combination process with a display device are deteriorated. In addition, since it is usually difficult for the flexible printed circuit board to bend along the shape of the end portion of the overcoat layer, a large gap may be formed between the exposed portion of the terminal section and the flexible printed circuit board. . Such voids can be a starting point for corrosion and electromigration.
On the other hand, when the flexible printed board does not run over the overcoat layer, a gap is formed between the end of the flexible printed board and the end of the overcoat layer. That is, the terminal portion has a portion that is not covered by either the overcoat layer or the flexible printed board. In this case, in order to ensure the protection of the terminal portion, it is preferable to protect the portion of the terminal portion that is not covered with either the overcoat layer or the flexible printed board with a further resin layer. However, in this case, the number of man-hours increases as much as the resin layer is formed.

  An object of this invention is to provide the touch detection module which can solve such a subject effectively.

  The present invention relates to a touch detection module including a touch panel sensor and a flexible printed circuit board bonded to the touch panel sensor, the touch panel sensor including an active area corresponding to an area where a touch position can be detected, and a periphery of the active area A non-active area located in the substrate, a transparent conductive pattern disposed in the active area of the base material, and disposed in the non-active area of the base material, electrically to the transparent conductive pattern A terminal portion connected to the terminal portion; and an overcoat layer provided on the terminal portion, wherein the overcoat layer is present as an exposed portion in which a part of the terminal portion is not covered by the overcoat layer. The terminal portion of the overcoat layer is provided on the terminal portion. The thickness of the portion in contact with the exposed portion is smaller than the average thickness of the overcoat layer, and the flexible printed circuit board has its end portion in contact with the exposed portion of the terminal portion in the overcoat layer. It is a touch detection module joined to the exposed part of the terminal part so as to be located on the part.

  In the touch detection module according to the present invention, a portion of the overcoat layer that contacts the exposed portion of the terminal portion may be configured as a tapered portion whose thickness decreases toward the exposed portion.

  In the touch detection module according to the present invention, a thickness of a portion of the overcoat layer that contacts the exposed portion of the terminal portion may be 30% or less of an average thickness of the overcoat layer.

  In the touch detection module according to the present invention, a portion of the overcoat layer that contacts the exposed portion of the terminal portion is located at a distance of 2.0 mm or less from an end portion of the overcoat layer on the exposed portion side, for example. Means part.

  In the touch detection module according to the present invention, the base material of the touch panel sensor functions as a protective plate for a display device, and the transparent conductive pattern, the terminal portion, and the overcoat layer of the touch panel sensor are all included. The surface of the substrate may be provided on the surface on the display device side.

  The present invention includes a display device, a touch panel sensor disposed on a display surface of the display device, and a flexible printed circuit board bonded to the touch panel sensor, and the touch panel sensor can detect a touch position. A substrate including an active area corresponding to the active area, an inactive area located around the active area, a transparent conductive pattern disposed in the active area of the substrate, and the inactive area of the substrate A terminal portion disposed and electrically connected to the transparent conductive pattern, and an overcoat layer provided on the terminal portion, wherein the overcoat layer has a portion of the terminal portion that is the overcoat layer. The overcoat is provided on the terminal part so as to exist as an exposed part not covered by a layer. The thickness of the portion of the layer that contacts the exposed portion of the terminal portion is smaller than the average thickness of the overcoat layer, and the flexible printed circuit board has an end portion of the terminal of the overcoat layer. It is a display device with a touch function joined to the exposed part of the terminal part so that it may be located on a part which touches the exposed part of a part.

  The present invention is a touch panel sensor used by being bonded to a flexible printed circuit board, and includes a base material including an active area corresponding to an area where a touch position can be detected, and an inactive area located around the active area. A transparent conductive pattern disposed in the active area of the base material; a terminal portion disposed in the inactive area of the base material and electrically connected to the transparent conductive pattern; and provided on the terminal portion. And the overcoat layer is provided on the terminal portion so that a part of the terminal portion exists as an exposed portion not covered by the overcoat layer, The thickness of the portion of the overcoat layer that contacts the exposed portion of the terminal portion is greater than the average thickness of the overcoat layer. Is smaller, a touch panel sensor.

  According to the present invention, the thickness of the portion of the overcoat layer that is in contact with the exposed portion of the terminal portion is smaller than the average thickness of the overcoat layer. Moreover, the flexible printed circuit board is joined to the exposed portion of the terminal portion so that the end portion thereof is located on the portion of the overcoat layer that is in contact with the exposed portion of the terminal portion. For this reason, it can suppress that a level | step difference arises between a touchscreen sensor and a flexible printed circuit board, and can suppress that a space | gap is formed between a terminal part and a flexible printed circuit board.

FIG. 1 is a development view showing a display device with a touch function according to an embodiment of the present invention. FIG. 2 is a plan view showing a touch panel sensor in the display device with a touch function of FIG. 1. 3 is a cross-sectional view of the touch panel sensor of FIG. 2 along the line III. 4A is an enlarged view showing a terminal portion and a flexible printed board of the touch panel sensor of FIG. 3. 4B (a) and 4 (b) are diagrams illustrating an example of a layer configuration of the flexible printed board in FIG. 4A. FIG. 5A is a diagram showing a state in which a resin material for constituting an overcoat layer is provided. FIG. 5B is a view showing an exposure step of irradiating the resin material with exposure light. FIG. 5C is a diagram showing an overcoat layer obtained by developing a resin material irradiated with exposure light. FIG. 6A is an enlarged view showing a terminal portion and an overcoat layer of the touch panel sensor according to the first comparative embodiment. FIG. 6B is an enlarged view showing a terminal portion and an overcoat layer of the touch panel sensor according to the second comparative embodiment. FIG. 7 is an enlarged view showing a terminal portion and an overcoat layer of a touch panel sensor according to a modification of the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5C. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual ones. Further, in the present specification, the terms “sheet”, “film”, and “plate” are not distinguished from each other only based on the difference in names. Therefore, for example, the “plate” is a concept including members and parts that can also be called sheets, films and the like.

Touch Panel Device and Display Device with Touch Function First, a touch panel device 20 including a touch panel sensor 30 and a display device 10 with a touch function including the touch panel device 20 will be described with reference to FIG. The touch panel device 20 shown in FIG. 1 is configured as a projection-type capacitive coupling method, and is configured to be able to detect a contact position of an external conductor (for example, a human finger) to the touch panel device 20. In addition, when the detection sensitivity of the capacitively coupled touch panel device 20 is excellent, it is possible to detect which region of the touch panel device the external conductor is approaching just by approaching the external conductor. Can do. Accordingly, the “contact position” used here is a concept including an approach position that is not actually in contact but can be detected. The “capacitive coupling” method is also referred to as “capacitance” method or “capacitance coupling” method in the technical field of touch panels. It is treated as a term synonymous with the “capacitive coupling” method.

  As shown in FIG. 1, the touch panel device 20 is used in combination with a display device (for example, a liquid crystal display device) 15 to constitute a display device 10 with a touch function. The illustrated display device 15 is configured as a flat panel display. The display device 15 includes a display panel 16 having a display surface 16 a and a display control unit (not shown) connected to the display panel 16. The display panel 16 includes an active area A1 that can display an image, and an inactive area (also referred to as a frame area) A2 that is disposed outside the active area A1 so as to surround the active area A1. . The display control unit processes information regarding the video to be displayed, and drives the display panel 16 based on the video information. The display panel 16 displays a predetermined image on the display surface 16a based on a control signal from the display control unit. That is, the display device 15 plays a role as an output device that outputs information such as characters and drawings as video.

  As illustrated in FIG. 1, the touch panel device 20 includes a touch panel sensor 30 disposed on the display surface 16 a of the display device 15. The touch panel sensor 30 is bonded to the display surface 16a of the display device 15 via an adhesive layer (not shown), for example. As shown in FIG. 1, one end of a flexible printed circuit board 21 is joined to the touch panel sensor 30. The other end of the flexible printed circuit board 21 is connected to a detection control unit (not shown) that processes a signal from the touch panel sensor 30. That is, a signal from the touch panel sensor 30 is transmitted to the detection control unit via the flexible printed board 21. A combination of the touch panel sensor 30 and the flexible printed circuit board 21 bonded to the touch panel sensor 30 is also referred to as a touch detection module 18.

  As illustrated in FIG. 1, the touch panel device 20 may further include a protective plate 12 having translucency on the observer side of the touch panel sensor 30, that is, on the side opposite to the display device 15. For example, the protective plate 12 is bonded to the surface of the touch panel sensor 30 on the viewer side with an adhesive layer or the like. This protective plate 12 is for preventing the pattern of the touch panel sensor 30 and the display device 15 from being damaged by contact with an external conductor such as a finger, and is also referred to as a so-called front plate.

Touch Panel Sensor Next, the touch panel sensor 30 will be described with reference to FIG. FIG. 2 is a plan view showing the touch panel sensor 30.

  As illustrated in FIG. 2, the touch panel sensor 30 includes a base material 31 including an active area Aa1 corresponding to a region where a touch position can be detected, and an inactive area Aa2 positioned around the active area Aa1, and a base material The transparent conductive patterns 32 and 33 disposed in the active area Aa1 of 31 and the terminal portion 37 disposed in the non-active area Aa2 of the base material 31 and electrically connected to the transparent conductive patterns 32 and 33 are provided. Yes. The active area Aa1 and the inactive area Aa2 of the base material 31 are respectively partitioned corresponding to the active area A1 and the inactive area A2 of the display panel 16.

  In the present embodiment, the transparent conductive patterns 32 and 33 and the terminal portion 37 are all provided on the surface 31 a on the display device 15 side of the surface of the base material 31. However, the present invention is not limited to this, and the transparent conductive patterns 32 and 33 and the terminal portion 37 are all provided on the surface of the base material 31 opposite to the surface 31a (the surface on the observer side). May be.

  The base material 31 functions as a dielectric in the touch panel sensor 30. The base material 31 may include a resin layer made of a material having sufficient translucency, such as polyethylene terephthalate (PET) or cycloolefin polymer (COP). Moreover, the base material 31 may be comprised using glass etc. so that it may have sufficient intensity | strength.

  As shown in FIG. 2, the transparent conductive patterns 32 and 33 include a plurality of first transparent conductive patterns 32 extending along the first direction, for example, along the horizontal direction of FIG. 2, and along the second direction, for example, And a plurality of second transparent conductive patterns 33 extending in the vertical direction of FIG. The 1st transparent conductive pattern 32 may have the 1st line part 32b extended linearly along the 1st direction, and the 1st bulging part 32a bulged from the 1st line part 32b. The first bulging portion 32 a is a portion that bulges from the first line portion 32 b along the surface of the base material 31. Similarly, the 2nd transparent conductive pattern 33 may have the 2nd line part 33b extended along the 2nd direction, and the 2nd bulge part 33a bulged from the 2nd line part 33b.

  The terminal portion 37 is provided in the inactive area Aa2 in order to transmit signals from the transparent conductive patterns 32 and 33 to the flexible printed circuit board 21. As shown in FIG. 2, the transparent conductive patterns 32 and 33 and the terminal portion 37 are connected by an extraction conductive pattern 36 having conductivity, and the terminal portion 37 is connected to the transparent conductive patterns 32 and 33 by the extraction conductive pattern 36. Is electrically connected. In FIG. 2, the flexible printed circuit board 21 bonded to the terminal portion 37 is indicated by a one-dot chain line for convenience. In the present embodiment, the flexible printed circuit board 21 is joined to a part of the terminal portion 37 instead of the entire terminal portion 37.

  As shown in FIG. 2, the touch panel sensor 30 further includes an overcoat layer 38 provided on the extraction conductive pattern 36 and the terminal portion 37. In the example shown in FIG. 2, the overcoat layer 38 is disposed in a part of the inactive area Aa2. Specifically, they are arranged in a region sandwiched between the inner one-dot chain line 38a and the outer one-dot chain line shown in FIG. The overcoat layer 38 is provided on the terminal portion 37 so that a part of the terminal portion 37 exists as an exposed portion 37 a that is not covered by the overcoat layer 38. The flexible printed circuit board 21 is joined to the terminal portion 37 at the exposed portion 37a.

  Next, the layer configuration of the touch panel sensor 30 will be described with reference to FIG. FIG. 3 is a cross-sectional view of the touch panel sensor 30 of FIG. 2 along the line III.

  The first line portion 32b and the second bulge portion 33a and the first bulge portion 32a (not shown in FIG. 3) may be formed on the same plane. In this case, the first bulging portion 32a, the first line portion 32b, and the second bulging portion 33a are simultaneously formed by patterning the transparent conductive layer 41 made of a transparent conductive material such as indium tin oxide (ITO). Is possible.

  As shown in FIGS. 2 and 3, the first line portion 32 b and the second line portion 33 b are formed so as to partially overlap each other when viewed from the normal direction of the base material 31. In this case, by interposing the insulating layer 34 between the first line portion 32b and the second line portion 33b, conduction between the first line portion 32b and the second line portion 33b can be prevented. . The insulating layer 34 may be provided not only between the first line portion 32b and the second line portion 33b but also on the second bulge portion 33a and the first bulge portion 32a.

  The second line portion 33b is connected to the second bulge portion 33a through a through hole formed in the insulating layer 34, so that the two adjacent second bulge portions 33a can be electrically connected. it can. As long as the 2nd line part 33b has electroconductivity, the material which comprises the 2nd line part 33b is not specifically limited. For example, the second line portion 33b may be made of a transparent conductive material such as indium tin oxide (ITO), or may be made of a metal material.

  As shown in FIG. 3, the extraction conductive pattern 36 and the terminal portion 37 include a metal layer 42 made of a metal material. Examples of the material constituting the metal layer 42 include aluminum, molybdenum, silver, chromium, copper, and alloys thereof. The extraction conductive pattern 36 and the terminal portion 37 may further include a transparent conductive layer 41. Thereby, the electrical resistance of the extraction conductive pattern 36 and the terminal portion 37 can be further reduced.

  As shown in FIG. 3, the overcoat layer 38 may be provided on the extraction conductive pattern 36 and the terminal portion 37 so as to be in contact with the insulating layer 34. Although not shown, one of the insulating layer 34 and the overcoat layer 38 may run on the other. Although not shown, the insulating layer 34 and the overcoat layer 38 may be integrally formed from the same material. That is, the insulating layer that functions as the overcoat layer 38 may extend over almost the entire area of the base material 31 except for the exposed portion 37a.

  As long as the extraction conductive pattern 36 and the terminal portion 37 can be appropriately protected, the material constituting the overcoat layer 38 is not particularly limited. For example, an acrylic resin or the like can be used as the material for the overcoat layer 38. The average thickness of the overcoat layer 38 is in the range of 5.0 to 20.0 μm, for example, about several μm. Note that most of the overcoat layer 38 is constituted by a portion having a substantially uniform thickness (a flat portion 38b described later). Therefore, the average thickness of the overcoat layer 38 may be considered to be the same as the thickness in the flat portion 38b.

  Next, with reference to FIG. 4A and FIG. 4B (a) (b), a mode that the flexible printed circuit board 21 is joined to the terminal part 37 of the touch panel sensor 30 is demonstrated in detail. 4A is an enlarged view showing the terminal portion 37 and the flexible printed board 21 of the touch panel sensor 30 of FIG. 4B (a) is a diagram showing an example of the layer configuration of the flexible printed circuit board 21, and FIG. 4B (b) shows the flexible printed circuit board 21 shown in FIG. It is a figure which shows a mode.

  First, the configuration of the flexible printed circuit board 21 will be described with reference to FIG. 4B (a). As shown in FIG. 4B (a), the flexible printed circuit board 21 includes at least a conductive layer 21b having conductivity. The conductive layer 21b is made of a conductive material such as a metal material, and is made of, for example, copper. As shown in FIG. 4B (a), the conductive layer 21b may be sandwiched between a pair of protective layers 21c and 21d. In this case, a through hole 21g for partially exposing the conductive layer 21b to the outside is formed in the protective layer 21d on the side facing the terminal portion 37 of the touch panel sensor 30. The protective layers 21c and 21d are made of an insulating resin material, for example, polyimide. Adhesive layers 21e and 21f for adhering the protective layers 21c and 21d to the conductive layer 21b may be interposed between the conductive layer 21b and the protective layers 21c and 21d. The thickness of the flexible printed circuit board 21 is in the range of 30.0 to 100.0 μm, for example, about 50 μm.

  As shown in FIG. 4A, the flexible printed circuit board 21 is joined to the exposed portion 37 a of the terminal portion 37. The specific joining method is not particularly limited, and various methods can be used. For example, as shown in FIG. 4B (b), the anisotropic conductive layer 22 having conductivity in the thickness direction (vertical direction in FIG. 4B (b)) is replaced with an exposed portion of the conductive layer 21b of the flexible printed circuit board 21 and the terminal portion 37. The flexible printed circuit board 21 and the exposed portion 37a of the terminal portion 37 may be joined by being interposed between the flexible printed circuit board 21 and the terminal portion 37. The anisotropic conductive layer 22 is a layer containing an anisotropic conductive material. For example, an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP) is used.

  As shown in FIG. 4A, the flexible printed circuit board 21 partially rides on the overcoat layer 38. Specifically, an end portion 38 a located on the exposed portion 37 a side of the terminal portion 37 among the end portions of the overcoat layer 38 is covered with the flexible printed circuit board 21. As a result, the upper surface of the terminal portion 37 is covered without a gap by the overcoat layer 38 or the flexible printed circuit board 21, whereby the terminal portion 37 can be strongly protected from the external environment.

  By the way, when the flexible printed circuit board 21 rides on the overcoat layer 38, the problem that the level | step difference based on the thickness of the flexible printed circuit board 21 arises between the touch panel sensor 30 and the flexible printed circuit board 21 as mentioned above may arise. Here, according to the present embodiment, as shown in FIG. 4A, the overcoat layer 38 has an average thickness of the portion of the overcoat layer 38 that is in contact with the exposed portion 37a of the terminal portion 37. It is comprised so that it may become smaller. Further, the flexible printed circuit board 21 is joined to the exposed portion 37a of the terminal portion 37 so that the end portion 21a is positioned on the above-mentioned “portion of the overcoat layer 38 that contacts the exposed portion 37a of the terminal portion 37”. Yes. As a result, according to the present embodiment, as shown in FIG. 4A, it is possible to prevent the step s between the upper surface of the overcoat layer 38 and the upper surface of the flexible printed board 21 from increasing.

The “portion of the overcoat layer 38 that contacts the exposed portion 37a of the terminal portion 37” refers to a portion of the overcoat layer 38 that is located at a distance d or less from the end portion 38a on the exposed portion 37a side. is there. Here, the distance d corresponds to a length necessary for appropriately bending the flexible printed circuit board 21. The value of the distance d is appropriately determined according to the shape of the overcoat layer 38, the elastic characteristics of the flexible printed circuit board 21, and the like. It is in the range of 0 mm (2.0 mm or less), more preferably in the range of 0.5 to 2.0 mm. In the following description, “the portion of the overcoat layer 38 that is in contact with the exposed portion 37a of the terminal portion 37” may be referred to as a proximity portion 38c. In FIG. 4A, the thickness of the proximity portion 38c is indicated by reference numeral t2. The thickness t2 means the thickness of the portion having the maximum thickness in the proximity portion 38c.
The “average thickness of the overcoat layer 38” means the thickness t1 of the portion having a substantially uniform thickness in the overcoat layer 38, that is, the flat portion 38b as described above.

  The extent to which the thickness t2 of the proximity portion 38c needs to be smaller than the thickness t1 of the flat portion 38b is appropriately determined according to the thickness of the flexible printed circuit board 21 and the like. The thickness t2 is 30% or less, more preferably 25% or less, of the thickness t1 of the flat portion 38b of the overcoat layer 38. Thus, by setting the thickness t2 of the proximity portion 38c, it is possible to prevent the step s between the touch panel sensor 30 and the flexible printed board 21 from becoming too large.

  As shown in FIG. 4A, the proximity portion 38 c of the overcoat layer 38 may be configured as a tapered portion 38 d whose thickness decreases toward the exposed portion 37 a of the terminal portion 37. As a result, the flexible printed circuit board 21 can be bent along the shape of the end portion 38 a of the overcoat layer 38, whereby a gap is formed between the flexible printed circuit board 21 and the terminal portion 37. Can be suppressed. In order to prevent the generation of voids, it is preferable that the tapered portion 38d has a curvature that is convex toward the inside at least in the vicinity of the end portion 38a.

  As shown in FIG. 4B (a), the flexible printed circuit board 21 is formed so that the conductive layer 21b does not reach the end 21a of the flexible printed circuit board 21, that is, in the vicinity of the end 21a of the flexible printed circuit board 21. You may be comprised so that 21b may not exist. In this case, as shown in FIG. 4B (b), only the portion of the flexible printed board 21 that does not include the conductive layer 21b can run on the overcoat layer 38. As a result, the flexible printed circuit board 21 is easily bent along the surface of the overcoat layer 38, thereby further suppressing the formation of a gap between the flexible printed circuit board 21 and the terminal portion 37. .

  Next, the operation and effect of the present embodiment having such a configuration will be described. Here, a method for manufacturing the touch panel sensor 30 and the touch detection module 18 will be described.

Method for Manufacturing Touch Panel Sensor First, the base material 31 is prepared. Next, the transparent conductive layer 41 is provided on the substrate 31, and then the transparent conductive layer 41 is patterned to form the first bulging portion 32a, the first line portion 32b, and the second bulging portion 33a. As the patterning method, for example, a photolithography method is used.

  Next, an insulating material containing a photosensitive material is provided on the first bulging portion 32a, the first line portion 32b, and the second bulging portion 33a, and then the insulating material is exposed and developed in a predetermined pattern. As a result, the above-described insulating layer 34 is formed. Next, a conductive material is provided on the insulating layer 34, and then the conductive material is patterned by a photolithography method, thereby forming the above-described second line portion 33b.

  Next, the process of forming the extraction conductive pattern 36, the terminal portion 37, and the overcoat layer 38 will be described with reference to FIGS. 5A to 5C.

  First, as shown in FIG. 5A, a laminated structure including the above-described transparent conductive layer 41, a metal layer 42 provided on the transparent conductive layer 41, and a resin material layer 43 provided on the metal layer 42 is prepared. To do. The resin material layer 43 includes a material for forming the overcoat layer 38, for example, an acrylic resin and a photosensitive material. The photosensitive material may be either a positive type or a negative type. Here, an example in which a negative type photosensitive material is used will be described.

  As the metal layer 42, a conductive material layer provided in the step of forming the second line portion 33b described above may be used. Alternatively, the metal layer 42 may be provided in a step different from the step of forming the second line portion 33b. As the resin material layer 43, an insulating material layer provided in the step of forming the insulating layer 34 described above may be used. Alternatively, the resin material layer 43 may be a layer provided in a process different from the process of forming the insulating layer 34 described above.

  Next, as shown in FIG. 5B, an exposure step of irradiating the resin material layer 43 with the exposure light L through the exposure mask 50 is performed. Here, a gradation mask capable of attenuating incident exposure light L with an arbitrary attenuation factor according to the position is used as the exposure mask 50. For this reason, as shown to FIG. 5B, distribution of the exposure light L which reduces continuously as it goes to the outer edge of the base material 31 is realizable.

  Thereafter, the exposed resin material layer 43 is developed. As a result, as shown in FIG. 5C, the touch panel sensor 30 having the overcoat layer 38 having a thickness corresponding to the intensity of the irradiated exposure light L, specifically, the tapered portion 38d described above can be obtained. it can. Then, the above-mentioned touch detection module 18 can be obtained by bonding the flexible printed circuit board 21 to the exposed portion 37 a of the terminal portion 37 of the touch panel sensor 30.

  Here, according to the present embodiment, the thickness of the portion of the overcoat layer 38 that contacts the exposed portion 37a of the terminal portion 37 (t2 of the adjacent portion 38c) is the average thickness of the overcoat layer 38 (the thickness of the flat portion 38b). It is smaller than t1). Further, the flexible printed circuit board 21 is joined to the exposed portion 37 a of the terminal portion 37 so that the end portion 21 a is located on the proximity portion 38 c of the overcoat layer 38. For this reason, it can suppress that the big level | step difference s arises between the touch panel sensor 30 and the flexible printed circuit board 21. FIG. Therefore, it is possible to suppress a reduction in productivity and workability of subsequent processes such as a transport process and a process of combining the touch detection module 18 and the display device 15. Moreover, according to this Embodiment, it can suppress that a space | gap is formed between the terminal part 37 and the flexible printed circuit board 21, and it can suppress that a corrosion and electromigration arise by this. .

First Comparison Mode Next, the effect of the present embodiment will be described in comparison with the first comparison mode. FIG. 6A is a longitudinal sectional view showing the touch panel sensor 130A and the flexible printed board 21 in the first comparative embodiment.

  In the touch panel sensor 130 </ b> A according to the comparative example shown in FIG. 6A, the overcoat layer 138 is provided on the terminal portion 37 with a uniform thickness, and the flexible printed circuit board 21 rides on the overcoat layer 138. . For this reason, the level | step difference s between 130A of touchscreen sensors and the flexible printed circuit board 21 has become large, and the big space | gap 45 has been formed between the terminal part 37 and the flexible printed circuit board 21. FIG.

  On the other hand, according to the present embodiment, as described above, the thickness of the adjacent portion 38c adjacent to the exposed portion 37a of the terminal portion 37 in the overcoat layer 38 is made smaller than the average thickness of the overcoat layer 38. As a result, the step can be reduced and the formation of voids can be suppressed.

Second Comparison Mode Next, the effect of the present embodiment will be described in comparison with the second comparison mode. FIG. 6B is a longitudinal sectional view showing the touch panel sensor 130B and the flexible printed circuit board 21 in the second comparative embodiment.

  Also in the touch panel sensor 130B according to the comparative form shown in FIG. 6B, the overcoat layer 138 is provided on the terminal portion 37 with a uniform thickness. On the other hand, the flexible printed circuit board 21 is bonded to the terminal portion 37 so as not to run over the overcoat layer 138. In this case, a gap is formed between the overcoat layer 138 and the flexible printed circuit board 21 as shown in FIG. 6B. That is, a portion that is not covered by either the overcoat layer 138 or the flexible printed circuit board 21 is generated in the terminal portion 37. In such a case, generally, as shown in FIG. 6B, a resin layer 47 that fills the gap is provided. Thus, in the second comparative embodiment, an extra process for forming the resin layer 47 occurs.

  On the other hand, according to the present embodiment, as described above, the thickness of the adjacent portion 38c adjacent to the exposed portion 37a of the terminal portion 37 in the overcoat layer 38 is made smaller than the average thickness of the overcoat layer 38. Thereby, the level | step difference between the touch panel sensor 30 and the flexible printed circuit board 21 can be reduced, without generating an extra process.

  Note that various modifications can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted. In addition, when it is clear that the operational effects obtained in the above-described embodiment can be obtained in the modified example, the description thereof may be omitted.

(Modification of the method for forming the overcoat layer)
In the above-described embodiment, the example in which the overcoat layer 38 including the tapered portion 38d is formed by using the exposure mask 50 configured as the gradation mask has been described. However, the method of forming the overcoat layer 38 including the tapered portion 38d is not limited to the exposure process using the gradation mask. For example, a coating liquid containing a resin material for forming the overcoat layer 38 and an appropriate solvent is applied onto the extraction conductive pattern 36 and the terminal portion 37 in a predetermined pattern, whereby the overcoat layer 38 is coated. May be formed. In this case, by appropriately adjusting the viscosity of the coating solution, the shape of the overcoat layer 38 can be made such that the thickness gradually decreases as it approaches the end 38a. That is, the above-described tapered portion 38d can be realized. A specific coating method is not particularly limited, and a known method such as a screen printing method can be appropriately used.

(Modification of the shape of the overcoat layer)
Further, in the above-described embodiment, the example in which the proximity portion 38c of the overcoat layer 38 is configured as the tapered portion 38d whose thickness decreases toward the exposed portion 37a of the terminal portion 37 is shown. However, as long as the thickness t2 of the proximity portion 38c is smaller than the thickness t1 of the flat portion 38b, and thereby the step s between the touch panel sensor 30 and the flexible printed board 21 can be reduced, the overcoat layer 38 has The specific shape of the proximity portion 38c is not particularly limited. For example, as shown in FIG. 7, the proximity portion 38c may be configured as a thickness reduction portion 38e having a reduced thickness compared to the flat portion 38b. In the example shown in FIG. 7 as well, the step s generated between the touch panel sensor 30 and the flexible printed circuit board 21 can be reduced compared to the case of the first comparative embodiment shown in FIG. 6A, and The gap 45 formed between the terminal portion 37 and the flexible printed board 21 can be reduced.
The method for forming the overcoat layer 38 shown in FIG. 7 is not particularly limited. For example, by performing an exposure process using a halftone mask as the exposure mask 50, the overcoat layer having the thickness reduction portion 38e. Layer 38 can be obtained.

(Modified example of transparent conductive pattern)
In the above-described embodiment, the transparent conductive patterns 32 and 33 are both provided on the display device 15 side surface or the viewer side surface of the base material 31. However, the present invention is not limited to this, and a transparent conductive pattern may be provided on both the display device 15 side surface and the viewer side surface of the base material 31. For example, the first transparent conductive pattern 32 may be provided on one surface of the substrate 31, and the second transparent conductive pattern 33 may be provided on the other surface of the substrate 31. Further, the extraction conductive pattern 36 and the terminal portion 37 may also be provided on both one surface and the other surface of the base material 31 according to the transparent conductive pattern. Also in this case, the above-described overcoat layer 38 having a reduced thickness is provided on the terminal portion 37 at a portion in contact with the exposed portion 37 a of the terminal portion 37. Thereby, it is possible to suppress the occurrence of a step between the touch panel sensor 30 and the flexible printed board 21 and to suppress the formation of a gap between the terminal portion 37 and the flexible printed board 21.

(Modification of base material)
Moreover, in the above-described embodiment, the example in which the touch panel sensor 30 having the base material 31 is combined with the protection plate 12 for protecting the touch panel sensor 30 and the display device 15 has been shown. However, the present invention is not limited to this, and although not shown, the base material 31 of the touch panel sensor 30 has a strength that can function as a protective plate for a display device, and Any of the transparent conductive patterns 32 and 33, the extraction conductive pattern 36, the terminal portion 37, and the overcoat layer 38 may be provided on the surface of the substrate 31 on the display device 15 side. In this case, the base material 31 of the touch panel sensor 30 not only supports the patterns such as the transparent conductive patterns 32 and 33 but can also play a role as protecting those patterns and the display device 15. The protective plate 12 can be omitted. That is, the touch panel sensor 30 may be a so-called cover glass integrated type.

  In addition, although some modified examples with respect to the above-described embodiment have been described, naturally, a plurality of modified examples can be applied in combination as appropriate.

DESCRIPTION OF SYMBOLS 10 Display apparatus with a touch function 12 Protection board 15 Display apparatus 18 Touch detection module 20 Touch panel apparatus 21 Flexible printed circuit board 21a End part 30 Touch panel sensor 31 Base material 32 1st transparent conductive pattern 33 2nd transparent conductive pattern 34 Insulating layer 36 Extraction conductive Pattern 37 Terminal portion 37a Exposed portion 38 Overcoat layer 38a End portion 38b Flat portion 38c Adjacent portion 38d Tapered portion 38e Thickness reducing portion 45 Void 47 Resin layer 50 Exposure mask

Claims (7)

A touch detection module comprising a touch panel sensor and a flexible printed circuit board bonded to the touch panel sensor,
The touch panel sensor
A substrate including an active area corresponding to an area where a touch position can be detected, and an inactive area located around the active area;
A transparent conductive pattern disposed in the active area of the substrate;
A terminal portion disposed in the inactive area of the base material and electrically connected to the transparent conductive pattern;
An overcoat layer provided on the terminal portion,
The overcoat layer is provided on the terminal part such that a part of the terminal part exists as an exposed part that is not covered by the overcoat layer,
The thickness of the portion of the overcoat layer that is in contact with the exposed portion of the terminal portion is smaller than the average thickness of the overcoat layer,
The touch detection module, wherein the flexible printed circuit board is bonded to the exposed portion of the terminal portion such that an end portion thereof is positioned on a portion of the overcoat layer that is in contact with the exposed portion of the terminal portion.   The touch detection module according to claim 1, wherein a portion of the overcoat layer that is in contact with the exposed portion of the terminal portion is configured as a tapered portion whose thickness decreases toward the exposed portion.   The touch detection module according to claim 1, wherein a thickness of a portion of the overcoat layer that is in contact with the exposed portion of the terminal portion is 30% or less of an average thickness of the overcoat layer.   The portion of the overcoat layer that is in contact with the exposed portion of the terminal portion is a portion that is located at a distance of 2.0 mm or less from the end portion of the overcoat layer on the exposed portion side. The touch detection module as described in any one of Claims. The base material of the touch panel sensor functions as a protective plate for a display device,
The transparent conductive pattern, the terminal portion, and the overcoat layer of the touch panel sensor are all provided on a surface on the display device side of the surface of the base material, according to any one of claims 1 to 4. The touch detection module described. A display device;
A touch panel sensor disposed on a display surface of the display device;
A flexible printed circuit board bonded to the touch panel sensor,
The touch panel sensor
A substrate including an active area corresponding to an area where a touch position can be detected, and an inactive area located around the active area;
A transparent conductive pattern disposed in the active area of the substrate;
A terminal portion disposed in the inactive area of the base material and electrically connected to the transparent conductive pattern;
An overcoat layer provided on the terminal portion,
The overcoat layer is provided on the terminal part such that a part of the terminal part exists as an exposed part that is not covered by the overcoat layer,
The thickness of the portion of the overcoat layer that is in contact with the exposed portion of the terminal portion is smaller than the average thickness of the overcoat layer,
The display device with a touch function, wherein the flexible printed circuit board is bonded to the exposed portion of the terminal portion so that an end portion thereof is located on a portion of the overcoat layer that is in contact with the exposed portion of the terminal portion. . A touch panel sensor used by being bonded to a flexible printed circuit board,
A substrate including an active area corresponding to an area where a touch position can be detected, and an inactive area located around the active area;
A transparent conductive pattern disposed in the active area of the substrate;
A terminal portion disposed in the inactive area of the base material and electrically connected to the transparent conductive pattern;
An overcoat layer provided on the terminal portion,
The overcoat layer is provided on the terminal part such that a part of the terminal part exists as an exposed part that is not covered by the overcoat layer,
The touch panel sensor, wherein a thickness of a portion of the overcoat layer that is in contact with the exposed portion of the terminal portion is smaller than an average thickness of the overcoat layer.

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