CN209929348U

CN209929348U - Display panel

Info

Publication number: CN209929348U
Application number: CN201921062750.6U
Authority: CN
Inventors: 杜晓松; 杨小龙; 周文斌; 张峰; 孙剑; 高裕弟
Original assignee: Kunshan Mengxian Electronic Technology Co Ltd
Current assignee: Kunshan Mengxian Electronic Technology Co Ltd
Priority date: 2019-07-09
Filing date: 2019-07-09
Publication date: 2020-01-10
Anticipated expiration: 2029-07-09

Abstract

The utility model provides a display panel, be in including drive backplate, setting pixel array on the drive backplate and setting are in pixel array's the outside and cover completely pixel array's thin film packaging layer, display panel is still including setting up the pixel definition layer at thin film packaging layer top and setting are in intraformational quantum dot is defined to the pixel to form polychrome and show. The utility model discloses a display panel has broken through the high accuracy metal mask plate's of high pixel density physical limit, can realize 2000 and higher pixel density's demonstration.

Description

Display panel

Technical Field

The utility model relates to a display panel especially relates to a display panel of high pixel density.

Background

The existing OLED display screen mostly adopts evaporation of different OLED materials to realize OLED patterning, which is not problematic when the pixel density is lower than 700, but when the pixel density is higher than 800, the existing manufacturing technology will enter into a physical bottleneck.

Therefore, it is a technical problem to be solved urgently to realize a multi-color display with high pixel density.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a display panel, it forms the quantum dot in the pixel definition layer, can realize high resolution display panel's polychrome demonstration.

In order to achieve the above object, the present invention provides a display panel, including the drive backplate, set up pixel array and setting on the drive backplate are in the outside of pixel array covers completely the film packaging layer of pixel array, display panel is still including setting up the pixel definition layer at film packaging layer top and setting are in intraformational quantum dot is defined to the pixel to form polychrome demonstration.

As a further improvement of the present invention, the quantum dots are formed in at least partial positions corresponding to the pixel array in the pixel defining layer.

As a further improvement of the present invention, the quantum dots include red quantum dots and green quantum dots.

As a further improvement of the present invention, the display panel further includes a black matrix disposed in the pixel definition layer and located between the red quantum dots and the green quantum dots.

As a further improvement of the present invention, the quantum dots and the black matrix are formed by an electrofluid printing process.

As a further improvement of the present invention, the display panel further includes an insulating protective layer disposed on the top side of the quantum dots, and the insulating protective layer covers the quantum dots.

As a further improvement of the present invention, the display panel further includes a glass cover plate, the glass cover plate is packaged on top of the insulating protective layer and completely covers the insulating protective layer.

As a further improvement of the utility model, the thickness of the insulating protective layer is 50 nm.

As a further improvement of the present invention, the driving circuit array is disposed on the driving backboard to be electrically connected to the corresponding pixel array, and the pixel array provides the driving voltage.

As a further improvement of the present invention, the thin film encapsulation layer includes an organic encapsulation layer and an inorganic encapsulation layer.

The utility model has the advantages that: the utility model discloses a display panel sets up pixel definition layer and is located the intraformational quantum dot of pixel definition through the top at the thin film encapsulation layer to make this display panel form polychrome demonstration, further adopt yellow light, sculpture technology to realize the display panel of high pixel graphically, broken through the physical limit of high pixel density's high accuracy metal mask board, can realize 2000 and higher pixel density's demonstration.

Drawings

Fig. 1 is a schematic diagram of a display panel according to the present invention before bonding a driving back plate and a light-emitting substrate.

Fig. 2 is a schematic diagram of the display panel shown in fig. 1 after bonding of the driving backplane and the light-emitting substrate.

Fig. 3 is a schematic view of the light emitting base plate of fig. 2 with the substrate removed.

Fig. 4 is a schematic view of forming a photoresist layer on the display panel shown in fig. 3.

Fig. 5 is a schematic diagram of a light emitting array and a metal bonding array arranged correspondingly on the display panel shown in fig. 4.

Fig. 6 is a schematic view illustrating an insulating layer formed on a metal bonding array corresponding to a light emitting array of the display panel shown in fig. 5.

Fig. 7 is a schematic view of forming an opening on an insulating layer of the display panel shown in fig. 6.

Fig. 8 is a schematic view of forming a metal layer on an insulating layer of the display panel shown in fig. 7.

Fig. 9 is a schematic view of forming a thin film encapsulation layer on the display panel shown in fig. 8.

Fig. 10 is a schematic view of forming a pixel defining layer on top of a thin film encapsulation layer of the display panel shown in fig. 9.

Fig. 11 is a schematic diagram illustrating quantum dots and a black matrix formed in a pixel defining layer of the display panel shown in fig. 10.

Fig. 12 is a schematic diagram of forming an insulating protective layer on the top side of the quantum dots and the black matrix of the display panel shown in fig. 11.

Fig. 13 is a schematic view of encapsulating a glass cover plate on the top side of the insulating protective layer of the display panel shown in fig. 12.

Detailed Description

In order to make the purpose, technical solution and effect of the present application clearer and clearer, the present application is further described in detail below with reference to the accompanying drawings and examples.

Referring to fig. 1 to 13, the present application provides a method for manufacturing a display panel 100, where the following method steps are a preferred embodiment of the method for manufacturing the display panel 100, and in this embodiment, the method for manufacturing the display panel 100 mainly includes the following steps:

a driving backplane 10 and a light emitting substrate 20 are provided. The driving backplane 10 includes a driving circuit array 101, a first bonding metal layer 31 is disposed on the driving backplane 10, and a second bonding metal layer 32 is disposed on the light-emitting substrate 20. Specifically, the Light-Emitting substrate 20 used in the present application is based on Micro Light Emitting Diode (Micro-LED) technology, and adopts a Multi Quantum Well (MQW) structure to emit Light, which has the advantages of high brightness, high response speed, low power consumption, long service life, and the like.

And carrying out metal bonding on the first bonding metal layer 31 of the driving back plate 10 and the second bonding metal layer 32 of the light-emitting substrate 20 to form a metal bonding layer 30. The thicknesses of the first bonding metal layer 31 and the second bonding metal layer 32 are the same or different, and the thickness of the metal bonding layer 30 formed after bonding may be two times or three times the thickness of one of the first bonding metal layer 31 or the second bonding metal layer 32. The utility model discloses choose for use the mode of metallic bond to connect drive backplate 10 with luminescent substrate 20 compares the current technique of having done earlier Micro-LED device and shifting to on the drive backplate again, has avoided the counterpoint precision scheduling problem in shifting in batches.

Patterning the light-emitting substrate 20 and the metal bonding layer 30 to form a desired pixel array 210 and a metal bonding array 301 corresponding to the pixel array 210, wherein the metal bonding array 301 can serve as an anode. Wherein, the light emitting substrate 20 and the metal bonding layer 30 may be patterned using yellow light and an etching process to form the desired pixel array 210 and metal bonding array 301. Compared with the existing scheme of realizing OLED imaging by using a mask plate and adopting an evaporation process, the method can realize Pixels with smaller size, and can improve the pixel density (Pixel PerInch, PPI) under the condition that the sizes of the display panels are the same.

A thin film encapsulation layer 60 is formed outside the pixel array 210, and the thin film encapsulation layer 60 completely covers the pixel array 210. A pixel defining layer 61 is formed on top of the thin film encapsulation layer 60 and quantum dots 50 are formed within the pixel defining layer 61, thereby forming a multicolor display.

Quantum dots 50 are formed within the pixel definition layer 61 at least in part corresponding to the pixel array 210 to form a multi-color display. Wherein, the light emitted from the light-emitting substrate 20 passes through the quantum dots 50 and then emits light of different colors, thereby realizing multicolor display. Specifically, the quantum dots 50 of this embodiment include red quantum dots 51 emitting red light R and green quantum dots 52 emitting green light G, and the light-emitting substrate 20 can directly emit blue light B, so that the display panel 100 has RGB three-color display.

The following describes the manufacturing method and structure of the display panel 100 in detail.

Referring to fig. 1, the driving backplane 10 is provided with a driving circuit array 101 corresponding to the pixel array 210, and is used for being electrically connected to the corresponding pixel array 210 to provide a driving voltage for the pixel array 210, so as to control the light emission of the pixel array 210. The driving backplate 10 may be a flexible backplate or a rigid backplate, which is not limited herein.

The driving backplate 10 has a first bonding metal layer 31 formed thereon. The material of the first bonding metal layer 31 may be gold (Au), copper (Cu), Gallium (GA), nickel (Ni), or an alloy of these metals, such as a nickel-gold alloy. The thickness of the first bonding metal layer 31 is 800-1200 nm. The first bonding metal layer 31 may be formed by deposition or evaporation, and specifically, the deposition may be Atomic Layer Deposition (ALD), Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), or other suitable methods.

The light-emitting substrate 20 includes a substrate 21 and a light-emitting layer 22 disposed on the substrate 21, and the second bonding metal layer 32 is disposed on the other side of the light-emitting layer 22 opposite to the substrate 21. The light emitting layer 22 includes a first semiconductor layer 220 disposed on the substrate 21, a multiple quantum well layer 221 disposed on the first semiconductor layer 220, and a second semiconductor layer 222 disposed on the multiple quantum well layer 221 in this order. The second semiconductor layer 222 is electrically connected to the second bonding metal layer 32.

In the present embodiment, the first semiconductor layer 220 is an N-type semiconductor layer, and the second semiconductor layer 222 is a P-type semiconductor layer. In various embodiments, the semiconductor material may be selected from different semiconductor materials, such as N-type gallium nitride (GaN), P-type gallium nitride (GaN), N-type aluminum (Al) -doped gallium nitride (AlGaN), P-type magnesium (Mg) -doped gallium nitride, N-type silicon (Si) -doped gallium nitride, and the like. The mqw layer 221 may be a gallium nitride quantum well layer composed of indium gallium nitride/gallium nitride (InGaN/GaN) layers repeatedly arranged in sequence. In other embodiments, the materials of the first semiconductor layer 220, the second semiconductor layer 222 and the mqw layer 221 may also be set according to actual requirements of the display panel, and are not limited herein.

The P-type second semiconductor layer 222, the multiple quantum well layer 221 and the N-type first semiconductor layer 220 form a light-emitting PN junction, and the light-emitting PN junction can be electrically connected to a driving circuit by electrically connecting the second semiconductor layer 222 and the first semiconductor layer 220 with electrodes on both sides, so that voltage can be applied to the light-emitting PN junction through the driving circuit. When the driving circuit applies a voltage to the light emitting PN junction, electrons are generated in the N-type first semiconductor layer 220 and injected into the multiple quantum well layer 221, and holes are generated in the P-type second semiconductor layer 222 and injected into the multiple quantum well layer 221; subsequently, in the mqw layer 221, the electrons and the holes recombine to emit photons, and conversion of electric energy into optical energy is completed, so that light emission of the light emitting layer 22 is realized.

Because the gallium nitride-based material is difficult to directly grow on the glass substrate, the substrate 21 is generally a sapphire substrate, and because sapphire has good stability and high mechanical strength, the gallium nitride-based material can be applied to a high-temperature growth process, and crystals with good crystal quality can be obtained when crystals are epitaxially grown on the sapphire substrate; and the production technology of the sapphire substrate is mature, the device quality is good, and the processing and cleaning are easy. Of course, in other embodiments, a silicon-based substrate (such as a silicon carbide (SiC) substrate or a silicon (Si) substrate) or a gallium nitride (GaN) substrate, etc. may be selected, and other usable substrate materials may also be used, which are not limited herein.

The second bonding metal layer 32 and the first bonding metal layer 31 may be the same or different in material and thickness, and preferably, the second bonding metal layer 32 and the first bonding metal layer 31 are the same in material, so that the bonding strength between the second bonding metal layer 32 and the first bonding metal layer 31 can be enhanced, interlayer separation is prevented, and the stability of the device is improved. Similarly, the second bonding metal layer 32 may also be formed by deposition or evaporation, which is specifically referred to the description of the above embodiments and is not repeated herein.

Referring to fig. 1 and fig. 2, the first bonding metal layer 31 of the driving backplane 10 is attached to the second bonding metal layer 32 of the light-emitting substrate 20, and the first bonding metal layer 31 and the second bonding metal layer 32 are bonded together under the action of a predetermined temperature and pressure to form the metal bonding layer 30.

Fig. 3 is a schematic diagram illustrating the substrate 21 of the light-emitting substrate 20 being removed. When the substrate 21 of the light emitting substrate 20 is removed, the substrate 21 may be peeled off by, for example, laser peeling, but the substrate 21 may be peeled off by other methods, which is not limited herein.

Referring to fig. 4 and 5, fig. 4 is a schematic diagram illustrating the light-emitting substrate 20 after the substrate 21 is removed and a photoresist layer 223 is formed on the first semiconductor layer 220, and fig. 5 is a schematic diagram illustrating the light-emitting substrate 20 is further patterned by a photolithography process. Specifically, a photoresist layer 223 is formed on the first semiconductor layer 220, and then exposed and developed to obtain the photoresist layer pattern, wherein the photoresist layer pattern corresponds to the arrangement manner of the pixel array 210. And then, etching the light-emitting substrate 20 and the metal bonding layer 30 by using the patterned photoresist layer 223 as a mask to form a light-emitting array 201 and a correspondingly arranged metal bonding array 301, wherein the metal bonding array 301 can be used as an anode. Specifically, the light-emitting substrate 20 and the metal bonding layer 30 may be etched by Reactive Ion Etching (RIE), and during Etching, the positioning may be performed by using a self-alignment principle. Of course, in other embodiments, other etching methods may be selected.

Referring to fig. 6, an insulating layer 224 is formed over the light emitting array 201 and the corresponding metal bonding array 301. The insulating layer 224 covers the light emitting array 201 and the metal bonding array 301. The thickness of the insulating layer 224 is 50 nm. The insulating layer 224 may be formed by Atomic Layer Deposition (ALD), Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), or the like. The material of the insulating layer 224 may be an inorganic material, and the inorganic material may be one or more of the following materials: al2O3, TiO2, ZrO2, MgO, HFO2, Ta2O5, Si3N4, AlN, SiN, SiNO, SiO2, SiC, SiCNx, ITO, IZO and the like.

Referring to fig. 7, an opening 225 is formed in the insulating layer 224. preferably, the opening 225 is formed in the insulating layer 224 by the yellow light process and RIE method. The specific method is similar to the above and is not described herein again.

Referring to fig. 8, a metal layer 40 is formed on the insulating layer 224, wherein the metal layer 40 has a thickness of 10nm and can be formed by Atomic Layer Deposition (ALD), Chemical Vapor Deposition (CVD), or Physical Vapor Deposition (PVD). The material of the metal layer 40 may be aluminum (Al), silver (Ag), or the like, and the metal layer 40 may serve as a cathode.

In this embodiment, the patterning of the pixel array 210 is realized by using a yellow light and etching process, so that pixels with smaller size can be manufactured. In this way, the width of the patterned metal bonding layer 30 can be as narrow as 5 μm, the obtained pixel pitch is 24 μm, and the sub-pixel pitch is 8 μm, so as to obtain a display panel with a PPI as high as 3000. The conventional method for realizing OLED imaging by evaporating different OLED materials can only achieve 700-800 PPI. This is because a high-precision Metal Mask (FMM) is required to be used when the OLED material is evaporated, but the FMM has a physical limit, and the minimum opening distance can only be 10 to 15 μm. And the utility model discloses when utilizing yellow light technology graphical pixel array 210, the nanometer level can be accomplished to the interval between the figure, through this method, can make high PPI's display panel under the certain circumstances of display panel size.

Fig. 9 is a schematic diagram illustrating the formation of a thin film encapsulation layer 60. The thin film encapsulation layer 60 may be formed to completely cover the pixel array 210 to block moisture and oxygen and protect the pixel array 210. The film encapsulation layer 60 generally comprises an organic encapsulation layer and an inorganic encapsulation layer, and the inorganic encapsulation layer has good barrier property to water vapor and oxygen; the existence of the organic packaging layer can ensure that the surface flatness of the device is better, which is beneficial to the formation of a subsequent inorganic packaging layer, and meanwhile, the bending resistance of the organic packaging layer is better.

Referring to fig. 10, a pixel defining layer 61 is formed on top of the thin film encapsulation layer 60 by the yellow light process and RIE method. The specific method is similar to the above and is not described herein again.

Referring to fig. 11, quantum dots 50 and a Black Matrix 70 (BM) are formed in the pixel defining layer 61. The quantum dots 50 are disposed directly above a portion of the opening 225. Specifically, the quantum dots 50 and the black matrix 70 are formed by an electrofluid printing process. The quantum dots 50 include red quantum dots 51 that can emit red light R and green quantum dots 52 that can emit green light G. In this embodiment, the light emitting color of the mqw layer 221 is blue, so that a light emitting region where the quantum dots 50 are not disposed can directly emit blue light B, thereby realizing RGB three-color display.

Specifically, the multiple quantum well layer 221 is made of an inorganic material, and there are no problems of short lifetime and poor stability. Especially, the multiple quantum well layer 221 based on gallium nitride (GaN) material, GaN as a wide bandgap semiconductor, has inherent advantages in a blue light emitting part, can achieve a light emitting efficiency of 400lM/w, has high brightness, low power consumption and long service life, and is an optimal blue light emitting material.

Referring to fig. 12, an insulating protection layer 53 is further formed on top of the quantum dots 50 and the black matrix 70. The insulating protective layer 53 covers the quantum dots 50 and the black matrix 70. The thickness of the insulating protective layer 53 is 50 nm. The insulating protection layer 53 may be formed by Atomic Layer Deposition (ALD), Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), or the like. The material of the insulating protection layer 53 may be an inorganic material, and the inorganic material may be one or more of the following materials: al2O3, TiO2, ZrO2, MgO, HFO2, Ta2O5, Si3N4, AlN, SiN, SiNO, SiO2, SiC, SiCNx, ITO, IZO and the like.

Referring to fig. 13, a glass cover plate 80 is further encapsulated on top of the insulating protection layer 53, and the glass cover plate 80 completely covers the insulating protection layer 53. The glass cover plate 80 is adhered and fixed by coating UV glue 90 on the periphery of the insulating protective layer 53 to protect the quantum dots 50.

In the above manner, the manufacturing method of the display panel 100 provided by the present application, in combination with the high resolution driving backplane 10, can realize the manufacturing of the high resolution display panel 100 with a PPI of 2000PPI or more, and the yellow light and etching processes are selected during the manufacturing process to realize the patterning of the pixel array with high PPI, which is not limited by the physical limit of FMM. Meanwhile, a pixel defining layer 61 is formed on the top of the thin film encapsulation layer 60, and red quantum dots 51 and green quantum dots 52 are formed in the pixel defining layer 61 by adopting an electrofluid printing process to realize red and green luminescence, thereby realizing RGB three-color display. In addition, the method provided by the application directly bonds the driving back plate 10 and the light-emitting substrate 20, and compared with the prior art that Micro-LED devices are manufactured firstly and then transferred onto the driving back plate, the problems of alignment precision and the like in batch transfer are avoided.

Based on this, the present application further provides a display panel 100, where the display panel 100 includes a driving backplane 10, a pixel array 210 disposed on the driving backplane 10, and a thin film encapsulation layer 60 disposed outside the pixel array 210 and completely covering the pixel array 210, the display panel 100 further includes a pixel definition layer 61 disposed on top of the thin film encapsulation layer 60, and quantum dots 50 disposed in the pixel definition layer 61, thereby forming a multicolor display.

The quantum dots 50 include red quantum dots 51 capable of emitting red light R and green quantum dots 52 capable of emitting green light G, and the light emitting color of the pixel array 210 is blue B, so that RGB three-color display can be realized.

The display panel 100 further includes a black matrix 70 disposed within the pixel defining layer 61 and between the red and

green quantum dots

51, 52.

The display panel 100 further includes an insulating protective layer 53 disposed on a top side of the quantum dots 50. Please refer to fig. 12 for a detailed structure, and please refer to the description of the above embodiments for a detailed description of the structure, which is not repeated herein.

The display panel 100 further includes a glass cover plate 80, and the glass cover plate 80 is encapsulated on top of the insulating protection layer 53 by UV glue 90 and completely covers the insulating protection layer 53.

The utility model discloses a display panel 100 has high PPI, and display effect is better, can regard as the display screen of equipment such as AR and VR.

The above description is only an embodiment of the present application, and not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes performed by the content of the present specification and the attached drawings, or directly or indirectly applied to other related technical fields, are also included in the scope of the present invention.

Claims

1. A display panel comprises a driving backboard, a pixel array arranged on the driving backboard, and a thin film packaging layer which is arranged at the outer side of the pixel array and completely covers the pixel array, and is characterized in that: the display panel further comprises a pixel definition layer arranged on the top of the thin film packaging layer and quantum dots arranged in the pixel definition layer to form multicolor display.

2. The display panel according to claim 1, characterized in that: the quantum dots are formed in at least a portion of the pixel definition layer corresponding to the pixel array.

3. The display panel according to claim 1, characterized in that: the quantum dots include red quantum dots and green quantum dots.

4. The display panel according to claim 3, wherein: the display panel further includes a black matrix disposed within the pixel definition layer and between the red and green quantum dots.

5. The display panel according to claim 4, wherein: the quantum dots and the black matrix are formed by adopting an electrofluid printing process.

6. The display panel according to claim 1, characterized in that: the display panel further includes an insulating protective layer disposed on a top side of the quantum dots, and the insulating protective layer covers the quantum dots.

7. The display panel according to claim 6, wherein: the display panel further includes a glass cover plate that is sealed on top of and completely covers the insulating protective layer.

8. The display panel according to claim 6, wherein: the thickness of the insulating protective layer is 50 nm.

9. The display panel according to claim 1, characterized in that: and the driving backboard is provided with a driving circuit array so as to be electrically connected with the corresponding pixel array and provide driving voltage for the pixel array.

10. The display panel according to claim 1, characterized in that: the thin film encapsulation layer comprises an organic encapsulation layer and an inorganic encapsulation layer.