KR102452861B1 - Debonding Layer and Method for Manufacturing the Same, Information Display Element and Method for Manufacturing the Same - Google Patents

Abstract

Disclosed is a method of manufacturing a debonding layer that includes the steps of: preparing a support substrate; and forming a graphene oxide layer on the support substrate. According to the present invention, the peel strength of a graphene oxide layer can be reduced by adjusting the size of graphene oxide forming the graphene oxide layer and adjusting the composition ratio of the graphene oxide of different sizes.

Description

Debonding Layer and Method for Manufacturing the Same, Information Display Element and Method for Manufacturing the Same

The present invention relates to a desorption layer with reduced peel strength, a method for manufacturing the same, an information display device and a method for manufacturing the same, by controlling the size of graphene oxide forming the desorption layer, and controlling the composition ratio of different sizes of graphene oxide The present invention relates to a detachable layer, a method for manufacturing the same, an information display device and a method for manufacturing the same, which can reduce the peel strength of the detachable layer by improving the coating rate of the graphene oxide layer by doing so.

The necessity and demand for flexible information display devices such as flexible displays are increasing as the commercialization of wearable devices such as smart glasses is accelerated.

In a manufacturing process of a flexible information display device, a manufacturing process is performed after laminating a flexible substrate on a support substrate, and a process of separating the flexible substrate from the support substrate is performed in the last process.

Polyimide is mainly used as a flexible substrate, and a glass substrate is used as a support substrate. As a method of forming the flexible substrate on the support substrate, polyimide varnish is coated on the support substrate and cured at a high temperature. During this process, chemical bonding occurs between the polyimide and the support substrate, and the adhesion between the support substrate and the flexible substrate increases, making it impossible to separate without an additional process.

Conventionally, in order to solve this problem, a laser-lift-off (LLO) process was mainly used as a process for separating a flexible substrate from a support substrate.

However, when using a laser, expensive laser lift-off equipment must be used, and there is a problem in that it is not suitable for a large-area process.

The present invention has been devised to solve the above problems, and an object of the present invention is to form a graphene oxide layer as a detachable layer of a flexible information display device, but the size of the graphene oxide forming the graphene oxide layer To provide a detachable layer, a method for manufacturing the same, an information display device and a method for manufacturing the same, in which the peel strength of the graphene oxide layer is reduced by adjusting the composition ratio of graphene oxide of different sizes.

Another object of the present invention is to provide a detachable layer, a method for manufacturing the same, an information display device, and a method for manufacturing the same, which is inexpensive because it does not require the use of expensive laser lift-off equipment, and can be used in a large-area process. .

Another object of the present invention is to omit the coating process of the aqueous cationic polymer electrolyte solution by performing electrospray coating when forming the graphene oxide layer, thereby saving the time of the manufacturing process and having a low manufacturing cost, the desorption layer, its To provide a manufacturing method, an information display device, and a manufacturing method thereof.

A method for manufacturing a detachable layer according to the present invention for achieving the above object, comprising the steps of preparing a support substrate; and forming a graphene oxide layer on the support substrate.

The desorption layer according to the present invention may be manufactured by the method of manufacturing the desorption layer.

According to another aspect of the present invention, there is provided a method of manufacturing an information display device, comprising: preparing a support substrate; forming a graphene oxide layer on the support substrate; forming a flexible substrate on the graphene oxide layer; and separating the support substrate and the flexible substrate.

The information display element according to the present invention can be manufactured by the method of manufacturing the information display element.

According to the present invention, it is not necessary to use expensive laser lift-off equipment, so the manufacturing cost thereof is low, and there are advantages that can be used in a large-area process.

In addition, by controlling the size of the graphene oxide constituting the graphene oxide layer and adjusting the composition ratio of graphene oxide of different sizes, the application rate of the desorption layer on the support substrate is increased, so that high temperature exposure and It is possible to achieve the effect of reducing the peel strength by preventing the chemical bonding between the glass substrate and the polyimide, which is a support substrate, under conditions such as high temperature and plasma during the display manufacturing process. In addition, since it is formed as a thin film layer while reducing peel strength, there is an advantage in that the light transmittance can be maintained at an excellent level.

In addition, in the present invention, since the graphene oxide dispersion can be finely sprayed using electrospray and voltage can be applied, electrostatic attraction between the support substrate and the graphene oxide dispersion is induced to form a thin-film graphene oxide layer. This is possible. Therefore, there is an advantage in that it is possible to omit the process of coating the aqueous solution of the cationic polymer electrolyte on the support substrate prior to the formation of the conventional graphene oxide layer.

1 is a flowchart of a method for manufacturing a detachable layer according to an embodiment of the present invention.
2 is a flowchart of a method of manufacturing an information display device according to an embodiment of the present invention.
3 is a flowchart of a flexible substrate forming process according to an embodiment of the present invention.
4 is a cross-sectional view schematically illustrating each layer formed in the method of manufacturing an information display device according to an embodiment of the present invention.
5 is a cross-sectional view schematically illustrating a separation process of a support substrate and a flexible substrate during a manufacturing process of an information display device according to an embodiment of the present invention.

It should be noted that the technical terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. In addition, the technical terms used in this specification should be interpreted in the meaning generally understood by those of ordinary skill in the art to which the present invention belongs, unless otherwise defined in this specification, and excessively inclusive. It should not be construed as a human meaning or in an excessively reduced meaning. In addition, when the technical terms used in this specification are incorrect technical terms that do not accurately express the spirit of the present invention, they should be understood by being replaced with technical terms that can be correctly understood by those skilled in the art.

In addition, general terms used in the present invention should be interpreted as defined in advance or according to the context before and after, and should not be interpreted in an excessively reduced meaning.

Also, as used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "consisting of" or "comprising" should not be construed as necessarily including all of the various components or various steps described in the specification, some of which components or some steps are It should be construed that it may not include, or may further include additional components or steps.

Hereinafter, the present invention will be described in more detail through examples, but the scope of the present invention is not limited to the following examples.

1 is a flowchart of a method for manufacturing a detachable layer according to an embodiment of the present invention.

Referring to FIG. 1 , the method for manufacturing a detachable layer according to an embodiment of the present invention may include a support substrate preparation step S10 and a graphene oxide layer forming step S20 .

In this case, the support substrate may be a glass substrate, a polymer film, or a silicon wafer. However, the support substrate according to the present invention is not necessarily limited thereto.

The support substrate may include cleaning the support substrate and surface-treating the support substrate.

In this case, the cleaning of the support substrate may include immersing the support substrate in an ethanol solution, and then cleaning the support substrate using ultrasonic waves. Thereafter, the support substrate may be immersed in an isopropyl alcohol solution, and then the support substrate may be cleaned using ultrasonic waves.

The support substrate that has undergone the cleaning process may be dried.

The graphene oxide layer forming step ( S20 ) may include coating the graphene oxide dispersion on the support substrate.

In this case, the coating may be an electrospray method.

The electrospray coating may be performed under conditions of a discharge rate of 70 to 90 μL/min, an air pressure of 0.2 to 0.3 MPa, and a voltage of 9 kV or more. Preferably, the discharge rate may be 80 μL/min, the air pressure may be 0.25 MPa, and the voltage may be 10 kV.

As the discharge rate is lower than 70 μL/min, the capacity is insufficient and the number of sprayed water droplets is small, making uniform application impossible. there is a problem to be

As the air pressure is lower than 0.2 MPa, there is a problem in that the spraying force is low, so that large water droplets are applied.

As the voltage is lower than 9kV, there is a problem that the size of the sprayed water droplets increases, and when the voltage is 9kV or more, fine spraying can be sufficiently performed.

The concentration of the graphene oxide dispersion may be 0.01 to 0.02% by weight. The concentration may preferably be 0.01% by weight.

As the concentration is lower than 0.01% by weight, there is a problem in that the coating rate is lowered and peel strength increases, and as the concentration is higher than 0.02% by weight, there is a problem in that the light transmittance is lowered.

According to one embodiment, the graphene oxide dispersion may include a first graphene oxide and a second graphene oxide, the size of the first graphene oxide may be 50 μm, and the size of the second graphene oxide The size may be 1um.

The graphene oxide dispersion may include the first graphene oxide and the second graphene oxide in a ratio of 5:5 to 8:2.

When the content of the second graphene oxide is greater than the content of the first graphene oxide, there is a problem in that the coating rate is lowered and peel strength is increased.

According to another embodiment, the graphene oxide dispersion may include graphene oxide having a size of 50 μm. In this case, the graphene oxide dispersion may not include graphene oxide having a size of 1 μm, but only include graphene oxide graphene having a size of 50 μm.

That is, in the present invention, the composition range of 50um-sized graphene oxide and 1um-sized graphene oxide is included together, but the composition range of 50um-sized graphene oxide and 1um-sized graphene oxide is 5:5 to 8:2. range or the graphene oxide contained in the graphene oxide dispersion is made of only graphene oxide having a size of 50 μm, so that the coating rate of the graphene oxide layer is increased, and as a result, the effect of reducing the peel strength of the desorption layer can be achieved. can

Such improvement in peel strength may have the effect of reducing peel strength during detachment after the information display device manufacturing process.

2 is a flowchart of a method of manufacturing an information display device according to an embodiment of the present invention. 3 is a flowchart of a flexible substrate forming process according to an embodiment of the present invention.

Referring to FIG. 2 , the method of manufacturing an information display device according to an embodiment of the present invention includes preparing a support substrate (S10), forming a graphene oxide layer (S20), forming a flexible substrate (S30), and a support substrate and It may include a flexible substrate separation step (S40).

The support substrate preparation step ( S10 ) and the graphene oxide layer forming step ( S20 ) are the same as those described with reference to FIG. 1 , and thus descriptions thereof will be omitted.

Referring to FIG. 3 , the flexible substrate forming step (S30) may include a flexible substrate material application step (S32) and a flexible substrate material heating step (S34).

In the flexible substrate material application step (S32), on the graphene oxide layer, polyimide, polyester, polyvinyl, polycarbonate, polyethylene, polyacetate, polyethersulfone, polyacrylate, polyethylenenaphthalate and polyethyleneether Any one material selected from the group consisting of phthalates may be applied. In the step of heat curing the applied material, curing conditions may vary depending on the applied material.

In the case of polyimide among the flexible substrate materials, a heat curing step is required using a polyimide varnish, and in the heating step (S34), it can be heated from room temperature to 350 ^o C, and at this time, the temperature can be raised by 5 ^o C per minute.

For example, it may be heated at 100 ^o C for 10 minutes, at 200 ^o C for 30 minutes, and at 350 ^o C for 30 minutes. After that, let it cool naturally for about 3 hours.

In the step of separating the support substrate and the flexible substrate ( S40 ), the support substrate and the flexible substrate may be separated by using a physical force.

4 is a cross-sectional view schematically illustrating each layer formed in the method of manufacturing an information display device according to an embodiment of the present invention. 5 is a cross-sectional view schematically illustrating a separation process of a support substrate and a flexible substrate during a manufacturing process of an information display device according to an embodiment of the present invention. The description of FIGS. 4 and 5 will be described in more detail in relation to the following embodiment.

Hereinafter, a process for manufacturing a desorption layer according to the present invention will be described in more detail through examples. The following examples are only provided for easier understanding of the present invention, and the content of the present invention is not limited by the examples.

<Raw materials used in Examples>

- bare Glass (Eagle XG, Corning)

- 0.01 wt% Graphene Oxide aqueous solution

Example 1

<Step of preparing the support substrate>

First, as the support substrate 10, each of the width and length are 100 mm, and a thickness of 0.5 mm Eagle XG glass (Corning Corporation) is prepared.

The support substrate 10 is immersed in an ethanol solution, followed by ultrasonic cleaning for about 15 minutes. Thereafter, the support substrate 10 is immersed in an isopropyl alcohol solution, and ultrasonic cleaning is performed for about 15 minutes. The cleaned support substrate 10 is placed in an oven and dried at about 80° C. for about 5 minutes.

<Step of forming a desorption layer>

Thereafter, for the formation of the graphene oxide layer, a 0.01 wt% graphene oxide (Graphene Oxide, GO) dispersion is prepared.

To explain this in more detail, graphene oxide is prepared using Hummer's method. The size of graphene oxide is controlled by using an ultrasonic pulverization method for graphene oxide with a size of 1 μm, and a shear stress method for graphene oxide with a size of 50 μm.

After taking 2 g of a graphene oxide solution of 1 μm with an initial concentration of 0.5 wt % and 2 g of a graphene oxide solution of 50 μm with an initial concentration of 0.5 wt %, 98 g of tertiary distilled water is added to each of 0.01 wt % of 1 μm of graphene. To prepare an oxide dispersion and 0.01 wt% of a graphene oxide dispersion having a size of 50 μm.

50 g of a 50 μm-sized graphene oxide dispersion of 0.01 wt % and 50 g of a 1 μm-sized graphene oxide dispersion of 0.01 wt % were mixed to prepare 100 g of a graphene oxide dispersion (0.01 wt % of a 50 μm-sized graphene oxide dispersion and 0.01% by weight of 1um graphene oxide dispersion is 5:5 ratio). 10ml of 100g of graphene oxide dispersion is injected into two syringes, and after combining the syringe and nozzle, it is installed in the electrospray equipment (NanoNC, model name: ESR200R2).

After setting the following conditions in the electrospray equipment, coating of graphene oxide on the support substrate is carried out.

graphene oxide
Dispersion Concentration discharge speed windage number of nozzles number of coatings Voltage distance 0.01% by weight 80 μL/min 0.25 MPa 2 nozzle 1 time 10 kV 10 cm

In the present invention, since the coating rate of the graphene oxide layer on the support substrate is increased by coating using a graphene oxide dispersion mixed with 1um-sized graphene oxide and 50um-sized graphene oxide, the effect of reducing the peel strength of the desorption layer can promote

In addition, by coating the graphene oxide using the electrospray equipment, there is an advantage in that the coating process of the aqueous solution of the cationic polymer electrolyte, which is conventionally performed before the formation of the graphene oxide layer, can be omitted. In addition, since the cationic polymer layer is not formed, there is an advantage in preventing a decrease in light transmittance by the coated cationic polymer.

Through the above-described process, the formation of the desorption layer 20 according to the present invention is completed.

<Step of forming a flexible substrate>

Next, a process for manufacturing the information display device according to the present invention will be described in more detail.

Previously, after the desorption layer manufacturing process is completed, a polyimide (PI) varnish is applied on the graphene oxide layer to a thickness of 8 μm using an applicator.

To improve imidization, heat treatment is performed at 100 ^o C for 10 minutes, 200 ^o C for 30 minutes, and 350 ^o C for 30 minutes. At this time, the rate of temperature increase in each temperature step is preferably 5 ^o C/min.

Formation of the flexible substrate 30 is completed through cooling for 3 hours after application of polyimide varnish and heating process.

<Step of manufacturing information display device>

Thereafter, the layer 40 including the TFT layer, the organic light emitting layer, and the encapsulation layer is formed, and the separation step of the support substrate 10 and the flexible substrate 30 may be performed.

In the present invention, by separating the flexible substrate 30 from the detachable layer 20, the separation step of the support substrate 10 and the flexible substrate 30 is performed, thereby completing the manufacturing process of the information display device according to the present invention. .

Examples 2 and 3

When preparing the graphene oxide dispersion during the <Forming the desorption layer> in Example 1, 0.01 wt% of the 50um-sized graphene oxide dispersion and 0.01 wt% of the 1um-sized graphene oxide dispersion were mixed in a 5:5 ratio Example 2 and 3 were carried out in the same manner except that the mixture was mixed at 7:3 and 8:2.

Example 4

When preparing the graphene oxide dispersion during the <Forming the desorption layer> in Example 1, 0.01 wt% of the 50um-sized graphene oxide dispersion and 0.01 wt% of the 1um-sized graphene oxide dispersion were mixed in a 5:5 ratio Example 4 by performing the same process except that 0.01% by weight of the graphene oxide dispersion of 1um size was not used, and the graphene oxide dispersion was prepared only with 0.01% by weight of the graphene oxide dispersion of 50um size. was carried out.

Comparative Examples 1 and 2

When preparing the graphene oxide dispersion during the <Forming the desorption layer> in Example 1, 0.01 wt% of the 50um-sized graphene oxide dispersion and 0.01 wt% of the 1um-sized graphene oxide dispersion were mixed in a 5:5 ratio Comparative Examples 1 and 2 were carried out by performing the same process except that the mixture was mixed at 3:7 and 2:8.

Comparative Example 3

When preparing the graphene oxide dispersion during the <Forming the desorption layer> in Example 1, 0.01 wt% of the 50um-sized graphene oxide dispersion and 0.01 wt% of the 1um-sized graphene oxide dispersion were mixed in a 5:5 ratio Comparative Example 3 was performed by performing the same process except that 0.01 wt% of the graphene oxide dispersion having a size of 1 μm was used, and 0.01 wt% of the graphene oxide dispersion having a size of 50 μm was not included.

Experimental Example 1

In order to measure the peel strength of the polyimide substrate, which is the flexible substrate 30 formed on the support substrate 10 prepared in the above example, the vertical peel strength was measured in a film adhesion test apparatus according to the test method of standard ASTMD3330. The testing machine was used by AMETEK (LS-1). The results are shown in Table 2.

Experimental Example 2

In order to measure the light transmittance according to the above embodiment, each of the width and length is 100 mm and the thickness is 0.5 mm Eagle XG glass (Corning) was used for calibration and the transmittance was measured. Measurements were made three times per sample to obtain an average value. At this time, the light transmittance measuring equipment used is DENSHOKU (NDH-7000). The results are shown in Table 2.

Example 1 (5:5) Example 2 (7:3) Example 3 (8:2) Example 4 (10:0) Peel strength (gf) 14.14 12.16 11.43 8.83 light transmittance
(at. 550nm) 99.91 99.95 99.92 99.91

As can be seen in Table 2 above, the peel strength was different depending on the composition ratio of the 50um-sized graphene oxide dispersion and the 1um-sized graphene oxide dispersion, and as the content of the 50um-sized graphene oxide dispersion increased, the application It can be seen that there is an effect of lowering the peel strength as the rate increases.

This is because, in the case of a graphene oxide dispersion having a small size of 1 μm, it has a dimension significantly smaller than the size of a droplet, so that only the edge of the droplet is coated in the process of water evaporation, overlapping between sheets occurs a lot, and the coating is locally will be done On the other hand, in the case of a 50 μm-sized graphene oxide dispersion having a large size, it has a size corresponding to the size of the water droplet. Compared to a small graphene oxide dispersion, the coating is uniformly performed over the entire area, which increases the application rate.

In addition, in terms of light transmittance, excellent light transmittance results were obtained in all examples.

Experimental Example 3

In order to measure the peel strength of the polyimide substrate, which is the flexible substrate 30 formed on the support substrate 10 prepared in the Comparative Example, the vertical peel strength was measured in a film adhesion test apparatus according to the test method of standard ASTMD3330. The testing machine was used by AMETEK (LS-1). The results are shown in Table 3.

Experimental Example 4

In order to measure the light transmittance according to the comparative example, each of the width and length is 100 mm and the thickness is 0.5 mm Eagle XG glass (Corning) was used for calibration and transmittance was measured. Measurements were made three times per sample to obtain an average value. At this time, the light transmittance measuring equipment used is DENSHOKU (NDH-7000). The results are shown in Table 3.

Comparative Example 1 (3:7) Comparative Example 2 (2:8) Comparative Example 3 (0:10) Peel strength (gf) 16.36 17.07 17.99 light transmittance
(at. 550nm) 99.96 99.93 99.91

As can be seen in Table 3, the peel strength was different depending on the composition ratio of the 50 μm-sized graphene oxide dispersion and the 1 μm-sized graphene oxide dispersion, and as the content of the 1 m-sized graphene oxide dispersion increased, the peeling It can be seen that there is a problem of increasing the strength.

In the above, specific preferred embodiments of the present invention have been described, but the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention as claimed in the claims Anyone with ordinary skill in the art can make various modifications, of course, and such modifications are within the scope of the claims.

S10 support substrate preparation
Formation of S20 graphene oxide layer
S30 flexible substrate formation
Separation of S40 support substrate and flexible substrate
10 Support substrate
20 Desorption layer
30 flexible substrate

Claims (20)

preparing a support substrate; and
Including; forming a graphene oxide layer on the support substrate;
Forming the graphene oxide layer comprises:
and coating the graphene oxide dispersion on the support substrate,
The graphene oxide dispersion includes a first graphene oxide and a second graphene oxide, the size of the first graphene oxide is 50 μm, and the size of the second graphene oxide is 1 μm. manufacturing method. delete The method of claim 1,
The step of coating the graphene oxide dispersion,
Preparation of a desorption layer comprising the step of coating the graphene oxide dispersion on the support substrate using electrospray under conditions of a discharge rate of 70 to 90 μL/min, an air pressure of 0.2 to 0.3 MPa, and a voltage of 9 kV or more Way. 4. The method of claim 3,
The discharge rate is 80 μL / min, the air pressure is 0.25 MPa, the method of manufacturing a desorption layer, characterized in that the voltage is 10 kV. The method of claim 1,
The method for producing a desorption layer, characterized in that the concentration of the graphene oxide dispersion is 0.01 to 0.02% by weight. 6. The method of claim 5,
The method for producing a desorption layer, characterized in that the concentration of the graphene oxide dispersion is 0.01% by weight. delete The method of claim 1,
The graphene oxide dispersion comprises the first graphene oxide and the second graphene oxide in a ratio of 5:5 to 10:0. A desorption layer, characterized in that manufactured according to any one of claims 1, 3 to 6, and any one of the manufacturing method of claim 8. preparing a support substrate;
forming a graphene oxide layer on the support substrate;
forming a flexible substrate on the graphene oxide layer; and
Including; separating the support substrate and the flexible substrate;
Forming the graphene oxide layer comprises:
and coating the graphene oxide dispersion on the support substrate,
The graphene oxide dispersion includes a first graphene oxide and a second graphene oxide, the size of the first graphene oxide is 50 μm, and the size of the second graphene oxide is 1 μm. A method of manufacturing a device. delete 11. The method of claim 10,
The step of coating the graphene oxide dispersion,
Manufacturing an information display device comprising the step of coating the graphene oxide dispersion on the support substrate using electrospray under conditions of a discharge rate of 70 to 90 μL/min, an air pressure of 0.2 to 0.3 MPa, and a voltage of 9 kV or more Way. 13. The method of claim 12,
The method of manufacturing an information display device, wherein the discharge rate is 80 μL/min, the air pressure is 0.25 MPa, and the voltage is 10 kV. 11. The method of claim 10,
The method of manufacturing an information display device, characterized in that the concentration of the graphene oxide dispersion is 0.01 to 0.02% by weight. 15. The method of claim 14,
The method of manufacturing an information display device, characterized in that the concentration of the graphene oxide dispersion is 0.01% by weight. delete 11. The method of claim 10,
The graphene oxide dispersion liquid comprises the first graphene oxide and the second graphene oxide in a ratio of 5:5 to 10:0. 11. The method of claim 10,
The step of forming the flexible substrate,
On the graphene oxide layer, any one material selected from the group consisting of polyimide, polyester, polyvinyl, polycarbonate, polyethylene, polyacetate, polyethersulfone, polyacrylate, polyethylenenaphthalate and polyethyleneetherphthalate applying; and
and heating the applied material. 19. The method of claim 18,
The step of heating the applied material,
The method for manufacturing an information display device, characterized in that the coated material is heated from room temperature to 350 ^o C, and the temperature is raised by 5 ^o C per minute. An information display element manufactured according to the manufacturing method in any one of Claims 10, 12-15, and Claims 17-19, The information display element characterized by the above-mentioned.

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