Transparent display and manufacturing method thereof

Abstract

The present invention relates to a transparent display and a manufacturing method thereof. The transparent display comprises: a first region including a substrate, an adhesive bonded to the substrate, and metal wiring bonded to the adhesive; and a second region including only the substrate. The method for manufacturing the transparent display is characterized by comprising: a step for bonding a metal thin film having an adhesive bonded to a lower portion thereof to a substrate by means of the adhesive; a step for bonding a photoresist onto the metal thin film; a step for patterning the photoresist; a step for etching the metal thin film; and a stripping step for removing the photoresist and the exposed adhesive.

Description

Transparent display and manufacturing method thereof

[0001] The present invention relates to a transparent display. More specifically, the present invention relates to a transparent display capable of cleanly removing an adhesive bonding metal wiring to a substrate through a photoresist stripping process, and a method for manufacturing the same.

[0002] With technological advancements, the display market is seeing a growing demand for large-area display devices. Research is actively underway on advanced electronic circuit technologies, such as Micro-LED and Mini-LED, which can individually control the brightness of each unit area. Furthermore, research is being conducted on photolithography techniques to simultaneously achieve high resolution and contrast ratio quality across large areas.

[0003] Korean Patent Publication No. 10-2019-0003025 discloses a circuit board and its manufacturing method, which uses a patterning process to form a metal layer on a glass substrate. The technical details demonstrate the use of plating, deposition, and other methods to create low-resistance metal wiring on the glass substrate. However, these methods have limitations in implementing large-area displays.

[0004] To overcome these limitations, recent attempts have been made to bond metal films to glass substrates using adhesives, then pattern the metal films using photolithography. However, this method of bonding metal films to glass substrates lacks sufficient adhesion between the metal films and the glass substrate. Furthermore, during the patterning process, the adhesive is often not completely removed and remains in the etched areas of the metal wiring. Residual adhesive can cause surface stains and reduced transmittance, and furthermore, when the adhesive comes into contact with the etchant, it can cause surface damage, reduced hardness, and haze on the substrate.

[0005] The purpose of the present invention is to cleanly dissolve and remove an adhesive that bonds a metal wiring to a substrate in a stripping process for forming a metal wiring using a stripping solution.

[0006] In addition, the present invention aims to prevent adhesive from remaining on metal wiring or a substrate during the patterning step of a metal thin film by cleanly removing the adhesive.

[0007] To achieve this purpose, the transparent display of the present invention includes a substrate, an adhesive, metal wiring, etc.

[0008] The substrate is supported by forming metal wiring on the upper surface using an adhesive.

[0009] The adhesive bonds to the substrate.

[0010] The transparent display of the present invention includes a first region including metal wiring bonded to an adhesive and a second region including only a substrate.

[0011] In the transparent display of the present invention, the second region including only the substrate may be formed such that after the peeling step of removing the photoresist and the exposed adhesive, the metal film and the adhesive are peeled off, leaving only the substrate.

[0012] In the transparent display of the present invention, the adhesive may be composed of an organic compound of the acrylic or silicone series.

[0013] The transparent display of the present invention may include a surface-mount component that is bonded to metal wiring. The surface-mount component may be an LED.

[0014] In the transparent display of the present invention, the substrate may be made of glass.

[0015]

[0016] The method for manufacturing a transparent display of the present invention may include a step of bonding a metal thin film having an adhesive bonded to a lower portion thereof to a substrate via the adhesive; a step of bonding a photoresist onto the metal thin film; a step of patterning the photoresist; a step of etching the metal thin film; and a step of removing the photoresist and the exposed adhesive.

[0017] In the method for manufacturing a transparent display of the present invention, the step of bonding a metal thin film to a substrate using an adhesive may include a step of removing a lower protective film from a laminate of a lower protective film, an adhesive, a metal thin film, and an upper protective film; a step of bonding the adhesive to the substrate; and a step of removing the upper protective film.

[0018] In the method for manufacturing a transparent display of the present invention, the step of bonding a metal thin film to a substrate using an adhesive may include the steps of coating the substrate with an adhesive; removing the lower protective film from a laminate of a lower protective film, a metal thin film, and an upper protective film; bonding the metal thin film to the adhesive; and removing the upper protective film.

[0019] In the method for manufacturing a transparent display of the present invention, the step of bonding a photoresist on a metal thin film can form a dry film resin on the metal thin film.

[0020] In the transparent display manufacturing method of the present invention, the step of bonding the metal thin film to the substrate may use an acrylic or silicone-based organic compound as the adhesive. The step of removing the adhesive may use an alkaline solution as the stripping agent.

[0021] In the method for manufacturing a transparent display of the present invention, a step of soft baking the adhesive may be further included prior to the peeling step of removing the adhesive.

[0022] In the transparent display manufacturing method of the present invention, the soft baking step can be performed at a temperature of 70 to 120°C for 20 to 60 minutes.

[0023] The transparent display of the present invention and its manufacturing method can cleanly dissolve and remove the adhesive exposed during the stripping process for forming metal wiring, thereby preventing any adhesive residue on the metal wiring or substrate. As a result, the present invention can increase the transmittance of the transparent display, reduce haze, and prevent external stains.

[0024] The transparent display of the present invention and its manufacturing method can be freely applied to various fields such as glass penetrating electrodes because no adhesive remains on the substrate.

[0025] In addition, the transparent display of the present invention and its manufacturing method can significantly improve processability, productivity, etc. by eliminating the problem of reactivity of adhesive with other materials such as OCR in the post-process.

[0026] Figure 1 is a cross-sectional view of a transparent display according to the present invention.

[0027] Figure 2 is a process diagram for manufacturing a transparent display according to the present invention.

[0028] Figure 3 is a first process diagram for forming a laminate including a peeling agent dissolving adhesive in the manufacture of a transparent display according to the present invention.

[0029] Figure 4 is a second process diagram for forming a laminate including a peeling agent dissolving adhesive in the manufacture of a transparent display according to the present invention.

[0030] Hereinafter, the present invention will be described in detail with reference to the attached drawings.

[0031]

[0032] Figure 1 is a cross-sectional view of a transparent display according to the present invention.

[0033] As shown in Fig. 1, the transparent display of the present invention may include a substrate (110), a peeling agent dissolving adhesive (120), metal wiring (130), etc.

[0034] The substrate (110) is formed by supporting a metal wire (130) by means of a peeling agent-dissolving adhesive (120) on the upper side, and can be made of a transparent material such as transparent glass or transparent plastic film.

[0035] The substrate (110) may be composed of glass, preferably tempered glass, considering thermal deformation, etc. The glass may be silicate glass, borate glass, phosphate glass, etc.

[0036] Glass can be configured with a thickness of 1 to 20 mm. If the glass thickness is less than 1 mm, it may be difficult to protect the metal wiring (120) or other laminated components from external impact. If the glass thickness exceeds 20 mm, it may be disadvantageous in terms of thinning and weight reduction.

[0037] Glass can form micro-roughnesses on its surface to disperse the strain generated during heat treatment or cooling. These micro-roughnesses can disperse the strain that may occur during heat treatment, thereby preventing warping of the substrate (110). These micro-roughnesses can also be etched to form through-holes or micro-channels. These micro-roughnesses, through-holes, or micro-channels can enhance the adhesion of metal wiring during the subsequent metal wiring formation process.

[0038] The substrate (110) can also be a transparent plastic film. Transparent plastic films are, for example, cycloolefin derivatives having units of monomers containing cycloolefins such as norbornene or polycyclic norbornene monomers, cellulose (diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, isobutyl ester cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose), ethylene vinyl acetate copolymer, polyester, polystyrene, polyamide, polyetherimide, polyacrylic, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, It can be composed of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyurethane, epoxy, etc.

[0039] The thickness of the transparent plastic film is not particularly limited, but can be configured to be 8 to 1000 ㎛, preferably 20 to 150 ㎛. If the thickness of the transparent plastic film is less than 8 ㎛, its strength may be reduced, resulting in poor processability. If the thickness of the transparent plastic film exceeds 1000 ㎛, its transparency may be reduced.

[0040] The peeling solution dissolving adhesive (120) is bonded to the substrate (110) to adhere the upper metal wiring (130) to the substrate (110), and can be composed of a material having adhesive (or bonding) properties.

[0041] The stripping solution dissolving adhesive (120) can be composed of a material that dissolves in the stripping solution during the stripping process of forming the metal wiring (130).

[0042] The peeling solution dissolving adhesive (120) can be appropriately selected depending on the peeling solution. The peeling solution dissolving adhesive (120) can be composed of, for example, a mixture of polyacrylic acid and methyl methacrylate.

[0043] Table 1 below illustrates the corresponding relationship between the peeling agent dissolving adhesive (120) and the peeling agent.

[0044] Remover Dissolution Adhesive Remover 1Polyacrylic Acid + Methyl Methacrylate MixtureNaOH or KOH2Polyacrylic Acid + Methyl Methacrylate MixtureMEK(Methyl Ethyl Ketone)3Tetraethyl orthosilicateTMAH(Tetramethylammonium Hydroxide)4Tetraethyl orthosilicateNaOH or KOH

[0045] In Table 1 above, it is preferable to use a mixture of polyacrylic acid and methyl methacrylate as the stripping agent dissolving adhesive, and sodium hydroxide (NaOH) or potassium hydroxide (KOH) as the corresponding stripping agent. This combination allows the adhesive to be dissolved quickly without residue due to the chemical solution, and is also inexpensive. The stripping agent dissolving adhesive (120) can be formed to have a thickness of 5 to 50 μm, preferably 5 to 30 μm, and more preferably 5 to 25 μm. If the thickness of the stripping agent dissolving adhesive (120) is less than 5 μm, it may be difficult to maintain sufficient adhesive strength with other members. If the thickness of the stripping agent dissolving adhesive (120) exceeds 50 μm, it may be disadvantageous to increase the thickness of the product.

[0046] The stripping agent dissolving adhesive (120) preferably uses an acrylic-based organic compound, such as an acrylic resin-based adhesive, which has excellent chemical resistance to metal etchants. If the adhesive is not damaged by the etchant, there is no need to separately provide an intermediate layer or protective layer, which were previously provided to protect the adhesive. As a result, processability is improved, manufacturing costs can be reduced, and it is also advantageous for film thinning.

[0047] When the peeling solution dissolving adhesive (120) is composed of an organic compound of the acrylic or silicone series, it has a distinct advantage over when it is composed of a metal material adhesive.

[0048] First, metal-based adhesives have the problem of warping when applied to glass substrates. However, organic compound adhesives are relatively free from warping.

[0049] Second, metal-based adhesives require expensive plating or sputtering processes, as well as etching processes for adhesive removal. However, organic compound adhesives offer relatively inexpensive and simple coating and substrate bonding processes for metal films. Furthermore, organic compound adhesives are removed during the photoresist stripping process, offering advantages in process simplification.

[0050] Third, metal adhesives can cause defects in the straightness of the metal film pattern when the adhesive comes into contact with the etchant during the etching process for removal. However, organic compound adhesives have no effect on the formation of the metal film pattern.

[0051] Methods for bonding a release agent-dissolved adhesive (120) to a substrate (110) include methods such as coating, drying / heat treatment, etc. of a liquid-form adhesive, and laminating in a film form. These methods can be appropriately selected and performed within a range that does not harm the purpose of the present invention.

[0052] Metal wiring (120) transmits an electric signal and can be formed on the substrate (110).

[0053] The metal wiring (120) may be composed of a conductive metal. The conductive metal may be composed of, for example, copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), silver (Ag), iron (Fe), gold (Au), cobalt (Co), titanium (Ti), tungsten (W), etc.

[0054] The metal wiring (120) may be formed to a thickness of 3 to 120 μm, preferably 3 to 70 μm, and more preferably 18 to 70 μm. If the thickness of the metal wiring (120) is less than 3 μm, it may not be easy to form a uniform thin film or pattern. If the thickness of the metal wiring (120) exceeds 120 μm, it may not be suitable for application to electronic devices having a thin film structure.

[0055]

[0056] Figure 2 is a process diagram for manufacturing a transparent display according to the present invention.

[0057] As shown in FIG. 2, the method for manufacturing a transparent display of the present invention can bond (form) a photoresist (210) to the upper surface of a laminate in which a substrate (110), a peeling agent-dissolved adhesive (120), and a metal thin film (130) are laminated, as shown in FIG. 2(a), specifically, to the upper surface of the metal thin film (130).

[0058] The peeling agent dissolving adhesive (120) constituting the laminate may be an adhesive that is easily dissolved / removed by the peeling agent used in the metal wiring (120) forming step described later among the plurality of peeling agent dissolving adhesives described above.

[0059] The photoresist (210) may be a dry film resin, and any known material in the art may be used without particular limitation. The dry film resin may include, for example, a binder resin, a photopolymerizable compound, a photopolymerization initiator, a solvent, and other additives.

[0060] Photoresists (210) can be categorized into positive and negative types depending on the development method. Positive types often require a heat treatment process as a bleaching process after the development process. On the other hand, negative types often do not require a bleaching process. Therefore, it may be preferable to use a negative type photosensitive resin composition for photoresists.

[0061] As shown in FIGS. 2(b) and (c), a step of patterning the photoresist (210) can be performed.

[0062] Patterning of the photoresist (210) may include a step of exposing the photoresist (210) to light through a mask (220), a step of dissolving / removing the photoresist (210) of an exposed or non-exposed area using a developer, a step of cleaning, etc.

[0063] As shown in Fig. 2(d), a step of etching (etching) a metal thin film (130) selectively exposed by a photoresist (210) can be performed.

[0064] Etching of the metal thin film (130) can be performed by dry etching, wet etching, etc. For example, wet etching can use an etchant (etching solution) containing at least one selected from the group consisting of nitric acid, phosphoric acid, and acetic acid.

[0065] As shown in Fig. 2(e), before the stripping step of removing the photoresist (210), a step of soft baking the stripping solution-dissolving adhesive (120) can be performed.

[0066] The soft baking step is to softly harden the stripping solution-dissolved adhesive (120), which can prevent the lower adhesive (120) of the metal wiring (130) from being dissolved by the stripping solution and thus from being peeled off. The soft baking step may involve heat treatment. The heat treatment may be performed, for example, at a temperature of 70 to 120°C for 20 to 60 minutes. The heat treatment temperature and time may be appropriately selected depending on the thickness of the stripping solution-dissolved adhesive (120), peeling characteristics, etc.

[0067] As shown in Fig. 2(f), a stripping process can be performed to dissolve / remove the photoresist (210) using a stripping solution.

[0068] Dissolution / removal of the photoresist (210) can be accomplished by immersing the object on which the resist pattern is formed in a stripping solution or spraying the stripping solution onto the object. After stripping solution treatment, an additional cleaning process can be performed to remove any stripping solution remaining on the object. Water or isopropyl alcohol can be used instead of the stripping solution for the cleaning process. The cleaning process can be the same as the stripping process.

[0069] In the stripping process of Fig. 2(f), the stripping solution-dissolved adhesive (120) revealed by etching of the metal thin film (130) in the process of dissolving / removing the photoresist (210) can also be cleanly dissolved / removed by the stripping solution. At this time, the stripping solution can be a stripping solution corresponding to the stripping solution-dissolved adhesive (120) exemplified in Table 1 above, for example, a basic solution such as sodium hydroxide (NaOH) or potassium hydroxide (KOH), which is commonly used. When a basic solution is used, the concentration of the stripping solution can be 2 to 25 wt%, the temperature can be 22 to 55°C, and the process time can be 20 to 300 seconds. Specific process conditions can be appropriately selected according to the thickness of the stripping solution-dissolved adhesive (120), the stripping characteristics, etc.

[0070]

[0071] Figure 3 is a first process diagram for forming a laminate including a peeling agent dissolving adhesive in the manufacture of a transparent display according to the present invention.

[0072] In order to manufacture a laminate in which a substrate (110), a peeling agent-dissolved adhesive (120), and a metal thin film (130) are laminated, first, as shown in FIG. 3(a), a step of separating the lower protective film (310) from the laminate of the lower protective film (310), the peeling agent-dissolved adhesive (120), the metal thin film (130), and the upper protective film (320) can be performed.

[0073] As shown in Fig. 3(b), a step of bonding the exposed peeling solution-dissolving adhesive (120) to the substrate (110) can be performed.

[0074] Thereafter, as shown in Fig. 3(c), when the upper protective film (320) is removed, a laminate of the substrate (110), the peeling agent dissolving adhesive (120), and the metal thin film (130) described in Fig. 2 above can be formed.

[0075] The method for manufacturing a laminate of the first embodiment illustrated in FIG. 3 can use a pre-formed (bonded) release agent-dissolved adhesive (120) on one surface of the metal thin film (130) when forming a laminate including the metal thin film (130). Using this allows the manufacturing process to be performed more easily and with less process time than the manufacturing process illustrated in FIG. 2.

[0076]

[0077] Figure 4 is a second process diagram for forming a laminate including a peeling agent dissolving adhesive in the manufacture of a transparent display according to the present invention.

[0078] In order to manufacture a laminate in which a substrate (110), a stripping agent-dissolved adhesive (120), and a metal film (130) are laminated, a step of forming a stripping agent-dissolved adhesive (120) on the substrate (110) may be performed, as shown in FIG. 4(a). The stripping agent-dissolved adhesive (120) may be selected from the stripping agent-dissolved adhesives exemplified in Table 1 above. The forming method may use a method such as coating or laminating.

[0079] As shown in Fig. 4(b), a step of separating the lower protective film (310) from the laminate of the lower protective film (310), the metal thin film (130), and the upper protective film (320) can be performed.

[0080] As shown in Fig. 4(c), a step of bonding a metal thin film (130) to the open surface of the peeling solution dissolving adhesive (120) can be performed.

[0081] Afterwards, as shown in FIGS. 4(d) and (e), when the upper protective film (320) is removed, a laminate of the substrate (110), the peeling agent-dissolving adhesive (120), and the metal thin film (130) described in FIG. 2 above can be formed.

[0082] The method for manufacturing a laminate of the second embodiment illustrated in FIG. 4 can be used when utilizing a general-type laminate (e.g., a metal thin film) in which a lower protective film (310), a metal thin film (130), and an upper protective film (320) are laminated. The method for manufacturing a laminate of the second embodiment additionally performs a step of forming a peeling agent-dissolved adhesive (120) on a substrate (110), as illustrated in FIG. 4(a). As a result, although the process time may be longer than that of the manufacturing method of FIG. 3, it may be advantageous in that a general-type metal thin film can be utilized.

[0083]

[0084] The present invention has been described in detail with several embodiments, which are intended to illustrate the invention. Those skilled in the art will readily appreciate the potential for modifications and variations to these embodiments. However, the scope of the present invention is defined by the claims below, and therefore, such modifications and variations are construed as falling within the scope of the present invention.

[0085] [Explanation of symbols]

[0086] 110: Description

[0087] 120: Stripping agent dissolving adhesive

[0088] 130: Metal wiring (or metal film)

[0089] 210: Photoresist

[0090] 220: Mask

[0091] 310: Lower protective film

[0092] 320: Top protective film

Claims

1. Description; An adhesive bonded to the above-mentioned substrate; A transparent display comprising a first region including a metal wiring bonded to the adhesive and a second region including only the substrate.

2. In paragraph 1, the second region including only the description A transparent display in which the metal film and adhesive are peeled off after a stripping step that removes the photoresist and exposed adhesive, leaving only the substrate.

3. In the second paragraph, the adhesive A transparent display composed of organic compounds of the acrylic or silicone series.

4. In any one of paragraphs 1 to 3, A transparent display comprising a surface-mount component bonded to the metal wiring.

5. In paragraph 4, the surface-mounted component LED, transparent display.

6. In paragraph 1, the description above A transparent display using glass.

7. A step of bonding a metal film having an adhesive bonded to a lower portion to a substrate using the adhesive; A step of bonding a photoresist onto the above metal thin film; A step of patterning the above photoresist; A step of etching the above metal thin film; A method for manufacturing a transparent display, comprising a peeling step of removing the photoresist and the exposed adhesive.

8. In the 7th paragraph, the step of bonding the metal film to the substrate using an adhesive is A step of removing the lower protective film from a laminate of the lower protective film, the adhesive, the metal thin film, and the upper protective film; a step of bonding the adhesive to the substrate; and A method for manufacturing a transparent display, comprising the step of removing the upper protective film.

9. In the 7th paragraph, the step of bonding the metal film to the substrate using an adhesive is A step of coating the adhesive on the above-mentioned substrate; A step of removing the lower protective film from the laminate of the lower protective film, the metal thin film, and the upper protective film; a step of bonding the metal film to the adhesive; and A method for manufacturing a transparent display, comprising the step of removing the upper protective film.

10. In the 7th paragraph, the step of bonding a photoresist onto the metal thin film is A method for manufacturing a transparent display, comprising forming a dry film resin on the metal thin film.

11. In paragraph 7, The step of bonding the above metal film to the substrate uses an acrylic or silicone-based organic compound as the adhesive, A method for manufacturing a transparent display, wherein the step of removing the adhesive uses an alkaline solution as a removing agent.

12. In any one of clauses 7 to 11, prior to the peeling step of removing the adhesive, A method for manufacturing a transparent display, further comprising a step of soft baking the adhesive.

13. In the 12th paragraph, the soft baking step A method for manufacturing a transparent display, performed at a temperature of 70 to 120°C for 20 to 60 minutes.

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