JP2013020347A - Touch panel and touch panel manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection-type capacitive touch panel, through easy manufacturing processes, that is used by being overlaid on a display screen of a flat-panel display device, has a transparent cover sheet integrated therewith, and is excellent in performance.SOLUTION: A touch panel integrated with a transparent cover sheet 2 is provided on a visible side of a flat-panel display device with a sensor electrode side facing the flat-panel display device. A touch panel 1 includes: plural transparent conductive film patterns serving as sensor electrodes 3 disposed two-dimensionally; jumper parts 4 electrically connecting the transparent conductive film patterns with one another; insulation parts 5 for preventing electrical short circuits between layers at the jumper parts; and wiring parts 6 for guiding wiring from the sensor electrodes to a terminal part. The jumper parts and the wiring parts are configured by laminating plural layers including a good conductor metal layer 8 and having the same configuration and by lowering the reflectivity of the interface between the transparent cover sheet and the plural layers.

Description

  The present invention relates to a touch panel formed integrally with a cover sheet.

  The touch panel is a component of an input device that allows the operator to touch a transparent surface on the display screen with a finger or a pen to detect a touched position and input data. Intuitive input is possible. For this reason, in recent years, it has come to be frequently used in operation units of various electronic devices such as mobile phones, portable information terminals, and car navigation systems.

  The touch panel can be used as an input device on a display screen of a flat display device such as a liquid crystal panel. Many of such touch panels are combined with a transparent cover sheet using decorative glass, which is used for input instructions, etc., and is used for decoration and surface protection such as a frame and on the display screen of a flat display device. At the time of bonding to each other, contrivances have been made to ensure excellent display quality (see Patent Document 1 and Patent Document 2).

  There are various touch panel detection methods such as a resistance type, a capacitance type, an ultrasonic type, and an optical type, and the structures thereof are various. The resistance type is relatively excellent in terms of manufacturing cost and detection accuracy, and is widely used. However, a resistance type touch panel having a structure in which an air layer is provided between two transparent conductive films has optical characteristics (transmission). However, the durability and the operating temperature characteristics are not sufficient, so that improvement has been demanded. Capacitive touch panels that do not have moving parts have high optical characteristics (transmittance) and superior durability and operating temperature characteristics compared to resistance types. Development is progressing toward

  Capacitive touch panels can be broadly classified into surface types and projection types. Surface types can be projected onto large items of size 10 and above (screen diagonal 25.4 cm size) or larger, and can be projected onto small items of size 6 or less for portable devices. A type is often used. As an electrode plate for a capacitive touch panel, a surface type that does not require a complicated pattern and has a simple structure is composed of a transparent substrate, a transparent conductive film, a simple terminal electrode pattern, and an insulating film. It is difficult to simultaneously detect contact points that are greater than or equal to a point. On the other hand, the structure of the electrode plate for the capacitive touch panel is such that the first transparent electrode pattern layer, the first insulating layer, the second transparent electrode pattern layer, and the metal electrode pattern layer serving as the terminal electrode are formed on the transparent substrate. There is also a projection type in which each layer is generally formed in this order in a laminated structure with two insulating layers. The projection type has a complicated structure and is suitable for a small size, but can detect two or more contact points simultaneously.

Moreover, as shown in the schematic diagram of the configuration of the flat display device with a touch panel in FIG. 3, the form in which the projected capacitive touch panel is used on the display screen of the flat display device is as shown in FIG. Apart from the touch panel independent type, there is also a cover glass integrated type shown in FIG. 3B, and the latter can be thinned as a whole with a simple configuration. That is, in FIG. 3A, an independent type is provided on the display surface side of the flat display device including the liquid crystal 23, the TFT element substrate 22, the color filter substrate 24, and the polarizing plates 21 and 25 via the air gap 26. The touch panel 12 is bonded, and a transparent cover sheet represented by a cover glass (front plate) 15 for providing a decorative pattern such as a frame 16 on the front surface to protect the surface is provided.
On the other hand, in the cover glass integrated type shown in FIG. 3B, the cover glass integrated touch panel 13 is bonded to the display surface side of the flat display device having the same configuration as the former through the same air gap 26. In addition, since the position of the board | substrate which directly supports a pattern has the reverse relationship in FIG. 3A and FIG. Note that the direction of is opposite.

  The electrode structure of the projected capacitive touch panel has been improved for simplification. As shown in the example of the transparent cover sheet integrated type represented by the cover glass integrated type in FIG. A plurality of transparent conductive film patterns which are two-dimensionally arranged sensor electrodes 3 on the same plane of the sheet 2, a jumper portion 41 for electrically connecting the transparent conductive film patterns, and an electrical short circuit between the layers at the jumper portion The insulating part 5 for preventing and the wiring part 61 that leads the wiring from the sensor electrode to the terminal part are configured. Of the above components, the operation plane area of the touch panel used over the effective area of the display screen of the flat display device is preferably as transparent as possible. Therefore, a transparent material is used for the jumper portion 41 and the insulating portion 5. Use. For example, the jumper portion 41 is formed separately using a transparent conductive film such as ITO (indium tin oxide), which is the same as the sensor electrode 3, after the transparent insulating portion is formed. On the other hand, since the wiring part leading to the terminal part outside the effective display area and reaching the terminal part places importance on conductivity rather than transparency, a metal material having better conductivity than ITO is used. Specifically, a thin film laminated material having a three-layer structure of molybdenum film 71 / aluminum film 81 / molybdenum film 91 is used in order from the surface of the transparent cover sheet 2.

  FIG. 2B shows a three-layer structure of molybdenum film / aluminum film / molybdenum film constituting the terminal part and the wiring part leading to the terminal part. Adhesion between the transparent cover sheet and the second layer of metal on the surface of one side corresponding to the display device side of the transparent cover sheet, which is often used as a cover glass, which is to be provided relative to the display screen of the flat display device The lower layer molybdenum film 71 as a protective metal layer that improves the properties and reinforces the resistance to various environments as a thin film is the first layer, the aluminum film 81 that has good conductivity and is suitable for fine patterning is the second layer, The uppermost molybdenum film 91 as a protective metal layer that reinforces mechanical strength and resistance to various environments is laminated as the third layer, and a wiring pattern is formed by forming a resist pattern by photolithography and etching.

JP 2007-178758 A JP 2009-069321 A

  As mentioned above, a touch panel with good performance can be made in a simple manufacturing process by making improvements to simplify the electrode structure in the capacitive touch panel or by simplifying the entire touch panel integrated type. However, since the structure of the insulating part and the jumper part for three-dimensionally connecting the sensor electrodes regularly arranged on the same plane is indispensable, the manufacturing process has been simplified.

  The present invention is proposed in view of the above-mentioned problems, and the problem to be solved by the present invention is that it is used by being superimposed on a display screen of a flat display device, and is a projection type integrated with a transparent cover sheet. In the capacitive touch panel, it is to provide a touch panel with excellent performance by a simple manufacturing process.

As a means for solving the above-mentioned problems, in the invention described in claim 1, the sensor electrode side is provided on the viewing side of the flat display device so as to be integrated with the transparent cover sheet and relative to the flat display device. A touch panel, wherein the touch panel prevents a plurality of transparent conductive film patterns that are two-dimensionally arranged sensor electrodes, a jumper portion that electrically connects between the transparent conductive film patterns, and an electrical short circuit between layers in the jumper portion It consists of an insulating part and a wiring part that leads the wiring from the sensor electrode to the terminal part, and the jumper part and the wiring part are laminated with the same configuration including a good conductive metal layer, and the transparent cover sheet and the multilayer It is a touch panel characterized by having a low reflectance at the interface.

  The invention described in claim 2 is characterized in that a multilayer having the same configuration is composed of three layers of a protective metal oxide layer, a good conductor metal layer, and a protective metal layer in order from the transparent cover sheet side. It is a touchscreen as described in.

  The invention according to claim 3 is characterized in that the protective metal oxide layer, the good conductor metal layer, and the protective metal layer are each composed of a molybdenum oxide film, an aluminum film, and a molybdenum film. It is a touch panel.

  According to the invention described in claim 4, after the layers constituting the jumper part and the wiring part are laminated on one surface of the transparent cover sheet, both parts are collectively formed by photolithography and etching. It is formed, It is a manufacturing method of the touch panel in any one of Claims 1-3 characterized by the above-mentioned.

  The invention according to claim 5 is the touch panel manufacturing method according to claim 4, wherein the step of forming the jumper portion and the wiring portion at once, the step of forming the insulating portion, the transparent conductive film pattern This is a method for manufacturing a touch panel, characterized in that the steps of forming are performed in this order.

In the configuration of each part of the touch panel in which the sensor electrode side is provided so as to be opposed to the flat display device by integrating the transparent cover sheet on the viewing side of the flat display device, the jumper portion and the wiring portion are good. Since the multilayer of the same configuration including the conductor metal layer is laminated, and the interface between the transparent cover sheet and the multilayer is reduced in reflectance,
A projection type capacitive touch panel integrated with a transparent cover sheet, which is used by being superimposed on the display screen of a flat display device, can provide a touch panel with excellent performance in a simple manufacturing process.

It is a schematic diagram for demonstrating the structure of an example of the touchscreen of this invention, Comprising: (a) shows the top view which expanded a part of main part, (b) is the same with a jumper part and a wiring part. A cross-sectional view of the configuration is shown. It is a schematic diagram for demonstrating the structure of an example of the conventional touch panel, Comprising: (a) shows the top view which expanded a part of main part, (b) shows sectional drawing of the structure of a wiring part. . It is a structure schematic diagram for comparing the structure of two types of flat display devices with a touch panel, (a) is a touch panel independent type, (b) shows a cover glass integrated type. BRIEF DESCRIPTION OF THE DRAWINGS It is a process order schematic diagram for demonstrating an example of the manufacturing method of the touchscreen of this invention, (a) is the process of forming a jumper part and a wiring part collectively, (b) is adding an insulation part. Step (c) of forming shows a step of additionally forming a transparent conductive film pattern which is a sensor electrode. It is process order schematic diagram for demonstrating an example of the manufacturing method of the conventional touch panel, Comprising: (a) is the process of pattern-forming a wiring part, (b) is forming the transparent conductive film pattern which is a sensor electrode additionally (C) shows a step of additionally forming an insulating portion, and (d) shows a step of additionally forming a jumper portion. It is a graph of the measurement result of the spectral reflectance for comparing the effect of low reflectance of the multilayer film in the composition of the present invention with the conventional example. It is a conceptual diagram which shows the measuring method of a spectral reflectance, Comprising: (a) is how to determine a reference, (b) is the measuring method of the conventional multilayer film, (c) is the measurement of the multilayer film which comprises this invention Is the method.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
1A and 1B are schematic views for explaining a configuration of an example of a touch panel according to the present invention. FIG. 1A is a plan view showing an enlarged part of a main part, and FIG. 1B is a jumper part and wiring. Sectional drawing of the same structure as a part is shown.

  The present invention is a touch panel that is integrated with a transparent cover sheet 2 on the viewing side of a flat display device and has a sensor electrode side facing the flat display device, and the touch panel 1 is formed in a two-dimensional matrix. A plurality of transparent conductive film patterns which are the arranged sensor electrodes 3, a jumper portion 4 for electrically connecting three-dimensionally between the transparent conductive film patterns in the horizontal direction in the figure, and an electrical short circuit between layers in the jumper portion are prevented. The insulating part 5 and the wiring part 6 which leads the wiring from the sensor electrode to the peripheral part in the vertical and horizontal directions and reaches the terminal part (not shown) are configured. The jumper part 4 and the wiring part 6 are made of a good conductor metal. A multilayer having the same configuration including the layer 8 is laminated, and the interface between the transparent cover sheet and the multilayer is reduced in reflectance.

  The multilayer having the same configuration corresponds to a configuration in which the conductivity in the wiring portion 6 is increased and the visibility in the jumper portion 4 is decreased. As a measure for increasing the conductivity, it is effective to include the good conductive metal layer 8 in the multilayer having the same configuration, and as a measure for reducing the visibility, the reflectance when viewed from the viewing side is effective. This is because it is effective to reduce the size. Reducing the reflectance when viewed from the viewing side can be achieved by the light interference effect by providing the metal oxide layer 7 between the metal layer 8 and the transparent cover sheet that increase the reflectance.

  In the conventional wiring part 61 shown in FIG. 2, the adhesiveness between the transparent cover sheet 2 and the second layer metal is improved on one surface corresponding to the display device side of the transparent cover sheet 2 that often uses a cover glass. A protective metal layer 71 that reinforces resistance to various environments as a thin film is provided. On the other hand, in this example, instead of the protective metal layer 71, a protective metal oxide layer 7 is provided in order to add a function of reducing the reflectance when viewed through the transparent cover sheet 2 to the above function. . Also, the good conductor metal layer 81 and the protective metal layer 91 provided in the conventional wiring part 61 are the same as the good conductor metal layer 8 for good conductivity and the mechanical strength. The protective metal layer 9 that reinforces the improvement and resistance to various environments can be formed in multiple layers, and in this example, it can be formed in the jumper portion 4 in addition to the wiring portion 6. That is, the above layers can be laminated in three layers of the protective metal oxide layer 7, the good conductor metal layer 8, and the protective metal layer 9 in order from the transparent cover sheet side. In addition to the above three layers, the present invention does not exclude the sandwiching of an intermediate layer, for example, for further improvement of adhesion and patterning shape.

  Further, the present invention can be configured such that the three layers of the protective metal oxide layer 7, the good conductor metal layer 8, and the protective metal layer 9 are a molybdenum oxide film, an aluminum film, and a molybdenum film, respectively. These specific films have the characteristics that each of the above-mentioned layers should have, and the film formation can be easily performed with high quality by a vacuum film forming technique such as sputtering, and photolithography and etching. Patterning means based on the method can be suitably employed.

The present invention is not limited to the molybdenum oxide film, the aluminum film, and the molybdenum film as specific films to be used, but the protective metal oxide layer 7 and the protective metal layer 9 are made of a common metal. Use in the base is preferable in terms of production.
In this example, when forming a multilayer film composed of three layers of the molybdenum oxide film 7, the aluminum film 8, and the molybdenum film 9 by the sputtering method, a sputtering target is prepared by two elements of molybdenum and aluminum, and the oxide film is formed. Reactive sputtering in which a certain amount of oxygen gas is introduced during film formation is possible without adding a source power source.

In addition, the touch panel manufacturing method of the present invention is formed by laminating the layers constituting the jumper portion 4 and the wiring portion 6 on the surface of one side of the transparent cover sheet 2, and then performing both by the photolithography method and the etching method. The portion is formed in a lump. Conventionally, different layers are provided in the jumper portion 4 and the wiring portion 6 and a separate pattern is formed. However, according to the present invention, the manufacturing process can be shortened.

4A and 4B are schematic views in order of steps for explaining an example of the touch panel manufacturing method of the present invention. FIG. 4A is a step of forming the jumper portion 4 and the wiring portion 6 in a lump; FIG. 5C shows the step of additionally forming the insulating portion 5, and FIG. 5C shows the step of additionally forming the transparent conductive film pattern 3 that is a sensor electrode in the order of forming each in alignment with one side of the transparent cover sheet 2. Further, FIG. 5 shown for comparison is a schematic diagram in order of steps for explaining an example of a conventional method for manufacturing a touch panel, in which (a) is a step of patterning the wiring part 61, and (b) is , A step of additionally forming the transparent conductive film pattern 3 as the sensor electrode, (c) a step of additionally forming the insulating portion 5, and (d) a step of additionally forming the jumper portion 41 as the second transparent conductive film pattern. The steps are shown in the order in which the steps are aligned with one side of the transparent cover sheet 2.
Although not shown, both the above-described method of the present invention and the conventional method can apply and form a uniform protective film with a transparent resin or the like as the final step.

  As shown in FIG. 4, the touch panel manufacturing method of the present invention includes (a) a step of forming the jumper portion 4 and the wiring portion 6 in a lump, (b) a step of forming the insulating portion 5, and (c) a transparent conductive material. The step of forming the film pattern 3 is performed in this order. If a film formation by a series of film formation or coating and a pattern formation using a photolithographic method are viewed as a set of large steps, the number of steps is reduced from four to three compared to the manufacturing method shown in FIG. Moreover, the formation order of each part which comprises a touch panel changes. That is, in this example, the jumper portion 4 is formed before the formation of the transparent conductive film pattern 3 that is a sensor electrode. The reason for this is that, in this example, in order to form the jumper portion 4 and the wiring portion 6 in a lump, not only is performed prior to the formation of the transparent conductive film pattern 3, but also a protective metal using a molybdenum oxide film. When the entire pattern of the oxide layer 7 is formed directly on the transparent cover sheet 2, the high reflectivity of the good conductive metal layer is higher than the area where the transparent conductive film is partially sandwiched. This is because the visibility can be reduced uniformly and the visibility can be reduced uniformly.

  The touch panel manufacturing method of the present invention will be described in more detail. (A) The multilayer film formation of the same configuration described above for forming the jumper section 4 and the wiring section 6 is performed, and the photoresist is applied, exposed and developed. , A subsequent photolithography method, and subsequent etching and removal of residual resist. Next, (b) a photosensitive resin material for forming the insulating portion 5 is applied, and a pattern is formed by aligning with the jumper portion 4 by photolithography. Next, (c) the transparent conductive film pattern 3 which is a sensor electrode is subjected to photo resist patterning by photolithography on the premise of alignment with the pattern position of the previous process after the ITO film is formed, for example, and then etched And can be formed through removal of residual resist.

  FIG. 6 is a graph of spectral reflectance measurement results for comparing the effect of lowering the reflectance of a multilayer film in the configuration of the present invention with a conventional example. FIG. 7 is a conceptual diagram showing a spectral reflectance measurement method, where (a) shows how to determine a reference, (b) shows a conventional multilayer film measurement method, and (c) shows the present invention. It is a measuring method of the multilayer film to comprise.

  The spectral reflectance can be measured using a commercially available spectrophotometer. As shown in FIG. 7 of the conceptual conceptual diagram, the radiated light (solid line display) from the light source (monochromator) is irradiated to the measurement sample, and in FIG. The received light (indicated by solid arrows) is received by the light receiving unit 32 and the intensity of the light is measured. Spectral reflectance is measured by continuously changing the wavelength of spectral irradiation light from the monochromator. A reference in measurement is an aluminum single layer film 80. That is, 100% of the reference for each measurement sample thereafter is the strength obtained with the aluminum single layer film 80. As shown in FIG. 7B, as an example of a conventional multilayer film, a multilayer film composed of a molybdenum film 71, an aluminum film 81, and a molybdenum film 91 formed on the transparent cover sheet 2 is formed on the transparent cover sheet 2. Next, as shown in FIG. 7C, as an example of a multilayer film constituting the present invention, a molybdenum oxide film 7, an aluminum film 8 and a molybdenum film formed on the transparent cover sheet 2 are measured. The multilayer film composed of the film 9 is measured from the surface where the transparent cover sheet 2 is not formed.

  As shown in FIG. 6, the multilayer film constituting the present invention can reduce the reflectance in the entire visible light region as compared with the conventional multilayer film. The measurement result in the ultraviolet region with a wavelength of less than 400 nm is not referred to because it does not show an accurate value in this measurement result. The shape of the spectral reflectance curve by the multilayer film according to the present invention, which has a low reflectance due to the light interference effect between the metal oxide layer and the metal layer, is determined by the refractive index characteristics and film thickness of the metal oxide layer used. However, it can be made lower than the reflectance of the conventional multilayer film.

  Next, Table 1 shows the result of comprehensive comparison of the multilayer film constituting the present invention with the conventional multilayer film. For each evaluation item, the pass / fail judgments with respect to the judgment criteria are shown in the table by ○ ×. When the multilayer film constituting the present invention is represented by an average reflectance at a wavelength of 500 to 600 nm and compared, the reflectance shows a marked improvement over the conventional multilayer film, while the etching time, sheet resistance value, It can be seen that the various items of adhesion are equivalent.

  The present invention lowers the reflectance of the interface between a transparent substrate and a multilayer film wiring pattern by a simple method, and reduces the visibility of the wiring pattern from the surface where the transparent substrate multilayer film is not provided. be able to. A similar measure can be easily considered to improve the characteristic quality related to the display performance of other electronic components and the like. For example, the visibility of the auxiliary wiring pattern including a metal layer for further reducing the resistance of the transparent conductive film can be reduced. In addition, the range in which the metal layer can be applied to various wiring patterns in electronic components, including wiring related to display devices in general, can be expanded, and the degree of freedom in product design can be greatly increased.

DESCRIPTION OF SYMBOLS 1, 11 ... Touch panel 2 ... Transparent cover sheet 3 ... Sensor electrode (transparent conductive film pattern)
4, 41 ... Jumper part 5 ... Insulating part 6, 61 ... Wiring part 7 ... Protective metal oxide layer (molybdenum oxide film)
71 ... Protective metal layer (molybdenum film)
8, 81 ... good conductor metal layer (aluminum film)
9, 91 ... Protective metal layer (molybdenum film)
DESCRIPTION OF SYMBOLS 10 ... Viewing side 12 ... Independent touch panel 13 ... Cover glass integrated touch panel 15 ... Cover glass (front plate)
16 ... Frame 21, 25 ... Polarizing plate 22 ... TFT element substrate 23 ... Liquid crystal 24 ... Color filter substrate 26 ... Air gap 31 ... Light source (monochromator)
32... Light receiving portion 80... Aluminum single layer film

Claims (5)

A touch panel that is integrated with the transparent cover sheet on the viewing side of the flat display device and the sensor electrode side is provided relative to the flat display device,
A touch panel having a plurality of transparent conductive film patterns that are two-dimensionally arranged sensor electrodes, a jumper portion that electrically connects the transparent conductive film patterns, an insulating portion that prevents an electrical short circuit between layers in the jumper portion, and a sensor It consists of a wiring part that leads the wiring from the electrode to the terminal part, and the jumper part and the wiring part are laminated with a multilayer of the same configuration including a good conductor metal layer, and the interface between the transparent cover sheet and the multilayer is reduced. A touch panel characterized by having a reflectivity.   The touch panel according to claim 1, wherein the multilayer having the same configuration includes three layers of a protective metal oxide layer, a good conductor metal layer, and a protective metal layer in order from the transparent cover sheet side.   The touch panel according to claim 2, wherein the protective metal oxide layer, the good conductor metal layer, and the protective metal layer are each composed of a molybdenum oxide film, an aluminum film, and a molybdenum film.   The layer comprising the jumper part and the wiring part is laminated on one side surface of the transparent cover sheet, and then both parts are collectively formed by a photolithography method and an etching method. The manufacturing method of the touchscreen in any one of 1-3. It is a manufacturing method of the touch panel according to claim 4,
A method for manufacturing a touch panel, wherein a step of collectively forming a jumper portion and a wiring portion, a step of forming an insulating portion, and a step of forming a transparent conductive film pattern are performed in this order.