KR20200045776A - Method for Manufacturing Touch Panel - Google Patents

Abstract

The present invention relates to a method for manufacturing a touch panel. The method for manufacturing a touch panel of the present invention can provde a touch panel for suppressing the occurrence of local curls or steps and improving flatness to improve the performance and quality of a touch function without malfunction due to poor patterns in handling a large-sized substrate film sheet in a process of manufacturing a touch panel in various ways. The method for manufacturing a touch panel comprises the steps of: attaching a transparent conductive film onto a carrier by using an adhesive; forming and patterning a photosensitive layer on the transparent conductive film; and forming a pattern for a conductive material on the transparent conductive film based on an exposure process.

Description

Method of manufacturing a touch panel {Method for Manufacturing Touch Panel}

The present invention relates to a touch panel and a display device including the same, and more particularly, to a touch panel having improved flatness of a flexible substrate and a display device including the same.

A touch panel for a touch screen is an input device for detecting a finger tip or a contact position of a stylus pen, and may be divided into a touch panel such as a resistive film, capacitance, ultrasonic wave, or optical method according to the structure and detection method. Among these methods, a capacitive touch panel having excellent accuracy, durability, transmittance, stability, and resolution characteristics has become the mainstream. Recently, much attention has been focused on a flexible (or foldable) touch screen module capable of folding or bending a screen. Flexible substrates used in flexible (or foldable) touch panels include flexible materials such as PET and PC. And, the thickness of the substrate is selected to a thin thickness of 3, 6, 12, 23, 50, 100 μm, etc. in consideration of optical properties, weight, and the like, and an ITO thin film sputtered and deposited on such a substrate is used as a transparent electrode, When a metal wiring electrode is required, a metal thin film such as Cu or Ag is selectively sputtered on the ITO thin film. In order to impart the function of the touch panel, a circuit is formed through a photo-lithography process such as photoresist coating or lamination, exposure, development, etching, and peeling of a photosensitive film.

In the conventional touch panel manufacturing method, during the photolithography process as described above, a sheet-sized substrate film, such as 500x500mm to 1000x1000mm, was placed on the equipment stage to carry out the process. In addition, the film sheet is handled manually by a human hand in the process-to-process movement.

However, when a film sheet having a thickness of several to several tens of μm and a size of several hundred mm is placed on a process equipment stage, local curls or steps may occur. Due to these local curls or steps, variations in CD (Critical Dimensions) or defects in circuit patterns occur, especially in recent years as CDs have been miniaturized to a few μm, the effect of this substrate flatness is amplified. As a result, the importance of substrate flatness is increasing in the quality of the touch panel. In addition, contamination or damage of the film sheet occurs due to manual handling of the film sheet having a large size, thereby causing defects.

In order to achieve the above technical problem, the present invention suppresses local curls or step occurrences and improves flatness in handling large-sized substrate film sheets in various types of touch panel manufacturing process, and improves flatness, thereby providing a function of touch without malfunction due to pattern defects. An object of the present invention is to provide a touch panel for improving performance and quality.

In order to achieve the above technical problem, a method of manufacturing a touch panel of the present invention includes attaching a transparent conductive film using an adhesive on a carrier; Forming and patterning a photosensitive layer on the transparent conductive film; And forming a pattern for the conductive material on the transparent conductive film based on the exposure process.

The manufacturing method of the touch panel is characterized in that the transparent conductive film is moved and processed on the carrier without manual movement between equipment movement for an exposure process, a cleaning process, an etching process, or a photosensitive layer peeling process.

The transparent conductive film may include a film formed of a transparent conductive material on a flexible transparent substrate.

Alternatively, the transparent conductive film may include a film on which a transparent conductive material and an opaque wiring material are sequentially formed on a flexible transparent substrate.

Furthermore, before forming the photosensitive layer, the method may further include forming an opaque wiring material on the transparent conductive film on which the transparent conductive material is formed on the flexible transparent substrate.

Before forming the photosensitive layer, the method may further include measuring a flatness of the transparent conductive film attached on the carrier using a laser displacement sensor.

The difference between the maximum height and the minimum height among the heights measured at predetermined one-dimensional or two-dimensional intervals with respect to the entire surface of the transparent conductive film may be measured as the flatness.

The manufacturing method of the touch panel is characterized in that the flatness of the transparent conductive film attached on the carrier is performed in a process of 200 μm or less.

The carrier may be made of glass, ceramic, plastic or metal.

The adhesive may include a coated form of a liquid adhesive solution, a double-sided adhesive tape form having an adhesive formed on both sides of a film substrate, or a adhesive tape form without a film base.

The thickness of the transparent conductive film is preferably 300 μm or less.

According to the method of manufacturing a touch panel of the present invention, in handling a large substrate film sheet, by suppressing local curls or step generation and improving flatness, touch panels such as resistive films, ultrasonic waves, and optical methods as well as capacitive methods are improved. Providing a touch panel that realizes excellent touch function by achieving stable performance and quality without malfunction due to pattern defects such as curl, step difference, disconnection, CD deviation of electrode materials such as ITO, metal mesh, and nanowire on the substrate during the manufacturing process. You can.

1 is a process flow chart for explaining a method of manufacturing a touch panel according to an embodiment of the present invention.
2 is a view for explaining a conductive material in a screen area and a bezel area of a touch panel according to an embodiment of the present invention.
3 is a view for explaining the definition of the flatness of the present invention.
4 is a view for explaining an example of the flatness measurement process of the present invention.
5 is a comparative example of an electrode pattern in the case of the touch panel substrate of the present invention and in the case of the conventional touch panel substrate.

Hereinafter, the present invention will be described by describing preferred embodiments of the present invention with reference to the drawings.

1 is a process flow chart for explaining a method of manufacturing a touch panel according to an embodiment of the present invention.

Referring to FIG. 1, a method of manufacturing a touch panel according to an embodiment of the present invention includes attaching a transparent conductive film 130 using an adhesive member 120 on a carrier 110 (FIG. )), The step of performing an exposure process to form and pattern a photosensitive layer (PR) on the transparent conductive film 130 (Fig. 1 (b)), and the step of patterning the conductive material on the transparent conductive film 130 (Fig. 1 (c)).

In the present invention, by attaching the transparent conductive film 130 on the carrier 110, and performing a process for manufacturing the touch panel, the equipment for the touch panel manufacturing process such as an exposure process, a cleaning process, an etching process, or a photosensitive layer peeling process is moved. The transparent conductive film 130 was moved and processed on the carrier 110 without manual movement of the liver. Each touch panel manufacturing process such as an exposure process, a cleaning process, an etching process, or a photosensitive layer peeling process may be performed in the same equipment by any two or more processes (e.g., cleaning, photosensitive layer peeling, etc.). Because it has the specificity of equipment, it is implemented in different equipment.

First, in Figure 1 (a), the carrier 110 is made of a glass, ceramic, plastic or metal material, etc., so as to impart rigidity to the transparent conductive film 130, the thickness of which is dozens μm without particular limitation It can be manufactured and used to several mm. The size of the top surface of the carrier 110 is a size capable of seating the sheet size of the transparent conductive film 130 without any particular limitation, and may be manufactured to a degree greater than the width / length of several tens of centimeters. For example, in order to seat the sheet size of the transparent conductive film 130, such as 500x500mm to 1000x1000mm, it may be manufactured to a degree greater than a few tens of cm in width / length. Here, in the case of glass, materials such as soda lime glass and alumina silicate glass may be used, and tempered glass to which methods such as chemical strengthening and thermal strengthening are applied may be used, or non-tempered glass may be used.

In addition, in Figure 1 (a), the pressure-sensitive adhesive member 120, the form of coating the liquid adhesive solution on the carrier 110, the form of using a double-sided adhesive tape having an adhesive formed on both sides of the film base material, or film base material It may be formed on the carrier 110 in the form of using a missing adhesive tape. The adhesive formed in the form of a liquid adhesive solution or a tape may be an acrylic or silicone-based adhesive. In a functional aspect, as the pressure-sensitive adhesive, it is possible to apply a temperature-sensitive pressure-sensitive adhesive whose adhesive strength changes with temperature, and a pressure-sensitive adhesive whose adhesive strength changes with ultraviolet irradiation. The liquid adhesive solution may be coated on the carrier 110 by spraying, slit, spin, or an inkjet method to form an adhesive member 120, and the film / tape type adhesive member 120 is provided on the carrier 110. It can be used by attaching it to a lamination method.

In Figure 1 (a), the transparent conductive film 130 attached through the adhesive member 120 formed on the carrier 110 is preferably applied to the touch screen with a thickness of 300 μm or less, but is not limited thereto. It can also be of a larger thickness as needed. The transparent conductive film 130 may be in the form of a film in which a transparent conductive material for a sensing electrode is formed on a flexible (or foldable) transparent substrate. For example, a flexible (or foldable) transparent substrate for an electrostatic capacitive method is PET (Polyethylene Terephthalate), PEN (Polyethylene naphthalate), PE (Polyethylene), PI (Polyimide), PC (Poly Carbonate), COP (cyclo) It may be in the form of an olefin polymer (PP), poly propylene (PP), colorless polyimide (CPI) film. The film form may be formed using a biaxial stretching method or a liquid coating solution. Transparent conductive materials include indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), fluorine Containing tin oxide (FTO, fluorine-doped tin oxide), zinc tin oxide (ZTO), tin oxide (SnO ₂ ), conductive polymer such as PEDOT: PSS, carbon nanotube (CNT, carbon nanotube), metal Mesh (Metal Mesh), silver nanowires (Ag Nano Wire), may be made of graphene (graphene) or a mixture of these. In addition, the transparent conductive material, a form in which the above-described transparent oxide electrode and metal metal are synthesized may also be applied. For example, the transparent conductive material may be composed of a transparent conductive film composed of ITO having a thickness of 20 nm, Ag (silver) having a thickness of 10 nm, and ITO having a thickness of 20 nm.

In addition, the transparent conductive film 130 sequentially forms a transparent conductive material for a sensing electrode and an opaque wiring material (dP, Cu, Ag, Ni, Ti, Cr, Mo, Fe, etc.) for the wiring electrode on the flexible transparent substrate. It may be in the form of a film. However, in order to pattern the wiring electrode in addition to the sensing electrode, the transparent conductive film 130 sequentially forming a transparent conductive material and an opaque wiring material may be used, but in some cases, the transparent conductive film 130 formed only of a transparent conductive material ) Is attached on the carrier 110, and the opaque wiring material may be formed in various ways before step (b) of FIG. 1. For example, to form an opaque wiring material, physical vapor deposition, chemical vapor deposition, atomic layer deposition, electrolytic plating, electroless plating, spin coating, gravure printing, inkjet printing, silk screen printing, etc. It can be deposited or deposited. Here, physical vapor deposition methods include direct current (DC) sputtering, radio frequency (RF) sputtering, mid-frequency (MF) sputtering, ion beam sputtering, laser induced deposition, and electron beam (E). -beam) evaporation method. In addition, the chemical vapor deposition method includes APCVD (Atmosphere Pressure Chemical Vapor Deposition), LPCVD (Low Pressure Chemical Vapor Deposition), PECVD (Plasma Enhanced Chemical Vapor Deposition), MOCVD (Metalorganic Chemical Vapor Deposition), and the like.

For example, as shown in FIG. 2, the transparent conductive material and the opaque wiring material on the transparent conductive film 130 are etched as in step (c) of FIG. 1, respectively, so that the screen area 50 has transparent conductivity for the sensing electrode. Patterning may be performed so that a pattern of the material 131 remains, and a pattern of the transparent conductive material 132 for the wiring electrode 40 and the opaque wiring material 133 remains in the bezel region 60.

Further, in the present invention, after the step of attaching the transparent conductive film 130 using the adhesive member 120 on the carrier 110, as shown in Figure 1 (a) is completed, the transparency attached to the carrier 110 The flatness of the conductive film 130 was performed to perform a subsequent process at 200 μm or less. As in the present invention, by carrying out the process for the large transparent conductive film 130 in a state attached to the carrier 110 in handling the sheet of the large transparent conductive film 130, local curl or step occurrence is suppressed and Flatness can be improved. Accordingly, in the process of manufacturing a touch panel such as a resistive film, ultrasonic wave, and optical method as well as a capacitive method, malfunction may occur due to a pattern defect such as curl or step difference, disconnection, CD deviation of electrode materials such as ITO, metal mesh, and nanowire on the substrate. It is possible to provide a touch panel that achieves excellent touch functions by achieving stable performance and quality without any effect.

To this end, prior to step (b) of FIG. 1, a transparent conductive film 130 attached on the carrier 110 using a predetermined laser displacement sensor 200 (eg, LK-6500 from Keyence) as shown in FIG. 4 ) Can measure the flatness. For example, among the heights (eg, 100 points in total) measured at predetermined one-dimensional or two-dimensional intervals (for example, horizontal 10 X vertical 10 points) with respect to the entire surface of the transparent conductive film 130, FIG. 3 and Likewise, the difference between the maximum height MAX and the minimum height MIN can be measured as flatness. Flatness measurement is required in the initial process setup, but is not always necessary on repeated process flows and can be performed intermittently after the initial process setup.

When the step of attaching the transparent conductive film 130 using the adhesive member 120 on the carrier 110 as shown in FIG. 1 (a) as above is completed, photoresist such as photoresist on the transparent conductive film 130 An exposure process of forming and patterning the layer PR is performed (Fig. 1 (b)). At this time, the carrier 110 to which the transparent conductive film 130 is attached is fixed to the exposure equipment stage 10 by a vacuum chuck or the like, and a liquid photoresist is coated or a photosensitive film (DFR, dry film resist) is laminated. After the pattern can be made. After the photo process using an exposure mask, a photoresist layer (PR) may be patterned so that only a necessary portion is left using a developer such as TMAH (Tetramethyl ammounium hydroxide). The photosensitive layer PR may be either positive or negative, and may also be a photoreactive type that develops immediately after exposure of the photosensitive layer PR, and also performs a baking process after exposure, thereby performing a photoreaction. It may be a chemically amplified type that promotes this.

In the present invention, by attaching the transparent conductive film 130 on the carrier 110, and performing a process for manufacturing the touch panel, the equipment for the touch panel manufacturing process such as an exposure process, a cleaning process, an etching process, or a photosensitive layer peeling process is moved. The transparent conductive film 130 was moved and processed on the carrier 110 without manual movement of the liver. After performing the exposure process as described above, the carrier 110 having the patterned photosensitive layer PR is moved and fixed to the stage 20 of the etching equipment by a vacuum chuck or the like and the conductive material on the transparent conductive film 130 is patterned. (Fig. 1 (c)).

For example, only a transparent conductive material on the transparent conductive film 130 may be etched and patterned by performing a photosensitive layer peeling process according to the touch panel structure or driving method, and as necessary, as shown in FIG. 2, the transparent conductive film 130 ) By patterning the transparent conductive material and the opaque wiring material on the screen, the pattern of the transparent conductive material 131 for the sensing electrode remains in the screen area 50, and the transparent conductive material for the wiring electrode in the bezel area 60 ( 132) and the pattern of the opaque wiring material 133 may be patterned so that the pattern remains.

Thereafter, a cleaning process may be performed in the process, and the transparent conductive film 130 on the carrier 110 on which all processes are completed is detached, and the touch panel suitable for the designed model is completed by separating them into corresponding unit cells. Each touch panel is mounted on a touch module for a touch screen test and can be applied to each product after the test is made.

For example, each touch panel, a liquid crystal display device (LCD), a plasma display panel (PDP), an organic light emitting display device (Organic Light Emitting Display Device: OLED), electrophoretic display A device (Electrophoretic Display Device: EPD) is coupled between a display panel and a predetermined protective cover, such as glass, and is connected to an external processing circuit or processor to perform a touch screen function.

<Example>

5 is a comparative example of an electrode pattern in the case of the touch panel substrate (a) of the present invention and in the case of the conventional touch panel substrate (b).

In the case of the conventional touch panel substrate (FIG. 5 (b)) is a case in which an exposure process, a cleaning process, an etching process, or a photosensitive layer peeling process is performed by being directly seated on an equipment stage without a carrier 110, a transparent conductive film As a result of measuring the flatness of the image, it was confirmed that it deviated from the standard by 360 μm or more. In the case of such a conventional technique, it can be seen that due to local non-uniformity of flatness, the exposure light source does not focus on the substrate surface and the pattern uniformity distribution is deteriorated during exposure, resulting in partial defects and productivity decreases. have.

On the other hand, in the case of the touch panel substrate of the present invention (Fig. 5 (a)), a soda lime glass having a size of 1100 x 1300 mm and a thickness of 0.7 mm was used as the carrier 110. The carrier 110 is a glass subjected to a strengthening treatment through a chemical strengthening method, and the flatness of the surface was measured to be 50 μm. In addition, the adhesive member 120 is a double-sided adhesive tape (e.g., the adhesive strength of one side is 5gf / inch and the adhesive strength of the other side is 3gf / inch) that forms a pressure-sensitive adhesive containing silicon on a 50 μm thick PET film substrate 1095 x 1295mm Cut to size and attached to the carrier 110 using lamination equipment, and a transparent conductive film 130 was attached thereon. After attaching the transparent conductive film 130, the flatness of the transparent conductive film 130 was measured and measured to be 50 μm.

Subsequently, as a result of performing the exposure process, the cleaning process, the etching process, or the photosensitive layer peeling process and manufacturing the touch panel, a pattern having good 3 μm line wiring (dark part) and 3 μm space (bright part) as shown in FIG. It was shown. In the case of the conventional touch panel substrate (FIG. 5 (b)), the pattern defect is so severe that it is difficult to implement a 3 μm wiring and space pattern.

As described above, as in the method of manufacturing the touch panel of the present invention, by suppressing local curl or step generation and improving flatness in handling a large-sized substrate film sheet, as well as a capacitive method, a resistive film, an ultrasonic wave, an optical method In the process of manufacturing touch panels, such as ITO, metal mesh, and nanowires on the substrate, it achieves excellent touch function by achieving stable performance and quality without malfunction due to pattern defects such as curl, step difference, disconnection, CD deviation, etc. It is possible to provide a touch panel.

Although the preferred embodiments of the present invention have been described above, the technical spirit of the present invention is not limited to the preferred embodiments described above, and may be variously implemented within a range not departing from the technical spirit of the present invention as specified in the claims. have.

Carrier (110)
Adhesive member (120)
Transparent conductive film (130)

Claims (11)

Attaching a transparent conductive film on the carrier using an adhesive;
Forming and patterning a photosensitive layer on the transparent conductive film; And
Forming a pattern for a conductive material on the transparent conductive film based on an exposure process
Method of manufacturing a touch panel comprising a. According to claim 1,
A method of manufacturing a touch panel, wherein the transparent conductive film is moved and processed on the carrier without manual movement between equipment movement for an exposure process, a cleaning process, an etching process, or a photosensitive layer peeling process. According to claim 1,
The transparent conductive film is a method of manufacturing a touch panel comprising a film formed of a transparent conductive material on a flexible transparent substrate. According to claim 1,
The transparent conductive film is a method of manufacturing a touch panel comprising a film formed of a transparent conductive material and an opaque wiring material sequentially on a flexible transparent substrate. According to claim 1,
Before the step of forming the photosensitive layer,
Forming an opaque wiring material on the transparent conductive film having a transparent conductive material formed on a flexible transparent substrate
The manufacturing method of the touch panel further comprising a. According to claim 1,
Before the step of forming the photosensitive layer,
Measuring the flatness of the transparent conductive film attached on the carrier using a laser displacement sensor
The manufacturing method of the touch panel further comprising a. The method of claim 6,
A method of manufacturing a touch panel, wherein the difference between the maximum height and the minimum height among the heights measured at predetermined one-dimensional or two-dimensional intervals with respect to the entire surface of the transparent conductive film is measured as the flatness. According to claim 1,
A method of manufacturing a touch panel, wherein the flatness of the transparent conductive film attached on the carrier is for performing a process at 200 μm or less. According to claim 1,
The carrier is a method of manufacturing a touch panel, characterized in that made of a glass, ceramic, plastic or metal material. According to claim 1,
The pressure-sensitive adhesive, a method of manufacturing a touch panel, characterized in that it comprises a coated form of a liquid adhesive solution, a double-sided adhesive tape form having an adhesive formed on both sides of a film base material, or an adhesive tape shape without a film base. According to claim 1,
The thickness of the transparent conductive film, the manufacturing method of the touch panel, characterized in that less than 300μm.

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