WO2015188486A1

WO2015188486A1 - Organic light emitting device, and manufacturing method thereof, and organic light emitting display device

Info

Publication number: WO2015188486A1
Application number: PCT/CN2014/086614
Authority: WO
Inventors: 罗程远; 王俊然; 于东慧
Original assignee: 京东方科技集团股份有限公司
Priority date: 2014-06-11
Filing date: 2014-09-16
Publication date: 2015-12-17
Also published as: CN104091890A; CN104091890B

Abstract

An organic light emitting device and, manufacturing method thereof, and organic light emitting display device, the organic light emitting device comprising: a substrate (1); an organic light emitting unit (2) disposed on the substrate (1); a passivation layer (3) covering the organic light emitting unit (2) for blockingand blocking environmental moisture and oxygen in the environment; and an packaging glue layer (4) provided on one side of the passivation layer (3) away from the organic light emitting unit (2), characterized in that the packaging glue adhesive layer (4) comprises thermally conductive particles (7). The thermally conductive particles (7) can improve the thermal conduction capacity of the packaging glue adhesive layer (4), thus preventing damage to the organic light emitting unit (2) from being damaged due to overheating after being powered on for a long time, and preventing the impact on the service life of the organic light emitting device.

Description

Organic light-emitting device, preparation method thereof and organic light-emitting display device

Technical field

The present invention belongs to the field of display technologies, and in particular, to an organic light emitting device, a method for fabricating the same, and an organic light emitting display device.

Background technique

Organic Light Emitting Diode (OLED) is the third generation display technology after liquid crystal display technology. Since 1987, organic light-emitting diodes have matured over the past two decades and have been widely used in various fields such as flat panel display, illumination, and display backlights, creating a huge and growing market.

The organic materials of OLED devices are highly sensitive to the external environment. Oxygen, moisture and other components in the atmospheric environment will oxidize or corrode the materials of OLED devices. Therefore, unpackaged OLED devices will cause their performance after being placed in the atmosphere. Drastically reduced or even completely lost function. In order to extend the lifetime of OLED devices and improve the stability of OLED devices, OLED devices must be packaged.

As shown in FIG. 1, the organic light emitting device includes: a substrate 1 and an organic light emitting unit 2 disposed on the substrate 1, and a passivation layer 3 covering the organic light emitting unit 2 for blocking the environment. The effect of moisture and oxygen on the organic light-emitting unit 2; the encapsulating layer 4 is disposed on a side of the passivation layer away from the organic light-emitting unit 2; and the side of the encapsulant layer 4 remote from the organic light-emitting unit 2 is provided The cover plate 5 serves as a heat sink for discharging heat generated by the organic light-emitting unit 2 through the encapsulant layer 4.

The encapsulant layer 4 (organic matter) used for sealing is a poor conductor of heat, so that heat dissipation is disadvantageous, and heat generated by the organic light-emitting unit 2 is not easily transmitted to the cap plate 5 through the encapsulant layer 4, so the organic light-emitting unit 2 is in a long time. It is easy to overheat after being energized, which is easily damaged and affects the service life of the organic light-emitting device.

Based on the above situation, improving the thermal conductivity of the encapsulant layer 4 has become an urgent problem to be solved.

Summary of the invention

The object of the present invention is to solve the problem that the organic light-emitting device is overheated due to poor thermal conductivity of the encapsulant layer and affects the service life of the organic light-emitting device and the organic light-emitting display device in the prior art, and provides an organic service with prolonged service life. A light emitting device and an organic light emitting display device including the same.

The technical solution adopted to solve the technical problem of the present invention includes an organic light emitting device, including:

Substrate

An organic light emitting unit disposed on the substrate;

Covering a passivation layer of the organic light emitting unit, the passivation layer for blocking moisture and oxygen in the environment;

An encapsulant layer is disposed on a side of the passivation layer away from the organic light emitting unit, wherein the encapsulant layer comprises thermally conductive particles.

Preferably, the thermally conductive particles have a core-shell structure; the core structure in the core-shell structure comprises metal nanoparticles having excellent thermal conductivity; and the shell structure in the core-shell structure comprises an isolation layer. The shell structure surrounds the core structure.

Preferably, the core structure has a particle size ranging from 1 to 40 nm.

Preferably, the metal nanoparticles are produced using any one or more of Al, Mg, Ag, Cu, and Au.

Preferably, the spacer layer is made of any one of Si ₃ N ₄ , SiC, and C.

Preferably, the thermally conductive particles have a particle diameter of from 1 to 50 nm.

Preferably, the thermally conductive particles comprise 30-40% of the volume fraction of the encapsulant layer.

Preferably, the encapsulant layer further comprises desiccant particles.

Preferably, the desiccant particles have a particle size of from 1 to 50 nm.

Preferably, the desiccant particles occupy 10%-20% of the volume fraction of the encapsulant layer; the sum of the desiccant particles and the heat conductive particles occupying the volume fraction of the encapsulant layer is less than Or equal to 50%.

Preferably, the desiccant particles are made of any one of CaO, BaO, MgO, TiO ₂ and Al ₂ O ₃ .

Preferably, the passivation layer is made of any one of Si ₃ N ₄ , SiO ₂ , SiC, TiO ₂ , Al ₂ O ₃ , ZnS, and ZnO.

Preferably, the encapsulant layer is formed of a UV epoxy encapsulant; the UV epoxy encapsulant comprises glycidyl acrylate, glycidyl methacrylate, methyl methacrylate, and In a light-sensitive resin of a homopolymer or copolymer of a monomer such as ethyl acrylate, n-butyl methacrylate, methyl polyacrylate 6,7-epoxyheptyl ester or 2-hydroxyethyl methacrylate Any one.

The technical solution adopted to solve the technical problem of the present invention includes a method for preparing an organic light emitting device, comprising the steps of:

Making an organic light emitting unit on the substrate;

Covering the organic light emitting unit with a passivation layer;

The thermally conductive particles and the desiccant particles having a core-shell structure are added to the encapsulant and mixed to obtain a uniformly mixed encapsulant mixture;

Applying the encapsulant mixture evenly to the cover; and

The cover plate coated with the encapsulant mixture is laminated with the passivation covering the organic light emitting unit, so that the encapsulant mixture uniformly covers the passivation layer, and then the encapsulating glue mixture is cured by ultraviolet irradiation.

The technical solution adopted to solve the technical problem of the present invention includes an organic light emitting display device including the above organic light emitting device.

In the organic light emitting device and the organic light emitting display device provided by the present invention, the encapsulant layer is provided with heat conductive particles, which can improve the thermal conductivity of the encapsulant layer, thereby preventing the organic light emitting unit from being damaged by overheating after being energized for a long time, and Affect the service life of organic light-emitting devices. Further, the encapsulant layer may further be provided with desiccant particles, and when the barrier property of the encapsulant layer is degraded to moisture and oxygen, the desiccant particles can absorb moisture, prevent moisture from diffusing to the organic light emitting unit, and affect the life of the organic light emitting device. .

DRAWINGS

1 is a schematic cross-sectional view of an organic light emitting device in the prior art;

2 is a schematic cross-sectional view of an organic light emitting device according to an embodiment of the present invention;

3 is a schematic cross-sectional view of thermally conductive particles in the organic light emitting device shown in FIG. 2.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

The present embodiment provides an organic light emitting device as shown in FIG. 2, comprising a substrate 1 and an organic light emitting unit 2 disposed on the substrate 1; and a passivation layer 3 covering the organic light emitting unit 2, The passivation layer 3 is used to block the influence of moisture and oxygen in the environment on the organic light-emitting unit 2; the encapsulating layer 4 is disposed on the side of the passivation layer 3 away from the organic light-emitting unit 2; One side of the organic light-emitting unit 2 is provided with a cover plate 5 as a heat sink, and the heat generated by the organic light-emitting unit 2 is led out through the encapsulant layer 4; the encapsulant layer 4 comprises thermally conductive particles 7.

Since the encapsulant layer 4 in the embodiment is provided with the heat conductive particles 7, the heat conductive particles 7 can improve the thermal conductivity of the encapsulant layer 4, and the heat generated by the organic light emitting unit 2 is transmitted to the cover 5, thereby preventing the organic light emitting unit. 2 Due to overheating after a long time of power-on, it is damaged and affects the service life of the organic light-emitting device.

Specifically, as shown in FIG. 3, the thermally conductive particles 7 may have a core-shell structure. The core structure 71 in the core-shell structure may include metal nanoparticles having excellent thermal conductivity. The metal nano-particles are added to the encapsulant layer 4 to enhance the heat dissipation performance of the encapsulant layer 4, and the heat generated by the organic light-emitting unit 2 is transmitted through the cover plate 5 in time to reduce damage to the organic light-emitting device. Preferably, the metal nanoparticles are made of any one or more of Al, Mg, Ag, Cu, and Au.

Wherein, the particle size of the core structure 71 may range from 1 to 40 nm, and if the particle size of the core structure 71 is too small, the shell layer is not easily coated, and the free nuclear structure 71 particles are likely to occur, and the particle size of the core structure 71 is too large. The particle size of the core-shell structure is too large, which affects the adhesion properties of the encapsulant layer 4 to its surrounding contact surface.

The shell structure 72 of the core-shell structure includes an isolation layer, and the shell structure 72 surrounds the core structure 71. The isolation layer is made of a material that has both good thermal conductivity, insulation properties, and moisture and oxygen barrier properties. The shell structure 72 can prevent the core structure 71 from being in contact with the electrode after the aging of the passivation layer 3 is damaged, and prevents the core structure 71 from being oxidized by moisture and oxygen.

The core-shell structure of the thermally conductive particles can be synthesized by a common method of manufacturing a nano metal core-shell composite particle such as a laser induced composite heating method, a sol-gel method, or a condensed phase separation method, and will not be further described herein.

Preferably, the isolation layer may be made of any one of Si ₃ N ₄ , SiC, and C.

Preferably, the thermally conductive particles 7 may have a particle diameter of 1 to 50 nm. If the particle size of the thermally conductive particles 7 is too small, the manufacturing cost is high and it is difficult to uniformly disperse, and if the particle size of the thermally conductive particles 7 is too large, the adhesion property of the encapsulant layer 4 to the surrounding contact surface thereof is affected.

Preferably, the thermally conductive particles 7 comprise 30-40% of the volume fraction of the encapsulant layer 4. When the volume fraction of the thermal conductive particles 7 in the encapsulating layer 4 is too small, the thermal conductivity is deteriorated, and if the thermal conductive particles 7 are too large, the adhesion property of the encapsulating layer 4 to the surrounding contact surface thereof is affected;

Since the thermally conductive particles 7 are added to the encapsulant layer 4, the adhesion of the encapsulant layer 4 to the substrate 1 is reduced, and moisture and oxygen are easily invaded from the poorly adhesive portion, thereby causing the encapsulant layer 4 to be infiltrated. The overall barrier to moisture and oxygen is degraded. Therefore, preferably, the desiccant particles 6 may be disposed in the above-mentioned encapsulant layer 4, and when the barrier property of the encapsulant layer 4 against moisture and oxygen is lowered, the desiccant particles 6 can absorb moisture and prevent moisture from diffusing to the organic light-emitting unit. 2. Affect the life of organic light-emitting devices.

Preferably, the desiccant particles 6 may have a particle diameter of 1 to 50 nm. When the particle size of the desiccant particles 6 is too small, it is difficult to manufacture, and the production cost is high, and if the particle diameter is too large, the adhesion property of the encapsulant layer 4 to the surrounding contact surface thereof is affected.

Preferably, the desiccant particles 6 may be made of any one of CaO, BaO, MgO, TiO ₂ and Al ₂ O ₃ .

Preferably, the desiccant particles 6 account for 10%-20% of the volume fraction of the encapsulant layer 4; the desiccant particles 6 occupying too small a volume fraction of the encapsulant layer 4 may reduce the drying effect, and if the desiccant particles 6 are too large, the package may be affected. Adhesion properties of the adhesive layer 4 to its surrounding contact surface.

The sum of the desiccant particles 6 and the thermally conductive particles 7 in the volume fraction of the encapsulating layer 4 may be less than or equal to 50%. When the volume fraction of the desiccant particles 6 and the heat conductive particles 7 in the encapsulant layer 4 is too small, the heat conduction effect and the drying effect are not obvious, and if the amount is too large, the adhesion property of the encapsulant layer 4 to the surrounding contact surface thereof is affected.

Example 2:

The embodiment provides a method for preparing the above organic light emitting device, comprising the following steps:

1) Making an organic light-emitting unit

An organic light-emitting unit is fabricated on a substrate (glass substrate). Of course, it is also possible to form a functional layer necessary for light emission such as an anode (indium tin oxide) and a cathode on a substrate. Since these functional layers can be produced by using methods already existing in the prior art, they will not be described again here.

2) Production of passivation layer

The organic light emitting unit is covered with a passivation layer.

Specifically, the passivation layer may be made of any one of Si ₃ N ₄ , SiO ₂ , SiC, TiO ₂ , Al ₂ O ₃ , ZnS, and ZnO; the passivation layer has a function of blocking moisture and oxygen; preferably The passivation layer may have a thickness of 500 to 1000 nm. The passivation layer can be obtained by different known methods, such as chemical vapor deposition, sputtering, atomic force deposition, spray coating, etc., depending on the materials used, and will not be described again. In addition, a mask is used in the fabrication process so that the passivation layer covers only the organic light-emitting unit.

3) Production of encapsulation layer

The thermally conductive particles and the desiccant particles having a core-shell structure are added to the encapsulant and mixed to obtain a uniformly mixed encapsulant mixture. The heat conductive particles may occupy 30-40% by volume of the encapsulating layer, and the desiccant particles may account for 10-20% of the encapsulating layer. It should be understood that it is suitable that the sum of the desiccant particles and the thermally conductive particles in the encapsulating layer volume fraction is less than or equal to 50%. Both the desiccant particles and the thermally conductive particles may have a particle diameter of 1 to 50 nm. In addition, for uniform mixing, the encapsulating mixture can be treated with ultrasonic waves.

Thereafter, the encapsulant mixture is evenly applied to the cover.

4) Cover pressing

The cover plate coated with the encapsulant mixture is laminated with the passivation covered by the step 2) and covered with the organic light-emitting unit, so that the encapsulant is uniformly covered with the passivation layer, and then cured by ultraviolet irradiation to obtain an organic light-emitting device.

Alternatively, other necessary functional units, such as an array substrate and various lead wires, may be fabricated, and are not described herein again.

It should be understood that the above encapsulant may be a UV epoxy encapsulant. Specifically, the UV epoxy encapsulant may include glycidyl acrylate, glycidyl methacrylate, methyl methacrylate, and A. In a light-sensitive resin such as a homopolymer or a copolymer of a monomer such as ethyl acrylate, n-butyl methacrylate, methyl polyacrylate 6,7-epoxyheptyl ester or 2-hydroxyethyl methacrylate; Any one;

The above encapsulant may also include known thermosetting resins (for example, melamine formaldehyde resin, unsaturated polyester resin, silicone resin, furan resin, etc.) as long as a low water permeability encapsulant can be formed.

Example 3-7

The organic light-emitting devices provided in Examples 3-7 were prepared by the method provided in Example 2, wherein the parameters of the main functional layers of the organic light-emitting device are shown in Table 1. It can be seen from Table 1 that the organic light-emitting device containing the heat conductive particles and the desiccant particles in the encapsulant layer has a prolonged service life with respect to the organic light-emitting device which does not contain the heat conductive particles and the desiccant particles in the encapsulant layer.

Comparative example

The present comparative example is an organic light-emitting device. Unlike the organic light-emitting device provided in Examples 3-7, the epoxy resin provided in the comparative example does not contain thermally conductive particles and desiccant particles.

Table 1 Parameters of main functional layers of the organic light-emitting device of Examples 3-7

Example 8

The present embodiment provides an organic light emitting display device comprising the above-described organic light emitting device, and of course, other necessary functional units, for example, an array substrate for controlling the light emitting unit, a polarizer for controlling the light direction, and the like.

In the organic light-emitting device and the organic light-emitting display device of the present invention, the encapsulant layer is provided with heat-conducting particles, which can improve the thermal conductivity of the encapsulant layer, and facilitate the conduction of heat generated by the organic light-emitting unit to the cover plate, thereby preventing organic The light-emitting unit is overheated after being energized for a long time and is damaged, and affects the service life of the organic light-emitting device. Further, the encapsulant layer may further be provided with desiccant particles, which can absorb moisture when the barrier property of the encapsulant layer is degraded to moisture and oxygen, prevent moisture from diffusing to the organic light emitting unit, and affect the life of the organic light emitting device.

It is to be understood that the above embodiments are merely exemplary embodiments employed to explain the principles of the invention, but the invention is not limited thereto. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and scope of the invention. These modifications and improvements are also considered to be within the scope of the invention.

Claims

An organic light emitting device comprising:

Substrate

An organic light emitting unit disposed on the substrate;

Covering a passivation layer of the organic light emitting unit, the passivation layer for blocking moisture and oxygen in the environment;

An encapsulant layer is disposed on a side of the passivation layer away from the organic light emitting unit, wherein the encapsulant layer comprises thermally conductive particles.
The organic light-emitting device according to claim 1, wherein said thermally conductive particles have a core-shell structure; said core structure of said core-shell structure comprises metal nanoparticles having excellent thermal conductivity; said core-shell structure The shell structure includes an isolation layer that surrounds the core structure.
The organic light-emitting device according to claim 2, wherein the core structure has a particle diameter ranging from 1 to 40 nm.
The organic light-emitting device according to claim 2, wherein the metal nanoparticles are made of any one or more of Al, Mg, Ag, Cu, and Au.
The organic light-emitting device according to claim 2, wherein the spacer layer is made of any one of Si 3 N 4 , SiC, and C.
The organic light-emitting device according to claim 1, wherein said thermally conductive particles have a particle diameter of from 1 to 50 nm.
The organic light-emitting device according to claim 1, wherein said thermally conductive particles comprise 30-40% by volume of said encapsulant layer.
The organic light-emitting device according to any one of claims 1 to 7, wherein The encapsulant layer further includes desiccant particles.
The organic light-emitting device according to claim 8, wherein said desiccant particles have a particle diameter of from 1 to 50 nm.
The organic light-emitting device according to claim 8, wherein said desiccant particles constitute 10% to 20% by volume of said encapsulant layer; said desiccant particles and said thermally conductive particles account for said The sum of the volume fractions of the encapsulant layer is less than or equal to 50%.
The organic light-emitting device according to claim 8, wherein said desiccant particles are made of any one of CaO, BaO, MgO, TiO 2 and Al 2 O 3 .
The organic light-emitting device according to claim 1, wherein said passivation layer is made of any one of Si 3 N 4 , SiO 2 , SiC, TiO 2 , Al 2 O 3 , ZnS, and ZnO.
The organic light emitting device according to claim 1, wherein said encapsulant layer is formed of a UV epoxy encapsulant; said UV epoxy encapsulant comprises propylene acrylate, methacrylate epoxy Homopolymerization of monomers of propyl ester, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, methyl polyacrylate 6,7-epoxyheptyl ester, 2-hydroxyethyl methacrylate Any one of light sensitive resins of the substance or copolymer.
A method for preparing an organic light emitting device, comprising the steps of:

Making an organic light emitting unit on the substrate;

Covering the organic light emitting unit with a passivation layer;

The thermally conductive particles and the desiccant particles having a core-shell structure are added to the encapsulant and mixed to obtain a uniformly mixed encapsulant mixture;

Evenly coating the encapsulant mixture on the cover;

The cover plate coated with the encapsulant mixture is laminated with the passivation covering the organic light emitting unit, so that the encapsulant mixture uniformly covers the passivation layer, and then the encapsulating glue mixture is cured by ultraviolet irradiation.
An organic light emitting display device, comprising the organic light emitting device according to any one of claims 1 to 13.