KR20120053716A - Method of manufacturing patterned transparent conductive film - Google Patents

Abstract

PURPOSE: A method for manufacturing a patterned transparent conductive film is provided to reduce production costs by recycling a residual transparent conductive film composition including unnecessary CNT(Carbon Nano Tube), a nanowire or a metal oxide, etc. CONSTITUTION: A photoresist layer is formed by applying photoresist on a substrate(S10). A photoresist pattern is formed by forming an open portion to expose the substrate in a partial area of the photoresist layer(S20). A conductive transparent composition is applied on the open portion(S30). A transparent conductive film is formed by drying the composition(S40). A pattern film having the transparent conductive film is formed into a desired pattern on the substrate after a residual photoresist pattern is eliminated(S50).

Description

Method of manufacturing patterned transparent conductive film {METHOD OF MANUFACTURING PATTERNED TRANSPARENT CONDUCTIVE FILM}

The present invention relates to a method for producing a patterned transparent conductive film, and more particularly, to a method for producing a patterned transparent conductive film usable as a flexible transparent conductive film.

The development of flexible display, transparent electrode, transparent optical film, and touch sensor technology for touch panel has huge market potential and huge market potential worldwide. The flexible display is thinner and lighter than the existing glass-based display, which is strong in impact and easy to carry, and is relatively free from space and shape constraints to secure various applications. have. Accordingly, research on technologies of transparent electrodes and transparent conductive films as well as materials of the substrate of the flexible display is being actively conducted.

As the transparent conductive film, tin oxide (SnO 2) film doped with antimony or fluorine, zinc oxide (ZnO) film doped with potassium, indium oxide (In 2 O 3) doped with tin, and the like are widely used. In particular, tin-doped indium oxide films, that is, In2O3-Sn-based films are called ITO (Indium tin oxide) films and are widely used because low resistance films can be easily obtained. In the case of ITO, it has excellent physical properties and many experiences in the process input to date, but since indium oxide (In2O3) is produced as a by-product from zinc (Zn) mine, supply and demand is unstable, and ITO film is inflexible Flexible materials such as polymer substrates can not be used. In addition, it can be manufactured in a high temperature and high pressure environment, the production cost is high, and in order to obtain a flexible display, etc., the conductive polymer may be coated on the upper surface of the polymer substrate, but since the film is not electrically conductive or transparent, Its use is limited.

Recently, techniques for coating carbon nanotubes on top of various substrates have been widely studied in order to solve these problems. The carbon nanotubes have electrical conductivity comparable to that of metals with an electrical resistance of 10-4 Ωcm, and the surface area is more than 1000 times higher than that of bulk materials and is thousands of times longer than the outer diameter. Therefore, there is an advantage that can improve the binding force to the substrate through the surface functionalization. In particular, it is expected that the use of the flexible substrate can be infinite.

Meanwhile, a method of manufacturing a conductive transparent film using nanowires has also been actively studied. The nanowires not only have excellent optical properties such as electron transfer characteristics and polarization phenomena in a specific direction, but also are suitable for micro device applications due to their small size, so that when used as a material for optical display devices, the nanowires have excellent conductivity and performance. It has optical properties.

In the related art, in order to apply the transparent conductive film made of the transparent conductive material as described above to a touch screen panel or the like, the transparent conductive film is formed and then patterned with a laser. In addition to lasers, wet etching or plasma etching may be used. Such a patterning operation is performed by cutting or etching the completed transparent conductive film in a desired pattern shape, and the patterning operation of the transparent conductive film is not only an expensive process because it must be performed using an expensive laser equipment or undergoes an etching process. Since the conductive film is formed on the entire surface of the substrate and the method is removed, the ratio of the amount to be removed is higher than that of the transparent conductive material to be commercialized, resulting in a waste of expensive transparent conductive compositions.

The present invention has been conceived based on these points, and the problem to be solved by the present invention is to provide a transparent conductive pattern film formed with a pattern without additional processing.

Another problem to be solved by the present invention is to provide a transparent conductive pattern film having a low production cost since there is no part where the pattern is directly formed and cut without an additional process.

Another problem to be solved by the present invention is to provide a transparent conductive pattern film having a low production cost by recovering and recycling an unnecessary remaining transparent conductive composition when directly forming a pattern.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

Method of manufacturing a patterned transparent conductive film according to an embodiment of the present invention for solving the above problems is to form a photoresist layer on the substrate, the open portion for patterning the photoresist layer to partially expose the substrate Forming a photoresist pattern to be defined, providing a transparent conductive composition in the open portion, drying the transparent conductive composition to form a transparent conductive film in the open portion, and removing the photoresist pattern.

Specific details of other embodiments are included in the detailed description and drawings.

According to embodiments of the present invention has at least the following effects.

Since it is possible to provide a transparent conductive film having a pattern formed without an additional process for forming a separate pattern, the production process is shortened and advantageous in terms of cost. In addition, since there is no non-pattern portion formed by directly forming a pattern and cutting and discarding the completed transparent conductive film, it is possible to provide a completed transparent conductive film with a higher yield than the transparent conductive composition.

In addition, a patterned transparent conductive film having low production cost may be provided by recovering and recycling a remaining transparent conductive film composition such as CNT, nanowire, or metal oxide, which is unnecessary when directly forming a pattern on a substrate.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a flowchart illustrating a method of manufacturing a patterned transparent conductive film according to an embodiment of the present invention.
2 illustrates a patterned transparent conductive film according to an embodiment of the present invention.
3 is a diagram of a photoresist pattern for fabricating a patterned transparent conductive film according to one embodiment of the invention.
4 is a view schematically showing the manufacturing method of FIG. 1 in the order of (a) to (e).
FIG. 5 is a view further adding a coupling functional group to FIG. 4B.
FIG. 6 is a view in which a blade is further added to recovering the transparent conductive composition performed between steps (c) and (d) of FIG. 4.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims.

And / or includes each and all combinations of one or more of the items mentioned. The spatially relative terms below, beneath, lower, upper, upper, etc., as shown in the figures, correlate one component with another. Can be used to easily describe the relationship. Spatially relative terms are to be understood as including terms in different directions of components in use or operation in addition to the directions shown in the figures. For example, when inverting the components shown in the figures, components described below or below other components may be placed above other components. Thus, the exemplary term below may include both the direction below and above. The components can be oriented in other directions as well, so that spatially relative terms can be interpreted according to the orientation. The term sheet used in the present specification may be used in the sense of a film or a plate.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention.

First, referring to FIG. 1, in the patterned transparent conductive film according to the exemplary embodiment of the present invention, the photoresist layer 30 is formed on the substrate 10 (S10), and the photoresist layer 30 is formed. Patterning to form a photoresist pattern 30 defining an open portion 31 that partially exposes the substrate 10 (S20), providing a transparent conductive composition 20 'in the open portion 31; (S30), drying the transparent conductive composition 20 'to form a transparent conductive film 20 (S40), and removing the photoresist pattern 30 (S50).

A patterned transparent conductive film produced by such a method of manufacturing a patterned transparent conductive film is shown in FIG. 2. That is, the patterned transparent conductive film according to the embodiment of the present invention includes a substrate 10 and a transparent conductive film 20 formed on the substrate 10, and the transparent conductive film 20 has a predetermined pattern. It is provided only in a partial region of the substrate 10 to form a.

On the other hand, the molding mold of the patterned transparent conductive film used to prepare the patterned transparent conductive film is shown in FIG. 3. That is, the molding mold of the patterned transparent conductive film according to the embodiment of the present invention includes a substrate 10 and a photoresist pattern 30 formed on the substrate 10, and the photoresist pattern 30 In some regions, the open part 31 is formed to expose the substrate 10.

4 is a diagram illustrating the process sequence of FIG. Hereinafter, a method of manufacturing a specific CNT pattern film according to an embodiment of the present invention will be described with reference to FIGS. 1 and 4.

1 and 4, the substrate 10 may be a transparent material capable of transmitting light, that is, a transparent material such as glass or a transparent plastic film or sheet, and in some cases, may be an opaque material suitable for application. Specifically, the transparent plastic film is polycarbonate-based, poly sulfone-based, polyacrylate-based, polystyrene-based, polyvinyl chloride-based, polyvinyl It may include a material of the alcohol (poly vinyl alcohol), poly norbornene (poly norbornene), polyester (polyester) series. For example, the substrate 10 may be made of polyethylene terephtalate, polyethylene naphthalate, or the like. Meanwhile, the substrate 10 may be manufactured from a polycarbonate-based, polyethersulfone-based, or polyarylate-based material, which is a transparent and flexible material so as to be applicable to a flexible display device.

As shown in FIG. 4A, a photoresist is provided on the substrate 10 made of the material to form a photoresist layer 30 '(S10). Photoresist is used in photolithography for forming various patterns. The photoresist refers to a photosensitive resin capable of obtaining an image corresponding to an exposure pattern by changing solubility in a developer by the action of light. Since the solubility in the negative developer increases and the exposed portion is removed in the developing process, the positive photoresist and the solubility in the exposed portion in the developing portion can obtain a desired pattern, and the non-exposed portion is removed in the developing process. It can be categorized as a negative photoresist capable of obtaining a desired pattern. Therefore, the photoresist may be mixed with a solvent or the like and coated on a substrate, and then exposed and developed to form a structure having a predetermined pattern.

In addition to the photoresist composition for patterning, an amorphous carbon film and a silicon oxynitride-based material used as a hard mask in a general photolithography process may be used to perform a mask function for forming a pattern instead of a photoresist. Hereinafter, a description will be given of the patterning of the photoresist composition for convenience of description, but the present invention is not limited thereto.

Specifically, after the photoresist composition is provided on the substrate 10, a dry bake is performed to evaporate the solvent to form the photoresist layer 30 ′. The photoresist composition may be applied to the substrate by spin coating, which method disperses the liquid photoresist on the substrate and accelerates the substrate 10 at a constant rotational speed before the desired photoresist layer 30 ' The rotation speed is kept constant so that the thickness of? Is achieved. Spin coating may be performed at various rotational speeds to adjust the thickness of the photoresist layer 30 '. In the process of forming the photoresist layer 30 ', in addition to spin coating, other coating methods such as roller coating, doctor bar coating, slot coating, dip coating, gravure coating, spray coating, and the like may be used. The resist composition may be applied to the substrate 10.

After coating the photoresist composition on the substrate 10, a dry bake is performed to evaporate the solvent. The dry bake can suitably adjust the drying conditions such that the final photoresist layer 30 'is formed into a viscous photosensitive film. Typical photoresist drying conditions are from 1 to 5 minutes at 65 ° C., followed by 5 to 30 minutes at 95 ° C. or more, if necessary, using a hot plate, wherein the substrate 10 is brought into contact with the surface of the hot plate or Get close. Such dry baking may be performed in a convection oven.

As shown in FIG. 4B, the open portion 31 is formed to expose the substrate 10 in a portion of the photoresist layer 30 ′ formed through the above process, thereby forming the photoresist pattern 30. ) Is formed (S20). The opening part 31 is formed to be used as a mold in the photoresist layer 30 ′ to selectively or partially provide the transparent conductive composition to the substrate 10. As shown in FIG. 3.

Forming the open portion 31 uses exposure and development. Exposure and development performed in one embodiment of the present invention are as follows. On the photoresist layer 30 'formed on the substrate 10, a pattern mask in which a desired pattern is formed in reverse phase is laminated. Thereafter, 300 nm to 500 nm near ultraviolet radiation from a medium or high pressure mercury lamp or x-ray radiation from a standard or synchrotron light source is used to expose through a photomask having opaque and transparent areas, or directly or Photographic image processing can be performed by electron beams through patterned exposure. Contact, proximity or projection printing can be used. The exposure process described above is exemplary, and the wavelength or specific conditions of light used for exposure may be modified.

After exposure, a post-exposure bake may be performed to promote the acid catalyzed polymerization of the region exposed to the light of the photoresist layer 30 '. Typical bake is carried out using a hotplate for 1 minute at 65 ° C and 5 minutes at 95 ° C. Preferably, the post-exposure bake may be performed by one bake at 95 ° C. for 1 to 10 minutes. Then, in order to dissolve the unpolymerized region, the organic solvent development of the photoresist layer 30 'is typically performed for 2 to 5 minutes depending on the desired thickness of the desired photoresist layer 30' and the solvent strength of the developer solvent. Impregnate The remaining developer is removed by washing the developed image with a washing solvent.

Suitable actinic rays for irradiating the photoresist layer 30 'according to one embodiment of the present invention are ultraviolet (UV) rays, X-rays and electron beam radiation. Specifically, ultraviolet rays and X-rays may be actinic rays, and ultraviolet rays emitted from mercury lamp lamps at wavelengths of 365 nm, 405 nm and 436 nm may be used. Suitable optical filters can be used to provide light of a single wavelength through the photomask.

Through this process, as shown in FIG. 3, the photoresist pattern 30 on which the open pattern portion 31 is formed may be provided as a mold for forming the transparent conductive film 20.

Next, as shown in FIG. 4C, the transparent conductive composition 20 ′ is applied to the open part 31 formed through the above process (S30). The transparent conductive composition 20 'or 20' may include one or more of CNTs, nanowires, and metal oxides, and may further include a dispersant and an organic solvent, water, or a mixture thereof, as necessary. It may include. Hereinafter, for convenience of description, the case where the transparent conductive composition 20 'is CNT will be described as an example. However, this does not limit the scope of the transparent conductive composition of the embodiments of the present invention.

In particular, a dispersant may be used to disperse the CNTs when the transparent conductive composition 20 'includes CNTs. The dispersant may be used as long as it can disperse CNT in a solvent such as water. Specific examples thereof include sodium dodecyl sulfate (SDS), triton X (Tigton X) (Sigma), and Tween20 (Polyoxyethyelene Sorbitan Monooleate). ) And CTAB (Cetyl Trimethyl Ammonium Bromide). And the content of the dispersant is preferably 0.005 to 1000 parts by weight based on 1 part by weight of CNT. If the content of the dispersant is less than the above, the dispersibility of the transparent conductive composition 20 'containing CNT is lowered. If the dispersant content is exceeded, the relative content of CNT in the composition 20' is decreased, thereby forming a transparent conductive film. Since the conductivity of (20) falls, it is not preferable. The content of such a dispersant is exemplary and may be incorporated in different weight ratios depending on the type of dispersant.

As the organic solvent, a conventional organic solvent may be used without limitation, and specifically, alcohols, ketones, glycols, glycol ethers, glycol ether acetates, acetates, terpineols, etc. may be used alone or in one kind. It can mix and use the above.

The prepared transparent conductive composition 20 'is coated on the substrate 10, which may be formed using a general coating method, for example, spin coating, spray coating, filtration or bar coating. In the above method, an appropriate method may be selected according to the characteristics of the solution and the intended use. In this case, the substrate 10 may be used by surface treatment in advance, and as the surface treatment method, known methods such as, for example, O 2 plasma treatment may be used without limitation, and in particular, the transparent conductive surface of the substrate 10 may be used. The process of coating the binding functional material 40 having the binding functional group may be further performed so that the materials can be bound more effectively.

Bonding agents 40 that may be used include hydroxyl (OH), amine (NH 2), mercapto (SH), carboxyl (COOH), sulfonyl chloride (SO 2 Cl), vinyl (-C = C), acrylate ( C = CC = O), epoxy groups, esters, and combinations thereof. By the bonding agent 40, the transparent conductive material may be more firmly bonded to the surface of the substrate 10. The bonding agent 40 may be replaced with a suitable functional group depending on the kind of the transparent conductive material.

The process of coating the bonding agent 40 may be performed on the entire surface of the substrate 10, but may be limited to the open portion 31 of the substrate 10. That is, since the transparent conductive composition 20 'is applied only to the open portion 31 of the substrate 10, as described below, the substrate 10 as shown in FIG. Only the open part 31 of) may be coated with the binding agent material 40.

When the transparent conductive composition 20 'is applied onto the substrate 10 as described above, the composition 20' is mainly applied to the open portion 31 of the photoresist pattern 30 and the composition 20 is applied to the substrate 10. ') Is combined to place the composition 20' in the desired pattern form. In the regions other than the open part 31, the exposure of the substrate 10 is blocked by the photoresist pattern 30, thereby preventing the transparent conductive composition 20 ′ from being deposited. Therefore, the coating may be performed such that the transparent conductive composition 20 ′ is not applied to the entire photoresist pattern 30 but is selectively applied only to the open portion 31 of the photoresist pattern 30.

Meanwhile, a process of recovering the transparent conductive composition 20 ′ remaining in the photoresist pattern 30 without being applied to the open part 31 may be further performed. That is, as described above, the transparent conductive film 20 is finally formed by the transparent conductive composition 20 'filled in the open portion 31, and the remaining residual composition 20' becomes unnecessary. Therefore, the operation of removing the composition 20 'outside the region of the open portion 31 may be performed. However, rather than simply removing the composition 20 ′, it is possible to reduce production costs by recovering and reusing the composition. The process of recovering the composition may include moving the recovery blade 50 whose height is adjusted to a position in close contact with the photoresist pattern 30 to one side of the photoresist pattern 30, as shown in FIG. 6. Can be. That is, as shown in FIG. 6, when the recovery blade 50 is in close contact with the photoresist pattern 30 and proceeds in one direction, the composition 20 ′ positioned in the open part 31 is maintained as it is. The composition 20 ′ positioned on the upper surface of the resist pattern 30 may be moved to one side along the traveling direction of the recovery blade 50, and finally collected by a recovery container (not shown). This process not only recovers the residual composition 20 ', but also fills the empty space of the open part 31 because it performs the function of secondarily filling the open part 31 with the composition 20'. There is.

The composition 20 'provided as described above is dried as shown in FIG. 4 (d) to form a transparent conductive film 20 (S40). As a drying process for forming the transparent conductive film 20, a drying method by general heat may be used. In the method of manufacturing a patterned transparent conductive film according to an embodiment of the present invention, the transparent conductive film 20 having a desired pattern is formed by performing a drying process by exposing within 80 to 120 ° C. within 30 seconds to 120 seconds. Can be.

After that, as shown in FIG. 4E, the remaining photoresist pattern 30 is removed to complete the pattern film on which the transparent conductive film 20 is formed, as desired, on the substrate 10. (S50). Strip processes and / or ashing processes that are generally performed may be used to remove unnecessary photoresist patterns 30. By removing the unnecessary photoresist pattern 30, the transparent conductive material remaining on the upper surface of the photoresist pattern 30 can be removed together to form only the transparent conductive film 20 of the desired pattern, and the remaining transparent conductive material Noise generation and the like due to this can be suppressed.

The patterned transparent conductive film finally obtained by the above process is shown in FIG. 2 as described above. The method of manufacturing a patterned transparent conductive film according to an embodiment of the present invention provides a patterned transparent conductive film in which a pattern is formed without an additional process for forming a separate pattern, thereby shortening the production process and being advantageous in terms of cost. The effect can be obtained. In addition, since the pattern is directly formed and there is no non-pattern portion that is cut off and discarded in the completed transparent conductive film, the finished pattern film can be provided at a higher yield than the composition. In addition, when the pattern is directly formed on the substrate 10, an unnecessary remaining transparent conductive composition may be recovered and recycled to provide a patterned transparent conductive film having low production cost.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

10: Substrate
20: transparent conductive film
20 ': transparent conductive composition
30: photoresist pattern
30 ': photoresist layer
31: open
40: binding agent
50: recovery blade

Claims (8)

Forming a photoresist layer on the substrate,
Patterning the photoresist layer to form a photoresist pattern defining an open portion that partially exposes the substrate,
Providing a transparent conductive composition in the open portion,
Drying the transparent conductive composition to form a transparent conductive film in the open portion,
Removing the photoresist pattern. The method of claim 1,
Forming the photoresist pattern comprises exposing and developing the photoresist layer. The method of claim 1,
Before forming the photoresist layer, further comprising coating a bonding agent on the entire surface of the substrate. The method of claim 1,
Prior to providing the transparent conductive composition, coating a bonding agent material on a surface of the substrate exposed by the open portion of the photoresist pattern. The method of claim 1,
Before drying the transparent conductive composition, recovering the transparent conductive composition not provided in the open portion and remaining on the surface of the photoresist pattern. The method of claim 5,
Recovering the transparent conductive composition comprises moving the blade in close contact with the surface of the photoresist pattern to one side. The method of claim 1,
Wherein said transparent conductive composition comprises at least one of CNTs, nanowires, and metal oxides. The method according to claim 3 or 4,
And wherein the bonding agent comprises at least one of hydroxyl, amine, mercapto, carboxyl, sulfonyl chloride, vinyl, acrylate, epoxy group and ester.

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