CN111403622B

CN111403622B - OLED display panel, manufacturing method thereof and display device

Info

Publication number: CN111403622B
Application number: CN202010221923.5A
Authority: CN
Inventors: 齐永莲; 曲连杰; 张珊; 赵合彬; 尤杨; 吕振华; 石广东
Original assignee: BOE Technology Group Co Ltd; Beijing BOE Display Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Beijing BOE Display Technology Co Ltd
Priority date: 2020-03-26
Filing date: 2020-03-26
Publication date: 2023-04-07
Anticipated expiration: 2040-03-26
Also published as: CN111403622A

Abstract

The invention provides an OLED display panel, a manufacturing method thereof and a display device, and belongs to the technical field of display. The OLED display panel comprises an OLED display substrate and an encapsulating cover plate, wherein the encapsulating cover plate is arranged on the OLED display substrate in a box-to-box mode, a plurality of conducting spacers are arranged on the encapsulating cover plate in an array mode, and a light-transmitting cathode of the OLED display substrate is in contact with the conducting spacers. By the technical scheme, the IR drop of the OLED display panel can be reduced, and the electrical performance of the OLED display panel is improved.

Description

OLED display panel, manufacturing method thereof and display device

Technical Field

The invention relates to the technical field of display, in particular to an OLED display panel, a manufacturing method thereof and a display device.

Background

Currently, small-sized top-emitting AMOLED (Active-matrix organic light-emitting diode) panels have been commercialized successfully, and have gained most market share in mobile phone brands, and large-sized, e.g., over 55 inches, bottom-emitting OLED panels also occupy the television market. However, a large size of the top-emitting OLED panel is not easy to implement, and the top-emitting OLED panel cannot be made in a large size because IR drop (voltage drop) of the top-emitting OLED panel is large.

Disclosure of Invention

The invention provides an OLED display panel, a manufacturing method thereof and a display device, and aims to reduce IR drop of the OLED display panel and improve electrical performance of the OLED display panel.

To solve the above technical problem, embodiments of the present invention provide the following technical solutions:

on the one hand, the OLED display panel comprises an OLED display substrate and an encapsulation cover plate, wherein the encapsulation cover plate is arranged on the OLED display substrate in a box-to-box mode, a plurality of conductive spacers are arranged on the encapsulation cover plate in an array mode, and a light-transmitting cathode of the OLED display substrate is in contact with the conductive spacers.

In some embodiments, the OLED display panel further includes:

the auxiliary electrode is positioned on one side, facing the packaging cover plate, of the conductive spacer and is of an integral structure with the conductive spacer.

In some embodiments, the OLED display panel further includes:

the auxiliary electrode is positioned on the packaging cover plate and is positioned between the conductive spacer and the packaging cover plate, and the orthographic projection of the auxiliary electrode on the packaging cover plate is positioned in the orthographic projection of the conductive spacer on the packaging cover plate.

In some embodiments, the conductive spacer includes a photoresist and nano-metal particles doped in the photoresist.

In some embodiments, the mass percentage of the nano-metal particles in the photoresist is 5% -20%.

In some embodiments, the diameter of the nano-metal particles is between 20nm and 200nm.

In some embodiments, the photoinitiator in the photoresist is present in an amount of no less than 5% by mass.

Embodiments of the present invention also provide a display device including the OLED display panel as described above.

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

providing a packaging cover plate;

forming a plurality of conductive spacers arranged in an array on the package cover plate;

and carrying out box alignment on the packaging cover plate and the OLED display substrate, so that the conductive spacer is in contact with the cathode of the OLED display substrate.

In some embodiments, the method specifically comprises:

forming the conductive spacer and a planar auxiliary electrode positioned on one side of the conductive spacer, which faces the packaging cover plate, by a one-time composition process; or

Before the conductive spacer is formed, an auxiliary electrode is formed on the packaging cover plate, and the orthographic projection of the auxiliary electrode on the packaging cover plate is positioned in the orthographic projection of the conductive spacer on the packaging cover plate.

The embodiment of the invention has the following beneficial effects:

in the scheme, the plurality of conductive spacers are arranged on the packaging cover plate in an array mode, and the light-transmitting cathode of the OLED display substrate is in contact with the conductive spacers, so that the conductive spacers are connected with the cathode in parallel, the resistance of the cathode can be reduced, the IR drop on the cathode is reduced, and the electrical performance of the OLED display panel is improved; in addition, the technical scheme of the invention does not need to specially manufacture a conductive structure connected with the light-transmitting cathode in parallel, but uses the conductive spacer to realize the parallel connection with the light-transmitting cathode, thereby simplifying the manufacturing process of the OLED display panel.

Drawings

FIG. 1 is a schematic structural diagram of a top-emitting OLED display panel;

FIGS. 2 and 3 are schematic diagrams illustrating the addition of nano-metal particles to a photoresist solution according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an embodiment of the present invention for coating a conductive spacer material on a package cover plate;

FIG. 5 is a schematic view of a layer of conductive spacer material exposed according to an embodiment of the present invention;

FIG. 6 is a schematic view of forming a conductive spacer according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of an OLED display panel according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of an OLED display panel according to another embodiment of the invention.

Reference numerals

1. Substrate

2. Pixel defining layer

3. Anode

4. Luminescent layer

5. Cathode electrode

6. Packaging cover plate

7. Auxiliary cathode

8. Shock insulator

11. Nano metal particles

12. Photoresist solution

13. Container

14. Packaging cover plate

15. Conductive spacer material layer

16. Mask plate

161. Light transmitting area

162. Opaque region

171. Auxiliary electrode

172. Conductive spacer

18. Auxiliary electrode

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved by the embodiments of the present invention clearer, the following detailed description is made with reference to the accompanying drawings and specific embodiments.

Fig. 1 is a schematic structural diagram of a top-emission OLED display panel, where the top-emission OLED display panel includes an OLED display substrate and an encapsulation cover plate arranged in a box-to-box relationship with the OLED display substrate, and the OLED display substrate includes a substrate 1, a pixel defining layer 2 located on the substrate 1, an anode 3, a light-emitting layer 4, and a cathode 5; the cathode 5 is a light-transmitting cathode, in order to reduce the voltage Drop of the cathode 5, an auxiliary cathode 7 may be formed on the encapsulating cover plate 6, the auxiliary cathode 7 is connected in parallel with the cathode 5, the resistance of the cathode 5 can be reduced, and then the IR Drop on the cathode 5 is reduced, but a special patterning process is required to manufacture the auxiliary cathode 7, which increases the complexity of the OLED display panel manufacturing process, and the auxiliary cathode 7 is a planar electrode, which may also affect the transmittance of the OLED display panel. Wherein 8 is a non-conductive spacer, and the substrate 1 comprises a substrate base plate and a thin film transistor circuit positioned on the substrate base plate.

An embodiment of the present invention provides an OLED display panel, as shown in fig. 7 and 8, including an OLED display substrate and an encapsulating cover plate disposed opposite to the OLED display substrate, where the OLED display substrate includes a substrate 1, a pixel defining layer 2 located on the substrate 1, an anode 3, a light emitting layer 4, and a cathode 5; wherein, the cathode 5 is a light-transmitting cathode; the encapsulating cover plate 14 is provided with a plurality of conductive spacers 172 arranged in an array, and the light-transmitting cathode 5 of the OLED display substrate is in contact with the conductive spacers 172.

In the embodiment, the plurality of conductive spacers are arranged in an array manner on the packaging cover plate, and the light-transmitting cathode of the OLED display substrate is in contact with the conductive spacers, so that the conductive spacers are connected with the cathode in parallel, the resistance of the cathode can be reduced, the IR drop on the cathode is reduced, the stability of display current is maintained, and the electrical performance of the OLED display panel is improved; in addition, the technical scheme of the invention does not need to specially manufacture a conductive structure connected with the light-transmitting cathode in parallel, but uses the conductive spacer to realize the parallel connection with the light-transmitting cathode, thereby simplifying the manufacturing process of the OLED display panel.

In some embodiments, as shown in fig. 7, the OLED display panel further includes:

and the auxiliary electrode 171 is positioned on one side of the conductive spacer 172 facing the package cover plate 14, and is integrated with the conductive spacer 172. The auxiliary electrode 171 and the conductive spacer 172 are integrated, so that the auxiliary electrode 171 and the conductive spacer 172 can be formed simultaneously through a one-step composition process, an additional process for manufacturing the auxiliary electrode is not required, the manufacturing process of the OLED display panel is simplified, and the cost of the OLED display panel is reduced. The auxiliary electrode 172 is planar and has a large area, and the resistance of the cathode 5 can be effectively reduced.

In some other embodiments, as shown in fig. 8, the OLED display panel further includes:

an auxiliary electrode 18 located on the package cover 14, the auxiliary electrode 18 being located between the conductive spacer 172 and the package cover 14, an orthographic projection of the auxiliary electrode 18 on the package cover 14 being located within an orthographic projection of the conductive spacer 172 on the package cover 14.

The auxiliary electrode 18 can be made of metal, the auxiliary electrode 18 can be formed firstly, then the conductive spacer 172 is formed, and the auxiliary electrode 18 is electrically connected with the cathode 5 through the conductive spacer 172, so that the resistance of the cathode 5 can be effectively reduced, and the uniformity of the brightness of the OLED display panel is improved; because the auxiliary electrode 18 is only arranged in the area where the conductive spacer 172 is located, not in the pixel opening area, and the pixel opening area is not shielded by the auxiliary electrode, the transmittance of the OLED display panel can be greatly improved.

In some embodiments, the conductive spacer includes a photoresist and nano-metal particles doped in the photoresist. The mass percentage of the nano metal particles in the photoresist can be 5% -20%, and the diameter of the nano metal particles can be 20nm-200nm.

In some embodiments, the photoinitiator in the photoresist is present in an amount of no less than 5% by weight.

Embodiments of the present invention also provide a display device including the OLED display panel described above.

The display device includes but is not limited to: radio frequency unit, network module, audio output unit, input unit, sensor, display unit, user input unit, interface unit, memory, processor, and power supply. It will be appreciated by those skilled in the art that the above described configuration of the display device does not constitute a limitation of the display device, and that the display device may comprise more or less of the components described above, or some components may be combined, or a different arrangement of components. In the embodiment of the present invention, the display device includes, but is not limited to, a display, a mobile phone, a tablet computer, a television, a wearable electronic device, a navigation display device, and the like.

The display device may be: the display device comprises a television, a display, a digital photo frame, a mobile phone, a tablet personal computer and any other product or component with a display function, wherein the display device further comprises a flexible circuit board, a printed circuit board and a back plate.

providing a packaging cover plate;

In this embodiment, the plurality of conductive spacers arranged in an array are disposed on the encapsulation cover plate, and the light-transmitting cathode of the OLED display substrate is in contact with the conductive spacers, so that the conductive spacers are connected in parallel with the cathode, thereby reducing the resistance of the cathode, reducing the IR drop on the cathode, and improving the electrical performance of the OLED display panel; in addition, the technical scheme of the invention does not need to specially manufacture a conductive structure connected with the light-transmitting cathode in parallel, but uses the conductive spacer to realize the parallel connection with the light-transmitting cathode, thereby simplifying the manufacturing process of the OLED display panel.

In some embodiments, the conductive spacer may be made of photoresist and nano metal particles doped in the photoresist. The mass percentage of the nano metal particles in the photoresist can be 5% -20%, and the diameter of the nano metal particles can be 20nm-200nm.

In one embodiment, a method for manufacturing an OLED display panel includes:

step 1, as shown in fig. 2 and 3, adding 5% -20% of nano metal particles 11 into a photoresist solution 12 contained in a container 13, and fully dispersing in a dispersion grinder to ensure that the nano metal particles 11 are fully dispersed in the photoresist solution 12, wherein the diameter of the nano metal particles 11 can be 20nm-200nm;

because the exposure effect of the photoresist is affected by adding the nano metal particles 11, the proportion of the photoinitiator in the photoresist can be adjusted according to the concentration of the nano metal particles 11, for example, the proportion of the photoinitiator can be increased from 3% to about 5%, so that the photoresist can be fully exposed in the subsequent exposure process;

step 2, as shown in fig. 4, coating the uniformly mixed photoresist solution on the package cover plate 14 to form a conductive spacer material layer 15;

step 3, as shown in fig. 5, exposing the conductive spacer material layer 15 by using a mask 16, wherein the mask 16 comprises a light transmission area 161 and a partial light transmission area 162, and the light transmittance of the partial light transmission area 162 is smaller than that of the light transmission area 161;

the conductive spacer material layer 15 in different areas can have different exposure through the mask 16, and the conductive spacer 172 area corresponds to the light-transmitting area 161 for full exposure.

Step 4, as shown in fig. 6, after developing, forming a conductive spacer 172 and an auxiliary electrode 171 integrated with the conductive spacer 172;

the height of the conductive spacer 172 may be about 10um, and the thickness of the auxiliary electrode 171 may be 2-5 um.

Step 5, as shown in fig. 7, the OLED display substrate and the encapsulating cover plate 14 are aligned to each other, so that the conductive spacer 172 is fully contacted with the cathode 5 to form parallel connection, thereby reducing the resistance of the cathode.

In another embodiment, a method for manufacturing an OLED display panel includes:

step 1, as shown in fig. 8, forming an auxiliary electrode 18 on the package cover plate 14;

the auxiliary electrode 18 may be made of metal;

step 2, as shown in fig. 2 and 3, adding 5% -20% of the nano metal particles 11 into the photoresist solution 12 contained in the container 13, and fully dispersing in a dispersion grinder to ensure that the nano metal particles 11 are fully dispersed in the photoresist solution 12, wherein the diameter of the nano metal particles 11 can be 20nm-200nm;

step 3, coating the uniformly mixed photoresist solution on the packaging cover plate to form a conductive spacer material layer;

step 4, exposing the conductive spacer material layer by using a mask plate, wherein the mask plate comprises a light-transmitting area and a light-proof area;

step 5, after development, forming a conductive spacer 172 corresponding to the light-transmitting area, wherein the conductive spacer 172 covers the auxiliary electrode 18;

step 6, as shown in fig. 8, the OLED display substrate and the encapsulation cover plate 14 are aligned to each other, so that the conductive spacers 172 are fully contacted with the cathode 5 to form parallel connection, thereby reducing the resistance of the cathode.

In the embodiment, a gray tone mask plate is not required for exposure, a common mask plate is used for manufacturing the conductive spacer, the auxiliary electrode 18 is connected with the cathode 5 through the conductive spacer 172, the resistance of the cathode is low after parallel connection, and the brightness uniformity of the OLED display panel is good

In the embodiments of the methods of the present invention, the sequence numbers of the steps are not used to limit the sequence of the steps, and for those skilled in the art, the sequence of the steps is not changed without creative efforts, and the protection scope of the present invention is also included.

It should be noted that, in the present specification, all the embodiments are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the embodiments, since they are substantially similar to the product embodiments, the description is simple, and the relevant points can be referred to the partial description of the product embodiments.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and the like in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item preceding the word comprises the element or item listed after the word and its equivalent, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element or intervening elements may be present.

In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present disclosure, and all the changes or substitutions should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. The OLED display panel is characterized by comprising an OLED display substrate and an encapsulation cover plate, wherein the encapsulation cover plate is arranged opposite to the OLED display substrate, a plurality of conductive spacers are arranged on the encapsulation cover plate in an array mode, and a light-transmitting cathode of the OLED display substrate is in contact with the conductive spacers;

the OLED display panel further includes:

the planar auxiliary electrode is positioned on the packaging cover plate, is positioned on one side of the conductive spacer facing the packaging cover plate and is integrated with the conductive spacer; forming the conductive spacer and the auxiliary electrode through a one-time composition process;

the conductive spacer is made of photoresist and nano metal particles doped in the photoresist;

the auxiliary electrode is made of photoresist and nano metal particles doped in the photoresist.

2. The OLED display panel according to claim 1, wherein the nano metal particles are present in the photoresist in an amount of 5-20% by mass.

3. The OLED display panel of claim 1, wherein the diameter of the nano-metal particles is 20nm to 200nm.

4. The OLED display panel claimed in claim 1, wherein the photoinitiator in the photoresist is present in an amount of not less than 5% by mass.

5. A display device comprising the OLED display panel according to any one of claims 1 to 4.

6. A manufacturing method of an OLED display panel is characterized by comprising the following steps:

providing a packaging cover plate;

carrying out box alignment on the packaging cover plate and the OLED display substrate, so that the conductive spacer is in contact with the cathode of the OLED display substrate;

the manufacturing method specifically comprises the following steps:

forming the conductive spacer and a planar auxiliary electrode positioned on one side of the conductive spacer, which faces the packaging cover plate, by a one-time composition process;