KR101351109B1 - Encapsulated structure for device and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an encapsulation encapsulation structure and a method of manufacturing the same, and more particularly, to depositing a pinhole of an organic layer with a fluid oxide thin film formed by depositing a silane compound and a nitrogen-containing gas at a low temperature as a reactant, and depositing it, compared to a conventional ALD deposition method. Improved production speed due to increased speed, and the deposition process at a lower temperature can significantly reduce the damage of the device. In particular, the film breakage phenomenon during bending can be improved to develop a light emitting device advantageous for flexible display applications.

Description

ENCAPSULATED STRUCTURE FOR DEVICE AND MANUFACTURING METHOD THEREOF}

The present invention relates to an encapsulation structure for a device and a method of manufacturing the same.

Flexible displays are the next generation of promising displays with new growth engines and are expected to generate rapid demand in the future in order to meet the ubiquitous environment.In the meantime, a lot of research has been done, but active driving devices (satisfied with stability, performance, and process compatibility) Due to the development of TFT) devices and the development of high-efficiency and long-life OLEDs for plastics, full-fledged market formation is delayed.

Flexible displays have the advantages of ultra-slim, unbreakable displays, and free display variations, which can replace existing displays.

The OLED applicable to the flexible display is formed by interposing a multilayer organic thin film composed of a light emitting layer and a hole injection layer / electron injection layer between a pair of electrodes on a substrate. The OLED uses a light emission phenomenon generated when electrons and holes injected into the light emitting layer recombine.

Fluorescent organic material as a material of the light emitting layer of the OLED is weak to moisture and oxygen, etc., the light emitting layer may be damaged or oxidation of the metal layer may occur. As a result, when the conventional OLED is driven in the atmosphere, its luminescence properties deteriorate rapidly. Therefore, it is necessary to extend the life of the device by encapsulating the device so that moisture, oxygen, or the like does not enter the OLED. The thin film type encapsulant of the OLED generally has an encapsulation structure in which a polymer layer and an inorganic barrier layer are alternately positioned. The inorganic barrier layer is used as a barrier layer to prevent the penetration of moisture and gas, but there is a problem in that fine cracks or pinholes are generated during bending.

As a method for filling the pin hole, there are Barix Sputter technology and a method using ALD (Atomic layer deposition) [Patent Documents 1 to 3]. This is a technology of minimizing the pinhole, which is a problem of a film composed of organic materials only by alternately stacking an organic thin film and an inorganic thin film, and securing flexibility, which is a problem of a film composed only of inorganic materials. In particular, ALD technology is a barrier film technology that prevents water permeation. However, due to the low deposition rate (0.5 ~ 3 Å / cycle) and relatively high deposition temperature (80 ℃ or more), there are still problems to be solved in productivity and application to the actual device.

U.S. Patent No.6.866.901 U.S. Patent No.7.198.832 U.S. Pat.No.7.510.913

Accordingly, the present inventors can lower the direct influence of the device due to heat because the F-Oxide thin film proceeds at a low process temperature as an inorganic layer to replace ALD. It was confirmed that the productivity can be increased because it has a high deposition rate.

Accordingly, an object of the present invention is to provide an encapsulation structure for a device including a flowable oxide thin film and a method of manufacturing the same, which is advantageous for flexible display applications.

As means for solving the above problems,

An element encapsulation structure comprising an encapsulation layer in which an organic layer and an inorganic layer are formed on a substrate on which an element is formed, wherein the inorganic layer provides an element encapsulation structure, which is a fluid oxide thin film.

As another means for solving the above problems,

Forming an organic layer on the substrate on which the device is formed; And

Forming a flowable oxide thin film on the organic layer

It provides a method for manufacturing a device encapsulation structure comprising a.

As another means for solving the above problems,

Provided is a flexible display including the encapsulation structure.

As another means for solving the above problems,

An encapsulation layer is formed on a substrate, and a method of forming a fluidized oxide thin film by low-temperature deposition of a silane compound and a nitrogen-containing gas into a gap formed in the encapsulation layer is provided.

The present invention improves the production speed due to the deposition rate improvement by filling the pinhole of the organic layer with a fluid oxide thin film formed by depositing at a low temperature, it is possible to reduce the damage of the device by the deposition process at a low temperature. In particular, the film breakage phenomenon during bending can be improved to manufacture a light emitting device that is advantageous for flexible display applications.

1 illustrates a process of filling pinholes by depositing with a flowable oxide according to the present invention [yellow: flowable oxide thin film, blue: organic layer].
Figure 2 shows an OELD encapsulation structure according to an embodiment of the present invention (arrow: bending display).
Figure 3 shows the process of filling the pinhole with the conventional ALD method.
Figure 4 shows the OELD encapsulation structure encapsulated by the conventional ALD method (arrow: bending display).
Figure 5 is a schematic diagram before and after the bending test of the encapsulation structure deposited by the flowable oxide thin film according to the present invention (the fluidic oxide thin film can fill the pinhole when the pinhole is generated, thereby no crack occurs when bending).
Figure 6 is a schematic diagram before and after the bending test of the encapsulation structure deposited by the conventional ALD method [ALD film can not fill the pinhole when the pinhole occurs, thereby causing cracks during bending.
Figure 7 shows a gap fill image for the encapsulation structure prepared according to the present invention.
8 is a schematic diagram of a Ca device for confirming a change in electrical characteristics of Ca.
Figure 9 shows the water vapor transmission rate results for the encapsulation structure prepared according to the present invention.
Figure 10 shows the moisture permeability results for before and after the bending test of the encapsulation structure prepared according to the present invention.
Figure 11 shows the moisture permeability results for before and after the bending test of the encapsulation structure produced by the ALD method

Hereinafter, the present invention will be described in detail.

The present invention relates to an encapsulation structure including an encapsulation layer in which an organic layer and an inorganic layer are formed on a substrate on which an element is formed, wherein the inorganic layer relates to an encapsulation structure for an element, which is a fluid oxide thin film.

The substrate may be a silicon wafer, a glass substrate or a plastic substrate. Examples of the plastic substrate include polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate; Polyalkylene naphthalates such as polyethylene naphthalate; Polycarbonate; Polyolefins such as polypropylene and polyethylene; Polybutene; Polybutadiene; Polyalkylpentenes such as polymethylpentene; Polyvinyl chloride; Triacetyl cellulose; Polyether sulfone; Polyurethane; Polyalkylene vinyl acetates such as polyethylene vinyl acetate; Ionomer resins; Alkylene- (meth) acrylic acid copolymers such as ethylene- (meth) acrylic acid copolymer; Alkylene- (meth) acrylic acid ester copolymers such as ethylene- (meth) acrylic acid ester copolymer; polystyrene; Polyimide; Polyamide; Polyamideimide; Fluoro resins; Copolymers thereof; And it may be made of a resin selected from the group consisting of a mixture thereof.

The device is preferably a light emitting device, more preferably OELD, but is not limited thereto.

In general, the substrate on which the device is formed refers to a structure in which a substrate, a cathode, a hole injection layer, a hole transport layer, an electron transport layer serving as a light emitting layer, and an anode are sequentially stacked.

The flowable oxide thin film constituting the inorganic layer is formed by depositing a silicon precursor containing hydrogen and a nitrogen containing gas at a low temperature as a reactant, and the silicon precursor containing hydrogen as a silane-based compound, specifically tetramethoxy Siloxane (TMOS), dichlorodiethoxysiloxane (DCDES), bis (diethylamino) silane, tri (dimethylamino) chlorosilane, trimethoxysiloxane (TRIMOS), octachlorotrisiloxane (OCTS), hexamethoxydisilaxane (HMDS-H), 1,4-dioxa-2,3,5,6-tetrasilacyclocarboxylic acid, 1,1,2,2-tetraethoxy-1,2-dimethyldisilane, triethoxysiloxane (TRIED), octamethyl-1,4-dioxa-2,3,5,6-tetrasilacyclohexane, hexamethyldisilazane (HMDS), tetrachlorosilane (TECS), octamethoxytrisiloxane (OMOTS) ), Chlorotriethoxysiloxane (CTES), tetrakis (dimethylamino) silane, hexachlorodisiloxane (HCDS), hexaethoxy Disilane, hexamethoxydisiloxane (HMODS), hexamethoxydisilane, dodecamethoxycyclohexasilane, octamethoxydometasiloxane (OMODDS), silatrane, methylsilatran, methyldiethoxysilane (MIDES) , Monophenylsilane (MPS) and the like are preferred, but are not limited thereto.

The nitrogen-containing gas is preferably an amine gas such as monomethylamine, dimethylamine, or trimethylamine, but is not limited thereto. The fluid oxide thin film according to the present invention refers to a polysilazane oxide [SiON] thin film formed by low temperature deposition of a silane compound and nitrogen-containing gas radicals.

The thickness of the flowable oxide thin film is preferably 50 nm to 3 μm in order to prevent cracks caused by particles during bending or to fill in pin holes and water penetration from the lower side of the device.

The organic layer can be used as long as it is generally used in the encapsulation structure for the device, preferably polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polypropylene, polyimide and triacetyl cellulose, polydimethylsiloxane and polymethyl meta At least one polymer layer selected from the group consisting of acrylates is suitable.

The configuration of the encapsulation structure is shown in FIG. 2 as an example.

As shown in FIG. 2, the organic layer and the inorganic layer of a fluidic oxide thin film are included as a barrier layer on the board | substrate with which the element was formed. In particular, by filling the pinhole with the flowable oxide thin film it is possible to improve the problem of the conventional ALD method (breaking of the film when bending in Figure 3), that is to prevent the bending cracks.

As shown in FIG. 9, as a result of measuring the WVTR of the encapsulation structure using the flowable oxide thin film of the present invention, a value of 2.1 × 10 ⁻² g / m ² / day was confirmed, thereby confirming that water infiltration was prevented. .

The present invention also provides a method of forming an organic layer on a substrate on which an element is formed; And forming a fluid oxide thin film on the organic layer.

First, an organic layer is formed on a substrate having a structure in which a substrate, a cathode, a hole injection layer, a hole transport layer, an electron transport layer serving as a light emitting layer, and a cathode are sequentially stacked. At this time, the organic layer is the same as described above.

Next, as a step of forming a flowable oxide thin film on the organic layer, by depositing a silane-based compound and nitrogen-containing gas at a low temperature as a reactant to form a flowable oxide thin film. At this time, the reaction gas is more preferably reacted in the form of a radical.

The deposition is preferably carried out by spin coating or plasma treatment under vacuum low temperature conditions, the low temperature means a temperature of 5 to 50 ℃, preferably 10 to 30 ℃. The plasma treatment is most preferably Remote-PECVD (plasma enhanced chemical vapor deposition), wherein the plasma is preferably 500 to 4000 watts. In addition, the deposition rate is preferably about 20 to 150 nm / min.

The encapsulation structure according to the present invention is applicable to OLED (organic light emitting device), OPV (organic solar cell), QD-LED (quantum dot-LED), QD-Solar Cell (quantum dot-solar cell), OTFT (organic transistor), etc. .

In addition, the encapsulation structure according to the present invention can be applied to a flexible display because the film breakage phenomenon is significantly reduced even when bending.

The present invention also includes a method in which an encapsulation layer is formed on a substrate and a fluidized oxide thin film is formed by depositing a silane-based compound and a nitrogen-containing gas at a low temperature as a reactant in a gap formed in the encapsulation layer.

The encapsulation layer may include an organic layer, an inorganic layer, and an organic / inorganic composite layer, and the gap refers to a hole having a diameter of 5 nm to 10 μm.

Hereinafter, the present invention will be described in more detail by way of examples. It should be noted, however, that the following examples are illustrative of the invention and are not intended to limit the scope of the invention.

Reference Example  One: OLED  Device formation

DH Lee, YP Liu, KH Lee, H. Chae, SM Cho, Org . Electron . , 11, 427-433, (2010) was produced as follows.

ITO (indium tin oxide) having a sheet resistance of 10Ω was used. ITO glass was put in acetone and methanol and ultrasonically cleaned for 10 minutes. The cleaned ITO glass was surface treated for 1 minute using oxygen plasma. At this time, the plasma power is 150 Watt, the ratio of oxygen and argon is 1: 1. PEDOT: PSS (AI4083) material was spin coated at 4000 rpm for 30 seconds. It is made of spin coated PEDOT thin film. The annealing temperature was 120 ° C. and performed for 10 minutes. The green luminescent ink was spin coated at 2000 rpm for 30 seconds. At this time, the material of the ink is CBP, TPD, PBD and Ir (ppy) ₃ , the ratio of each material (CBP: TPD: PBD: Ir (ppy) ₃ = 10: 1.5: 6: 1, weight ratio). This ink was dissolved in 1.5 wt% of DCE (1,2-Dichloroethane) solvent. Annealing the spin-coated green light emitting thin film, the annealing temperature is 80 ℃, was carried out for 10 minutes. After depositing LiF 1 nm thickness at a vacuum degree of 5 × 10 ⁻⁶ Pa or less, Al 100 nm thickness was deposited.

Example  1: Preparation of Encapsulation Structure

On the OLED device manufactured as in Reference Example 1, PDMS or PMMA was spin-coated in a nitrogen atmosphere and then cured at 150 ° C. for 10 minutes to laminate an organic layer.

The organic layer was transferred into a plasma-enhanced chemical vapor deposition (Remote-PECVD) reactor. Plasma power-2000 watts were added in Remote-PECVD to generate nitrogen-containing gas (1250 sccm) radicals. A silane compound (750 sccm) was added to the Remote-PECVD to react the nitrogen-containing radical and the silane compound under normal temperature (25 ° C.) and vacuum conditions to prepare polysilazane. The polysilazane was converted into an oxide (SiON) form of the flowable polysilazane by adding 500 sccm of oxygen in a vacuum chamber and reacting for 5 minutes.

As shown in FIG. 7, as a Gap Fill Image of an encapsulation layer having a 30 nm hole size having an aspect ratio (1: 1000), it can be seen that a fluid oxide thin film is filled to the bottom of the gap.

Experimental Example  1: check for moisture penetration

The flowable oxide thin film formed in Example 1 was transferred to an evaporator in a grove-box for Ca-test. The procedure was tested under a nitrogen atmosphere with about 8 ppm moisture present (almost none).

Formation of electrode (150 nm thick, 5 μs / sec) by Al deposition on the barrier film. Ca deposition on the Al electrode was formed (300nm thickness 5 s / sec)

Uv-curable epoxy resin was coated on the side where Ca was deposited by UV curing for 3 minutes.

In order to measure the moisture permeability, the electrical properties (conductivity measurement) were observed through Ca-Test in a constant temperature and humidity chamber.

Ca is easily oxidized to water and oxygen to CaO or CaOH, reducing the electrical conductivity. Based on this principle, WVTR can be measured by substituting Equation 1 [REVIEW OF SCIENTIFIC INSTRUMENTS 78, 064701 (2007)].

[Equation 1]

In order to perform a thin film Ca test, a flowable oxide receiving film was deposited on a plastic film (PEN), and cured by UV using an epoxy resin (see FIG. 8).

Ca deposition (50% relative humidity, 25 ° C.) after deposition of a 150 nm thick fluid oxide thin film revealed that 2 × 10 ⁻² g / m ² / day after 30 hours. As a result, it can be seen that the flowable oxide thin film has excellent moisture barrier property (see FIG. 9).

Experimental Example  2: Bending  Test

The Ca test was performed after the bending test (bending test 1000 times at a radius of 5 cm of curvature) of various thicknesses (50 to 125 nm) made by using the encapsulation structure manufacturing process of Example 1.

Small changes within 5% of the WVTR were seen (determining the WVTR from the slope). This shows that the encapsulation structure of the present invention can be used as a flexible moisture barrier film (see FIG. 10).

On the other hand, after the bending test (curvature radius 5cm, the number of repetitions of 1000) of the encapsulation structure made through ALD, the Ca test results show that the value of WVTR decreases by more than 50% as the number of bending increases. [See FIG. 11]. This means that the moisture blocking effect is poor.

Experimental Example  3: Check the production speed

While the deposition rate of the flowable oxide thin film according to Example 1 was 135 nm / min, in the case of a thin film manufactured using ALD, the deposition rate was 1 Å / Cycle at a deposition rate of 1 min / cycle. Therefore, it can be seen that the production rate of the flowable oxide thin film according to the present invention is excellent.

Claims (12)

An encapsulation structure for an element comprising an encapsulation layer in which an organic layer and an inorganic layer are formed on a substrate on which an element is formed,
The inorganic layer is an encapsulation structure for a flexible display device, characterized in that the fluid oxide thin film formed by depositing a silane compound and a nitrogen-containing radical at vacuum and 5 to 50 ℃.
delete The method of claim 1,
The encapsulation structure is a flexible display applicable to OLED (organic light emitting device), OPV (organic solar cell), QD-LED (quantum dot-LED), QD-Solar Cell (quantum dot-solar cell) or OTFT (organic transistor) display) Encapsulation structure for device.
Forming an organic layer on the substrate on which the device is formed; And
Depositing a silane compound and a nitrogen-containing gas on the organic layer by a remote-plasma treatment under vacuum and 5 to 50 ° C. to form a flowable oxide thin film.
Method of manufacturing a sealing structure for a flexible display device comprising a.
delete delete delete delete 5. The method of claim 4,
The deposition is a method of manufacturing an encapsulation structure for a flexible display (flexible display) device is carried out at a deposition rate of 20 ~ 150 nm / min.
A flexible display comprising an encapsulation structure according to claim 1 or an encapsulation structure produced by the method according to claim 4.
An encapsulation layer is formed on the substrate, and a fluidized oxide thin film is formed by depositing a silane compound and a nitrogen-containing gas in a gap formed in the encapsulation layer by a remote-plasma treatment under vacuum and 5 to 50 ° C. How to.
An encapsulation structure for a flexible display device manufactured by the method according to claim 4.

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