CN111584744A

CN111584744A - Display panel and preparation method thereof

Info

Publication number: CN111584744A
Application number: CN202010400956.6A
Authority: CN
Inventors: 王敏
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2020-05-13
Filing date: 2020-05-13
Publication date: 2020-08-25

Abstract

The invention provides a display panel and a preparation method thereof. The display panel comprises a substrate, an organic light-emitting device layer, a first packaging layer and a second packaging layer. Wherein the first encapsulation layer includes a silicon oxide layer and a silicon nitride layer.

Description

Display panel and preparation method thereof

Technical Field

The invention relates to the field of display devices, in particular to a display panel and a preparation method thereof.

Background

The Organic Light-Emitting Diode (OLED) display panel has the advantages of being Light, thin, wide in color gamut, wide in viewing angle, low in power consumption, high in resolution and the like, has a wide application prospect in the aspects of intelligent household appliances, wearable equipment and the like, and especially, the coming of the 5G era further pulls the demand of people on large-size 8K OLED products. At present, a top-emitting OLED device generally uses metal with strong light reflection as an anode, metal with good light transmission as a cathode, and then a glass cover plate is used for packaging the metal, so that color display is realized. Compared with the a-Si TFT, the IGZOTFT technology has higher electron mobility, can meet the requirement of large-size 8K OLED products on high electron mobility, has low manufacturing cost, and is the best choice for the large-size 8K OLED products. The organic light emitting layer of the OLED is sensitive to water and oxygen, and the light emitting performance of the OLED is influenced, so that the packaging structure and the material are very important.

Disclosure of Invention

The invention aims to provide a display panel and a preparation method thereof, and aims to solve the problems that in the prior art, an OLED display panel is poor in packaging effect and the like.

To achieve the above objective, the present invention provides a display panel, which includes a substrate, an organic light emitting device layer, a first encapsulation layer, and a second encapsulation layer. The organic light emitting device layer is arranged on the substrate. The first encapsulation layer covers the organic light emitting device layer. The second packaging layer is arranged on one surface of the first packaging layer far away from the organic light-emitting device layer.

Wherein the first encapsulation layer includes a silicon oxide layer and a silicon nitride layer. The silicon oxide layer is disposed on the organic light emitting device layer. The silicon nitride layer is arranged on the silicon oxide layer.

Furthermore, the display panel generally comprises a covering layer and a cover plate. The capping layer is disposed between the silicon oxide layer and the organic light emitting device layer. The cover plate is arranged on one surface, far away from the first packaging layer, of the second packaging layer.

Further, the organic light emitting device layer includes a light emitting layer and a cathode layer. The light emitting layer is arranged on the substrate. The cathode layer is arranged on one surface of the light-emitting layer far away from the substrate.

Further, the second packaging layer comprises a first adhesive layer, a second adhesive layer and a third adhesive layer. The first adhesive layer is arranged on the silicon nitride layer and corresponds to the organic light-emitting device layer. The second adhesive layer is arranged on the silicon nitride layer and surrounds the first adhesive layer. The third adhesive layer is arranged on the silicon nitride layer and surrounds the second adhesive layer. Wherein, the second glue layer is provided with a moisture absorbent.

Further, the width of the silicon nitride layer is larger than that of the silicon oxide layer.

The invention also provides a preparation method of the display panel, which comprises the following steps:

a substrate is provided. An organic light emitting device layer is formed on the substrate. A first encapsulation layer is formed on the organic light emitting device layer. A second encapsulation layer is formed on the first encapsulation layer.

Wherein the step of forming a first encapsulation layer on the organic light emitting device layer comprises:

and depositing a layer of silicon oxide material on the organic light-emitting device layer to form a silicon oxide layer. And depositing a layer of silicon nitride material on the silicon oxide layer to form a silicon nitride layer.

Further, the step of forming an organic light emitting device layer on the substrate includes the steps of:

a light-emitting layer is formed on the substrate by an evaporation method or an ink-jet printing method. And forming a cathode layer on the light-emitting layer by magnetron sputtering or evaporation.

Further, the method also comprises the following steps after the step of forming the OLED device on the substrate: and forming a covering layer on the OLED device by an evaporation method.

The method also comprises the following steps before the step of forming a second packaging layer on the first packaging layer: a cover plate is provided.

Further, the step of forming a second encapsulation layer on the first encapsulation layer includes:

and a second adhesive layer and a third adhesive layer are sequentially formed on the edge of the cover plate. And filling a first adhesive material on one side of the second adhesive layer, which is far away from the second adhesive layer, and attaching the adhesive material to the first packaging layer by a vacuum compression method. And curing the adhesive material by ultraviolet irradiation or heating to form a first adhesive layer.

The invention also provides a display device, which comprises the display panel.

The invention has the advantages that: according to the display panel provided by the invention, the silicon oxide layer is added in the first packaging layer, so that hydrogen atoms can be prevented from invading the thin film transistor substrate and the organic light-emitting device layer in the process of preparing the silicon nitride layer, the damage caused by the invasion of the hydrogen atoms is prevented, the packaging effect can be further improved, the invasion of water and oxygen is further prevented, the stability of the display panel is improved, and the service life of the display panel is prolonged. Meanwhile, the preparation process of the silicon oxide layer is simple, and the silicon oxide layer and the silicon nitride layer can be prepared in the same equipment cavity without preparing additional equipment.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a layer structure of a display panel according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart of a preparation method in an embodiment of the present invention;

FIG. 3 is a schematic view of the layered structure in step 20 of the production method in the embodiment of the present invention;

FIG. 4 is a schematic view of the layered structure in step 30 of the production method in the embodiment of the present invention;

FIG. 5 is a schematic view of the layered structure in step 40 of the manufacturing method in the embodiment of the present invention;

fig. 6 is a schematic view of the layered structure in step 60 of the manufacturing method in the embodiment of the present invention.

The components in the figures are represented as follows:

a display panel 100;

a substrate 10; an organic light emitting device layer 20;

a light-emitting layer 21; a cathode layer 22;

a cover layer 30; a first encapsulation layer 40;

a silicon oxide layer 41; a silicon nitride layer 42;

a second encapsulation layer 50; a first adhesive layer 51;

a second glue layer 52; a third glue layer 53;

a cover plate 60.

Detailed Description

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, which are included to demonstrate that the invention can be practiced, and to provide those skilled in the art with a complete description of the invention so that the technical content thereof will be more clear and readily understood. The present invention may be embodied in many different forms of embodiments and should not be construed as limited to the embodiments set forth herein.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

Furthermore, the following description of the various embodiments of the invention refers to the accompanying drawings that illustrate specific embodiments of the invention, by which the invention may be practiced. Directional phrases used in this disclosure, such as, for example, "upper," "lower," "front," "rear," "left," "right," "inner," "outer," "side," and the like, refer only to the orientation of the appended drawings and are, therefore, used herein for better and clearer illustration and understanding of the invention, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

When certain components are described as being "on" another component, the components can be directly on the other component; there may also be an intermediate member disposed on the intermediate member and the intermediate member disposed on the other member. When an element is referred to as being "mounted to" or "connected to" another element, they may be directly "mounted to" or "connected to" the other element or indirectly "mounted to" or "connected to" the other element through an intermediate element.

The embodiment of the invention provides a display device, which is an organic light-Emitting Diode (OLED) display device, and can be a device with a picture display function, such as a notebook computer, a mobile phone, a tablet computer, a television, and the like.

The display device has a display panel 100, and the display panel 100 is used for providing a display screen for the display device. As shown in fig. 1, the display panel 100 includes a substrate 10, an organic light emitting device layer 20, a first encapsulating layer 40, a second encapsulating layer 50 and a cover plate 60.

The substrate 10 is a Thin Film Transistor (TFT) substrate for controlling light emission of the organic light emitting device layer 20.

The organic light emitting device layer 20 is provided on the substrate 10, and has a layered structure of an anode layer, a cathode layer 22, a light emitting layer 21, and the like. As shown in fig. 1, the light emitting layer 21 is disposed on the substrate 10, and the cathode layer 22 is disposed on a surface of the light emitting layer 21 away from the substrate 10. The cathode layer 22 is a transparent cathode layer 22, which does not affect the transmission of light emitted from the light emitting layer 21, and the material of the cathode layer includes a conductive material, such as magnesium, silver, indium zinc oxide, and the like. Under the action of the electric field, holes generated in the anode and electrons generated in the cathode layer 22 move, migrate into the light emitting layer 21, and combine with each other in the light emitting layer 21 to generate energy excitons, so as to excite the light emitting molecules to finally generate visible light, thereby providing a light source for the display panel 100 and realizing the display of pictures.

The display panel 100 has a cover layer 30, the cover layer 30 is disposed on a surface of the organic light emitting device layer 20 away from the substrate 10, and a width of the cover layer 30 is greater than or equal to a width of the organic light emitting device layer 20. When the width of the capping layer 30 is greater than that of the organic light emitting device layer 20, the capping layer 30 covers the organic light emitting device layer 20. The cover layer 30 is made of an organic material, and is used to improve the light extraction of the display panel 100 and reduce the damage to the cathode layer 22 in the organic light emitting device layer 20 during the manufacturing process of the display panel 100.

The first encapsulation layer 40 is disposed on a surface of the cover layer 30 away from the organic light emitting device, and includes a silicon oxide layer 41 and a silicon nitride layer 42. The silicon oxide layer 41 is disposed on the cover layer 30, has a width greater than that of the cover layer 30, and covers the cover layer 30. The silicon nitride layer 42 is disposed on the silicon oxide layer 41, has a width larger than that of the silicon oxide layer 41, and covers the silicon oxide layer 41. The silicon oxide layer 41 is used to protect the organic light emitting device layer 20 and the thin film transistor substrate 10 under the organic light emitting device layer 20, prevent hydrogen gas generated during the preparation of the silicon nitride layer 42 from damaging the thin film transistor in the substrate 10, and improve the stability of the display panel 100. The silicon nitride in the silicon nitride layer 42 has excellent water resistance, and can prevent water vapor from invading and corroding the organic light-emitting device layer 20 and the substrate 10. The first encapsulation layer 40 of the two-layer structure has a better encapsulation effect.

The second encapsulant layer 50 is disposed on a surface of the first encapsulant layer 40 away from the cover layer 30, and includes a first adhesive layer 51, a second adhesive layer 52, and a third adhesive layer 53. The first adhesive layer 51 is disposed on the silicon nitride layer 42 and corresponds to the organic light emitting device layer 20, and may be a photosensitive adhesive or a thermosetting adhesive. The second adhesive layer 52 and the third adhesive layer 53 are arranged on the same layer as the first adhesive layer 51, the second adhesive layer 52 surrounds the first adhesive layer 51, and the third adhesive layer 53 surrounds the second adhesive layer 52. The second glue layer 52 contains moisture absorbent, such as metal oxide like calcium oxide, which has the function of absorbing moisture while protecting the package. One or more resin materials such as epoxy resin and acrylic resin are contained in the third adhesive layer 53. The width of the second encapsulation layer 50 is the same as the width of the first encapsulation layer 40.

The cover plate 60 is disposed on the second encapsulation layer 50, and may be transparent glass or a color film substrate.

The embodiment of the present invention further provides a preparation method of the display panel 100, wherein a preparation flow of the preparation method is shown in fig. 2, and the preparation method specifically comprises the following steps:

step S10) provides a substrate 10: the substrate 10 is a thin film transistor substrate.

Step S20) preparing the organic light emitting device layer 20: as shown in fig. 3, a light emitting layer 21 is formed on the substrate 10 by an evaporation method or an ink jet printing method; and preparing a layer of transparent conductive material on one surface of the light-emitting layer 21 far away from the substrate 10 by a magnetron sputtering method or an evaporation method to form a cathode layer 22. The light emitting layer 21 and the cathode layer 22 combine to form the organic light emitting device layer 20.

Step S30) preparing the cover layer 30: as shown in fig. 4, a layer of organic material is evaporated on a surface of the organic light emitting device layer 20 away from the substrate 10, and the organic material covers the organic light emitting device layer 20.

Step S40) preparing the first encapsulation layer 40: as shown in fig. 5, depositing a layer of silicon oxide material on a surface of the cover layer 30 away from the organic light emitting device layer 20 by a plasma enhanced chemical vapor deposition method to form a silicon oxide layer 41, where the silicon oxide layer 41 covers the cover layer 30; a silicon nitride layer 42 is also deposited on a surface of the silicon oxide layer 41 away from the cover layer 30 by a plasma enhanced chemical vapor deposition method, and the silicon nitride layer 42 covers the silicon oxide layer 41. While depositing the silicon nitride layer 42, hydrogen is added into the deposition chamber, and the hydrogen can saturate dangling bonds in the silicon nitride and increase the tightness of the material. The silicon oxide layer 41 and the silicon nitride layer 42 combine to form the first encapsulation layer 40.

Step S50) provides a cover plate 60: the cover plate 60 may be a transparent glass or a color film substrate.

Step S60) preparing the second encapsulation layer 50: as shown in fig. 6, a resin adhesive material is coated on the edge of one surface of the cover plate 60 to form a third adhesive layer 53; coating the inner side of the third glue layer 53 with a glue material with a moisture absorbent to form a second glue layer 52; the first adhesive layer 51 is formed by filling photosensitive adhesive or thermosetting adhesive on the inner side of the second adhesive layer 52. The first step of attaching one surface of the first adhesive layer 51, the second adhesive layer 52 and the third adhesive layer 53 away from the cover surface to a surface of the silicon nitride layer 42 away from the silicon oxide layer 41 by using a vacuum press fit method, wherein the first adhesive layer 51 is in a bead shape as shown in fig. 6 when being filled, and the bead-shaped first adhesive layer 51 is leveled after the vacuum press fit to form the layered first adhesive layer 51 as shown in fig. 1; finally, ultraviolet irradiation or heating is selected according to the photosensitive adhesive or the thermosetting adhesive to cure the first adhesive layer 51 and the third adhesive layer 53, so that the second encapsulation layer 50 is prepared, and the display panel 100 shown in fig. 1 is formed.

In the display panel 100, the silicon oxide layer 41 is added to the first encapsulation layer 40, so that hydrogen atoms can be prevented from invading the thin film transistor substrate 10 and the organic light emitting device layer 20 in the process of preparing the silicon nitride layer 42, damage caused by the invasion of the hydrogen atoms is prevented, the encapsulation effect can be further improved, invasion of water and oxygen is further prevented, and the stability and the service life of the display panel 100 are improved. Meanwhile, the preparation process of the silicon oxide layer 41 is simple, and the silicon oxide layer and the silicon nitride layer 42 can be prepared in the same equipment chamber without preparing additional equipment.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.

Claims

1. A display panel, comprising:

a substrate;

the organic light-emitting device layer is arranged on the substrate;

a first encapsulation layer covering the organic light emitting device layer;

the second packaging layer is arranged on one surface of the first packaging layer, which is far away from the organic light-emitting device layer;

wherein the first encapsulation layer comprises:

a silicon oxide layer disposed on the organic light emitting device layer;

and the silicon nitride layer is arranged on the silicon oxide layer.

2. The display panel of claim 1, further comprising:

a covering layer arranged between the silicon oxide layer and the organic light-emitting device layer;

and the cover plate is arranged on one surface of the second packaging layer far away from the first packaging layer.

3. The display panel of claim 1, wherein the organic light emitting device layer comprises:

the light-emitting layer is arranged on the substrate;

the cathode layer is arranged on one surface of the light-emitting layer far away from the substrate.

4. The display panel of claim 1, wherein the second encapsulation layer comprises:

the first adhesive layer is arranged on the silicon nitride layer and corresponds to the organic light-emitting device layer;

the second adhesive layer is arranged on the silicon nitride layer and surrounds the first adhesive layer;

the third adhesive layer is arranged on the silicon nitride layer and surrounds the second adhesive layer;

wherein, the second glue layer is provided with a moisture absorbent.

5. The display panel of claim 1, wherein the silicon nitride layer has a width greater than a width of the silicon oxide layer.

6. A preparation method of a display panel is characterized by comprising the following steps:

providing a substrate;

forming an organic light emitting device layer on the substrate;

forming a first encapsulation layer on the organic light emitting device layer;

forming a second encapsulation layer on the first encapsulation layer;

depositing a layer of silicon oxide material on the organic light-emitting device layer to form a silicon oxide layer;

and depositing a layer of silicon nitride material on the silicon oxide layer to form a silicon nitride layer.

7. The method of manufacturing a display panel according to claim 6, wherein the step of forming an organic light emitting device layer on the substrate includes the steps of:

forming a light emitting layer on the substrate by an evaporation method or an ink jet printing method;

and forming a cathode layer on the light-emitting layer by magnetron sputtering or evaporation.

8. The method for manufacturing a display panel according to claim 6,

the method also comprises the following steps after the step of forming the OLED device on the substrate:

forming a covering layer on the OLED device through an evaporation method;

the method also comprises the following steps before the step of forming a second packaging layer on the first packaging layer:

a cover plate is provided.

9. The method for manufacturing a display panel according to claim 8, wherein the step of forming a second encapsulation layer on the first encapsulation layer comprises:

forming a second adhesive layer and a third adhesive layer on the edge of the cover plate in sequence;

filling a glue material on one side of the second glue layer, which is far away from the second glue layer, and attaching the glue material to the first packaging layer through a vacuum compression method;

and curing the adhesive material by ultraviolet irradiation or heating to form a first adhesive layer.

10. A display device characterized by comprising the display panel according to any one of claims 1 to 5.