KR20160085620A - Preparing method for flexible substrate - Google Patents

Abstract

The present invention relates to a method for manufacturing a flexible substrate and, more specifically, to a method for manufacturing a flexible substrate, comprising: a step of forming a separation layer on a carrier substrate; a step of forming an electrode pattern layer on the separation layer; a step of forming a polymer layer on the separation layer on which the electrode pattern layer is formed; a step of making at least some portions of periphery portions of the carrier substrate and the separation layer to come into contact with water-based stripper and peeling off the separation layer from the substrate. Therefore, the method may prevent an electrode pattern layer or the like from being damaged, when the flexible substrate is peeled off from a carrier substrate, and allow a user to easily perform a peel-off process.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a flexible substrate,

The present invention relates to a method of manufacturing a flexible substrate.

There have been attempts to introduce a touch input method into a wider variety of electronic devices while the touch input method is being watched as a next generation input method. Accordingly, research and development on a touch sensor capable of being applied to various environments and capable of accurate touch recognition are actively performed have.

For example, in the case of an electronic device having a touch-type display, an ultra-thin flexible display which achieves light weight, low power and improved portability has been attracting attention as a next generation display, and development of a touch sensor applicable to such a display has been required.

Flexible display means a display made on a flexible substrate that can bend, bend or twist without loss of properties, and technology development is underway in the form of flexible LCDs, flexible OLEDs, and electronic paper.

In order to apply the touch input method to such a flexible display, a touch sensor having excellent flexing and restoring force and excellent flexibility and stretchability is required.

As for the film touch sensor for manufacturing such a flexible display, a wiring board including wiring buried in a transparent resin base is proposed.

A wiring forming step of forming a metal wiring on the substrate; a lamination step of forming a transparent resin base material by applying and drying a transparent resin solution so as to cover the metal wiring; and a peeling step of peeling the transparent resin base material from the substrate .

In order to smoothly carry out the peeling process, an organic peeling material such as silicone resin or fluororesin, a diamond like carbon (DLC) thin film, a zirconium oxide thin film, or other inorganic peeling material is applied to the surface of the substrate A method of forming in advance is used.

However, when an inorganic stripping material is used, there is a problem that the metal wiring and the substrate remain on the surface of the substrate because the separation of the wiring and the substrate does not proceed smoothly when the substrate and the metal wiring are separated from the substrate. There is a problem in that the organic material is buried on the surface of the wiring and the substrate.

That is, there is a problem that the metal wiring of the wiring substrate can not be completely peeled off from the substrate even when the peeling material is used.

In order to solve such a problem, Korean Patent No. 10-1191865 discloses a method for manufacturing a flexible substrate in the form of a buried metal wiring, a sacrificial layer which can be removed by light or a solvent, After the polymer material (flexible substrate) is formed on the substrate, the sacrificial layer is removed by using light or a solvent to separate the metal wiring and the polymer material (flexible substrate) from the substrate.

However, such a method has a problem that it is difficult to remove the sacrificial layer in a large size, and when the sacrificial layer is not completely dissolved, it is visually recognized as a foreign matter. In addition, there is a problem that a high-temperature process can not be performed and various film substrates can not be used.

Korean Patent No. 1191865

An object of the present invention is to provide a method of manufacturing a flexible substrate which can prevent damage from peeling off from a carrier substrate.

An object of the present invention is to provide a method for producing a flexible substrate which is easy to peel off from a carrier substrate.

1. forming a separation layer on a carrier substrate;

Forming an electrode pattern layer on the isolation layer;

Forming a polymer layer on the separation layer on which the electrode pattern layer is formed; And

Contacting at least a part of a boundary portion between the carrier substrate and the separating layer to an aqueous stripping liquid containing not less than 50% by weight of water; And

And separating the separation layer from the carrier substrate.

2. The method for producing a flexible substrate according to 1 above, wherein the separation layer has a surface energy of 5 to 20 Nm / m increase in peeled surface as compared with before peeling.

3. The flexible substrate according to 1 above, wherein said separation layer has a surface energy of 30 to 55 Nm / m before peeling

4. The method of producing a flexible substrate according to 1 above, wherein the separation layer has a surface energy of 55 to 70 Nm / m at the peeled surface after peeling.

5. The separator according to claim 1, wherein the separation layer is formed of a material selected from the group consisting of polyimide, poly vinyl alcohol, polyamic acid, polyamide, polyethylene, polystyrene, Polyimides such as polynorbornene, phenylmaleimide copolymer, polyazobenzene, polyphenylenephthalamide, polyester, polymethyl methacrylate, polyarylene, At least one material selected from the group consisting of polyarylate, cinnamate, coumarin, phthalimidine, chalcone, and aromatic acetylene polymer is used. Wherein the substrate is made of a composition for forming a separation layer.

6. The process for producing a flexible substrate according to 1 above, wherein the aqueous stripping solution further comprises a low boiling point solvent.

7. The method of manufacturing a flexible substrate according to 1 above, further comprising the step of attaching a flexible substrate on the polymer layer.

In the present invention, a process is performed on a carrier substrate in forming a flexible substrate having an electrode pattern layer, so that the process can be easily proceeded even though a thin flexible substrate is used.

INDUSTRIAL APPLICABILITY The present invention prevents damage to the electrode pattern layer and the like during peeling from a carrier substrate of a flexible substrate, and is easily peelable.

The present invention minimizes the foreign matter on the release surface and does not require a separate cleaning step for stripping, thereby remarkably improving the process efficiency.

1 schematically shows a process sequence of a method of manufacturing a flexible substrate according to an embodiment of the present invention.
2 schematically shows a process sequence of a method of manufacturing a flexible substrate according to an embodiment of the present invention.
3 illustrates the boundary between the carrier substrate and the separation layer in the flexible substrate of the present invention.
Fig. 4 shows the peeled surface of the flexible substrate of Comparative Example 1. Fig.

The present invention provides a method of forming a semiconductor device, comprising: forming a separation layer on a carrier substrate; Forming an electrode pattern layer on the isolation layer; Forming a polymer layer on the separation layer on which the electrode pattern layer is formed; And a step of bringing at least a part of the boundary between the carrier substrate and the separating layer into contact with an aqueous separating liquid containing not less than 50% by weight of water and separating the separating layer from the substrate, To a method of manufacturing a flexible substrate which can be easily peeled off.

1 and 2 schematically show a manufacturing process of a flexible substrate according to an embodiment of the present invention. Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, as shown in Fig. 1 (a), a separation layer 20 is formed on a carrier substrate 10.

The separation layer 20 is a layer formed for separation from the carrier substrate 10 and serves as a layer for protecting the electrode pattern layer 30 by covering the electrode pattern layer 30. [

The separation layer 20 may be formed of, for example, polyimide, polyvinyl alcohol, polyamic acid, polyamide, polyethylene, polystyrene, The present invention relates to a method for producing a polyimide precursor composition comprising a polymer selected from the group consisting of polynorbornene, phenylmaleimide copolymer, polyazobenzene, polyphenylenephthalamide, polyester, polymethyl methacrylate, and at least one material selected from the group consisting of polyarylates, cinnamate polymers, coumarin polymers, phthalimidine polymers, chalcone polymers, and aromatic acetylene polymers. Or may be formed by applying a composition for forming a separation layer on the carrier substrate 10. The contact angle, which will be described later, may preferably include a polymer such as polyarylate or polyimide in terms of surface energy.

The coating method is not particularly limited and includes, for example, slit coating, knife coating, spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, A method known in the art such as a spraying method, a spray coating method, a screen printing method, a gravure printing method, a flexo printing method, an offset printing method, an ink jet coating method, a dispenser printing method, a nozzle coating method, have.

After the application of the composition for forming the separation layer, an additional curing process may be further carried out, either by photocuring or thermosetting, or by both of the above methods. The order of the photo-curing and the thermal curing is not particularly limited.

The separating layer 20 preferably has a water contact angle of less than 75 degrees. When the water contact angle is 75 DEG or more, the application of the composition for forming a polymer layer may not be smooth or adhesion with the polymer layer may not be sufficient at the time of forming a polymer layer to be described later.

When the separating layer 20 is peeled from the carrier substrate 10, the water contact angle of the peeling surface is lowered and the surface energy can be increased. The separating layer 20 has a water contact angle of not less than 25 deg. To less than 55 [deg.].

If the water contact angle is less than 25 deg., The water-based exfoliation liquid to be described later may remain on the surface of the separating layer, resulting in water spots or foreign matter. If it is 55 DEG or more, the interfacial penetration force of the water-based exfoliation liquid becomes weak, so that the deterioration of the peeling force and the effect of suppressing damage may not be sufficient.

Further, in the case of the surface energy of the separation layer 20, it is preferable that the surface energy of the release surface after peeling is increased by 5 to 20 Nm / m compared to before peeling. In such a case, it is possible to easily penetrate the aqueous detachment solution to the site where the surface energy is increased during the separation step of the separation layer to be described later.

If the surface energy before peeling is too high, there is a fear of re-adhesion after peeling, and foreign matter is likely to be adsorbed in the peeling process. Also, when the surface energy is too low, it is difficult to form an organic layer or the like on the formed separation membrane in the same manner as the water contact angle, and there is a possibility of peeling off even after film formation, so that the surface energy before peeling is preferably 30 to 55 Nm / m.

The carrier substrate 10 may be used without any particular limitation as long as it is a material that provides adequate strength to be fixed without being bent or twisted during processing, and has little effect on heat or chemical treatment. For example, glass, quartz, silicon wafer, cloth or the like can be used, and preferably, glass can be used.

The carrier substrate 10 preferably has a water contact angle of 8 to 20 after peeling. In such a case, in the peeling step to be described later, the difference in water contact angle with the peeling surface of the separating layer 20 is large, and the peeling liquid can be easily peeled off. It remains.

2 (b), an electrode pattern layer 30 is formed on the separation layer 20. Then, as shown in FIG.

As the electrode pattern layer 30, any conductive material may be used without limitation, and examples thereof include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum zinc oxide (AZO) Indium zinc oxide (IZO-Ag-IZO), indium zinc oxide (ITO-Ag-ITO), gallium zinc oxide (GZO), florine tin oxide (FTO), indium tin oxide- Metal oxide materials selected from the group consisting of tin oxide-silver-indium zinc tin oxide (IZTO-Ag-IZTO) and aluminum zinc oxide-silver-aluminum zinc oxide (AZO-Ag-AZO); Metals selected from the group consisting of gold (Au), silver (Ag), copper (Cu), molybdenum (Mo) and APC; Nanowires of metals selected from the group consisting of gold, silver, copper and lead; Carbon-based materials selected from the group consisting of carbon nanotubes (CNT) and graphene; And a conductive polymer material selected from the group consisting of poly (3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI). These may be used alone or in combination of two or more.

The method of forming the electrode pattern layer 30 is not particularly limited and may be selected from physical vapor deposition, chemical vapor deposition, plasma deposition, plasma polymerization, thermal vapor deposition, thermal oxidation, anodization, Printing methods such as LEXO printing method, offset printing method, inkjet coating method, and dispenser printing method.

Next, a polymer layer 40 is formed on the separation layer 20 on which the electrode pattern layer 30 is formed, as shown in FIG. 2 (c).

The polymer layer 40 electrically insulates unit patterns of the electrode pattern layer 30 and protects the electrode pattern layer 30 to protect the electrode patterns 30.

Examples of the polymer constituting the polymer layer 40 include polyethylene terephthalate (PET), polyethylene sulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), polymethylmethacrylate (PMMA) (PI), ethylene vinyl acetate (EVA), amorphous polyethylene terephthalate (APET), polypropylene terephthalate (PPT), polyethylene terephthalate glycerol (PETG), polycyclohexylenedimethylene terephthalate (CPA), polyarylate (PAR), polyetherimide (PEI), polyacetaldehyde (PEI), polyacetaldehyde ), Polydimethylsilonane (PDMS), silicone resin, fluororesin, and modified epoxy resin.

The method of forming the polymer layer 40 is not particularly limited, and can be formed by, for example, the same method as the separation layer 20 described above.

2 (f), at least a part of the boundary between the carrier substrate 10 and the separation layer 20 is brought into contact with an aqueous stripping liquid containing not less than 50% by weight of water, and the separation layer 20 And peeled off from the substrate.

The boundary between the carrier substrate 10 and the separation layer 20 means a boundary therebetween. For example, when the carrier substrate 10 and the separation layer 20 are stacked as shown in FIG. 3, 10 and the separation layer 20 may be a portion including a reddish portion.

If the at least a part of the boundary portion between the carrier substrate 10 and the separation layer 20 is brought into contact with the aqueous separating liquid, the aqueous separating liquid penetrates into the interface between the carrier substrate 10 and the separating layer 20 by capillary phenomenon, . Accordingly, peeling of the carrier substrate 10 and the separation layer 20 can be easily performed, and damage to the electrode pattern layer 30 and the like can be minimized during peeling.

In addition, it is possible to suppress the static electricity that may occur during peeling, and to make the peeling surface smoother by absorbing foreign substances present at the interface.

Even if at least a part of the boundary portion between the carrier substrate 10 and the separation layer 20 is brought into contact with the aqueous separation solution, the above effect can be realized because the boundary is spread at the interface with the aqueous separation solution as described above. It is possible.

The content of water in the aqueous detachment solution may be, for example, 50% by weight to 100% by weight. When the content of water is less than 50% by weight, the peeling force between the carrier substrate 10 and the separating layer 20 is increased by the use of the aqueous separating liquid, or cracks are generated in the separating layer, the electrode pattern layer, .

Preferably, the low boiling point solvent may be mixed to minimize water spots that may occur after drying the aqueous stripping solution.

In this specification, the low-boiling solvent is a solvent having a boiling point of less than 100 ° C and at least a part of which can be mixed with water, for example, methanol, ethanol, and the like. These may be used alone or in combination of two or more.

If necessary, the aqueous detachment solution may further contain a surfactant.

The surfactant facilitates the penetration of the water-based exfoliation liquid into the interface and serves to remove foreign matter from the exfoliation surface.

As the surfactant, for example, a silicone surfactant or a fluorine surfactant can be used.

The silicone surfactant is not particularly limited, and examples thereof include DC3PA, DC7PA, SH11PA, SH21PA, and SH8400 of Dow Corning Toray Silicone Co., Ltd.; TS F-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460 and TSF-4452 of GE Toshiba Silicones.

Examples of the fluorochemical surfactant include, but are not limited to, Megapis F-470, F-471, F-475, F-482 and F-489 commercially available from Dainippon Ink and Chemicals, Incorporated.

The surfactant may be contained in an amount of 10% by weight or less based on the total weight of the water-based exfoliation solution.

The method of bringing the boundary into contact with the water-based exfoliation liquid is not particularly limited. The method of immersing the water-based exfoliation liquid in the above-mentioned method, spraying the water-based exfoliation liquid, or contacting a brush, roller, Method can be used.

The method of manufacturing a flexible substrate of the present invention further includes the step of attaching the flexible substrate 50 onto the polymer layer 40 before or after the step of peeling the separation layer 20 from the carrier substrate 10 .

That is, the polymer layer 40 is formed on the separation layer 20 on which the electrode pattern layer 30 is formed, the flexible substrate 50 is attached on the polymer layer 40, Or the flexible substrate 50 may be attached onto the polymer layer 40 after the separation layer 20 is peeled from the substrate. FIG. 2 illustrates a process in which the flexible substrate 50 is first attached and then the separation layer 20 is peeled from the substrate.

The flexible substrate 50 may be adhered using a water-based adhesive, an adhesive, or a photo-curable or thermosetting adhesive or an adhesive known in the art.

The flexible substrate 50 can be used without limitation to a transparent film made of a material widely used in the art, for example, a cellulose ester (e.g., cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate pro Polyanhydrides such as polyethylene terephthalate, polyethylene naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene 1,2-diphenoxyethane- 4,4'-dicarboxylate and polybutylene terephthalate, polystyrenes such as syndiotactic polystyrene, polyolefins such as polypropylene, polyethylene and polymethylpentene, polysulfone, polyethersulfone, Polyarylate, polyether-imide, polymethylmethacrylate, polyetherketone, poly Vinyl alcohol, and polyvinyl chloride, or a mixture thereof.

The present invention also provides a flexible substrate manufactured by the above method.

The flexible substrate manufactured by the above method includes the separation layer 20 as it is, so that the separation layer 20 protects the electrode pattern layer 30 and has an unimpaired electrode pattern layer 30 and the like.

The flexible substrate of the present invention can be applied without limitation to any field to which various flexible substrates such as an image display device, a solar cell, and the like are applied.

Further, the present invention provides an image display apparatus provided with the flexible substrate.

The flexible substrate of the present invention is applicable not only to a general liquid crystal display device but also to various image display devices such as an electroluminescent display device, a plasma display device, and a field emission display device.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Example  And Comparative Example

One. Example  One

After the glass substrate was cleaned with isopropyl alcohol, O ₂ plasma treatment (O ₂ gas of 1 sccm, process pressure of 10 mTorr, treatment with DC power of 500 W for 300 seconds) was performed to modify the substrate surface to be hydrophilic, The glass substrate was used as a carrier substrate.

A polyarylate (unifiner: 22 wt%) was applied to the carrier substrate using a Doctor blading method with a thickness of 7 탆, followed by heat treatment at a hot plate at 90 캜 for 5 minutes and then at 150 캜 in an oven for 20 minutes Post-baking to form a separation layer.

An Ag nanowire (cambrios) was coated on the separation layer using a bar coating equipment and a pattern was formed by an etching process to form an electrode pattern layer having a thickness of 20 m and a line width of 20 m.

Next, a composition for forming a polymer layer containing a polyarylate resin was applied on the separation layer having the electrode pattern layer formed thereon by a doctor blading method to a thickness of 3 탆, irradiated with UVA 356 nm at a wavelength of 200 mJ, Treated at 130 DEG C for 40 minutes to form a polymer layer.

Next, a film of OCA (3M company: 8146-2 thickness 50um) was bonded to the separating layer using a laminator, and a PET flexible substrate having a thickness of 50 占 퐉 was laminated again to form a flexible substrate. Thereafter, an aqueous separating liquid was sprayed onto the interface between the carrier substrate and the separating layer, and the separating layer was separated from the carrier substrate to prepare a flexible substrate.

2. Example  2-3 and Comparative Example  1-3

A flexible substrate was prepared in the same manner as in Example 1, except that the composition of the separation layer and the solvent sprayed on the interface were used as shown in Table 1 below.

division Water contact angle after peeling of carrier substrate
(°) Composition for separation layer formation Separation layer
Water contact angle (˚) Separation layer
Surface energy (Nm / m) menstruum Before peeling After peeling Before peeling After peeling Example 1 8 A 67 46 43 55 Water 100 wt% Example 2 8 A 67 46 43 55 0.5% by weight of a silicone surfactant (BYK UV-3530, BYK)
Water 99.5 wt% Example 3 8 A 67 46 43 55 5% by weight of ethanol, 95% by weight of water, Comparative Example 1 8 A 67 46 43 55 100% by weight of toluene Comparative Example 2 8 B 96 80 40 48 100% by weight of toluene Comparative Example 3 8 A 67 46 43 55 46% by weight of water, 54% by weight of ethanol, A: Polyarylate (unifiner M-2040) N-methylpyrrolidone solution (solid content 22% by weight)
B: an adhesive composition comprising 97 wt% of an epoxy resin (KR-500, Asahi Denka Kogyo K.K.) and 3 wt% of 3- (N, N-dimethylaminopropyl) trimethoxysilane (SID3547.0 Gelest)

Experimental Example

(One) Peel force  Measure

In the flexible substrate manufacturing processes of Examples and Comparative Examples, the peeling force at 90 deg. Peeling (0.3 m / min) before and after solvent spraying was measured with an automatic gragh (UTM) equipment of Shimadzu Corporation.

(2) crack  Occurrence

The cracks in the flexible substrate prepared in Examples and Comparative Examples were peeled off from the carrier substrate by an Auto gragh 90 ° jig (sample size: 25 mm x 150 mm). The specific evaluation method is as follows.

A transparent polycarbonate film (25 mm X 150 mm) having a pressure-sensitive adhesive bonded to a flexible substrate was bonded. Thereafter, the substrate was peeled off at 90 ° using an auto gragh machine to check the state of the flexible substrate, and the evaluation was made according to the following criteria.

○: Crack is not recognized

△: Cracks were recognized as 5 or less

X: Cracked more than 5

(3) Check the surface condition when peeling off

The occurrence of fine cracks and the presence of foreign matter on the release surface (separation layer) of the flexible substrate prepared in Examples and Comparative Examples were confirmed.

The occurrence of microcracks was confirmed by observing the cleaved surface in an optical microscope (X150) reflection mode.

Foreign matter may exist on the separation surface due to non-uniform separation when the flexible substrate is peeled from the carrier substrate. The remaining part of the foreign object was visually observed, and when the foreign object was not visually recognized by the transmitted light or the reflected light, it was evaluated as X. When it was visually confirmed,

division Peel force (N / 25mm) Crack occurrence grade Peeled surface state Before solvent spraying After solvent injection Example 1 0.34 0.01 ○ ○ Example 2 0.34 0.06 ○ ○ Example 3 0.34 0.09 ○ ○ Comparative Example 1 0.34 3.1 X X Comparative Example 2 6.0 8.7 X X Comparative Example 3 0.34 1.3 X ○

Referring to Table 2, in the flexible substrates of Examples 1 to 3, the peeling force between the carrier substrate and the separating layer was lowered after the water-based peeling liquid was contacted, so that cracks were not generated at peeling, and the surface state of peeling was good.

However, in the flexible substrates of Comparative Examples 1 to 3, the peeling force was increased by the peeling liquid contact, cracking occurred, and the surface state of the peeling surface was not good.

Fig. 4 shows the surface state of Comparative Example 1, and it can be confirmed that the light transmittance is lowered due to the occurrence of cracks.

10: carrier substrate 20: separating layer
30: electrode pattern layer 40: polymer layer
50: flexible substrate

Claims (7)

Forming a separation layer on the carrier substrate;
Forming an electrode pattern layer on the isolation layer;
Forming a polymer layer on the separation layer on which the electrode pattern layer is formed; And
Contacting at least a part of a boundary portion between the carrier substrate and the separating layer to an aqueous separating liquid containing not less than 50% by weight of water, and peeling the separating layer from the substrate.
The method of manufacturing a flexible substrate according to claim 1, wherein the separation layer has a surface energy of 5 to 20 Nm / m increase in peeled surface after peeling and peeling.
The method of manufacturing a flexible substrate according to claim 1, wherein the separation layer has a surface energy before peeling of 30 to 55 Nm / m
The method of manufacturing a flexible substrate according to claim 1, wherein the separation layer has a surface energy of peeling-off surface of 55 to 70 Nm / m.
[4] The method of claim 1, wherein the separation layer is formed of a material selected from the group consisting of polyimide, poly vinyl alcohol, polyamic acid, polyamide, polyethylene, polystyrene, The present invention relates to a method for producing a polyimide precursor composition comprising a polymer selected from the group consisting of polynorbornene, phenylmaleimide copolymer, polyazobenzene, polyphenylenephthalamide, polyester, polymethyl methacrylate, and at least one material selected from the group consisting of polyarylates, cinnamate polymers, coumarin polymers, phthalimidine polymers, chalcone polymers, and aromatic acetylene polymers. Wherein the separation layer is formed from a composition for forming a separation layer containing a composition for forming a separation layer.
The method of manufacturing a flexible substrate according to claim 1, wherein the aqueous peeling solution further comprises a low boiling point solvent.
The method according to claim 1, further comprising the step of attaching a flexible substrate on the polymer layer.

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