KR20150095408A - method for manufacturing buried electrode by laser heat-transferring and buried electrode manufactured by the same - Google Patents

Abstract

The present invention relates to an embedded electrode and a method for manufacturing the same by using a laser heat transfer technique. The method includes the steps of: 1) preparing a laser induced thermal imaging (LITI) base film including a base substrate, a light-heat conversion layer, and an intermediate layer; 2) coating a photo-curing resin on a pattern substrate, applying a master film having a mesh-shaped pattern onto the pattern substrate to copy the mesh-shaped pattern, and depositing a metal on the mesh-shaped pattern to form an embossed or intagliated metal pattern layer on the pattern substrate; 3) making the intermediate layer of the LITI base film and the embossed or intagliated metal pattern layer on the pattern substrate to come in contact with each other and radiating laser thereto; and 4) separating the base film and the pattern substrate to transfer the embossed or intagliated metal pattern layer firmly in contact with the intermediate layer to the base film to selectively form the metal layer on the base film and the pattern substrate.

Description

[0001] The present invention relates to a method for fabricating a buried electrode by a laser thermal transfer method and a buried electrode manufactured by the method,

The present invention relates to a method for manufacturing a buried electrode through a laser thermal transfer method and a buried electrode fabricated thereby.

Methods for selectively forming a pattern include a method of selectively forming a photoresist layer pattern in advance, and a method of applying a material to a substrate on which a pattern has already been formed and then transferring the material to a second substrate.

In the method using the photolithography process, various steps such as the production of a photomask, etching, and resist removal are required, and the shape size of the pattern is also limited. In addition, a method using a transfer process through a general substrate-to-substrate contact has difficulty in separating a pattern selectively or entirely without a special substrate processing when a material such as a metal is deposited.

Accordingly, the inventors of the present invention found that by using laser induced thermal imaging (LITI), which has been used for selective transfer of materials of low molecular organic materials such as OLEDs, We have developed a pattern transfer method using a quartz process.

KR 10-2012-0138691 A KR 10-0700828 B

In order to solve the problems of the prior art as described above,

A thin film patterning method using a laser capable of simultaneously achieving a large size while maintaining a high resolution in thin film patterning.

 It is still another object of the present invention to provide a thin film patterning method using a laser capable of selectively forming an arbitrary pattern desired by a user on a desired substrate without melting / evaporating and condensing the material.

According to an aspect of the present invention, there is provided a method of manufacturing a laser induced thermal imaging (LITI) substrate comprising: (1) preparing a substrate film for LITI (Laser Induced Thermal Imaging) comprising a base substrate, 2) applying a photocurable resin to a pattern substrate, applying a master film having a mesh pattern to replicate the mesh pattern on the pattern substrate, and then depositing metal on the mesh pattern to form a relief pattern on the pattern substrate, ; 3) irradiating the intermediate layer of the substrate film for LITI with a relief or concave metal pattern layer of the pattern substrate, followed by laser irradiation; And 4) separating the base film and the pattern substrate to selectively form the metal pattern layer on the base film and the pattern substrate by transferring the metal pattern layer firmly adhered to the intermediate layer to the base film The present invention also provides a method of fabricating a buried electrode through a laser thermal transfer technique.

In addition, the present invention provides a buried electrode, which comprises an intaglio metal pattern layer formed in accordance with the above manufacturing method and having the shape of a net connected to each other.

According to the present invention, various patterns can be selectively removed or formed by selectively separating the upper end material by using a structural step without melting / evaporating the material using a laser, and a structure such as a buried electrode can be easily formed .

According to the present invention, it is possible to quickly form a metal pattern for an electrode or a wiring by using a laser, and it is possible to easily form a buried structure electrode on a flexible substrate such as a polymer film.

FIG. 1 illustrates a process of fabricating a buried electrode using a laser induced thermal imaging technique according to the present invention.
FIG. 2 is a view showing a process in which a metal thin film is selectively removed from an engraved mesh pattern according to Example 1, and only a mesh line portion is left with an SEM image.
FIG. 3 is a view showing a process in which a metal thin film is selectively removed from a relief mesh pattern in Example 2, and only a mesh line portion remains, together with an SEM image.
FIG. 4 is an SEM image of a buried electrode manufactured using an engraved pattern substrate according to Example 1 (left side: transmission mode microscope image, right side: SEM image of enlarged line).
5 is a SEM image of the surface of the LITI film used for transferring after each step of Example 1 and 2.

Hereinafter, the present invention will be described in detail.

A method for manufacturing a buried type electrode using a laser induced thermal imaging method according to the present invention comprises the steps of: 1) preparing a substrate film for LITI (Laser Induced Thermal Imaging) including a base substrate, a photo-thermal conversion layer and an intermediate layer; 2) applying a photocurable resin to a pattern substrate, applying a master film having a mesh pattern to replicate the mesh pattern on the pattern substrate, and then depositing metal on the mesh pattern to form a relief pattern on the pattern substrate, ; 3) irradiating the intermediate layer of the substrate film for LITI with a relief or concave metal pattern layer of the pattern substrate, followed by laser irradiation; And 4) separating the base film and the pattern substrate, and selectively transferring the metal pattern layer to the base film and the pattern substrate by transferring the positive or negative metal pattern layer firmly adhered to the intermediate layer to the base film .

In the step 1), a substrate for LITI including a base substrate, a light-to-heat conversion (LTHC) and an intermediate layer is prepared.

The base substrate serves as a support for the base film, and glass, a transparent film or a polymer film can be used. Among them, polyester, polycarbonate, polyolefin, polyvinyl resin, and the like can be used as the polymer film, but not limited thereto. Polyethylene terephthalate (PET) or polyethylene naphthalate is used in view of processability, thermal stability and transparency . More preferably, it is preferable to use a material having a light transmittance of 90% or more in order to increase the transmittance of light irradiated during the LITI process.

It is preferable that the thickness of the base substrate is 10 [mu] m to 200 [mu] m.

The light-to-heat conversion layer (LTHC layer) is a layer made of a light absorbing material that absorbs laser light and converts the laser light into heat. The thickness of the layer is determined according to a light absorbing material and a forming method.

For example, when it is made of a metal or an oxide of a metal, it is preferably 100 to 5000 angstroms by a vacuum deposition method, an electron beam deposition method, or a sputtering method. When the film is formed of an organic film, it may be formed by an extrusion, a gravure, 2 mu m.

When the thickness of the photo-thermal conversion layer is less than the above-mentioned range, the energy absorption heat is low and the amount of energy converted from light into heat is low, so that the expansion pressure becomes low. Edge open failure may occur.

The intermediate layer is a layer in which a volume expansion occurs due to heat energy emitted from a light heat conversion layer that absorbs laser light and converts it into thermal energy.

Examples of the intermediate layer include, but are not limited to, urethane acrylate, epoxy acrylate, and polyester acrylate.

The thickness of the intermediate layer is preferably 0.5 to 3 mu m. If the thickness exceeds 3 占 퐉, an edge opening (eg, open defect) may occur due to a step between the base film and the pattern substrate.

In the step 2), the embossed or embossed metal pattern layer is formed on the pattern substrate using the master film having the mesh pattern.

To this end, a photocurable resin is first applied to a pattern substrate and a master film having a mesh pattern is applied to replicate the pattern.

The pattern substrate serves as a support for the positive or negative metal pattern layer, and glass, a transparent film or a polymer film can be used. Among them, polyester, polycarbonate, polyolefin, polyvinyl resin, and the like can be used as the polymer film, but not limited thereto. Polyethylene terephthalate (PET) or polyethylene naphthalate is used in view of processability, thermal stability and transparency . More preferably, it is preferable to use a material having a light transmittance of 90% or more in order to increase the transmittance of light irradiated during the LITI process.

The photocurable resin is cured by ultraviolet rays and may be a composition comprising an oligomer such as polyester acrylate, epoxy acrylate, polyurethane acrylate, polyether acrylate, or silicone acrylate.

The photocurable resin may be applied by a method such as extrusion, gravure, spin, knife coating, vacuum deposition, CVD, or the like.

The master film having the mesh pattern may be prepared by various methods such as general photolithography, e-beam lithography, nano-implant, and soft lithography, but is not limited thereto.

The mesh pattern means that the structure of the pattern is a network of interconnected meshes. The mesh-shaped pattern may be replicated on the patterned substrate in an embossed or engraved manner.

In the case of the mesh pattern, even though the aspect ratio of the transferred metal pattern is somewhat higher than 2, the metal pattern layers are connected to each other, so that uniform contact between the substrate film including the base film and the metal pattern layer during the LITI process, And the process of optimizing the process considering the thermal stress due to the difference of the thermal expansion coefficients between the respective layers, the distortion of the transferred pattern can be minimized.

The process of replicating the mesh pattern by applying the master film having the mesh pattern on the pattern substrate can be performed by forming a resist layer on the film substrate using the hard master prepared by the above method and copying it by UV curing or heat curing method, Or a roll-printing method such as a gravure offset in which the master substrate is cliched.

A metal is deposited on the replicated mesh pattern to form a relief or depressed metal pattern layer.

The metal pattern layer may be formed of a metal such as Ag, Cu, Al, Au, Ni, Ti, Mo, W, Cr, (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), indium zinc tin oxide (IZTO), aluminum zinc oxide-based alloys such as indium tin oxide Indium zinc oxide (IZO-Ag-IZO), indium tin oxide-silver-indium tin oxide (ITO-Ag-ITO), indium zinc tin oxide Oxide-silver-indium zinc tin oxide (IZTO-Ag-IZTO), and metal-containing mixed electrode materials.

The metal pattern layer may be formed by a printing method such as photolithography, inkjet, gravure, imprinting, offset, electroplating, vacuum evaporation, thermal evaporation, sputtering or electron beam evaporation. It is not limited.

The line width of the metal pattern layer is not particularly limited, but may be 50 nm to 20 탆.

The thickness of the metal pattern layer is not particularly limited, but may be 50 to 200 nm.

The thickness (height) of the metal pattern layer may vary depending on the line width of the pattern and the electrical characteristics (conductivity and specific resistance) required for the application device.

In step 3), the surface having the intermediate layer of the substrate film for LITI and the surface having the embossed or intaglio metal pattern layer of the pattern substrate are placed facing each other, and the CW laser is scanned by a predetermined area. At this time, the light emitted from the laser is absorbed in the photo-thermal conversion layer of the LITI substrate film and converted into thermal energy, and the converted thermal energy is transferred to the intermediate layer, resulting in volume expansion of the intermediate layer, and firm adhesion to the metal pattern layer is achieved.

When the LITI substrate film and the pattern substrate are separated in step 4), the metal pattern layer firmly adhered to the intermediate layer of the LITI substrate film is transferred to the LITI substrate film, and a metal pattern layer is selectively formed on the substrate film The metal pattern layer which is not in close contact with the intermediate layer of the base film remains on the pattern substrate.

The intermediate layer has a surface energy of 30 mN / m or more, preferably 30 to 50 mN / m, more preferably 35 to 40 mN / m, so that the metal pattern layer can be separated from the pattern substrate in a state in which the metal pattern layer is in close contact with the intermediate layer .

Further, at this time, the surface energy of the pattern substrate is preferably controlled to be lower than the surface energy of the intermediate layer but lower than 25 mN / m and lower than 35 mN / m.

Step 4) separates the base film from which the metal pattern layer is transferred from the pattern substrate.

At this time, all the physical methods can be used without any particular restriction as the separation method.

For example, when a wind is slightly blown to a contact portion between a base film and a pattern substrate by using a nitrogen gun, peeling easily occurs due to a low surface energy between the release material and the base film. In a continuous process through a general roll- The release can be physically progressed by separating the substrate roll and the substrate roll path formed with the metal pattern layer.

The present invention provides a buried electrode manufactured according to the manufacturing method of the present invention, wherein the metal pattern layer is embedded in a patterned substrate.

More specifically, the present invention provides a buried electrode, which comprises an intaglio metal pattern layer formed in accordance with the method of manufacture of the present invention and having the shape of a net connected to each other.

The line width of the intaglio metal pattern layer is not particularly limited, but may be 50 nm to 20 탆.

The thickness of the intaglio metal pattern layer is not particularly limited, but may be 50 to 200 nm.

Hereinafter, the present invention will be described more specifically based on the following examples. It should be noted, however, that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

≪ Example 1 >

A LITI base film composed of PET, a photo-thermal conversion layer and an intermediate layer was prepared. The photothermal conversion layer consisted of a mixture of black matrix and carbon black in a thermosetting resin of 2 μm or less, and the intermediate layer was made of a thermosetting urethane transparent material having a thickness of 1.5 μm or less. A master substrate having a mesh pattern was prepared and an engraved mesh pattern was replicated on a PET substrate using a polyurethane acrylate resin. Aluminum was deposited to a thickness of 100 nm by using a sputtering method on the thus-replicated pattern.

The intermediate layer side of the LITI substrate film and the substrate on which the aluminum thin film was deposited were placed facing each other and scanned with a 1064 nm CW IR laser at a constant area. The homogenizer was passed through a f-theta lens to form a square beam with a focal length of about 0.2 mm x 0.2 mm.

After the scan was completed, the two substrates were separated and the aluminum pattern was transferred to the LITI film surface to produce a buried electrode in which the metal pattern was selectively formed.

4 is an SEM image of a buried electrode manufactured using an engraved pattern substrate according to Example 1 (left side: transmission mode microscope image, right side: SEM image of enlarged line portion).

≪ Example 2 >

A buried electrode was prepared in the same manner as in Example 1, except that the embossed mesh pattern was replicated on the PET substrate.

Claims (11)

1) preparing a base film for LITI (Laser Induced Thermal Imaging) including a base substrate, a photo-thermal conversion layer and an intermediate layer;
2) applying a photocurable resin to a pattern substrate, applying a master film having a mesh pattern to replicate the mesh pattern on the pattern substrate, and then depositing metal on the mesh pattern to form a relief pattern on the pattern substrate, ;
3) irradiating the intermediate layer of the substrate film for LITI with a relief or concave metal pattern layer of the pattern substrate, followed by laser irradiation; And
4) selectively forming a metal pattern layer on the base film and the pattern substrate by separating the base film and the pattern substrate and transferring the positive or negative metal pattern layer firmly adhered to the intermediate layer to the base film; The method comprising the steps of: The method according to claim 1, wherein the thickness of the base substrate is in the range of 10 탆 to 200 탆. The method according to claim 1, wherein the base substrate has a light transmittance of 90% or more. The method of claim 1, wherein the intermediate layer is a urethane acrylate, an epoxy acrylate, or a polyester acrylate. The method according to claim 1, wherein the intermediate layer has a thickness of 0.5 to 3 占 퐉. The method according to claim 1, wherein the line width of the metal pattern layer is 50 nm to 20 탆. The method according to claim 1, wherein the metal pattern layer has a thickness of 50 to 200 nm. The method according to claim 1, wherein the intermediate layer has a surface energy of 30 to 50 mN / m. A buried electrode comprising an intaglio metal pattern layer made according to the method of claim 1 and having the shape of a network of interconnected interconnections. The buried electrode according to claim 9, wherein the line width of the intaglio metal pattern layer is 50 nm to 20 탆. [12] The buried electrode according to claim 9, wherein the intaglio metal pattern layer has a thickness of 50 to 200 nm.

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