KR20200026533A - Improved Quantum Dot Film and Manufacturing Method Thereof - Google Patents

Abstract

The present invention discloses an improved quantum dot film and a method for manufacturing the same. The method for manufacturing a QD film according to the present invention comprises following steps of: a) forming an alumina thin film equipped with a porous region formed by anodizing the surface of the untreated aluminum provided on a support layer film; b) filling a QD material in the porous region formed on the alumina thin film; c) drying or curing the QD material filled in the porous region; and d) bonding an upper barrier film to the top of the alumina thin film. The present invention significantly improves an effect of preventing permeation to oxygen and moisture.

Description

Improved Quantum Dot Film and Manufacturing Method Thereof

The present invention relates to an improved quantum dot film and a method of manufacturing the same.

More specifically, the present invention anodizes aluminum to produce alumina having a honeycomb-shaped porous region, filling a QD material into the porous region, and drying or The present invention relates to a quantum dot film produced by bonding a barrier film to both upper and upper and lower surfaces thereof after curing, and a method of manufacturing the same.

BACKGROUND OF THE INVENTION Flat panel displays such as liquid crystal displays (LCDs) have a small power consumption, and their use is expanding year by year as image display devices that save space. In recent liquid crystal display devices, additional power saving, color reproducibility improvement, and the like are required as LCD performance improvements.

A wavelength conversion layer including a quantum dot (QD) as a light emitting material (phosphor) that converts the wavelength of incident light and emits light in order to increase light utilization efficiency and improve color reproducibility according to the power saving of the backlight of the LCD. It is proposed to use.

A quantum dot is a zero-dimensional semiconductor crystal with a diameter of several tens of nanometers or less, and refers to a material that emits light of various colors without a separate device depending on the size and voltage of the crystal. A core and a shell surrounding the core ( Shell), which can be colored differently depending on the size of the core. In other words, by changing the size of the quantum dots, the absorption wavelength and the emission wavelength of light can be controlled.

In general, such a quantum dot is dispersed in a resin or the like and, for example, is disposed between the backlight and the liquid crystal panel as a quantum dot film for wavelength conversion.

When excitation light enters into a film containing quantum dots (hereinafter referred to as "quantum dot film") from the backlight, the quantum dots are excited to emit fluorescence. Here, by using quantum dots having different light emission characteristics and emitting light having a narrow half-value width of red light, green light or blue light on each quantum dot, high color reproducibility of white light can be realized.

However, quantum dots tend to be degraded by oxygen and moisture, and in particular, there is a problem that the luminescence intensity is lowered by the photooxidation reaction. For this reason, the wavelength conversion member protects the quantum dot layer by laminating gas barrier films on both main surfaces of a resin layer (hereinafter, also referred to as a "quantum dot layer") containing a quantum dot which is a wavelength conversion layer including quantum dots. Although only the main surface of the quantum dot layer is protected by the gas barrier film, oxygen and moisture are introduced from the end surface not protected by the gas barrier film, thereby deteriorating the quantum dot.

In order to solve the above-mentioned problem, a method of protecting the entire circumference of the quantum dot layer with a barrier film or a color conversion layer (phosphor layer) for converting at least a part of the color light emitted from the light source unit into other color light, and an adhesive having a vapor barrier property A light emitting device made of a material and having an impermeable sealing sheet for sealing the color conversion layer has been proposed.

By the way, the wavelength conversion layer containing a quantum dot used for LCD is a thin film about 50 micrometers-350 micrometers. It is very difficult to coat the whole surface of such a very thin film with a sealing sheet such as a gas barrier film, and there is a problem that productivity is poor. This problem is not limited to quantum dots, but the same problem also occurs in all phosphor-containing films having phosphors that react with oxygen and moisture.

On the other hand, in order to manufacture phosphor-containing films containing phosphors such as quantum dots with high production efficiency, the coating process and the curing process are sequentially performed on a long film by a roll-to-roll method, and after forming a laminated structure, Although a method of cutting to a size is preferable, when the phosphor-containing film of a desired size is cut from the long film, the phosphor-containing layer is exposed to the outside air at the cut surface, thereby causing a problem of exposure to the ingress of oxygen and moisture from the cut surface.

One of the measures to solve the problem of the thin film containing the quantum dot phosphor as described above was filed under the name of the invention "phosphor-containing film and backlight unit" by Kei Kei Kei et al., Republic of Korea published on March 12, 2018 It is disclosed in Japanese Patent Laid-Open No. 10-2018-0026489 (hereinafter referred to as "prior art").

More specifically, Figure 1 is a perspective view showing a schematic configuration of the phosphor-containing film according to the prior art, Figure 2 is a plan view of the phosphor-containing film according to the prior art, Figure 3 is a detailed view of the phosphor-containing film according to the prior art It is sectional drawing which shows a structure.

1 to 3, the phosphor-containing film 1 of the prior art reacts with oxygen and moisture when exposed to oxygen and moisture on the first substrate film 10 and the first substrate film 10. The region 35 including the phosphor 31 deteriorated by the plurality of regions 35 is discretely disposed, and the region 35 including the phosphor 31 disposed discretely (hereinafter referred to as “fluorescent region 35”). ), A phosphor-containing layer 30 on which a resin layer 38 having impermeability to oxygen and moisture is disposed. The fluorescent region 35 has a cylindrical shape (disc shape) formed by dispersing the phosphor 31 in the binder 33 and has impermeability to oxygen and moisture in a two-dimensional direction along the film surface of the base film 10. It is wrapped in the resin layer 38 which it has, and is isolated, respectively, and the penetration | invasion of oxygen and moisture from the two-dimensional direction along the film surface of the base film 10 to each fluorescent region 35 is blocked. Also, a layer that is impermeable to both oxygen and moisture is referred to as a "barrier layer".

In order to manufacture the phosphor-containing film 1 according to the above-described prior art, a photoresist (PR) for forming the resin layer 38 is formed on the upper surface of the first base film 10, which is typically a lower barrier layer, and then A cylindrical cavity shape (i.e., fluorescent region 35) is formed by photo-lithography, and a quantum dot (QD) material (i.e., phosphor 31 and binder 33 of FIG. 3) is formed within the formed cylindrical cavity shape. After the insertion, the second base film 20 as the upper barrier layer may be bonded to each other. As shown in FIG. 4, the fluorescent region 35 may have a hexagonal honeycomb shape, but is not limited thereto.

In the above-mentioned phosphor-containing film 1 of the prior art, since the fluorescent region 35 is discretely arranged in the two-dimensional direction, when the phosphor-containing film shown in FIG. 2 is assumed as part of the long film, broken lines Even if it cuts linearly in any place as shown by the above, the fluorescent region 35 other than the fluorescent region 35 which became the cutting point can be wrapped by the resin layer 38, and can maintain the sealed state.

However, in the phosphor-containing layer 30 of the phosphor-containing film 1 of the prior art, other fluorescent regions separated from the cut surface can be kept sealed by a resin having an impermeability to oxygen and moisture, so that the phosphor-containing layer 30 can be kept in place. Although the deterioration of the performance of the phosphor 31 in the fluorescent region 35 can be suppressed, the fluorescent region 35 located at the cutting point (cutting surface) is exposed to the outside air, and the phosphor 31 in the fluorescent region 35 is exposed. Has a problem in that performance is degraded by reacting with oxygen and moisture. For example, in the case where the phosphor-containing film 1 is cut in the broken line K in FIG. 2, a problem occurs that the phosphor 31 in the region 35K through which the broken line K passes.

In addition, in the case of the phosphor-containing film 1 of the prior art, the fluorescent region 35 is formed by using a photoresist and photolithography. In this case, the size of the fluorescent region 35 that can be manufactured at present is approximately 50 to 150. It is a relatively large size in the micrometer range. As a result, when the phosphor-containing film 1 of the prior art is cut linearly as described above, the possibility of the region of the fluorescent region 35 to be included in the cutting location increases, thereby degrading performance by reacting with oxygen and moisture. The problem arises that the possibility that the total area of the fluorescent region 35 to be increased increases.

Further, in the phosphor-containing film 1 of the prior art, since the fluorescent region 35 is formed by using an expensive photoresist and photolithography method, there is a problem in that the overall manufacturing cost increases. In addition, although the resin layer 38 made of the photoresist material, which is used in the phosphor-containing film 1 of the prior art, has a certain level of moisture permeation prevention effect against oxygen and moisture, such an effect is limited so that the number of photoresist materials is limited. The use of a material having a higher blocking effect on oxygen and moisture than in the case of using the layer 38 is required.

Therefore, a new method for solving the above-mentioned problems of the prior art is required.

Patent Document 1: Republic of Korea Patent Publication No. 10-2018-0026489 Patent Document 2: Republic of Korea Patent No. 10-1045367 Patent Document 3: Republic of Korea Patent No. 10-1250931

[Non-Patent Document 1] Structures of Anodic Aluminum Oxide from Anodization with Various Temperatures, Electrical Potentials, and Basal Plane Surfaces] . 225-230, March 2016/225]

The present invention is to solve the above-mentioned problems of the prior art, anodizing aluminum to produce an alumina having a honeycomb-shaped porous region, and a quantum dot (QD) in the porous region The present invention provides a quantum dot film and a method of manufacturing the same, which are prepared by bonding a barrier film to both upper and upper and lower surfaces thereof after filling, drying, and curing the material.

Method for producing a quantum dot film according to a first aspect of the present invention comprises the steps of: a) generating a thin film of alumina having a porous region formed by anodizing the surface of the untreated aluminum provided on the support layer film; b) filling a quantum dot (QD) material into the porous region formed on the alumina thin film; c) drying or curing the quantum dot material filled in the porous region; And d) bonding the upper barrier film to the upper portion of the alumina thin film.

A quantum dot film according to a second aspect of the present invention is an alumina thin film having a porous region formed by anodizing the surface of untreated aluminum; A support layer film provided below the untreated aluminum; And an upper barrier film provided on the alumina thin film and bonded to the alumina thin film, wherein the porous region is filled with a quantum dot material and dried or cured.

Using the improved quantum dot film according to an embodiment of the present invention and a manufacturing method thereof, the following effects are achieved.

1. Instead of fabricating the fluorescent region 35 of the prior art using expensive photoresist and photolithography, a thin film of alumina was prepared to have a honeycomb-shaped porous region formed by self-assembly on an untreated aluminum surface, thereby producing a quantum dot. The overall cost of the film and its manufacturing method is significantly reduced.

2. Since the size of the porous region can be realized in the size of tens to hundreds of nanometers (that is, the number of micrometers from one to several tens of micrometers), compared to the prior art, fluorescence that is degraded by reacting with oxygen and moisture during edge cutting. The total area of the area is significantly reduced or minimized.

3. Compared to the photoresist used to form the fluorescent region of the prior art, in the present invention, since the outer surface of the alumina thin film surrounding the porous region is formed of alumina, which is a metal oxide, the permeation prevention effect against oxygen and moisture is remarkably improved. do.

4. Not only the porous region can be partitioned into R, G, and B regions, but also the control of the concentration of the quantum dot (QD) material and the area or volume containing the quantum dot (QD) material, and the quantum dot (QD) material Since it is possible to separately charge in the R, G, and B region it is possible to implement a white light having a color coordinate to be implemented from the final product (ie, quantum dot film).

5. Each quantum dot (QD) material filled in the porous region 635 partitioned into R, G, and B regions is also partitioned, so that energy transfer and self-absorption between these quantum dots (QD) are suppressed, resulting in a significant light efficiency. Increase, and color purity is greatly improved.

6. The life of the quantum dot film is greatly increased by the effects described in the above 1 to 5.

Further advantages of the invention can be clearly understood from the following description with reference to the accompanying drawings in which like or like reference numerals indicate like elements.

1 is a perspective view showing a schematic configuration of a phosphor-containing film according to the prior art.
2 is a plan view of a phosphor-containing film according to the prior art.
3 is a cross-sectional view showing a detailed configuration of a phosphor-containing film according to the prior art.
Figure 4 is a plan view showing another embodiment of the pattern when viewed in plan view the fluorescent region of the phosphor-containing film according to the prior art.
5 is a flowchart illustrating a method of manufacturing a quantum dot film according to an embodiment of the present invention.
6A to 6E are views for explaining a method of manufacturing a quantum dot film according to an embodiment of the present invention shown in FIG.
FIG. 7 is a diagram illustrating a case in which a quantum dot film manufactured by a method of manufacturing a quantum dot film according to an embodiment of the present invention is cut along an inclined line AA in the width direction.

The present inventors have used porous alumina to form a honeycomb shape by self-assembly instead of the phosphor-containing layer 30 of the prior art including the resin layer 38 having a fluorescent region containing a quantum dot (QD) phosphor constituting a quantum dot film. By using it, the above-mentioned problem of the prior art was solved.

Hereinafter, the present invention will be described with reference to embodiments and drawings of the present invention.

5 is a flowchart illustrating a method of manufacturing a quantum dot film according to an embodiment of the present invention, Figures 6a to 6e is a method of manufacturing a quantum dot film according to an embodiment of the present invention shown in FIG. It is a figure shown for description.

Referring to FIG. 5 together with FIGS. 6A to 6E, a method 500 of manufacturing a quantum dot film according to an embodiment of the present invention may include a) anodizing a surface of an untreated aluminum 638a provided on a support layer film 610. Generating 510 an alumina thin film 630 having a porous region 635 formed by anodizing; b) filling (520) a quantum dot (QD) material 631 into the porous region 635 formed on the alumina thin film 630; c) curing (530) the quantum dot (QD) material 631 filled in the porous region 635; And d) attaching the upper barrier film 620 to the upper portion of the alumina thin film 630 (540).

Hereinafter, the specific configuration and operation of the method 500 for manufacturing a quantum dot film according to an embodiment of the present invention will be described in detail.

Referring again to FIG. 5 with FIGS. 6A to 6E, the method 500 for manufacturing a quantum dot film according to an embodiment of the present invention may include a) a surface of an untreated aluminum 638a provided on a support layer film 610. And producing 510 an alumina thin film 630 having a porous region 635 formed by anodizing. Since the alumina thin film 630 having the porous region 635 has a problem that it is difficult to handle with a very brittle material, in order to solve this problem in the present invention, as shown in FIG. 6A, untreated aluminum Three processes for providing a support layer film 610 at 638a are shown. These three processes include 1) depositing aluminum to a thickness of approximately 3 to 50 μm on a support layer film 610 as a substrate, and 2) laminating the support layer film 610 under the aluminum foil. And 3) coating the support layer film 610 on the lower portion of the aluminum foil, but it should be noted that the present invention is not limited thereto. Anodizing the surface of the untreated aluminum 638a provided on the support layer film 610 by one of these three processes forms a porous region 635 and forms a phosphor in the formed porous region 635. Finally, an alumina thin film 630 having a porous region 635 may be formed (see FIG. 6B, but the illustration of the support layer film 610 is omitted in FIG. 6B for convenience of description). Should be noted). In this case, the support layer film 610 provided under the alumina thin film 630 may correspond to the first base film 10 which is a lower barrier layer disclosed in the prior art. In addition, if necessary, it should be noted that a separate lower barrier layer or lower barrier film (not shown) may be further formed under the support layer film 610.

In addition, the porous region 635 is formed to have a honeycomb shape in a self-assembly manner (see FIGS. 6B and 6C). The size of the porous region 635 formed in this manner is approximately tens to hundreds of nm. Here, the specific method for producing the alumina thin film 630 having the porous region 635 is referred to as the non-patent literature prior art of the present invention "Structures of the anodized aluminum according to the temperature and voltage and the shape of the bottom surface (Structures of Anodic Aluminum Oxide from Anodization with Various Temperatures, Electrical Potentials, and Basal Plane Surfaces). 225-230, March 2016/225], so that those skilled in the art will fully understand the drawings shown in FIGS. 6A to 6C.

Then, in the method 500 of manufacturing a quantum dot film according to an embodiment of the present invention, a quantum dot (QD) material 631 is filled in the porous region 635 formed on the alumina thin film 630 (step 520). In this case, the quantum dot (QD) material 631 should be filled into the porous region 635 of approximately tens to hundreds of nm size. To this end, for example, an inkjet printer or a nozzle dispenser (not shown) is used to drop or eject the QD material 631 in a glove box in a size of about tens to hundreds of nm. Into the porous region 635. Here, the inkjet printer or the nozzle dispenser (not shown) may use the inkjet printing device or the dispensing nozzle device (not shown) disclosed in Korean Patent Nos. 10-1045367 and 10-1250931, respectively, registered by the present applicant. .

Then, in the method 500 of manufacturing a quantum dot film according to an embodiment of the present invention, the quantum dot (QD) material 631 filled in the porous region 635 is dried or cured (step ( 530)). When the drying or curing step 530 is completed, the upper barrier film 620 is bonded to the top of the alumina thin film 630 (step 540). As a result. Finally, the quantum dot film 600 is manufactured.

In the quantum dot film 600 manufactured by the quantum dot film manufacturing method (500,501) according to an embodiment of the present invention described in detail with reference to FIGS. 5 to 6e described above, the alumina thin film constituting the quantum dot film 600 The outer surface 638 of the alumina thin film 630 surrounding the honeycomb shaped or structured porous region 635 formed within 630 also has a honeycomb shaped or structure. Accordingly, in the quantum dot film 600 manufactured according to the embodiment of the present invention, the honeycomb shape (ie, the porous region) has a size of several tens to several hundred nanometers (ie, several micrometers of tens of micrometers). Since the outer surface 638 of the alumina thin film 630 has a honeycomb shape or structure, the total area of the fluorescent region that may degrade performance by reacting with oxygen and moisture during edge cutting is significantly reduced. Or minimized.

In addition, since the outer surface 638 of the alumina thin film 630 surrounding the porous region 635 is formed of alumina, which is a metal, a moisture permeation prevention effect against oxygen and moisture is greatly improved.

The inkjet printing apparatus or dispensing nozzle apparatus (not shown) is also used to fill the quantum dot (QD) material 631 into the porous region 635 so that the porous region 635 is divided into R, G, and B regions. In addition, the concentration of the quantum dot (QD) material 631 and the area or volume for accommodating the quantum dot (QD) material 631 may be adjusted, and the quantum dot (QD) material 631 may be R, G, And since it is possible to separately fill in the B region it is possible to implement white light from the final product (ie, the quantum dot film 600).

In addition, since the respective quantum dot (QD) materials filled in the porous region 635 partitioned into R, G, and B regions are also separated, the energy transfer and magnetic absorption between these quantum dots (QD) are suppressed, so that the light efficiency is remarkably increased. Increase, and color purity is greatly improved.

In addition, the respective quantum dot (QD) materials 631 filled in the porous region 635 partitioned into R, G, and B regions are also partitioned, so that energy transfer and dexter energy between these quantum dots QD are performed. Transfer and self absorption are suppressed to significantly increase light efficiency, greatly improve color purity, and accordingly, life of the quantum dot film 600 may be greatly increased.

FIG. 7 is a diagram illustrating a case in which a quantum dot film manufactured by a method of manufacturing a quantum dot film according to an embodiment of the present invention is cut along an inclined line A-A in a width direction.

Referring to FIG. 7, in the quantum dot film 600 manufactured by the method 500 for manufacturing a quantum dot film according to an embodiment of the present invention, the support layer film 610 and the upper portion shown in FIG. 6E are provided for convenience of description. Note that only the alumina thin film 630 in which the porous region 635 is formed by omitting the illustration of the barrier film 620 is shown.

As can be clearly understood from FIG. 7, in the alumina thin film 630, the porous region 635 cut at the cutting surface by the edge cutting along the AA line has seven cutting points (the number of such cutting points is the direction of the cutting plane). And the size of each fluorescent region 635 in the range of tens to hundreds of nm, which is approximately 50 to 150 micrometers in size, which is the size of the fluorescent region 35 shown in FIG. Compared to hundreds to one thousandths, the total area of the cut porous region 635 is significantly reduced compared to the total area of the cut fluorescent region 35 shown in FIG. Accordingly, in the present invention, the total area of the uncut porous region 635 is also significantly increased compared to the total area of the uncut fluorescent region 35 shown in FIG. It can be readily understood that the overall area of the fluorescent region 635 whose performance is to be degraded is significantly reduced or minimized depending on the response of.

The quantum dot film 600 manufactured by the method 500 for manufacturing a quantum dot film according to an embodiment of the present invention described above is a porous region 635 formed by anodizing the surface of the untreated aluminum 638a. An alumina thin film 630 having a; A support layer film 610 provided below the untreated aluminum 638a; And an upper barrier film 620 provided on the alumina thin film 630 to be bonded to the alumina thin film 630, wherein the quantum dot (QD) material 631 is filled in the porous region 635. It is characterized by being cured.

As various modifications may be made to the constructions and methods described and illustrated herein without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings be exemplary, and not intended to limit the invention. It is not. Therefore, the scope of the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

1: phosphor-containing film 10: first base film 20: second base film
30 phosphor-containing layer 31 phosphor 33 binder
35 fluorescent region 38 resin layer 600 quantum dot film
610: support layer film 620: barrier film 630: alumina thin film
631: QD material 635: porous region 638a: untreated aluminum

Claims (11)

In the manufacturing method of a quantum dot film,
a) producing an alumina thin film having a porous region formed by anodizing the surface of aluminum provided on the support layer film;
b) filling a quantum dot (QD) material into the porous region formed on the alumina thin film;
c) drying or curing the quantum dot material filled in the porous region; And
d) bonding an upper barrier film on top of the alumina thin film
Method for producing a quantum dot film comprising a. The method of claim 1,
Step a) may include i) depositing aluminum on the support layer film; ii) laminating the support layer film under the aluminum foil; And iii) a step of coating the support layer film on a lower portion of the aluminum foil. The method of claim 1,
The porous region is a method of manufacturing a quantum dot film is formed to have a honeycomb shape in a self-assembly manner. The method of claim 1,
The size of the porous region is a method of producing a quantum dot film having a range of approximately tens to hundreds of nm. The method according to any one of claims 1 to 4,
The filling of the quantum dot material is performed by filling the quantum dot material into the porous region by a dropping or ejecting method in a glove box using an inkjet printer or a nozzle dispenser. The method of claim 5,
And the inkjet printer or nozzle dispenser partitions the porous region into R, G, and B regions to fill the quantum dot material. In quantum dot film,
An alumina thin film having a porous region formed by anodizing an untreated aluminum surface;
A support layer film provided below the untreated aluminum; And
An upper barrier film provided on the alumina thin film and bonded to the alumina thin film
Including,
The porous region is filled with a quantum dot material is dried or cured
Quantum dot film. The method of claim 7, wherein
The porous region is a quantum dot film formed to have a honeycomb shape in a self-assembly manner. The method of claim 7, wherein
The porous region has a size of approximately tens to hundreds of nm in quantum dot film. The method according to any one of claims 7 to 9,
And the quantum dot material is filled into the porous region by a dropping or ejecting method in a glove box using an inkjet printer or a nozzle dispenser. The method of claim 10,
And the porous region is divided into R, G, and B regions, and the quantum dot material is filled into the partitioned R, G, and B regions to realize white light.

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