CN111725421B

CN111725421B - Organic light emitting diode display panel and display device

Info

Publication number: CN111725421B
Application number: CN202010517045.1A
Authority: CN
Inventors: 王幸; 王国超
Original assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2020-06-09
Filing date: 2020-06-09
Publication date: 2023-02-03
Anticipated expiration: 2040-06-09
Also published as: CN111725421A

Abstract

The invention provides an organic light emitting diode display panel and a display device. According to the invention, the conical structure is formed in the drilling area, so that after the packaging flat layer in a wet film state is covered, the conical structure can enable the packaging flat layer to be filled in the at least one groove, bubbles existing in the at least one groove are reduced, and the packaging flat layer can be coated smoothly.

Description

Organic light emitting diode display panel and display device

Technical Field

The invention relates to the technical field of display, in particular to an organic light emitting diode display panel and a display device.

Background

As the visual impact requirements of users on display panels become more and more diversified, a high-screen-to-body ratio (screen-to-body ratio) has become a necessary specification of an intelligent terminal in a rapidly developing intelligent terminal market. The display panel of the intelligent terminal has been developed so far to be capable of increasing the screen occupation ratio to a degree of being almost a full screen, and based on the structural design of the full screen concept, devices such as a camera, a receiver and a proximity sensor need to be installed in a range surrounded by a display area of the display panel in a drilling mode (as shown in fig. 1, a drilling area 1 is arranged in the display panel 2). As shown in fig. 2, most of the display panels with drilled holes in the market are liquid crystal display panels, when the drilling technology is applied to an oled display panel, bubbles usually exist in the groove 4 facing the water blocking area, the groove 4 cannot be completely filled with the package flat layer 3, and after the reduced pressure drying, the film layer is broken due to the bubbles, and the problem that the package flat layer cannot be smoothly coated exists, thereby reducing the yield.

Therefore, it is desirable to provide an oled display panel and a display device to solve the problems of the prior art.

Disclosure of Invention

The invention aims to provide an organic light emitting diode display panel and a display device, which are used for solving the problem that an encapsulation flat layer cannot be coated smoothly.

In order to achieve the above object, a first aspect of the present invention provides an oled display panel including a display region, a water blocking region and a drilling region, wherein the water blocking region is disposed around the drilling region, and the display region is disposed around the water blocking region, the oled display panel including:

a first substrate; and

a second substrate disposed over the first substrate;

the water blocking area comprises at least one groove which is arranged on the second substrate and used for blocking external water and oxygen from invading the display area; and

wherein, the drilling area comprises a taper structure which is positioned on the second substrate and is used for supporting the packaging flat layer in a wet film state, so that the packaging flat layer reflows along the taper structure and fills the at least one groove.

Further, the display panel further includes on the water blocking region:

and the retaining wall is positioned on the second substrate, is arranged along the periphery of the water blocking area and is used for blocking the overflow of the organic materials in the display area.

Furthermore, the display panel further includes a film stack structure on the display area, the film stack structure is disposed on the second substrate, and the film stack structure includes a thin film transistor array.

Further, the film stack comprises:

a first gate insulating layer disposed on the second substrate;

a second gate insulating layer disposed on the first gate insulating layer and having a plurality of first gates disposed therein;

a dielectric film disposed on the second gate insulating layer and having a plurality of second gates disposed therein;

a first planarization layer disposed on the dielectric film and having a plurality of first source/drain electrodes disposed therein;

the second flat layer is arranged on the first flat layer, and a plurality of second source/drain electrodes are arranged in the second flat layer; and

and the pixel definition layer is arranged on the second flat layer.

Further, the retaining wall comprises the material of the film laminated structure.

Further, the tapered structure comprises material of the film stack.

Further, the at least one trench has an undercut structure.

Further, the first substrate includes a first flexible substrate and a barrier layer disposed thereon.

Further, the second substrate includes a second flexible substrate and a buffer layer disposed thereon.

A second aspect of the invention provides a display device comprising an organic light emitting diode display panel as described in any one of the above.

According to the invention, the conical structure is formed in the drilling area, so that after the packaging flat layer in a wet film state is covered, the conical structure can enable the packaging flat layer to be filled in the at least one groove, bubbles existing in the at least one groove are reduced, and the packaging flat layer can be coated smoothly.

Drawings

FIG. 1 is a schematic view of a display panel with a drilled hole.

Fig. 2 shows that the package planarization layer in the prior art cannot be applied to the trench.

Fig. 3 is a schematic diagram of an oled display panel according to an embodiment of the invention.

Fig. 4 is a further schematic illustration of the dashed box in fig. 3.

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The following description of the embodiments refers to the accompanying drawings for illustrating the embodiments of the invention, and the directional terminology used herein is for the purpose of referring to the drawings. Accordingly, the directional terms used are used for the purpose of illustration and understanding, and are not to be construed as limiting the invention.

Referring to fig. 3, fig. 3 is a schematic view of an organic light emitting diode display panel according to an embodiment of the invention. The display panel comprises a first substrate 10 and a second substrate 20 arranged above the first substrate, and the display panel is provided with a display area, a water blocking area and a drilling area, wherein electronic devices (such as a camera, a receiver, a proximity sensor and the like) can be arranged below the drilling area after drilling so as to realize corresponding device functions; the water blocking area is arranged around the drilling area and used for blocking external water oxygen from invading the display area along the drilling area after drilling; the display area is arranged around the water blocking area and used for displaying images.

Specifically, the display panel includes the first substrate 10, the second substrate 20, and a film stack 30 in the display region, and the film stack 30 may be a thin film transistor array for driving the organic light emitting unit (not shown). The film stack 30 may also include a thin film transistor array and an organic light emitting unit. The present invention may be applied to a flexible display device, and thus the first substrate 10 may include a first flexible substrate 101 (e.g., a polyimide substrate) and a barrier layer 102 disposed thereon, and the second substrate 20 may include a second flexible substrate 201 (e.g., a polyimide substrate) and a buffer layer 202 disposed thereon, wherein the barrier layer 102 may prevent external water and oxygen from invading the display region along the first flexible substrate 101. It will be appreciated that the film laminate 30 is disposed along the periphery of the water blocking region, and the film laminates 30 on the left and right sides of fig. 3 are continuous film laminates 30.

In the present embodiment, the film stack 30 includes a first gate insulating layer 301, a second gate insulating layer 302, a plurality of first gates 303, a dielectric film 304, a plurality of second gates 305, a planar layer 306, a plurality of first source/drain electrodes 307, a second planar layer 308, a plurality of second source/drain electrodes 309, and a pixel defining layer 310, wherein the first gate insulating layer 301 is disposed on the second substrate 20; the second gate insulating layer 302 is disposed on the first gate insulating layer 301, and the plurality of first gates 303 are further disposed therein; the dielectric film 304 is disposed on the second gate insulating layer 302, and the plurality of second gates 305 are further disposed therein; the first planarization layer 306 is disposed on the dielectric film 304, and the plurality of first source/drain electrodes 307 are further disposed therein; the second planarization layer 308 is disposed on the first planarization layer 306, and the plurality of second source/drain electrodes 309 are further disposed therein; the pixel defining layer 310 is disposed on the second flat layer 308. In another embodiment, the film stack 30 may have other structures, which should not be construed as limiting the invention. It is understood that the functions of the respective layers in the film stack 30 are common knowledge of those skilled in the art and will not be described herein.

Specifically, the display panel includes the first substrate 10, the second substrate 20, a dam 50, and at least one groove 60 in the water blocking region. In order to prevent external water oxygen from entering the display region along the drilled region after drilling, the film stack 30 originally existing in the water blocking region is excavated to the second substrate 20, and a corresponding water oxygen blocking structure is fabricated on the water blocking region.

Further, in one embodiment, the retaining wall 50 is formed at the same time as the film stack 30 is prepared, so that the retaining wall 50 includes the material of the film stack 30. That is, portions of the retaining wall 50 are retained when the film laminate 30 of the water blocking region is excavated. In another embodiment, the retaining walls 50 are formed after the film stack 30 is excavated, and can be formed by a general process (e.g., film formation, exposure, development, etching, etc.), and can be made of an organic material such as photoresist, polyacrylic resin, polyimide resin, etc.

Further, the retaining wall 50 is disposed along the periphery of the water blocking area to prevent the organic material in the display area from overflowing, and the at least one trench 60 is opened in the second substrate 20 of the water blocking area and disposed around the retaining wall 50. Specifically, a first groove 601 is arranged between the retaining wall 50 and the film laminated structure 30, a second groove 602 to a ninth groove 609 are further arranged in the direction of the retaining wall 50 away from the first groove 601, and the grooves 601 to 609 can prolong the path of external water oxygen invasion, so that external water oxygen is prevented from invading the display area along the drilling area after drilling, and the display area is protected from water oxygen invasion. It is understood that the position and shape of the retaining wall 50 and the number of the at least one groove 60 can be set according to the circumstances, and are only used for illustrating the present invention and should not be construed as limiting the present invention.

Further, the at least one trench 60 may be first subjected to dry etching on the buffer layer 202, and then subjected to isotropic wet etching on the second flexible substrate 201 by using a solution having a high selectivity ratio for the second flexible substrate 201 and the barrier layer 102, so as to form the at least one trench 60 having an undercut structure.

In the present embodiment, the width of the water blocking region is preferably set to be not less than 240 μm to extend the path of the external water oxygen penetrating into the display region, for example, the number of the grooves 60 is increased as described above, and the width of the water blocking region is extended without changing other structures.

Fig. 4 is a further schematic illustration of the dashed box in fig. 3. In order to prevent the invasion of external water, oxygen or ambient air from affecting the operation of the display panel, a Thin Film Encapsulation (TFE) structure 40 is usually covered on the above structure. The thin film encapsulation structure 40 is composed of one or more inorganic layers 401 and one or more organic layers 402 which are overlapped with each other, the inorganic layers 401 are used for avoiding water and oxygen invasion, the organic layers 402 are used for buffering the stress of the flexible display device when the flexible display device is bent or folded, and damage to a panel caused by overlarge stress is reduced. The organic layer 402 is bounded by the dam 50, and this arrangement prevents external water oxygen from entering the drilled region after drilling along the path formed by the organic material. The material of the organic layer 402 may be acrylic resin, methacrylic resin, polyisoprene, or the like, and the material of the inorganic layer 401 may be silicon nitride, aluminum nitride, titanium nitride, silicon oxynitride, or the like.

After the thin film encapsulation structure 40 is covered, the encapsulation planarization layer 80 is covered to facilitate the subsequent encapsulation process. However, in the prior art, since the undercut structure at the at least one trench 60 is prone to accumulate bubbles, the encapsulation planarization layer 80 cannot fill the at least one trench 60 after being covered, so that the bubble pressure changes and the film layer is broken after being dried under reduced pressure, and thus the encapsulation planarization layer 80 cannot be coated smoothly. In order to solve the above problem, the present invention forms a tapered structure (e.g., a conical structure) 70 on the second substrate 20 in the drilling region.

Specifically, in one embodiment, the tapered structure 70 is formed at the same time as the film stack 30 is prepared, so the tapered structure 70 has the material of the film stack 30. That is, the water blocking area is hollowed out while the tapered structure 70 remains. In another embodiment, the tapered structure 70 may also be formed after digging out the film stack 30 originally existing in the drilled region, and may be formed by a general process (e.g., film formation, exposure, development, etching, etc.).

Further, after the tapered structure 70 is remained (or formed), the thin film encapsulation structure 40 and the encapsulation planarization layer 80 are further covered (as shown in fig. 3). The material of the package planarization layer 80 may be an organic photoresist, which has excellent film forming property. After the organic photoresist is coated on the thin film encapsulation structure 40, the organic photoresist is placed in a drying oven for reduced pressure drying to be dried into a film, so as to form the encapsulation flat layer 80. Meanwhile, the tapered structure 70 may provide support for the package planarization layer 80 (i.e., the organic photoresist) in a wet film state, so that the package planarization layer may reflow along the tapered structure 70 and fill the at least one trench 60, thereby reducing the occurrence of bubbles existing in the at least one trench 60, and reducing the occurrence of film cracking due to the pressure change of bubbles after the subsequent decompression drying. It is understood that the temperature setting and the time setting for performing the decompression drying may be adjusted according to the need, and the present invention is not particularly limited thereto.

Although the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present invention.

Claims

1. The utility model provides an organic light emitting diode display panel, includes display area, blocks water district and drilling district, block water the district set up in around the drilling district, the display area set up in block water around the district, its characterized in that, display panel includes:

a first substrate; and

a second substrate disposed over the first substrate;

the display area further comprises a film lamination structure which is arranged on the second substrate and comprises a thin film transistor array;

wherein, a tapered structure is included in the drilling area, which is located on the second substrate, and is used to support the package flat layer in a wet film state, so that the package flat layer reflows along the tapered structure and fills the at least one trench, the tapered structure includes the material of the film stack, and the tapered structure and the film stack are formed simultaneously.

2. The display panel of claim 1, further comprising on the water blocking region:

3. The display panel of claim 2, wherein the film stack comprises:

the first grid insulating layer is arranged on the second substrate;

and the pixel definition layer is arranged on the second flat layer.

4. The display panel according to claim 2, characterized in that: the retaining wall comprises the materials of the film laminated structure.

5. The display panel according to claim 1, characterized in that: the at least one trench has an undercut structure.

6. The display panel according to claim 1, characterized in that: the first substrate includes a first flexible substrate and a barrier layer disposed thereon.

7. The display panel according to claim 1, characterized in that: the second substrate includes a second flexible substrate and a buffer layer disposed thereon.

8. A display device characterized in that it comprises the display panel of any one of claims 1 to 7.