KR101940974B1 - Process of fabricating flexible electronic device and flexible electronic device fabriacated by the same - Google Patents

Abstract

A method for manufacturing a flexible electronic device, comprising the steps of: (a) forming a peeling aid layer made of a two-dimensional inorganic material on at least one surface of a relatively rigid support substrate by evaporation spray lamination; (b) (C) forming an electronic device on the flexible plastic film substrate; and (d) peeling the flexible plastic film substrate from the supporting substrate. The present invention relates to a method of manufacturing a flexible electronic device.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing a flexible electronic device and a flexible electronic device manufactured from the flexible electronic device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a flexible electronic device and a flexible electronic device fabricated therefrom, which comprises forming a flexible plastic film base on a rigid support substrate having a release tactile layer made of a two- A manufacturing method of a flexible electronic device manufacturing method in which an electronic device is formed on an upper portion of a plastic film substrate and then the flexible electronic device is separated from a glass support substrate to facilitate separation without damaging or deforming the electronic device, To a flexible electronic device.

Most of the flat panel display devices or lighting devices transmit light and are manufactured on the surface of a ceramic or glass substrate having excellent electrical insulation characteristics. However, these substrates are mechanically fragile and easily broken due to external impact or bending stress , It is difficult to apply to a flexible information display device or a portable electronic device which is bent or folded. Flexible flexible electronic devices and lighting devices are expected to be applied to various portable information display devices including smart phones (Smart Mobile Phones) and various form factor capable devices.

In order to manufacture such a flexible electronic device, a plastic film excellent in flexibility including polyimide is required as a substrate. Since these substrates are thin and have excellent flexibility, the substrate is bent or folded in various manufacturing processes such as a cleaning process, a thin film deposition process, a coating process, an exposure process, a development process, an etching process, etc., There is a problem in that it is difficult to precisely align the masks used in the process or cause irregularities in device characteristics.

In order to solve the problem that the flexible plastic film substrate is bent or folded during the process, a liquid varnish material, which is a raw material of the flexible plastic film substrate, is coated on the surface of a rigid supporting substrate such as a glass substrate, And the flexible electronic device is detached from the supporting substrate and the flexible electronic device is manufactured when the flexible plastic film base is temporarily adhered to the supporting substrate and the flexible electronic device is detached from the supporting substrate when the process is completed, The desorption method is proposed / used as a manufacturing process of a flexible electronic device.

In this regard, Korean Patent No. 10-1580015 discloses a provisional adhesive / desorption mechanical peeling layer and a method for producing the same which provide an adhesive / desorption layer in which an organic material or a plate-like ceramic material layer is alternately stacked by an electrostatic attraction / . Specifically, a charged polyelectrolyte material or a plate-shaped ceramic material having a thickness of 0.1 nm to 1000 nm, preferably 0.1 nm to 10 nm, is layer-coated by electrostatic attraction, and this process is repeated Thereby providing a layer having temporary adhesion / desorption properties.

The 0.1 nm to 10 nm plate-like inorganic material provided in the above-mentioned patent in the optimum thickness range contains a plurality of atomic layers therein. That is, a graphene layer having a thickness of about 0.3 nm has one to thirty layers, a graphene oxide layer having a thickness of about 0.7 nm has one to 14 layers, The montmorillonite having a thickness of about 1 nm is a plate material composed of about 1 to 10 layers. As described above, the temporary adherent / desorbent layer formed using the multilayered plate-like inorganic material has a wide desorption strength. FIG. 1 shows that a montmorillonite material, which is a layered silicate material composed of two to five atomic layers, is coated and measured for pull-off desorption strength, which indicates a very high desorption strength. The spread of such a wide range of desorption strength is very likely to cause damage to the product during desorption.

2A is a schematic cross-sectional view of a temporary adherent / desorbent layer in which a plurality of plate-shaped ceramics having a plurality of atomic layers are laminated. When mechanical stress is applied to and detached from a substrate composed of a glass substrate, an adhesive layer, and a polyimide containing these temporary adhesion / desorption layers, desorption occurs through a portion having the lowest adhesive strength among various interfaces. In the structure of the temporary adhesive / desorption layer material, the adhesive strength between the plate-like inorganic material and the plate-like inorganic material, 2) the adhesive strength between the layers in the plate-like inorganic material, 3) There is an adhesive strength between the inorganic material-polyimide film. Assuming that the interface having the lowest adhesive force is the interface between the plate-like inorganic material and the plate-like inorganic material, in the structure in which the multilayer inorganic material exists in various thicknesses, as shown in FIG. 2B, In such a case, the desorption path is vertically deviated from the existing path, or the desorption path is formed through an interface different from the lowest adhesive strength interface (for example, an interlayer interface of the plate-like inorganic material) This change in the desorption pathway causes scattering of the adhesion force.

Further, in the process of coating the polyimide varnish on the temporary adhesive / desorption layer made of the relatively thick multilayer inorganic plate material, the bubbles can be collected between the plate inorganic material gaps and the layers. The bubbles thus collected grow into bubbles of a size that can be easily recognized by the naked eye during the manufacturing process, resulting in product failure.

In addition, in the above patent, the polymer electrolyte material, which is a positively charged organic material, forms a coating layer by inducing an electrostatic attracting force of a negatively charged inorganic layer material. The organic material contained in the coating layer is generally decomposed and vaporized while the polyimide varnish is thermally cured. The thermosetting process of the polyimide varnish is repeated several times to increase and maintain the temperature stepwise from room temperature, and the maximum curing temperature is generally from 470 ° C to 480 ° C. Meanwhile, FIG. 3 is a result of thermogravimetric analysis of the PDDA polymer electrolyte material provided in the patent, and it can be seen that the material is decomposed and vaporized at a temperature of 400 ° C or lower. The decomposition of such a polymer electrolyte material causes the generation of bubbles in the temporary adherent / desorbent layer, resulting in a large number of quality defects due to adhesion failure or scattering of the desorption strength.

In addition, since the temporary adherent / desorbent layer composed of the polymer electrolyte / layered inorganic material decomposes and disappears in various heat treatment manufacturing processes such as polyimide varnish thermal curing process and the like, / Desorption layer has a layered inorganic material or a structure in which these layered inorganic materials are laminated in multiple layers. As a result, the polymer electrolyte layer is used as an intermediate layer for forming a temporary adherent / desorbent layer, and it has no role in actual desorption process.

The process of forming a temporary adherent / desorption layer of a 1 dyad layer composed of the polymer electrolyte / layered inorganic material provided in the above patent includes: 1) surface treatment of the supporting substrate by a pyran solution or plasma, 2) coating of a polymer electrolyte, 3) Washing with water, 4) drying, 5) coating with a layered inorganic material such as oxidized graphene, 6) water washing, and 7) drying. According to Example 3 provided in the above patent, there is provided a method of depositing a supporting substrate in a coating liquid for 30 minutes to 1 hour. In addition, it can be seen that the processes of 2) to 4) corresponding to the half of the above process are used for coating the polymer electrolyte material as an intermediate layer. Therefore, according to the method provided in the patent, there is a problem that a film forming process line for forming a temporary adhesive / desorption layer becomes very long.

On the other hand, the desorption layer and the desorption method disclosed in Korean Patent Laid-Open No. 10-2015-0009289 provide a desorption layer using graphene oxide (GO), and Korean Patent No. 10-1530378 Discloses a method for providing montmorillonite as a desorption layer. These patents also share similar problems with the above patent.

Therefore, there is a great need to develop a process for manufacturing a flexible electronic device by minimizing the process steps, reducing the contamination to mutual steps, and economically. That is, in order to economically produce a flexible electronic device, it is necessary to develop new processes and materials that can solve the above-mentioned problems of the proposed processes in the conventional mechanical stripping method.

(1) Korean Patent No. 10-1580015 (2) Korean Patent Publication No. 10-2015-0009289 (3) Korean Patent No. 10-1530378

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

Specifically, it is an object of the present invention to provide an evaporation spray lamination method for replacing a lamination process using an electrostatic force at the time of forming a peeling aid layer made of a two-dimensional inorganic material for mechanical peeling, And the process time is reduced from 30 minutes to 1 hour to 1 minute, the possibility of pore defects due to the generation of gas generated in the heat treatment process of the peeling aid layer is minimized, and the desorption strength of the peeling aid layer is made uniform And a method of manufacturing the flexible electronic device.

It is still another object of the present invention to provide a high-quality flexible electronic device manufactured by the above method and reduced in manufacturing cost.

In order to achieve the above object, a manufacturing method according to the present invention is a method for manufacturing a flexible electronic device,

(a) forming a peeling aid layer made of a two-dimensional inorganic material on at least one side of a relatively rigid support substrate by evaporation spray lamination;

(b) forming a flexible plastic film base material on the peeling aid layer;

(c) forming an electronic device on the flexible plastic film substrate; And

(d) peeling the flexible plastic film base material from the supporting base material;

And a control unit.

That is, the method for manufacturing a flexible electronic device according to the present invention includes a step of forming a separation tidal force layer made of a two-dimensional inorganic material on the surface of a relatively rigid supporting substrate by an evaporation spray lamination method, And does not require a multi-step film-forming step using.

In the conventional laminating process using static electricity, the charged polymer electrolyte and the charged plate-like inorganic material are alternately laminated using the electrostatic attraction and the repulsive force. In order to form the desorption layer of 1 dyad, the glass substrate is cleaned. Seven processes of charging (plasma treatment) → coating of polymer electrolyte → water washing → air knife → coating of plate inorganic material → water washing → air knife are required and 25 processes are required for desorption layer of 4 dyads The cleaning of the substrate and the charging treatment of the glass substrate are required only at the initial stage, so that they are excluded when the process is repeated).

On the other hand, in the manufacturing method according to the present invention, only two processes of cleaning → evaporation spray coating of the supporting substrate are required in order to form the peeling aid layer composed of the two-dimensional inorganic material on the supporting substrate, The thickness of the peeling aid layer can be adjusted, so that the desired peeling effect can be obtained by the above two processes alone.

Therefore, compared with the conventional process, the process steps are remarkably shortened, so that the pollution factor generated when the process moves is reduced, the process time is shortened, and the area occupied by the equipment in the clean room is reduced. A high-resolution flexible electronic device can be economically manufactured.

In the conventional electrostatic laminating method, a polyelectrolyte for forming a plate-shaped inorganic material layer is usually used by using an electrostatic attractive force. In the evaporation spray lamination method of the present invention, these organic layers are not required. In the polymer electrolyte, the decomposed gas may be trapped at the interface between the flexible substrate and the supporting substrate to generate pores. However, since the manufacturing method according to the present invention does not use the polymer electrolyte, the above problems do not occur .

Hereinafter, each process of the production method according to the present invention will be described in further detail.

First, in the above process (a), a peeling aid layer made of a two-dimensional inorganic material is formed on at least one surface of a relatively rigid support substrate. The supporting substrate is not particularly limited as long as it is a rigid and rigid material so as to support the flexible plastic film substrate, and in one example, it may be a glass substrate.

The thickness of the supporting substrate may be in the range of 0.3 mm to 1 mm in detail. When the thickness of the supporting substrate is more than 1 mm, the material cost increases, and when the thickness of the supporting substrate is less than 0.3 mm, it is difficult to obtain sufficient rigidity to support the plastic film substrate during the manufacturing process I do not. For the same reason, the thickness of the supporting substrate is more preferably in the range of 0.5 mm to 0.7 mm.

In one specific example, chemical cleaning and / or physical cleaning may be performed to remove contamination of the surface so that a uniform coating may be applied to the surface of the supporting substrate. In chemical cleaning, contaminants on the surface are removed using a cleaning liquid such as distilled water, acetone, or alcohol. In the physical cleaning method, surface contaminants are mechanically wiped off using a cloth, wire brush, etc., and surface treatment is performed using oxygen plasma or the like. This is an example of the surface cleaning of the supporting substrate, but it is not limited thereto, and various cleaning methods can be used depending on the contamination state of the surface and the material of the supporting substrate.

On the other hand, the peeling aid layer made of the two-dimensional inorganic material facilitates peeling between the flexible plastic film substrate and the supporting substrate after the formation of the electronic device,

i) not decompose or deteriorate at various temperatures and atmospheres of the electronic device manufacturing process;

ii) adhere the flexible plastic film substrate and the supporting substrate so that they are not separated by stress while minimizing size variations of the flexible plastic film substrate in various temperature and process environments;

iii) dissolve in the solvent used in the various device manufacturing processes of the electronic device or not react with the chemical;

iv) After the manufacturing process of the electronic device is completed, when the flexible electronic device is peeled from the supporting substrate, the elements constituting the electronic device must be easily separated from the supporting substrate by mechanical stress that is not damaged.

In one specific example, the release aid layer may comprise a carbon-based material or a clay-based material having a two-dimensional crystal structure.

The carbon-based material may be at least one selected from the group consisting of graphene, graphene oxide, and hexagonal boron nitride, and may be a single-atom layer two-dimensional material or a composite two-dimensional material Atomic layer.

The two-dimensional clay-based material is a two-dimensional clay-based material in which, for example, tetrahedrons formed by oxygen-silicon are arranged two-dimensionally and aluminum-oxygen-hydroxy (OH) The branch may be any one or more selected from the group consisting of crystalline silicate, chalcogenide, talc, vermiculite and montmorillonite, and may be a single crystal layer or a composite crystal layer .

The oxidized graphene or the reduced oxidized graphene may be obtained by oxidizing graphite with potassium permanganate (KMnO ₄ ) and concentrated sulfuric acid (H ₂ SO ₄ ), and subjecting the obtained graphite oxide to intercalation And Hummer method (WS Hummers and RE Offeman, J. Am. Chem. Soc., 1958, 80, 1339) manufactured through a peeling process. Oxidation of graphite and intercalation and exfoliation of oxidized graphite are provided by various methods other than the Hummer method. Any method can be used as long as it is an oxide graphene uniformly dispersed in a solution. At this time, the oxidized graphene and the reduced graphene may be composed of one to two graphene layers, and more preferably one two-dimensional atomic layer.

The clay-based material may be a Kaolin group in which a sheet in which a Si-O tetrahedron is arranged in a plane and a sheet in which an Al-O-OH hexahedron is arranged in a plane is sandwiched and sandwiched at a ratio of 1: 1 or 2: And a smectite group. The kaolin group includes kaolinite, serpentine, dickite and the like. The smectite group includes talc, vermiculite, montmorillonite, etc. . These clay-based materials usually have a laminate structure in the form of a plate, and when it is peeled off for more than one week in an aqueous solution, a peeled two-dimensional material having a thickness of 1 nm can be obtained.

When a coating layer is formed by an evaporation spray lamination method using a suspension in which the graphene oxide is dispersed, the distance between the layers is approximately 1 nm. FIG. 4 shows a result of X-ray rotation analysis of a coating layer in which a plurality of graphene grains are stacked. It can be seen that the distance between layers is about 1 nm. That is, when three to four layers of the separation aid layer are used, the thickness of the appropriate separation aid layer is in the range of 3 nm to 5 nm.

The thickness of the peeling aid layer made of the two-dimensional inorganic material may be in the range of 2 nm to 10 nm, and more specifically in the range of 2 nm to 5 nm.

If the thickness of the peeling aid layer is out of the above range and the thickness of the peeling aid layer is more than 10 nm, the peeling aid layer is formed in excess of the thickness necessary for mechanical peeling, and the process efficiency becomes poor. On the contrary, The peeling strength is too high, and the possibility of causing a peeling defect in the electronic device at the time of peeling becomes high.

In the evaporation spray lamination method of the present invention for forming such a separation helping layer, a suspension in which nanoparticle-like particles for forming a separation aid layer are uniformly dispersed is atomized to a fine droplet size. The spraying method may be a method of spraying the suspension through fine nozzles, spraying ultrasonic waves to the suspension, or a combination of these two methods.

Therefore, in the above process (a), the suspension in which the particles for forming the separation aid layer are dispersed is sprayed in a droplet state by the suspension liquid droplet generating device, and a separation aid layer is formed on the surface of the support substrate heated to a predetermined temperature In one specific example, the suspension droplet generating device may be a spray nozzle device, an ultrasonic vibrating mesh nebulizer, or an ultrasonic wave nebulizer.

The suspension liquid in which the two-dimensional nanoparticle material is dispersed is transferred to the surface of the supporting substrate by using a carrier gas such as nitrogen or air to form a coating layer. At this time, the suspension liquid is wetted on the surface of the support substrate, and the solvent is evaporated to coat the surface of the support substrate with the two-dimensional nanoparticles contained in the droplet. For proper coating, the solvent constituting the droplet needs to be vaporized at a suitable rate at the surface of the supporting substrate, and the evaporation rate of the solvent may be controlled by various factors such as the temperature of the supporting substrate, the size of the droplet, the vaporization temperature of the solvent, The evaporation rate can be controlled through an appropriate combination of these variables.

In addition, it is required that the droplet impinging on the surface of the supporting substrate has a proper wetting angle with the surface of the substrate. As the droplet is evaporated at a small angle on the surface of the supporting substrate, the two-dimensional inorganic material dispersed in the droplet is coated in the unfurled state. Therefore, the wettability of the droplets can be appropriately controlled, and the two-dimensional inorganic material can be uniformly coated with a large area in layers.

As described above, since the evaporation rate of the solvent and the wetting angle of the droplet change in an interdependent relationship of various factors, it is possible to control by adjusting the appropriate parameters of the variables within a range that can satisfy the uniform coating of the two- Needless to say,

As the solvent of the suspension, various liquids can be used. The two-dimensional inorganic material is uniformly dispersed in the solvent, the boiling point is low and the evaporation easily occurs even when the temperature of the supporting substrate is low. It is not particularly limited as long as it has a property of forming a small wetting angle with the supporting substrate. The solvent of the suspension may be selected from the group consisting of heptane, hexane, ethanol, methanol, butanol, propanol, methylene chloride, trichlorethylene, ethyl But are not limited to, ethyl acetate, acetone, methyl ethyl ketone, diethylamine, di-isopropylamine, isopropylamine, water, and the like. It is possible that two or more mixed solvents are used.

The suspension may further include an additive for assisting dispersion of the two-dimensional inorganic material and reducing the surface tension of the solvent to improve the wettability with the supporting substrate. Examples of such additives include sodium dodecyl sulfate (SDS), ammonium lauryl sulfate (SLS), perfluorooctanesulfonate (PFOS), and cetrimonium bromide (CTAB), which are various additives, surfactants, surface tension modifiers, defoaming agents, ), Cetylpyridinium chloride (CPC), Benzalkonium chloride (BAC), Benzethonium chloride (BZT), Dimethyldioctadecylammonium chloride, Dioctadecyldimethylammonium bromide (DODAB), Polyethylene glycol octylphenyl ethers, Glyceryl laurate, Cocamide MEA, cocamide DEA and Dodecyldimethylamine oxide. But it is not limited thereto.

On the other hand, the peeling aid layer made of the two-dimensional inorganic material may be formed on the entire surface of the supporting substrate, or may be formed only on a part thereof.

In one specific example, in the case where the peeling aid layer is formed only in a part, the non-coating portion in which the peeling aid layer is not present is formed along the outer periphery of the supporting substrate, and in the non- As shown in FIG.

In another specific example, the coating portion composed of the peeling aid layer and the non-coating portion in which the peeling aid layer is not present may be formed in a regular pattern on the supporting substrate.

The regular pattern may, for example,

A pattern structure in which a plurality of coating portions are uniformly arranged as independent islands, and an uncoated portion exists between the coating portions;

A pattern structure in which a plurality of uncoated portions are uniformly arranged as respective independent islands, and a coating portion is present between the uncoated portions;

And the like.

This patterning of the peeling aid layer can be performed by various methods.

As a first exemplary method, a mask or a film having a pattern is attached to the surface of the supporting substrate, and a peeling aid layer is formed by an evaporation spraying lamination method so that a two-dimensional inorganic material is coated only on a portion where the substrate is exposed The release tie layer is pattern-coated.

As a second exemplary method, a separation assistant layer that is uniformly coated is etched using a laser, a plasma, or an ozone gas. That is, the mask is brought into close contact with the supporting substrate on which the peeling aid layer made of the two-dimensional inorganic material is uniformly coated, and the peeling aid layer is exposed to laser, oxygen plasma, ozone gas or the like, To be patterned.

As described above, the patterning of the peeling aid layer increases the adhesive force between the plastic film substrate and the supporting substrate at the portion where the peeling aid layer is not formed or removed. That is, at the portion where the peeling aid layer is not coated, the plastic film base and the supporting base material are directly adhered to each other, so that the adhesive strength of this portion is much higher than the portion where the peeling aid layer made of the two-dimensional inorganic material is coated. Therefore, the portion having a high adhesive force serves to firmly fix the flexible plastic film base material firmly to the supporting substrate during the process of manufacturing the electronic device, and at the portion where the separation auxiliary layer is coated, after the electronic device manufacturing process is completed, . Thus, the peeling aid layer patterned in this way has an advantage that the flexible plastic film base material is firmly supported on the support substrate and is easily peeled off in the process of peeling off the flexible substrate, so that the damage to the electronic device is minimized.

The supporting substrate may preferably be heated to a temperature of 30 to 200 DEG C, more preferably 50 to 120 DEG C, for smooth evaporation of the solvent while preventing deterioration of the material.

In one specific example, the support substrate is a glass substrate, the suspension is ethanol in which graphene oxide is dispersed, the temperature of the glass substrate is 60 占 폚, and the carrier gas may be air. In this case, the graphene oxide, which is a two-dimensional inorganic material, is uniformly coated on the surface of the glass substrate with a layered structure.

Next, in the process (b), a flexible plastic film substrate is formed on a peeling aid layer made of a two-dimensional inorganic material formed on the surface of the supporting substrate.

In one specific example, a monomer or oligomer for producing a flexible plastic film substrate is added to the peeling aid layer of the supporting substrate and polymerized, or a polymer material for producing a flexible plastic film base is added in a molten or dissolved state to form a flexible plastic film To form a substrate.

Examples of the method of adding the monomer, oligomer and polymer include a method of coating a substrate with a coating solution such as a coating solution, such as a slot die coating, a spin coating, a table coater method, a doctor blade coating, a dip coating coating, and bar coating may be used. However, the present invention is not limited thereto. Screen coating and inkjet printing may also be used.

The monomer and oligomer coated on the peeling aid layer or the polymer material in a molten or dissolved state requires a polymerization or curing process, and in the process (b), a heat treatment process may further be included. Such a heat treatment process may be performed by a method such as heat curing, UV curing, natural drying curing, or the like, and may be performed at a temperature of 4 ° C to 500 ° C.

The thinner the thickness of the flexible plastic film base material is, the easier it is to realize a curved surface, but the thickness and thickness of the layers and elements formed thereon are such that the layers and elements can be held by the flexible plastic film base material even after separating the supporting base material Therefore, it is preferable that the thickness is 5 占 퐉 to 0.1 mm.

If the thickness of the plastic film base material is more than 0.1 mm, it is difficult to secure a predetermined flexibility and it is not preferable as a base material of a flexible device. If the thickness of the plastic film base material is less than 5 탆, It may be easily broken in the process of manufacturing and using the device. For the same reason, the thickness of the plastic film base material is more preferably in the range of 5 탆 to 20 탆.

The material of such a flexible plastic film base material is not particularly limited as long as it has high transparency to visible light and is insulating and heat-resistant. For example, acrylic, parylene, naphthalene (PEN), polycarbonate, polyurethane, polystyrene Mylar, polyethylene, polypropylene, polyester, nylon, polyvinyl chloride, ethylene vinyl acetate, polyimide (PI), polyimide Polyimide, polyimide, polyethylene terephthalate (PET), polyether sulfone (PES), and other plastic materials. However, the present invention is not limited thereto, and a known flexible plastic film A substrate may also be used.

Among them, polyimide has excellent mechanical properties and heat resistance. Therefore, it has thermal stability even in forming a later electronic device and in a high-temperature process. Therefore, in the process of low temperature polysilicon and activation heat treatment of a- And the thermal stability is maintained. Therefore, the plastic film base material may be polyimide in detail.

Next, in the step (c), an OLED display, an OLED illumination, a printed PCB (Printed Circuit Borad), a flexible sensor and an actuator, a flexible photovoltaic device, and the like are formed on a flexible plastic substrate by a process of forming an electronic device A flexible electronic device or the like is formed. These electronic devices are not limited to these examples, and include electronic devices using this method.

Next, in the above step (d), the flexible electronic device is peeled from the supporting substrate. In one specific example, the peeling step (d) can be performed by a mechanical peeling method, which is lower in initial investment and maintenance cost than the laser peeling method, has high process productivity, and minimizes the occurrence of defects in the desorption process There is an advantage that can be.

Various methods can be applied to the mechanical peeling method, and a flexible member can be separated from the supporting substrate by applying a mechanical stress after attaching a member having adhesive strength to the flexible electronic element.

For example, as shown in Fig. 6A, first, a cylinder roll jig having a predetermined radius is prepared, and a tape having a predetermined adhesive force is adhered to its surface. Thereafter, the jig having the adhesive force is brought into contact with the surface of the electronic device located on the upper surface of the flexible substrate, and the jig is rotated while being adhered to the electronic device at a constant pressure, thereby separating the flexible electronic device from the supporting substrate. The electronic device desorbed by the cylinder is again desorbed by applying a mechanical force.

This method minimizes the mechanical damage to the electronic device because the flexible electronic device removes the flexible device from the supporting substrate without applying a local stress to the electronic device in the process of peeling and uniform stress. At this time, the adhesive strength of the surface of the jig must satisfy a condition that is higher than the adhesive strength of the support substrate / release helical layer / electronic device interface, and after the separation from the support substrate is completed, the electronic device is separated from the jig to produce a flexible electronic device .

However, it should be understood that various separation methods can be used without being limited to the above methods, and these are all to be construed as falling within the scope of the present invention.

The present invention also provides various flexible electronic devices manufactured by the manufacturing method including the above processes. The flexible electronic device includes, but is not limited to, a flexible touch panel, a flexible information display device, a flexible OLED, a flexible OLED lighting, a flexible PCB (Printed Circuit Board), a flexible sensor and an actuator, a flexible photovoltaic device, All electronic devices that use this process are included.

The above flexible electronic device includes an information display device including a TFT, a pixel, or a color filter formed on one surface of a flexible plastic film substrate, and a separation tactile layer made of the above two-dimensional inorganic material on the other surface .

The separation assistant layer made of the two-dimensional inorganic material includes a carbon-based or clay-based material, and in some cases, may include a conductive material. Such a conductive material reduces the static electricity generated in the flexible plastic film substrate and prevents the breakage of the TFT caused by the electrostatic discharge. Therefore, there is an advantage of improving the production yield of electronic devices.

If necessary, the flexible plastic film substrate may be further provided with a barrier layer for preventing penetration of moisture before the electronic element including the TFT is formed. In this case, Standard process can be applied without additional pretreatment process in device manufacturing process.

The barrier layer may use only an inorganic layer or a composite layer of an inorganic layer and a polymer layer.

The inorganic layer may be a metal oxide, a metal nitride, a metal carbide, a metal oxynitride, or a compound thereof. As the metal oxide, SiO ₂ , alumina, titania, zirconia (Zirconium Oxide) and a compound thereof can be used. The metal nitride includes, for example, aluminum nitride, silicon nitride, titanium nitride, zirconium nitride, and the like, Examples of the metal carbide include silicon carbide, and examples of the metal oxynitride include silicon oxynitride. As the inorganic layer, any inorganic material capable of blocking the penetration of water and oxygen, such as silicon, may be used in addition to the above compound.

Such an inorganic layer can be formed by vapor deposition. When the inorganic layer is deposited, there is a limit that the void provided in the inorganic layer is directly grown. Therefore, in order to prevent such voids from continuing to grow at the same position, a polymer layer may be further provided in addition to the inorganic layer.

As the polymer layer, an organic polymer, an inorganic polymer, an organometallic polymer, and a hybrid organic / inorganic polymer may be used.

The barrier layer is formed by a known vapor deposition method such as the PEVCD method, and an information display element including a thin film transistor (hereinafter referred to as TFT) element is formed on the barrier layer. As the TFT element, a polysilicon TFT, an a-silicon TFT, an oxide TFT, an organic TFT, and the like can be used. Typically, an organic light emitting diode (OLED: Organic Light Emitting Diode) can be used. ) As a light emitting source, and the like.

As described above, the manufacturing method of a flexible electronic device according to the present invention provides various advantages.

First, the investment cost of manufacturing equipment is drastically reduced. In other words, by providing a separation tractive layer composed of a two-dimensional inorganic material using a highly productive evaporative spray deposition method, the productivity of the process is remarkably improved and the process step is reduced to less than 1/10 of the conventional electrostatic lamination method By providing the material and the process of the peeling aid layer, the investment cost of the process equipment can be drastically reduced.

Second, it is expected that the yield of the electronic device is improved by preventing the generation of pores in the peeling aid layer by providing the peeling aid layer made of only the two-dimensional inorganic material. That is, by using a two-dimensional material having a thickness of about the atomic diameter, bubbles are prevented from being trapped when the liquid polyimide varnish is coated, and since the organic polymer electrolyte is not used in the coating layer, The generated gas is minimized, the occurrence of pores in the peeling aid layer is minimized, thereby improving the yield of the production process and improving the economical efficiency of the production process.

In some cases, when the peeling aid layer made of the two-dimensional inorganic material is patterned, it is possible to adjust the peel strength and the peel strength depending on the shape of the pattern, which in turn increases the stability and productivity of the manufacturing process Ultimately improving the economical efficiency of the manufacturing process.

As a result, the method provided by the present invention provides a method capable of enhancing price competitiveness by reducing the device investment cost and improving the yield of the flexible electronic device, and economically manufacturing a high-quality electronic device.

1 is an experimental result showing the pull-off adhesive strength distribution when the sheet-like silicate material is coated with the temporary adhesive / desorption layer;
Figures 2a and 2b are schematic diagrams of a schematic and desorption path of a temporary adherent / desorbent layer in which two-dimensional inorganic materials with various atomic layers are laminated in multiple layers;
3 is a thermogravimetric analysis result of the PDDA polymer electrolyte material;
4 is an X-ray diffraction analysis graph of a coating layer in which a plurality of oxide graphene layers are stacked by evaporation spray lamination;
Figures 5A-5C are schematic diagrams showing patterns of the release tie layer formed on the surface of the support substrate in accordance with some embodiments of the present invention;
6A to 6C are schematic diagrams showing the schematic diagrams of mechanical peeling methods and the cross-sectional structure of an electronic device according to some embodiments of the present invention;
7A is a diagram illustrating a process of forming a suspension liquid droplet using a fine atomizing nozzle and forming a liquid droplet on a surface of a support substrate using a two-dimensional inorganic material by an evaporation spray deposition method according to an embodiment of the present invention, Respectively; Fig.
7B and 7C are diagrams illustrating a method of forming a suspension containing a release tributary layer made of a two-dimensional inorganic material by droplet formation using an ultrasonic method and then forming the droplet on the surface of the support substrate by an evaporation spray lamination method according to some embodiments of the present invention Are diagrams schematically showing the respective processes;
8 is a Scanning Electron Microscope (SEM) photograph of a peeling aid layer made of a two-dimensional inorganic material formed through the process of Example 1;
9 is a photograph showing a mechanical peeling process of a flexible plastic film including the TFT manufactured in Example 1;
10 is a scanning electron microscope (SEM) image of a peeling aid layer made of a two-dimensional inorganic material formed through the process of Example 2;
11 is a photograph showing the microstructure of the montmorillonite peeling aid layer transferred onto a plastic film containing the TFT device manufactured in Example 2. Fig.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

7A and 7B schematically show a process of forming a separation assistant layer made of a two-dimensional inorganic material on a supporting substrate by an evaporation spray lamination method.

Specifically, in FIG. 7A, a suspension liquid droplet is formed by a spray nozzle that forms a droplet by passing a high-pressure atomizing gas through a suspension, and then a liquid droplet of the suspension is sprayed onto the surface To thereby form a coating layer.

Referring to FIG. 7A, a suspension in which a two-dimensional inorganic material for peeling assistant is dispersed and a carrier gas are passed through a spray nozzle 400 linearly arranged against the supporting substrate 600 to form droplets, And a fine droplet is sprayed onto the surface of the supporting substrate 600 to collide with the surface of the supporting substrate 600 to be coated. In this coating method, the supporting base material 600 is heated at 30 to 200 ° C using various heating devices (not shown) such as a contact / non-contact heating device so that the droplet can be easily evaporated from the surface of the supporting base material 600 Preferably from 50 [deg.] C to 120 [deg.] C.

FIG. 7B schematically shows a process of forming a suspension droplet using an ultrasonic droplet generator and then moving a droplet to the surface of a supporting substrate using a carrier gas to form a coating layer. As the ultrasonic wave generator for use herein, an ultrasonic vibrating mesh nebulizer capable of generating droplets by applying ultrasonic waves to the mesh-type medium to vibrate may be used. In addition, ultrasonic vibrating mesh nebulizers may be used, It is also possible to use an ultrasonic wave nebulizer for generating a droplet by applying an ultrasonic wave.

Referring to FIG. 7B, the droplet of the suspension generated through the ultrasonic droplet generator 200 is moved to the coating chamber 210 by the carrier gas. At this time, in order to prevent the droplet from condensing on the wall in the movement path, the wall is heated by a temperature above the temperature at which the suspension solvent does not cause condensation, and the flow pattern of the fluid is adjusted to minimize the collision between the droplet and the wall Select working conditions in the conditions.

The coating chamber 210 causes the droplets to uniformly spray on the surface of the supporting substrate to form a uniform coating of the peeling aid layer 500 on the surface of the supporting substrate 600 in a large area. The coating nozzle 220 can be used in various forms such as a linear slit type, a plate-like shower type, and a nozzle having a linear shape, and is not particularly limited as long as it can uniformly coat the supporting substrate . At this time, the supporting base material 600 is heated to a temperature of 30 to 200 占 폚 by using various heating apparatuses such as a contact / non-contact heating apparatus (not shown) so that the droplet can be easily evaporated from the surface of the supporting substrate 600 Preferably in the range of 50 [deg.] C to 120 [deg.] C.

On the other hand, the sprayed droplet should be at least the size that can contain the two-dimensional inorganic material, and the concentration of the two-dimensional inorganic material should be so large that the two-dimensional inorganic material can be contained in the droplet. The size of such a droplet may be roughly in the range of 50 nm to 100 탆 in diameter, but it may be varied depending on the kind of the two-dimensional inorganic material, and therefore can be appropriately adjusted accordingly.

On the other hand, the peeling aid layer of the supporting substrate need not necessarily be applied to the entire surface of the supporting substrate. That is, the separation assistant layer made of the two-dimensional inorganic material can be formed to have various patterns on a part of the supporting substrate, and FIGS. 5A to 5C show a state in which, after the process of FIG. 7A or 7B, Sectional views and plan views of a supporting substrate on which a layer is formed.

5A, a peeling aid layer 500 made of a two-dimensional inorganic material is formed over the entire surface of the supporting substrate 600. In FIGS. 5B and 5C, the peeling aid layer 500 is formed on the supporting substrate 600, As shown in FIG.

5B, the peeling aid layer 500 is not coated on the outer edge portion 610 of the supporting substrate 600, so that the outer peripheral portion 610 of the supporting substrate 600 is covered with the plastic film substrate Not directly). At this time, the width of the outer side on which the peeling aid layer is not coated is, for example, in the range of 1 mm to 25 mm, and preferably in the range of 5 mm to 15 mm.

5C, the peeling aid layer 500 is formed on the supporting substrate 600 in a small rectangular island pattern. The pattern unit is not necessarily limited to a rectangle, and it is of course possible to have a polygonal or circular pattern surrounded by a straight line or a curve, if necessary. At this time, the width of the pattern in which the peeling aid layer is not coated may be in the range of, for example, 1 mm to 25 mm, and preferably in the range of 2 mm to 10 mm.

In this way, the formation of the separation assistant layer made of the two-dimensional inorganic material is completed on the supporting substrate, which is a supporting substrate for manufacturing a flexible electronic device. Referring to these drawings, a peeling aid layer 500 made of a two-dimensional inorganic material is formed on a supporting substrate 600 by an evaporation spray lamination method.

Thereafter, as shown in FIG. 7C, the plastic resin 101 is applied to form a flexible plastic film base material having a predetermined thickness on the peeling aid layer 500 made of a two-dimensional inorganic material.

In general, the flexible plastic film substrate plays a role of a flexible substrate in the final electronic device, has a characteristic that it is not breakable and can be curved, but has a disadvantage that it has a large coefficient of thermal expansion and bends well during the process.

Thus, in the state of being attached to the supporting substrate 600, TFT elements and various electronic / electric elements having various electric / electronic functions are formed on the upper surface of the flexible plastic film substrate.

The flexible plastic film substrate on which the flexible electronic element is formed (sometimes referred to as 'flexible information display element') is separated from the supporting substrate by mechanical stress in the following process by a mechanical stripping method.

6A shows an example of a method of mechanically detaching the flexible information display element 900 from a rigid supporting substrate 600 using a desorption roller. First, the double-sided adhesive film 710 having a double-sided adhesive force is attached to the surface of the desorption roller 700, the detachable roller 700 is adhered to the surface of the flexible information display element 900, The flexible information display element 900 is detached from the double-sided adhesive film 710. Next, the flexible information display element 900 is separated from the double- In some cases, it is also possible to attach the double-sided adhesive film 710 to the surface of the flexible information display element 900 first, and to remove the adhesive film 710 by moving the desorption roller 700 thereon.

6B shows an example of a method of mechanically removing the flexible information display element using a vacuum chuck. Specifically, the flexible information display element 900 attached to the supporting substrate 600 is fixed with a vacuum chuck 701, and then a desorption stress is applied to mechanically detach it. This method has the advantage of not using a desiccant adhesive film.

The method of attaching and detaching the flexible electronic device adhered to the surface of the supporting substrate is not limited to the mechanical method provided above. If the flexible electronic device is not damaged in the process of attaching and removing by mechanical stress, Methods are also available.

6C shows an example of a removable and flexible information display element. 6C, the flexible information display element 900 includes an information display element 800 including a TFT or the like, and a flexible film substrate 100. The flexible information display element 900 is formed of a two-dimensional inorganic material A part of the separation assist layer 500 remains. When the separation auxiliary layer 500 made of a two-dimensional inorganic material includes a conductive material, there is an advantage that the electrostatic discharge is reduced in the following process and the yield of the information display device is improved.

In the following Examples and Comparative Examples, the contents of the present invention will be described in more detail, but the present invention is not limited thereto.

≪ Example 1 >

The graphene grains having a size ranging from 0.01 μm to 50 μm are prepared by using the Hummer method and uniformly dispersed in methanol to prepare a coating solution (graphene oxide concentration: 0.05 g / L). The solution was sprayed onto the surface of a glass substrate which had been heated to 60 ° C with a spray nozzle to coat the surface of the glass substrate with the oxidized graphene.

FIG. 8 shows a scanning electron microscope photograph of a graphene separation layer coated on the surface of a glass substrate by the above method. Referring to FIG. 8, it can be confirmed that the graphene oxide layer is uniformly coated.

Thereafter, the polyimide solution was coated on the surface of the oxidative graphene separation assist layer by using a table coater, and in order to effectively induce the imidization reaction, each temperature step of 140 DEG C, 240 DEG C, 350 DEG C, At a heating rate of 5 DEG C / min, maintained at each temperature stage for 1 hour, and cooled to room temperature. Through this curing process, the thickness of the polyimide substrate (plastic film base) formed on the surface of the glass substrate was 15 μm, and a 1-μm thick Si-O-N barrier layer was formed on the surface of the polyimide substrate (plastic film base) using a PECVD process.

After the manufacturing process of the TFT element for a flexible OLED display device was performed on the surface of the barrier layer, mechanical desorption was performed. As a result, as shown in Fig. 9, it was observed that the TFT element for an OLED display element was easily detached from the glass substrate without being damaged.

≪ Comparative Example 1 &

As a result of repeating the experiment in the same manner as in Example 1 except that the separation auxiliary layer was not formed, the organic substrate was broken in the process of separating the flexible polyimide substrate formed directly on the surface of the glass substrate without the separation auxiliary layer .

≪ Example 2 >

An aqueous solution of a layered montmorillonite dispersion having a size ranging from 0.01 mu m to 2 mu m was ultrasonicated. Specifically, Na ⁺ - montmorillonite (South-West Clay Co.) was added to the distilled water and ultrasonication was performed for 2 hours to obtain a two-dimensional montmorillonite dispersion (montmorillonite concentration: 0.03 g / L). This dispersion was subjected to a solvent substitution method to obtain a suspension in which ethanol was substituted with a solvent. This suspension was made into droplets through a spray nozzle and coated on the surface of a glass substrate, which was a support substrate heated to 60 캜, by evaporation spray lamination.

FIG. 10 shows a scanning electron microscope photograph of the two-dimensional montmorillonite peeling aid layer coated on the surface of the glass substrate by the above method. Referring to FIG. 10, it is confirmed that the two-dimensional montmorillonite layer is uniformly coated.

The polyimide solution was coated on the surface of the formed two-dimensional montmorillonite peeling aid layer by using a table coater. The polyimide solution was coated at a temperature of 5 ° C / min to 140 ° C, Min, maintained at each temperature step for 1 hour, and cooled to room temperature. A polyimide substrate (plastic film base) formed on the surface of the glass substrate through the curing process was 15 μm thick, and a Si-O-N barrier layer having a thickness of 1 μm was formed on the surface thereof by using a PECVD process.

After the fabrication process of the flexible OLED display device was performed on the surface of the barrier layer, mechanical desorption was performed. As a result, it was observed that the TFT element was easily detached from the glass substrate without being damaged, and it was observed that a part of the montmorillonite as a two-dimensional material adhered to the surface of the flexible substrate and remained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. will be.

Claims (19)

A method of manufacturing a flexible electronic device,
(a) forming a peeling aid layer made of a two-dimensional inorganic material on at least one side of a relatively rigid support substrate by evaporation spray lamination;
(b) forming a flexible plastic film base material on the peeling aid layer;
(c) forming an electronic device on the flexible plastic film substrate; And
(d) peeling the flexible plastic film base material from the supporting base material;
Lt; / RTI >
The peeling aid layer made of the two-dimensional inorganic material includes a carbon-based material or a clay-based material having a two-dimensional crystal structure,
In the step (a), the suspension in which the two-dimensional inorganic materials for forming the separation helper layer are dispersed is sprayed in a droplet state by the suspension liquid droplet generating device, and the release helper layer Lt; / RTI >
Wherein the non-coating portion in which the peeling aid layer is not present is formed along the outer periphery of the supporting substrate so that the supporting substrate is directly faced to the flexible plastic film base material in the non-coating portion or the coating portion made of the peeling aid layer Wherein the non-coating portion in which the peeling aid layer is not present is formed while forming a regular pattern on the supporting substrate. The method of manufacturing a flexible electronic device according to claim 1, wherein the thickness of the flexible plastic film base material is in the range of 5 to 0.1 mm, and the thickness of the supporting base material is in the range of 0.3 to 1 mm. delete The method according to claim 1,
The carbon-based material is at least one selected from the group of two-dimensional inorganic materials consisting of a single atom layer of graphene, oxide graphene, and hexagonal boron nitride;
The clay-based material may be any one selected from the group of two-dimensional inorganic materials consisting of a single crystalline layer of crystalline silicate, chalcogenide, talc, vermiculite, and montmorillonite Of the total area of the flexible electronic device. The manufacturing method of a flexible electronic device according to claim 1, wherein the thickness of the peeling aid layer is in the range of 2 nm to 10 nm. delete The method of claim 1, wherein the suspension liquid droplet generating device is a spray nozzle device, an ultrasonic vibrating mesh nebulizer, or an ultrasonic wave nebulizer. The method of manufacturing a flexible electronic device according to claim 1, wherein the supporting substrate is heated in a range of 30 占 폚 to 200 占 폚. The flexible electronic device according to claim 1, wherein the suspension further comprises an additive for assisting dispersion of the two-dimensional inorganic material and reducing the surface tension of the solvent to improve the wettability with the supporting substrate Way. The process for producing a flexible plastic film base material according to claim 1, wherein the step (b) is carried out by polymerizing a monomer or oligomer for producing a flexible plastic film base material on a peeling aid layer, or polymerizing the polymer material for producing a flexible plastic film base in a molten or dissolved state And forming a flexible plastic film base material. The flexible plastic film base material according to claim 10, wherein the flexible plastic film base material is selected from the group consisting of acrylic, parylene, naphthalene (PEN), polycarbonate, polyurethane, polystyrene, mylar, polyethylene, polypropylene, Nylon, Polyvinyl Chloride, Ethylene Vinyl Acetate, Polyimide, Polyethylene Terephthalate (PET), and Polyether Sulfone (PES) ). ≪ / RTI > A method of manufacturing a flexible electronic device, The manufacturing method of a flexible electronic device according to claim 1, further comprising a heat treatment step in the step (b). delete The manufacturing method of a flexible electronic device according to claim 1, wherein the non-coated portion formed along the outer periphery of the supporting substrate has a width of 1 mm to 25 mm. delete The method of claim 1,
A pattern structure in which a plurality of coating portions are uniformly arranged as independent islands, and an uncoated portion exists between the coating portions; or
A pattern structure in which a plurality of uncoated portions are uniformly arranged as respective independent islands, and a coating portion is present between the uncoated portions;
Wherein the step of forming the flexible electronic element comprises the steps of: The manufacturing method of a flexible electronic device according to claim 16, wherein the non-coated portion formed between the coating patterns has a width of 1 mm to 25 mm. The manufacturing method of a flexible electronic device according to claim 1, wherein the step (d) comprises peeling the flexible plastic film base material on which the flexible electronic device is formed from the supporting base material by applying a mechanical stress. delete

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