This application claims the benefit of Korean Patent Application No. 10-2011-0097497, filed on Sep. 27, 2011, entitled “Method of Manufacturing Touch Panel,” which is hereby incorporated by reference in its entirety into this application.
1. Technical Field
The present invention relates to a method of manufacturing a touch panel.
2. Description of the Related Art
With the development of computers using a digital technology, devices assisting computers have also been developed, and personal computers, portable transmitters and other personal information processors execute processing of text and graphics using a variety of input devices such as a keyboard and a mouse.
While the rapid advancement of an information-oriented society has been widening the use of computers more and more, it is difficult to efficiently operate products using only a keyboard and mouse currently serving as an input device. Therefore, the necessity for a device that is simple, has minimum malfunction, and is capable of easily inputting information has increased.
In addition, current techniques for input devices have progressed toward techniques related to high reliability, durability, innovation, designing and processing beyond the level of satisfying general functions. To this end, a touch panel has been developed as an input device capable of inputting information such as text, graphics, or the like.
This touch panel is mounted on a display surface of an image display device such as an electronic organizer, a flat panel display device including a liquid crystal display (LCD) device, a plasma display panel (PDP), an electroluminescence (El) element, or the like, or a cathode ray tube
(CRT) to thereby be used to allow a user to select desired information while viewing the image display device.
Meanwhile, the touch panel is classified into a resistive type touch panel, a capacitive type touch panel, an electromagnetic type touch panel, a surface acoustic wave (SAW) type touch panel, and an infrared type touch panel. These various types of touch panels are adapted for electronic products in consideration of a signal amplification problem, a resolution difference, a level of difficulty of designing and processing technologies, optical characteristics, electrical characteristics, mechanical characteristics, resistance to an environment, input characteristics, durability, and economic efficiency. Currently, the resistive type touch panel and the capacitive type touch panel have been prominently used in a wide range of fields.
ITO as the transparent electrode according to the prior art has been the most widely used for a plasma display panel (PDP), a liquid crystal display (LCD) device, a light emitting diode (LED) device, an organic light emitting display (OLED) device, a touch panel, a solar cell, or the like.
However, since indium oxide (In2O3) of the ITO is generated as by-product in a zinc (Zn) mine, the supply and demand thereof is unstable and the flexibility thereof lacks. Therefore, there is a problem in that the ITO is not used for a flexible material such as a polymer substrate, or the like. Further, there is a problem in that the ITO is manufactured only under a high temperature and high pressure environment to increase manufacturing costs. To solve the problems, many attempts to replace the ITO have been conducted. An electrode using CNT, grapheme, metal grid, metal wire, and conductive polymer is a result of these attempts. ITO substitute electrodes have various problems in terms of dispersion, filtering, printing line width, coating, or the like. In particular, when a mixture of metal and an organic-binder material is used, the metals are enclosed with organic materials, such that it is difficult to contact metals to each other. As a result, it is difficult to obtain uniform conductivity and to form fine patterning.
The present invention has been made in an effort to provide a method of manufacturing a transparent electrode capable of improving visibility of a touch panel and conductivity of a sensing electrode forming the touch panel and facilitating patterning by forming a mesh skeleton of a fabric-type non-conductive material by an electrospinning method and then, coating a surface of the touch panel by electroless plating, and a sensing electrode using the same.
According to a first preferred embodiment of the present invention, there is provided a method of manufacturing a touch panel, including: forming a non-conductive mesh skeleton on a transparent substrate using an electrospinning solution by an electrospinning method ; and forming an electrode layer on the non-conductive mesh skeleton by performing electroless plating processing.
The method of manufacturing a touch panel may further include after the performing of the electroless plating processing, patterning the electrode layer.
The patterning of the electrode layer may include: disposing a patterned mask on the electrode layer; and forming the sensing electrode by patterning the electrode layer by irradiating a laser thereto so as to correspond to the patterned mask.
The forming of the non-conductive mesh skeleton by the electrospinning method may include: providing the electrospinning solution to a capillary tube; disposing a current collector on the other surface of the transparent substrate; and forming the electrode layer by applying the spinning solution to one surface of the transparent substrate from the capillary tube by applying voltage between the spinning solution and the current collector.
The electrospinning solution may be a non-conductive polymer material and may include at least one selected from silicon resin, phenol resin, natural modified phenol resin, epoxy resin, polyvinyl alcohol-based resin, and cellulose-based resin.
The electrospinning solution may include at least one selected from polyolefin-based resin, styrene-based resin, and acrylic resin.
The electrospinning solution may include a seed material using at least one selected from tin (Sn), gold (Au), silver (Ag), copper (Cu), nickel (Ni), iron (Fe), cadmium (Cd), lead (Pb), rhodium (Rd), palladium (Pd), and rubidium (Ru) as a plating nucleus.
According to a second preferred embodiment of the present invention, there is provided a method of manufacturing a touch panel, including: applying a photoresist to one surface of a transparent substrate; patterning the photoresist by an exposure process and a developing process so that an opening part is formed; forming a non-conductive mesh skeleton by applying an electrospinning solution to the transparent substrate exposed from the opening part; forming an electrode layer by performing an electroless plating processing on the non-conductive mesh skeleton; and removing the photoresist.
The forming of the non-conductive mesh skeleton by the electrospinning method may include: providing the electrospinning solution to a capillary tube; disposing a current collector on the other surface of the transparent substrate; and forming the mesh skeleton by applying the spinning solution to one surface of the transparent substrate from the capillary tube by applying voltage between the spinning solution and the current collector.
The electrospinning solution may be a non-conductive polymer material and may include at least one selected from silicon resin, phenol resin, natural modified phenol resin, epoxy resin, polyvinyl alcohol-based resin, and cellulose-based resin.
The electrospinning solution may include at least one selected from polyolefin-based resin, styrene-based resin, and acrylic resin.
The electrospinning solution may include a seed material using at least one selected from tin (Sn), gold (Au), silver (Ag), copper (Cu), nickel (Ni), iron (Fe), cadmium (Cd), lead (Pb), rhodium (Rd), palladium (Pd), and rubidium (Ru) as a plating nucleus.
Various features and advantages of the present invention will be more obvious from the following description with reference to the accompanying drawings.
The terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept of the term to describe most appropriately the best method he or she knows for carrying out the invention.
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. In the specification, in adding reference numerals to components throughout the drawings, it is to be noted that like reference numerals designate like components even though components are shown in different drawings. In addition, the terms “first,” “second,” “one surface,” “the other surface” and so on are used to distinguish one element from another element, and the elements are not defined by the above terms. In describing the present invention, a detailed description of related known functions or configurations will be omitted so as not to obscure the gist of the present invention.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
A method of manufacturing a sensing electrode 125 of a touch panel according to a first preferred embodiment of the present invention includes forming a non-conductive mesh skeleton 121 on a transparent substrate 110 using an electrospinning solution by an electrospinning method (S10); and forming an electrode layer 120 on the non-conductive mesh skeleton 121 by performing electroless plating processing (S20).
The method of manufacturing a sensing electrode 125 further includes patterning the electrode layer 120 subjected to the electroless plating processing so as to be used as the sensing electrode 125 of the touch panel (S30). The patterning of the electrode layer 120 (S30) includes disposing a patterned mask 165 on the electrode layer 120; and forming the sensing electrode 125 by patterning the electrode layer 120 by irradiating a laser 160 thereto so as to correspond to the patterned mask 165. The preferred embodiment of the present invention shows the patterning by irradiating the laser 160. However, in this case, various patterning methods, such as a patterning method using chemical etching, or the like, in addition to the laser, may be selectively applied.
The forming of the non-conductive mesh skeleton 121 by the electrospinning method (S10) is performed including providing an electrospinning solution 130 to a capillary tube 140; disposing a current collector 150 on the other surface of the transparent substrate 110; and forming the electrode layer 120 by applying the spinning solution 130 to one surface of the transparent substrate 110 from the capillary tube 140 by applying voltage between the spinning solution 130 and the current collector 150.
As shown in
In detail, an example of a non-conductive material (polymer) may include silicon resin, phenol resin, natural modified phenol resin, epoxy resin, polyvinyl alcohol-based resin, cellulose-based resin, or the like, or modified materials such as polyolefin-based resin, styrene-based resin, acrylic resin, or the like, or surface treating materials by corona discharge, or the like.
A silane coupling agent as the coupling agent may be used. The silane coupling agent has a hydrolysable functional group generating a silanol group by hydrolysis. An example of the hydrolysable functional group may include alkoxy (—OR) group that is directly coupled with Si atom. R forming the alkoxy group is any one of linear, branched, and cyclic alkyl groups and may have a carbon number of 1 to 6. In detail, an example of the alkoxy group may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an iso-butyl group, sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclo pentyl group, a cyclo hexyl group, or the like.
The seed material for electroless plating may use at least one selected from tin (Sn), gold (Au), silver (Ag), copper (Cu), nickel (Ni), iron (Fe), cadmium (Cd), lead (Pb), rhodium (Rd), palladium (Pd), and rubidium (Ru) as a plating nucleus.
As the electrospinning process, a process of forming the non-conductive mesh skeleton 121 will be described in detail below. First, the spinning solution 130 is provided to the capillary tube 140 and the current collector 150 is disposed on the other surface (a surface opposite to one surface of the transparent substrate 110 to which the spinning solution 130 is applied) of the transparent substrate 110. Thereafter, 10 kV to 20 kV of voltage is supplied to the spinning solution 130 by a voltage supplier 155 and a predetermined voltage is applied between the spinning solution 130 and the current collector 150 by grounding the current collector 150. When the predetermined voltage is applied between the spinning solution 130 and the current collector 150, electric field is applied to fine drops of the spinning solution 130 hung to a distal end of the capillary tube 140 due to a surface tension, such that charges are induced to the surface of the fine drop. In this case, the mutual repulsive force of the induced charge is generated in an opposite direction to a surface tension of a fine drop. The fine drop of the spinning solution 130 hung to the distal end of the capillary tube 140 is modified to a Taylor cone 133 due to the mutual repulsive force of the charge and when the mutual repulsive force of the charge is stronger than the surface tension, a jet 135 of the spinning solution 130 with charges is discharged from the capillary tube 140. A solvent is volatized while the jet 135 of the spinning solution 130 goes into the air and the jet 135 of the spinning solution 130 is applied to one surface of the transparent substrate 110 in a web type to form the non-conductive mesh skeleton 121 on the entire surface of the transparent substrate 110. In this configuration, the non-conductive mesh skeleton 121 is formed in a web type through the electrospinning process and thus, may be implemented in a mesh type having a line width in a nanometer (nm) unit. Therefore, when the electrode layer 120 using the non-conductive mesh skeleton 121 is formed, it is difficult for a user to recognize the electrode layer 120 and the mesh type is irregularly formed to prevent the moiré phenomenon from occurring. Finally, the visibility of the touch panel 100 may be improved.
In addition, the process of forming the non-conductive mesh skeleton 121 by the electrospinning process does not necessarily use the single capillary tube 140 and provides different spinning solutions 130 to each capillary tube 140 by using the plurality of capillary tubes, thereby forming the electrode layer 120 by mixing several materials.
Meanwhile, the reason why the current collector 150 is disposed on the other surface of the transparent substrate 110 while performing the electrospinning process is that the current collector 150 cannot be grounded, since the transparent substrate 110 is an insulator. In this case, the material of the transparent substrate 110 may be made of polyethylene terephthalate (PET), polycarbonate (PC), poly methyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyethersulpon (PES), cyclic olefin polymer (COC), triacetylcellulose (TAC) film, polyvinyl alcohol (PVA) polyimide (PI) film, polystyrene (PS), biaxially stretched polystyrene (K resin containing biaxially oriented PS; BOPS), glass, tempered glass, or the like, but is not particularly limited thereto. For example, when the transparent substrate 110 is a flexible substrate such as polyethylene terephthalate (PET), the efficiency of the manufacturing process may be improved by a roll to roll process. In addition, when the transparent substrate 110 is a substrate having excellent support force such as glass or tempered glass, a large-area transparent substrate 110 is provided with the electrode layer 120 and then, may be cut into a cell unit. However, when the transparent substrate 110 is made of glass or tempered glass, the transparent substrate 110 is necessarily cut in a cell unit by using the large-area transparent substrate 110 and the transparent substrate 110 in the cell unit may be formed with the electrode layer 120, if necessary.
Next, as shown in
In the preferred embodiment of the present invention, the method of forming the electrode layer 120 using the electroless plating layer 122 attaches the seed material used as the plating nucleus to the surface of the non-conductive mesh skeleton 121 by attaching a treating solution including the silane coupling agent, a hydrolysis catalyst, and a metal salt to the non-conductive mesh skeleton 121 and then, precipitating the metal of the metal salt by a reducing agent. Thereafter, the electrode layer 120 may be formed by a method of precipitating metals on the surface of the mesh skeleton 121 by putting the mesh skeleton 121 into a plating bath. The silane coupling agent used in a method of forming a metal thin film according to the preferred embodiment of the present invention has a functional group forming chelate for the metal of the metal salt. An example of the functional group forming the chelate for the metal of the metal salt may include a polar group or a hydrophilic group. In detail, it is preferable that the functional group includes at least one selected from a nitrogen atom, a sulfur atom, and an oxygen atom. An example of the functional group may include at least one selected from a group consisting of —SH, —CN, —NH2, —SO2OH, —SOOH, —OPO (OH)2, and —COOH. The functional group may be one forming a salt. When the functional group is an acid group, such as —OH, —SH, —SO2OH, —SOOH, —OPO(OH)2, —COOH, or the like, an example of the salt may include alkali metal salt such as sodium, potassium, lithium, or the like, or an ammonium salt, or the like. Meanwhile, when the functional group is a base group such as —NH2, or the like, an example of the salt may include an inorganic acid salt such as hydrochloric acid, sulfuric acid, nitric acid, or the like, and an organic acid salt such as formic acid, acetic acid, propionic acid, trifluoro acetic acid, or the like. In addition, the seed material may use at least one selected from tin (Sn), gold (Au), silver (Ag), copper (Cu), nickel (Ni), iron (Fe), cadmium (Cd), lead (Pb), rhodium (Rd), palladium (Pd), and rubidium (Ru) used as the plating nucleus.
Alternatively, the electrode layer 120 may be formed by mixing the seed material for forming the electroless plating layer 122 with the electrospinning solution 130 for forming the non-conductive mesh skeleton 121, the mesh skeleton 121 using the electrospinning solution 130 by the electrospinning method, and then, immersing the mesh skeleton 121 in the plating bath to precipitate metals.
Next, as shown in
In addition, as the laser 160 patterning the electrode layer 120, a CO2 laser, a YAG laser, an excimer laser, a fiber laser, or the like, may be used, but is not limited thereto. Therefore, all the types of processing lasers known to the art may be used.
Meanwhile, as shown in
The sensing electrode 125 formed through the above-mentioned process generates signals when being touched by the input unit to allow the controller to serve to recognize touch coordinates.
Next, as shown in
The method of manufacturing a touch panel according to a second preferred embodiment of the present invention includes applying a photoresist 180 to one surface of the transparent substrate, patterning the photoresist 180 through an exposure process and a developing process so that an opening part 185 is formed, forming the non-conductive mesh skeleton 121 by applying the electrospinning solution 130 to the transparent substrate 110 exposed from the opening part 185; and forming the electrode layer 120 by performing the electroless plating processing on the non-conductive mesh skeleton 121.
The difference from the first preferred embodiment of the present invention is that the sensing electrode 125 of the touch panel is formed by performing the patterning using the photolithography process using the photoresist 180 and then, forming the non-conductive mesh skeleton 121 by the electrospinning method and forming the electroless plating layer 122, before the non-conductive mesh skeleton 121 is formed by the electrospinning method.
First, as shown in
Next, as shown in
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In the case of the touch panel 100 according to the preferred embodiment of the present invention, a self capacitive type touch panel or a mutual capacitive type touch panel may be manufactured using the sensing electrode 125 having 1-layer structure. However, the touch panel according to the preferred embodiment of the present invention is not limited thereto but may be manufactured in various types having the configurations, as described below.
As shown in
As set forth above, the preferred embodiments of the present invention can easily form the sensing electrodes of the touch panel using the flexible material by forming the mesh skeletons using the non-conductive electrospinning solution by the electrospinning method and forming the electrode layers on the mesh skeletons by the electroless plating.
In addition, the preferred embodiments of the present invention can implement the irregular mesh electrodes by forming the sensing electrodes having the mesh skeletons by the electrospinning method to prevent the moiré phenomenon while improving the visibility of the touch panel.
Further, the preferred embodiments of the present invention can improve the production and reduce the production lead time without performing the processes such as the deposition for forming the separate electrodes, or the like, by forming the non-conductive mesh skeletons by the electrospinning method and then, forming the electrode layers by the electroless plating.
Further, the preferred embodiments of the present invention can implement the uniform conductivity for all the electrode layers by preventing the irregular conductivity between the mesh skeletons by forming the non-conductive mesh skeletons by the electrospinning method and then, forming the electrode layers by the electroless plating.
Further, the preferred embodiments of the present invention can easily implement the fine patterning of the sensing electrodes by forming the non-conductive mesh skeleton by the electrospinning method and then, forming the electrode layers by the electroless plating.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, they are for specifically explaining the present invention and thus a method of manufacturing a touch panel according to the present invention is not limited thereto, but those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
Accordingly, any and all modifications, variations or equivalent arrangements should be considered to be within the scope of the invention, and the detailed scope of the invention will be disclosed by the accompanying claims.
Number | Date | Country | Kind |
---|---|---|---|
1020110097497 | Sep 2011 | KR | national |