CN108417598B

CN108417598B - OLED display panel, packaging method and preparation method of organic film

Info

Publication number: CN108417598B
Application number: CN201810097751.8A
Authority: CN
Inventors: 杨星星
Original assignee: Kunshan Govisionox Optoelectronics Co Ltd
Current assignee: Kunshan Govisionox Optoelectronics Co Ltd
Priority date: 2018-01-31
Filing date: 2018-01-31
Publication date: 2021-03-23
Anticipated expiration: 2038-01-31
Also published as: CN108417598A

Abstract

The invention discloses an OLED display panel, an encapsulation method and a preparation method of an organic film, wherein the OLED display panel comprises an array substrate and an encapsulation cover plate arranged opposite to the array substrate, a pixel limiting layer is arranged on the array substrate, a plurality of pixel areas are limited and formed on the array substrate by the pixel limiting layer, the adjacent pixel areas are spaced by the pixel limiting layer, the encapsulation cover plate is provided with the organic film on one side facing the array substrate, the organic film is convexly provided with a first bulge facing the array substrate at the position corresponding to the pixel limiting layer, and the first bulge is abutted to the pixel limiting layer and used for supporting the encapsulation cover plate. The organic film replaces the original spacing support, the problems that the original spacing support is easy to fall off and shift are solved, and the shock resistance of the OLED display panel is improved.

Description

OLED display panel, packaging method and preparation method of organic film

Technical Field

The invention relates to the technical field of OLED display panels, in particular to an OLED display panel, an encapsulating method and a preparation method of an organic film.

Background

As a new generation of Display devices, OLED (Organic Light-Emitting Diode) devices, i.e., Organic Light-Emitting displays, have advantages that are not comparable to those of conventional displays, such as self-luminescence, no need of backlight, realization of ultra-thin Display and flexible Display, low driving voltage, power saving, fast response speed, and the like. However, OLED devices are very sensitive to oxygen and moisture, and are subject to oxygen and moisture attack, which can degrade performance and ultimately fail. The lifetime of the OLED device is therefore strongly affected by the encapsulation process. At present, the OLED device is widely sealed and protected by adopting a glass material packaging method.

As shown in fig. 1, in the conventional glass Frit sealing method, an array substrate 10 and a sealing cover plate 20 are generally manufactured separately, and then a glass Frit 30 is disposed between the array substrate 10 and the sealing cover plate 20 and the two substrates are bonded by Frit sealing technology, i.e., a box is formed. In order to provide a certain pressure resistance to the package cover plate 20 and prevent the generation of newton rings affecting the display effect during the laser sealing process, in the prior art, a plurality of spacer pillars 4(photo spacers) are usually fabricated on the array substrate 10, and the spacer pillars 4 also play a role of supporting the screen and maintaining the cell thickness, and each spacer pillar 4 is fabricated on the pixel defining layer 1 at present, and then the cathode electrode layer 2 and the PDL layer 3 are fabricated above the spacer pillar 4. Since the spacing pillars 4 are independent from each other, when the spacing pillars 4 are impacted by an external force, the spacing pillars 4 in the impacted area are likely to fall off and shift, and the spacing pillars 4 after shifting block the pixel area 11 (opening area), thereby generating a black ball drop.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide an OLED display panel, an encapsulation method and a preparation method of an organic film, and solve the problem of black spots caused by easy falling of spacing pillars.

The purpose of the invention is realized by the following technical scheme:

the invention provides an OLED display panel, which comprises an array substrate and an encapsulation cover plate arranged opposite to the array substrate, wherein a pixel limiting layer is arranged on the array substrate, a plurality of pixel areas are limited and formed on the array substrate by the pixel limiting layer, the adjacent pixel areas are spaced by the pixel limiting layer, an organic film is arranged on one side of the encapsulation cover plate facing the array substrate, a first bulge is arranged on the organic film in a protruding mode facing the array substrate at the position corresponding to the pixel limiting layer, and the first bulge abuts against the pixel limiting layer and supports the encapsulation cover plate.

Further, the first protrusion is a semi-sphere, a truncated cone or a cylinder, and the top of the first protrusion faces the array substrate and abuts against the pixel defining layer.

Further, the organic film is provided with a light extraction area corresponding to each pixel area, and the light extraction area is provided with a hemispherical second bulge.

Further, the height of the second protrusion is smaller than the height of the first protrusion.

Furthermore, the first bulges are arranged around each pixel area in a surrounding mode, and the second bulges which are arranged corresponding to each pixel area are multiple and are mutually and tightly arranged.

Further, the CPL layer is arranged on the pixel region and the pixel limiting layer in a covering mode on the whole surface, and the first protrusions are directly abutted and contacted with the CPL layer.

The invention also provides an encapsulation method of the OLED display panel, which comprises the following steps:

providing an encapsulation cover plate and an array substrate, attaching an organic film with a first bulge on one side of the encapsulation cover plate facing the array substrate, and enabling the first bulge to abut against a pixel limiting layer on the array substrate and support the encapsulation cover plate;

and packaging the packaging cover plate and the array substrate together by using Frit materials.

The present invention also provides a method for preparing an organic film, the method comprising:

coating a photoresist on a substrate;

exposing and developing the photoresist by using a gray scale mask plate to pattern the photoresist, and forming a first pit and a second pit with different pit depths in the photoresist;

injecting a liquid organic material into the first and second recesses of the photoresist;

and heating and hardening the organic material to form an organic film, wherein the organic film forms a first bump at a position corresponding to the first pit, and the organic film forms a second bump at a position corresponding to the second pit.

The invention has the beneficial effects that: the organic film is used for replacing an original spacing support column arranged on the pixel limiting layer, all first bulges for supporting the packaging cover plate are connected into a whole through the organic film, the first bulges are not easy to fall off, the shock resistance of the OLED display panel is improved, and the black spots generated by the opening area due to the fact that the original spacing support column is easy to fall off and the position of the first bulges is deviated are reduced.

Drawings

Fig. 1 is a schematic structural diagram of a conventional OLED display panel.

Fig. 2 is a schematic structural diagram of an OLED display panel according to a first embodiment of the present invention.

Fig. 3 is a top view of an array substrate according to a first embodiment of the present invention.

Fig. 4 is a schematic view of the structure of an organic film in the first embodiment of the present invention.

Fig. 5 is a schematic structural diagram of an OLED display panel according to a second embodiment of the present invention.

Fig. 6a is a schematic view illustrating an encapsulation method of an OLED display panel according to a third embodiment of the present invention.

FIG. 6b is a schematic diagram illustrating a step of fabricating an organic film according to a third embodiment of the present invention.

Fig. 7a to 7d are schematic views illustrating a process of fabricating an organic film according to a third embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and specific examples, but the scope of the present invention is not limited thereto.

[ first embodiment ]

As shown in fig. 2, a first embodiment of the present invention provides an OLED display panel, which includes an array substrate 10 and an encapsulation cover plate 20 disposed opposite to the array substrate 10, wherein a pixel definition layer 1 is disposed on the array substrate 10, and the pixel definition layer 1 may be made of a polyimide material through photolithography or printing. A plurality of pixel regions 11 are defined by a pixel defining layer 1 on an array substrate 10, the pixel defining layer 1 is arranged around each pixel region 11, adjacent pixel regions 11 are spaced from each other by the pixel defining layer 1, and the pixel defining layer 1 is used for isolating the adjacent pixel regions 11.

The encapsulation cover plate 20 is provided with an organic film 5 on a side facing the array substrate 10, and specifically, the organic film 5 is attached on an inner side surface of the encapsulation cover plate 20. The organic film 5 is provided with a first protrusion 51 protruding toward the array substrate 10 at a position corresponding to the pixel defining layer 1, and the first protrusion 51 abuts against the pixel defining layer 1 and supports the encapsulation cover 20. The organic film 5 further includes a substrate 50, and the first protrusions 51 of the organic film 5 are integrally connected through the substrate 50.

In the present embodiment, the respective first protrusions 51 supporting the encapsulation cover plate 20 are disposed on the organic film 5, rather than being directly fabricated on the encapsulation cover plate 20, for the following reasons: since the package cover plate 20 is thin, it is not easy to etch, and when the package cover plate 20 is etched deeply, the strength of the package cover plate 20 is easily affected; to facilitate etching, the thickness of the encapsulating cover plate 20 may be increased, but this may affect the light extraction efficiency of the OLED display panel.

The pixel region 11 is provided with an anode electrode layer (not shown), an organic light emitting layer (not shown), and a cathode electrode layer 2. The organic light emitting layer includes, for example, organic functional film layers such as a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Electron Transport Layer (ETL), and an Electron Injection Layer (EIL). A pixel circuit layer (not shown) is formed on the array substrate 10, and the pixel circuit layer mainly includes a Thin Film Transistor (TFT), a line (a scan line, a data line, etc.) connected to the TFT, and a storage capacitor, which are well known to those skilled in the art and are not described herein. The light emitting principle of the OLED device is that a semiconductor material and an organic light emitting material emit light under the drive of an electric field through carrier injection and recombination. Specifically, the OLED device generally uses ITO and metal as an anode and a cathode of the device, respectively, and under a certain voltage, electrons and holes are injected from the cathode and the anode to an electron transport layer and a hole transport layer, respectively, and the electrons and the holes migrate to a light emitting layer through the electron transport layer and the hole transport layer, respectively, and meet in the light emitting layer to form excitons and excite light emitting molecules, which emit visible light through radiation relaxation.

Further, the CPL layer 3 is disposed over the entire surface of the pixel region 11 and the pixel defining layer 1. CPL (capping layer) is a light extraction material with high refractive index and small absorption coefficient, so as to improve the light extraction efficiency of the OLED display panel. In the present embodiment, the first projection 51 is in direct abutting contact with the CPL layer 3 on the pixel defining layer 1.

Further, the first protrusion 51 is shaped like a hemisphere, the top of the first protrusion 51 faces the array substrate 10, and the contact areas between the first protrusion 51 and the CPL layer 3 are different under different stress conditions, so that the impact resistance of the OLED display panel can be improved.

Further, the organic film 5 is provided with a light extraction region 55 at a position corresponding to each pixel region 11, the light extraction region 55 has a second protrusion 52, in this embodiment, the second protrusion 52 is a hemisphere, and the size of the second protrusion 52 is smaller than that of the first protrusion 51, so that the height of the second protrusion 52 is smaller than that of the first protrusion 51. The first bump 51 and the second bump 52 on the organic film 5 are integrally connected through the base 50.

Referring to fig. 3 and 4, fig. 3 is a schematic plan view of the pixel defining layer 1, and fig. 4 is a schematic plan view of the organic film 5. As can be seen from fig. 3, a plurality of pixel regions 11 arranged in an array are defined by the pixel defining layer 1, and each square blank region in fig. 3 represents one pixel region 11. As can be seen from fig. 4, the first protrusions 51 on the organic film 5 are disposed at positions corresponding to the pixel defining layer 1, and the first protrusions 51 are disposed around each pixel region 11, while the second protrusions 52 on the organic film 5 are disposed at positions corresponding to each pixel region 11, and the second protrusions 52 disposed corresponding to each pixel region 11 are plural and closely arranged to each other. Since the second protrusions 52 face the light emitting direction of the organic light emitting layer in each pixel region 11, the hemispherical second protrusions 52 can converge light, reduce the total reflection of light in the OLED display panel, and further improve the light emitting efficiency of the display panel.

In this embodiment, the organic material forming the organic film 5 is, for example, Polydimethylsiloxane (PDMS), which has the characteristics of low cost, optical transparency, inertia, non-toxicity, and non-flammability.

As shown in fig. 2, the array substrate 10 and the package cover plate 20 are bonded together by glass Frit 30 using Frit packaging technology, which is to prepare glass Frit into a solution with a certain viscosity, coat the solution on the package glass, heat the solution to remove the solvent, then bond the glass Frit with the glass to be packaged, and use laser to instantly burn the Frit glass to melt the glass Frit, thereby bonding two pieces of flat glass together.

In the OLED display panel of this embodiment, the organic film 5 is disposed on the encapsulation cover plate 20, the organic film 5 protrudes toward the array substrate 10 and is provided with a first protrusion 51 for supporting the encapsulation cover plate 20, the first protrusion 51 abuts against the pixel defining layer 1, the first protrusion 51 of the organic film 5 replaces the original spacing pillar 4 disposed on the pixel defining layer 1, the first protrusions 51 supporting the encapsulation cover plate 20 are connected into a whole through the base 50, and the falling or the position deviation is not easy to occur, thereby reducing the black spot generated by the pixel region 11 (opening region) due to the easy falling and the position deviation of the original spacing pillar 4.

[ second embodiment ]

As shown in fig. 5, the OLED display panel according to the second embodiment of the present invention is substantially the same as the OLED display panel according to the first embodiment (fig. 2), except that in this embodiment, the first protrusion 51 of the organic film 5 is a truncated cone, which is simpler to manufacture, and in the same way, the skilled person can set the first protrusion 51 to be any other shape, such as a cylinder, as needed to meet the actual requirement.

The rest of the structure and the operation principle of this embodiment are the same as those of the first embodiment, and are not described herein again.

[ third embodiment ]

As shown in fig. 6a and 6b, a third embodiment of the present invention provides an encapsulation method of an OLED display panel, including:

providing an encapsulation cover plate 20 and an array substrate 10, attaching an organic film 5 with a first bump 51 on one side of the encapsulation cover plate 20 facing the array substrate 10, and enabling the first bump 51 to abut against a pixel definition layer 1 on the array substrate 10 and support the encapsulation cover plate 20;

the package cover plate 20 is packaged with the array substrate 10.

Specifically, a pixel defining layer 1, an anode electrode layer, an organic light emitting layer and a cathode electrode layer 2 are formed on the array substrate 10, wherein a plurality of pixel regions 11 are defined by the pixel defining layer 1, and the anode electrode layer, the organic light emitting layer and the cathode electrode layer 2 are disposed in the pixel regions 11.

Specifically, when the package cover plate 20 is packaged with the array substrate 10, the glass Frit 30 may be coated on the package cover plate 20, and the package of the array substrate 10 and the package cover plate 20 may be implemented by using Frit 30 using Frit packaging technology.

As shown in fig. 7a to 7d, the third embodiment of the present invention also provides a method for manufacturing an organic film 5, the method comprising:

as shown in fig. 7a, a photoresist 60 is coated on a substrate 70;

as shown in fig. 7a and 7b, the photoresist 60 is exposed and developed by using a gray-scale mask 80, so that the photoresist 60 is patterned, and a first pit 61 and a second pit 62 with different recess depths are formed in the photoresist 60;

as shown in fig. 7c, a liquid organic material is injected into the first and

second recesses

61 and 62 of the photoresist 60;

as shown in fig. 7d, the organic material is heated and cured to form the organic film 5, wherein the organic film 5 has a first protrusion 51 formed at a position corresponding to the first recess 61, a second protrusion 52 formed at a position corresponding to the second recess 62, and a base 50 formed at a position other than the positions corresponding to the first recess 61 and the second recess 62, wherein the base 50 is used for connecting with the package cover 20.

The present embodiment can manufacture the organic films 5 with different hardness by heating the organic material to different degrees, so as to adapt to different OLED display panels.

According to the packaging method of the OLED display panel, the organic film 5 is arranged on the packaging cover plate 20, the first protrusion 51 used for supporting the packaging cover plate 20 is arranged on the organic film 5 in a protruding mode towards the array substrate 10, the first protrusion 51 abuts against the CPL layer 3 on the pixel limiting layer 1, the first protrusion 51 of the organic film 5 replaces the original spacing support post 4 arranged on the pixel limiting layer 1, all the first protrusions 51 are connected into a whole through the base body 50, the problem that the original spacing support post 4 is prone to falling off and position deviation is solved, and the shock resistance of the OLED display panel is improved.

The above embodiments are only examples of the present invention and are not intended to limit the scope of the present invention, and all equivalent changes and modifications made according to the contents described in the claims of the present invention should be included in the claims of the present invention.

Claims

1. An OLED display panel comprising an array substrate (10) and an encapsulating cover plate (20) arranged opposite to the array substrate (10), the array substrate (10) being provided with a pixel defining layer (1), the array substrate (10) being defined by the pixel defining layer (1) to form a plurality of pixel regions (11), adjacent pixel regions (11) being spaced apart from each other by the pixel defining layer (1), characterized in that the encapsulating cover plate (20) is provided with an organic film (5) on a side facing the array substrate (10), the organic film (5) being provided with a first protrusion (51) protruding toward the array substrate (10) at a position corresponding to the pixel defining layer (1), the first protrusion (51) abutting against the pixel defining layer (1) and supporting the encapsulating cover plate (20), the organic film (5) further having a light extraction area (55) arranged corresponding to each pixel region (11), the light extraction area (55) is provided with a hemispherical second bulge (52), and the second bulge (52) is right opposite to the light outlet direction of the organic light emitting layer in each pixel area (11).

2. The OLED display panel according to claim 1, wherein the first protrusion (51) is a semi-sphere or a truncated cone or a cylinder, and a top of the first protrusion (51) faces the array substrate (10) and abuts against the pixel defining layer (1).

3. The OLED display panel according to claim 1, wherein the height of the second protrusion (52) is smaller than the height of the first protrusion (51).

4. The OLED display panel according to claim 1, wherein the first protrusions (51) are circumferentially disposed around each pixel region (11), and the second protrusions (52) corresponding to each pixel region (11) are a plurality of and closely arranged to each other.

5. The OLED display panel according to claim 1, characterized in that the pixel region (11) and the pixel defining layer (1) are further provided with a CPL layer (3) entirely covering them, the first protrusion (51) being in direct abutting contact with the CPL layer (3).

6. An encapsulating method of an OLED display panel, the method comprising:

providing a package cover plate (20) and an array substrate (10), wherein a pixel limiting layer (1) is arranged on the array substrate (10), a plurality of pixel areas (11) are defined on the array substrate (10) by the pixel defining layer (1), adjacent pixel areas (11) are spaced from each other by the pixel defining layer (1), attaching an organic film (5) having a first protrusion (51) and a light extraction region (55) having a hemispherical second protrusion (52) to a side of the encapsulation cover plate (20) facing the array substrate (10), making the first protrusion (51) abut against the pixel defining layer (1) on the array substrate (10) and supporting the encapsulation cover plate (20), and the second protrusion (52) in the light extraction region (55) is opposite to the light-emitting direction of the organic light-emitting layer in each pixel region (11);

and packaging the packaging cover plate (20) and the array substrate (10) together by using a Frit material.