CN111868930A

CN111868930A - Display screen, preparation method thereof and mobile terminal

Info

Publication number: CN111868930A
Application number: CN201880091330.2A
Authority: CN
Inventors: 贺虎
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-03-21
Filing date: 2018-03-21
Publication date: 2020-10-30
Also published as: WO2019178782A1

Abstract

The application discloses a display screen and a preparation method thereof, and a mobile terminal, wherein the display screen comprises: the laminated transparent substrate, the thin film transistor layer, the anode layer, the luminescent layer, the common layer and the packaging film layer; the common layer comprises at least one layer of a structure, and for each layer of the structure, the common layer comprises a first part and a second part which are spliced. When the display screen is prepared, a first hole or a fourth hole which is communicated with the thin film transistor layer, the anode layer, the luminescent layer and the common layer is formed, and when the first hole or the fourth hole is formed in the common layer, the first hole or the fourth hole is positioned at the splicing position of the first part and the second part on each layer of the layer structure. The layer that its includes of transparent region in this application only is base plate and encapsulation rete, has reduced the setting of transparent region layer structure, and then has improved the transmissivity of light, has reduced the loss of light when penetrating transparent region, has improved the printing opacity effect of display screen. In addition, in the scheme, the packaging film layer packages the gap between each layer on the side wall of the first hole or the fourth hole, so that the waterproof oxygen corrosion effect of the display screen is improved.

Description

Display screen, preparation method thereof and mobile terminal

Technical Field

The application relates to the technical field of communication, in particular to a display screen, a manufacturing method of the display screen and a mobile terminal.

Background

Full screen display has become a development trend of the current mobile phone screen display technology. However, since a space is reserved for the front camera in the display area of the screen, the current manufacturers cannot produce a full-screen mobile phone in the true sense.

For example, in the prior art, a hole digging type scheme is adopted to arrange a front camera on a front panel of a mobile phone. Referring to fig. 1, the hole digging scheme is to dig a small hole 02 in a mobile phone screen 01, and arrange a camera 03 inside the small hole 02. In this way, the area of the screen 01 other than the small hole 02 can be used for displaying a Graphical User Interface (GUI) of the mobile phone, for example, information, images, various menus, and the like provided to the user by the mobile phone.

The mobile phone screen mainly includes a Liquid Crystal Display (LCD) screen and an Organic Light Emitting Display (OLED) screen. Among them, the OLED display usually uses an organic light emitting material as a light emitting layer, can realize self-luminescence, and has advantages of low power consumption, fast reaction speed, and the like, thereby gaining more and more attention.

For the OLED display, when the hole-digging type scheme shown in FIG. 1 is adopted, the cross-sectional view of the OLED display 01 shown in FIG. 2 can be obtained according to the sectional line 001 shown in FIG. 1. In fig. 2, 011 denotes a common layer (common layer) made of an organic material, which includes a plurality of layers such as a cathode layer, an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer, etc., 012 denotes an encapsulation layer (encapsulation layer), and 013 denotes a transparent substrate (substrate). Since the organic material is easy to absorb substances such as moisture and gas, in the small hole 02 shown in fig. 2, harmful substances (represented by circles in fig. 2) such as moisture and harmful gas (e.g., oxygen) in the air easily enter the inside of the OLED display 01 through the common layer 011 made of the organic material, thereby causing problems such as darkening of light emitting pixels of the OLED display 01, and affecting the performance and the service life of the OLED display 01 and a mobile phone.

Disclosure of Invention

The application provides a display screen, a preparation method thereof and a mobile terminal, which are used for improving the light transmission effect of a light transmission area of the display screen.

In a first aspect, a display screen is provided, which includes a stacked transparent substrate, a thin film transistor layer, an anode layer, a light emitting layer, a cathode layer, and a packaging film layer covering the cathode layer, wherein the thin film transistor layer, the anode layer, the light emitting layer, and the cathode layer are disposed on the transparent substrate and stacked along a direction away from the transparent substrate; when specifically forming the transparent region in display area, dispel several layer upon layer structures that the light transmissivity is relatively poor or lightproof among the layer structure of display screen, the mode that specifically adopts is: first holes are respectively formed in the thin film transistor layer, the anode layer, the light emitting layer and the cathode layer, and vertical projections of the first holes in the thin film transistor layer, the anode layer, the light emitting layer and the cathode layer on a first plane are at least partially overlapped, wherein the first plane is the surface of the transparent substrate facing the thin film transistor layer; wherein the overlapping portion of the first holes forms the transparent region, and the sealing performance of the formed light transmission region is improved. The encapsulation film layer covers at least a sidewall of the first hole on the cathode layer.

It can be seen through the above-mentioned description that the layer that transparent region in this application it includes only is the better layer of transparent substrate and printing opacity effect, compare with among the prior art transparent region of display screen still including other structures in the sharing layer except base plate and encapsulation rete, the transparent region of the display screen disclosed in this application has reduced the setting of layer structure, and then has improved the transmissivity of light, the loss of light when penetrating transparent region has been reduced, the printing opacity effect of display screen has been improved. In addition, in the scheme, the packaging film layer packages the gaps among the layers on the side wall of the first hole, so that the waterproof oxygen corrosion effect of the display screen is improved.

When specifically setting up the number in first hole, the number in first hole can be a plurality of, specifically is: the number of the first holes on the cathode layer is two or more. When the number of the first holes arranged on the cathode layer is multiple, the number of the corresponding other layers is also multiple, and the first holes are in one-to-one correspondence with the first holes on the cathode layer.

In the case where the number of the first holes in the cathode layer is two or more, the shapes and sizes of the two or more first holes may be the same or different, and in one specific embodiment, the shapes and/or sizes of the two or more first holes in the cathode layer are different. So that different light transmission regions can be formed.

In a specific arrangement, the first holes may be located at different positions of the cathode layer, and in a specific arrangement, the first holes on the cathode layer are located at the top of the cathode layer.

In a specific embodiment, when the display screen comprises the thin film transistor layer, the anode layer, the light-emitting layer and the cathode layer, the first holes on the thin film transistor layer, the anode layer, the light-emitting layer and the cathode layer are communicated to form the second holes. When the structure is adopted, the light-transmitting area only comprises the transparent substrate and the packaging film layer, so that the light-transmitting effect of the light-transmitting area of the display screen is improved.

When the thin film transistor layer, the anode layer, the light emitting layer and the cathode layer are specifically arranged, the first holes of the layer structures are arranged on the same center line, and the size of one hole of each layer is consistent, or the size of the first hole is gradually reduced along the direction far away from the transparent substrate. Thereby facilitating the encapsulation of the encapsulating film.

In a specific embodiment, a third hole is disposed on the transparent substrate and the encapsulation film layer, and is in communication with the second hole. The number of layers of the layer structure in the light-transmitting area is further reduced, and the light-transmitting effect is further improved.

In a specific embodiment, the display screen further comprises other layer structures, specifically: the cathode layer is arranged between the anode layer and the light-emitting layer, and the electron transport layer and the electron injection layer are arranged between the cathode layer and the light-emitting layer. In this case, the layer structure in the light-transmitting region also includes the above-described arrangement of several layers.

In a specific embodiment, a fourth hole is disposed on at least one of the hole transport layer, the hole injection layer, the electron transport layer, and the electron injection layer, and a vertical projection of the fourth hole on the first plane at least partially overlaps with the first holes on the thin-film transistor layer, the anode layer, the light-emitting layer, and the cathode layer. The layer structure in the transparent areas is reduced.

In a specific embodiment, the hole transport layer, the hole injection layer, the electron transport layer and the electron injection layer are respectively provided with fourth holes, and the fourth holes on the hole transport layer, the hole injection layer, the electron transport layer and the electron injection layer are communicated with the first holes on the thin film transistor layer, the anode layer, the light-emitting layer and the cathode layer to form fifth holes. Further, the layer structure of the transparent region is reduced.

In a specific embodiment, a third hole is disposed on the transparent substrate and the encapsulation film layer, and the third hole is in communication with the fifth hole. And the layer structure of the transparent area is further improved, and the light transmission effect of the transparent area of the display screen is improved.

In a specific embodiment, the transparent substrate is a flexible transparent substrate or a glass substrate. So that a flexible display or a rigid display can be formed.

In a second aspect, a method for manufacturing a display screen is provided, and the method includes the following steps:

preparing a thin film transistor layer, an anode layer and a light-emitting layer on a transparent substrate; and forming first holes respectively when evaporating the thin film transistor layer, the anode layer and the light-emitting layer;

forming a cathode layer on the luminous layer by a process of twice evaporation; forming a first part of the cathode layer through first evaporation, forming a second part of the cathode layer through second evaporation, and forming a first hole at the splicing position of the first part and the second part;

and preparing a packaging film layer on the cathode layer, wherein the packaging film layer covers the side wall of the first hole on the cathode layer.

The preparation method also comprises the following steps: forming a hole injection layer on the prepared anode layer by evaporation;

preparing and forming a hole transport layer on the prepared hole injection layer; the light-emitting layer is prepared on the hole transport layer;

forming an electron transport layer on the prepared luminescent layer by evaporation;

and an electron injection layer is formed on the prepared electron transport layer by evaporation, and the cathode layer is prepared on the electron injection layer.

Forming a layer structure by at least one layer structure of a hole injection layer, a hole transport layer, an electron injection layer and an electron transport layer in a twice evaporation mode; and forming a first part of the layer structure by first evaporation, forming a second part of the layer structure by second evaporation, and forming a fourth hole at the joint of the first part and the second part. Therefore, the layer structure in the transparent area can be reduced, and the light transmission effect of the transparent area is improved.

In the case of forming the above-mentioned each layer structure by two evaporation, different masks may be used for preparation, for example, in a specific embodiment, when the layer structure of the cathode layer or the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer is formed by two evaporation processes, the first portion is formed by a first mask evaporation; the first rectangular shielding plate is connected with a first bulge used for shielding the first hole or the fourth hole;

forming the second part by a second mask plate through evaporation; the second rectangular shielding plate is arranged on the second mask plate and used for shielding the first part, and a second protrusion used for shielding the first hole or the fourth hole is connected to the second rectangular shielding plate.

In another specific embodiment, the formation of the cathode layer or the layer-by-layer structure of the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer by a two-time evaporation process specifically includes:

forming the first portion by a first mask evaporation; the first rectangular shielding plate is connected with a first bulge used for shielding the first hole or the fourth hole;

forming the second part by a second mask plate through evaporation; and a second rectangular shielding plate for shielding the first part position and the first hole or the fourth hole position is arranged on the second mask plate.

When the layer structure is formed by two times of evaporation, a first part formed by the first evaporation is overlapped with a second part formed by the second evaporation at a splicing position. Thereby improving the uniformity of the layer structure and reducing the influence of the splicing part on the display screen.

During specific preparation, a thin film transistor layer, an anode layer and a light-emitting layer are prepared on a transparent substrate; forming a first hole when the thin film transistor layer, the anode layer and the luminous layer are evaporated; the method specifically comprises the following steps:

sequentially forming the thin film transistor layer, the anode layer and the light-emitting layer on the transparent substrate through a third mask plate; and a plate-shaped structure for shielding the first hole is arranged on the third mask plate.

The preparation method also comprises the following steps: and forming a second through hole which is communicated with the first hole or the fourth hole on the transparent substrate and the packaging film layer. The layer structure of the transparent area is further improved, and the light transmission effect of the transparent area is further improved.

In a third aspect, a mobile terminal is provided, which comprises the display screen of any one of the above items.

Drawings

FIG. 1 is a schematic diagram of a prior art display screen;

FIG. 2 is a cross-sectional view of FIG. 1;

fig. 3 is a schematic structural diagram of a display screen provided in the present application;

FIG. 4 is a front view of a mobile terminal provided herein;

FIG. 5 is a cross-sectional view taken at A-A of FIG. 4;

fig. 6 is a schematic structural diagram of a third mask provided in the embodiment of the present application;

fig. 7a is a schematic structural diagram of a first mask provided in an embodiment of the present application;

fig. 7b is a first partial top view after evaporation by using a first mask plate in the embodiment of the present application;

FIG. 7c is a cross-sectional view taken at B-B of FIG. 7B;

FIG. 7d is a cross-sectional view at C-C of FIG. 7 b;

fig. 8a is a schematic structural diagram of a second mask provided in the embodiment of the present application;

fig. 8b is a second partial top view after evaporation by using a second mask plate in the embodiment of the present application;

FIG. 8c is a cross-sectional view at B '-B' of FIG. 8B;

FIG. 8d is a cross-sectional view at C '-C' of FIG. 8 b;

fig. 9 is a schematic structural diagram of a cathode layer prepared by using a first mask and a second mask according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a first mask of an array provided in the present application;

fig. 11 is a schematic structural diagram of a second mask of the array provided in the present application;

fig. 12a to 12c are flow charts of the preparation of cathode layers provided in the examples of the present application;

fig. 13a is a schematic structural diagram of another first mask provided in the embodiment of the present application;

fig. 13b is a first partial top view after evaporation by using a first mask plate in the embodiment of the present application;

FIG. 13c is a cross-sectional view taken at H-H of FIG. 13 b;

FIG. 13d is a cross-sectional view taken at I-I of FIG. 13 b;

fig. 14a is a schematic structural view of another second mask provided in the embodiment of the present application;

fig. 14b is a second partial top view after evaporation by using a second mask plate in the embodiment of the present application;

FIG. 14c is a cross-sectional view at H '-H' of FIG. 14 b;

FIG. 14d is a cross-sectional view at I '-I' of FIG. 14 b;

fig. 15a is a schematic structural diagram of another first mask provided in the embodiment of the present application;

fig. 15b is a schematic structural diagram of another second mask provided in the embodiment of the present application;

fig. 16a is a schematic structural diagram of a first mask provided in an embodiment of the present application;

fig. 16b is a schematic structural diagram of a second mask provided in the embodiment of the present application;

fig. 17 is an exploded view of another display screen provided in an embodiment of the present application;

FIG. 18 is a cross-sectional view of another display screen provided in accordance with an embodiment of the present application;

FIG. 19 is a cross-sectional view of another display screen provided in accordance with an embodiment of the present application;

FIG. 20 is a cross-sectional view of another display screen provided herein;

FIGS. 21a to 21c are flow charts illustrating the manufacturing process of another display panel provided in the present application;

fig. 22 is a schematic structural diagram of a mobile terminal according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings.

In order to solve the problem that harmful substances (represented by circles in fig. 2) such as moisture and harmful gases (for example, oxygen) in the air easily enter the OLED display screen 01 through the common layer 011 made of organic materials, so that light-emitting pixels of the OLED display screen 01 become dark, and the like, and the performance and the service life of the OLED display screen 01 and a mobile phone are affected, the embodiment of the application provides a display screen. The display screen is an Organic Light-Emitting Diode (OLED) display screen.

In order to facilitate understanding of the display screen provided in the embodiments of the present application, a structure of the OLED display screen will be described first. OLED displays are generally made of thin organic light emitting material coatings and glass substrates, and the organic light emitting materials themselves emit light when current flows therethrough. Compared with an LCD screen, the OLED display screen can be thinner and has a larger visual angle, and the power consumption of the terminal can be saved.

It should be noted that the OLED display screen provided in the embodiment of the present application may be an OLED display screen commonly used in the prior art, and may be a display screen in various different classification manners in the prior art, for example, an Active Matrix OLED (AMOLED) and a Passive Matrix OLED (PMOLED); as another example, rigid (rigid) OLED displays and flexible OLED displays may be included. The specific distinction lies in the material of the substrate of the display screen, and when the display screen is a flexible OLED display screen, the substrate of the display screen is a flexible transparent substrate, such as a substrate made of polyimide materials. When the display screen is a rigid display screen, the transparent substrate may be a glass substrate. Among the two display screens, the flexible OLED display screen can be bent and has good flexibility. The OLED display screen can also be an integral touch display screen Y-OCTA and a non-integral touch display screen, such as Youm and the like. The Y-OCTA refers to a mode of directly integrating the touch sensor into the display panel in the manufacturing process of the OLED display screen; the non-integrated touch display screen is a mode of attaching a thin film type touch sensor to a display panel of an OLED display screen. It should be understood that the above only lists a few specific OLED display panels, and the display panels in the embodiments of the present application include all OLED display panels known in the art.

For the transparent area set on the display screen 100 according to the embodiment of the present application, it corresponds to the camera 200 or other photosensitive components (e.g., laser sensor, etc.) on the mobile terminal. For convenience of understanding, taking the camera 200 as an example, reference is also made to fig. 3 and fig. 4, where fig. 3 shows a schematic diagram of the display screen 100 and the camera 200 in cooperation, and fig. 4 shows a cross-sectional view at AA in fig. 3. As shown in fig. 4, the camera 200 is positioned below the display screen 100, and the lens of the camera 200 is positioned at a lower area of the transparent area so that external light can be irradiated into the lens through the transparent area.

In the embodiment of the present application, as shown in fig. 3, the display screen 100 includes the following layers: a transparent substrate, a thin film transistor layer (not shown), an anode layer, a light-emitting layer, a cathode layer, and a packaging film layer. When the thin film transistor layer, the anode layer, the light emitting layer, the cathode layer and the packaging film layer are arranged along the direction far away from the transparent substrate. The cathode layer, the anode layer and the thin film transistor layer are matched to drive the light-emitting pixels in the light-emitting layer to emit light.

When the transparent area is specifically set, referring to fig. 3 and 5 together, the transparent area is set in the display area of the display screen 100, for example, at the middle position or the position near the middle of the display screen 100. In particular, when forming the transparent region, several layers of the display screen 100 with poor light transmittance or without light transmittance are removed, so that the remaining layers form a counter bore to form the transparent region in the display region of the display screen 100.

For convenience of description, the display panel shown in fig. 5 includes a transparent substrate 10, a thin film transistor layer 20, an anode layer 30, a light emitting layer 40, a cathode layer 50, and an encapsulation film layer 60. When the transparent region is provided, since the thin film transistor layer 20, the anode layer 30, the light emitting layer 40, and the cathode layer 50 have poor light transmittance properties, first holes 71 are formed in the thin film transistor layer 20, the anode layer 30, the light emitting layer 40 and the cathode layer 50, when the first holes 71 of different layers are specifically arranged, the vertical projections of the first holes 71 of the thin-film transistor layer 20, the anode layer 30, the light-emitting layer 40 and the cathode layer 50 on the first plane at least partially overlap, the first side is shown as side a in fig. 5, which is the side of the transparent substrate 10 facing the thin-film transistor layer 20, when the display screen structure comprises the thin film transistor layer 20, the anode layer 30, the light emitting layer 40 and the cathode layer 50, the first holes 71 on the thin-film transistor layer 20, the anode layer 30, the light-emitting layer 40 and the cathode layer 50 are communicated to form a second hole 70, and the communicated parts correspond to the transparent area on the display screen. In a specific embodiment, the first holes 71 of the above-mentioned several layers are coaxially arranged and have the same shape and size, and the second hole 70 is a through hole; or, the size of the first hole 71 is gradually increased along the direction away from the transparent substrate 10, so that the sidewall forming the second hole 70 has a slope to facilitate the encapsulation of the encapsulating film 60. Wherein the oval dotted lines in fig. 5 are auxiliary lines indicating the positions of the holes.

As shown in fig. 5, when the second hole 70 penetrates the thin-film transistor layer 20, the anode layer 30, the light emitting layer 40, and the cathode layer 50, a gap between the layer structures inevitably occurs on the sidewall of the second hole 70. In order to prevent impurities from entering into the gap, when the encapsulation film 60 is disposed, the encapsulation film 60 covers at least the sidewall of the first hole 71 on the cathode layer 50. When the structure shown in fig. 5 is employed, the encapsulation film layer 60 covers the sidewalls of the second hole 70. With continued reference to fig. 5, when the encapsulation film 60 covers the second hole 70, an inverted zigzag structure is formed, the vertical portion of the encapsulation film 60 covers the sidewall of the second hole 70, and the encapsulation film 60 covers the exposed transparent substrate 10 at the bottom of the second hole 70. Thereby make between base plate 10 and each layer structure to and the gap between each adjacent layer structure all encapsulated by encapsulation rete 60, avoid external impurity to enter into the display screen inside, thereby improved the waterproof oxygen erosion effect of display screen, and then improved the display effect of display screen when using.

As can be seen from the above description, the structure of the transparent region in the display panel disclosed in the embodiment of the present application includes the encapsulation film layer 60 and the transparent substrate 10. The thin film transistor layer 20, the anode layer 30 and the cathode layer 50 are all cut off in the transparent area, so that the layer structure of the transparent area is reduced, and the light transmission effect of the transparent area is improved.

When the layer structure is specifically reduced, the thin film transistor layer 20, the anode layer 30, and the light-emitting layer 40 therein are prepared by using a third mask 700, the third mask 700 is made of a high-precision metal mask (FMM), and the structure of the third mask is as shown in fig. 6, and the FMM may be specifically a pattern mask (pattern mask), so that when the thin film transistor layer, the anode layer, and the light-emitting layer are prepared, the first hole may be formed when the thin film transistor 20, the anode layer 30, and the light-emitting layer 40 in fig. 5 are prepared by setting the pattern mask corresponding to the first hole to be a solid plate-shaped structure 701. Specifically, the thin film transistor 20, the anode layer 30 and the light emitting layer 40 may be formed by sputtering, etching and the like, which are common in the prior art, and are not described in detail herein.

In the preparation of the cathode layer, as shown in fig. 7a to 9, it should be noted that the preparation of the cathode layer on the supporting substrate 400 is exemplified in the schematic diagrams of the preparation of the cathode layer shown in fig. 7a to 9. In forming the display panel, the cathode layer may be formed directly on the light emitting layer in the same manner as the preparation illustrated in fig. 7a to 9. Referring first to fig. 7a and 8a, fig. 7a illustrates a structure of a first mask 300, and fig. 8a illustrates a structure of a second mask. When the cathode layer is specifically prepared, firstly, a first mask 300 is used for evaporation, the first mask 300 is correspondingly provided with a hollow structure 303 corresponding to the first part 51, the first mask 300 is provided with a first rectangular shielding plate 301 for shielding the second part, and the first rectangular shielding plate 301 is connected with a first protrusion 302 for shielding the first hole 71. During evaporation, as shown in fig. 7B, a first part 51 forming the cathode layer is evaporated in a right area on the carrier substrate 400, and a first hole 71 is formed at a position blocked by the first protrusion 302, for convenience of understanding the structure of the formed first part 51, the structure in fig. 7C and fig. 7D is corresponded with an auxiliary line in fig. 7B, wherein B-B, C-C is a cross-sectional view, and E-E, D-D is a boundary line of the first hole 71 in a vertical direction; FIG. 7c shows a cross-sectional view B-B, as in FIG. 7c, and therefore, when taken in cross-section, the cross-sectional line cuts through first aperture 71, as indicated by the boundary line of first aperture 71 at E-E, D-D in FIG. 7 c; in the cross-sectional configuration shown in fig. 7d, the first hole 71 is not cut through by the C-C cross-section, and therefore the first portion 51 reaches directly at E-E to the left in fig. 7 d.

After the first evaporation is completed, a second mask 500 shown in fig. 8a is used for second evaporation, and as shown in fig. 8a to 8b, a hollow structure 503 corresponding to the second portion 52 is disposed on the second mask 500, and a second rectangular shielding plate 501 for shielding the first portion is disposed, and the second rectangular shielding plate 501 is connected with a second protrusion 502 for shielding the first hole. During vapor deposition, as shown in fig. 8b, the second portion 52 is formed on the left side of the carrier substrate by the hollow structure 503, and the position shielded by the second protrusion 502 overlaps with the position shielded by the first protrusion in fig. 8a, so as to form the first hole 71. For the convenience of understanding the structure of the formed second portion 52, the structures in fig. 8C and 8D are corresponding to the auxiliary lines in fig. 8B, wherein B '-B', C '-C' are sectional lines, E '-E', D '-D' are boundary lines of the first hole in the vertical direction; FIG. 8c shows a cross-sectional view B '-B', as shown in FIG. 8c, and thus, in cross-section, the line of sight cuts through the first hole, as shown by D '-D', E '-E' in FIG. 8c, which correspond to the boundaries of the first hole; in the cross-sectional configuration shown in fig. 8d, the first hole is not cut through the C '-C' cross-sectional view, and thus, the first and second portions 52 form an integral body.

Referring to fig. 9, fig. 9 is a schematic structural view of the cathode layer formed by the above-described two evaporation processes. As can be seen from fig. 9, a layer structure with holes can be directly formed on the carrier substrate by two times of evaporation, for example, in fig. 9, the holes are formed as rectangular holes, but the holes may also be formed in other shapes, such as circular or oval. As can be seen from the description in conjunction with fig. 7a to 8, the cathode layer includes two portions, namely, the first portion 51 and the second portion 52, and the first hole 71 is located at the joint of the first portion 51 and the second portion 52, and the second hole 70 is formed at the position shown in fig. 3, where the position of the second hole 70 on the screen may be on the center line of the screen display area, or may not be on the center line of the screen, such as on the upper left or upper right of the screen display area. Or as shown in fig. 22, fig. 22 is a schematic structural diagram of the mobile terminal, and in fig. 22, the first hole 71 is located at the top of the cathode layer, which is an end of the cathode layer away from the touch key of the mobile terminal. As can be seen from comparing fig. 7a and 8a, the first mask 300 and the second mask 500 are of an opposite structure, that is, the left side of the first mask 300 in fig. 7a is covered, and the right side of the first mask is hollow, while the left side of the second mask 500 in fig. 8a is hollow, and the right side of the second mask is covered, and the first mask 300 and the second mask 500 are respectively provided with the first protrusion 302 and the second protrusion 502 which are opposite; when the first protrusion 302 and the second protrusion 502 are shielded, the shielding portions overlap. Thus, after two times of evaporation, a layer structure with holes can be formed.

In the case of manufacturing the display panel shown in fig. 5, the cathode layer 50 may be formed directly on the light-emitting layer 40 by the above-described cathode layer manufacturing method, so that the cathode layer 50 may also include the first holes 71 of the light-emitting layer 40, the anode layer 30, and the like, and one second hole 70 may be formed to penetrate the above-described layers.

In addition, when preparing a display screen, it is common to prepare a large screen including a plurality of display screens arranged in an array. After the screen is prepared, the screen is cut into independent display screens. In order to adapt to such a preparation method, the first mask 300 and the second mask 500 provided in the embodiment of the present application may also be arranged in an array manner, as shown in fig. 10 and 11, where fig. 10 shows a structure of the first mask arranged in an array, and fig. 11 shows a structure of the second mask arranged in an array.

In addition, since the first part and the second part are formed in the layer structure of the cathode layer in a splicing manner, the thickness of the formed layer structure is easily uneven. If the thickness of the formed layer structure is not uniform, the performance of the display screen is reduced, and even the microcavity design of the OLED thereon is changed. In order to avoid the above situation, embodiments of the present application provide a method for preparing a cathode layer as shown in fig. 12a to 12 c. As shown in fig. 12a to 12c, the example shown in fig. 12a is described by taking an example in which a cathode layer is deposited on a carrier substrate 400. When the coating by vaporization, be located the top that bears base plate 400 through first mask plate 300 to carry out the coating by vaporization through the coating by vaporization source 600 that is located first mask plate 300 top, because there is certain interval between first mask plate 300 and the bearing base plate 400, there is certain angle in coating by vaporization source 600's itself moreover, consequently can cause outside the fretwork when the material deposit can cause on bearing base plate 400 certain material coating by vaporization, and has certain angle. In order to improve the uniformity of the thickness of the formed layer structure, in the layer structure of the cathode layer in the present application, the first portion 51 and the second portion 52 are overlapped at the splice. Therefore, the uniformity of the thickness is improved, and the display effect of the display screen is improved. After the first portion 51 is deposited, as shown in fig. 12b, a second deposition is performed through the second mask 500, and after the second deposition, a second portion 52 is formed, and when the second portion 52 is deposited, the second portion 52 overlaps the first portion 51, and a specific overlapping width is a width in which the first portion 51 and the second portion 52 form an inclined region during deposition, as shown by two dotted lines in fig. 12b, so that a cathode layer as shown in fig. 12c is formed.

For the cathode layer, the specific joints of the first part and the second part can be formed in different manners, either in a left-right joint manner as shown in fig. 7b and 8b, or in a top-bottom joint manner as shown in fig. 13a to 14d, the manufacturing approach shown in fig. 13 a-14 d is similar to that shown in fig. 7 a-9, which will only be briefly described here, in which, FIGS. 13a and 14a show another structure of the first mask 300 and the second mask 500, and in concrete terms, as the first part is fabricated, as shown in fig. 13b to 13d, the first part located below is first prepared, and thereafter, as shown in fig. 14b and 14d, a second portion located above is prepared by the second mask 500, among them, the auxiliary lines in fig. 13b to 13d can be described with reference to the auxiliary lines in fig. 7b to 7d described above. The descriptions of the auxiliary lines in fig. 14b to 14d can refer to the descriptions of the auxiliary lines in fig. 8b to 8d, and are not described in detail herein.

As a modification of fig. 13a and 14a, a mask plate structure as shown in fig. 15a and 15b may be used. As shown in fig. 15a, a first rectangular shielding plate 301 for shielding a second portion is disposed on the first mask 300, the first rectangular shielding plate 301 is connected to a first protrusion 302 for shielding a first hole, and a hollow structure corresponding to the first portion is disposed on the first mask 300; as shown in fig. 15b, the second mask 500 is provided with a second rectangular shielding plate 501 for shielding the first partial position and the first hole. During the first evaporation, the first mask plate 300 is used for shielding, due to the shielding of the first rectangular shielding plate 301 and the first protrusion 302, the second part and the position corresponding to the first hole are shielded by the first mask plate 300, only the first part is formed, and after the evaporation is finished, the second part is formed by the evaporation through the second mask plate 500, due to the shielding of the second rectangular shielding plate 501, the first part and the position corresponding to the first hole are shielded; in addition, during two times of evaporation, the position of the first hole is respectively shielded by the first protrusion 302 and the second rectangular shielding plate 501, so that the material is not evaporated at the first hole, and a hole-shaped structure is formed.

In addition, the number of the first holes in the cathode layer, that is, the number of the transparent regions, may be displayed as needed, and one first hole may be provided, or two or more first holes may be provided, and when the first holes are specifically prepared, the shapes and sizes of the first holes may be the same or different, as shown in fig. 22, fig. 22 shows the structure of the mobile terminal, in fig. 22, the number of the first holes 71 is three, the sizes and shapes of the first holes 71 located at both sides are different, and the size and shape of the first hole 71 located in the middle are different from those of the first holes 71 located at both sides. Taking two first holes 71 as an example, in the specific preparation, as shown in fig. 16a and 16b, fig. 16a shows the structure of the first mask 300, and fig. 16b shows the structure of the second mask 500. Fig. 16a and 16b can be regarded as a modification of fig. 15a and 15b, in which the number of the first protrusions 302 shown in fig. 16a is two, and the two first protrusions correspond to the first holes, respectively. It should be understood that when the mask structure shown in fig. 16a and 16b is used, the first protrusions 302 may be disposed on both the first mask 300 and the second mask 500, and specifically, may be disposed according to actual requirements, and will not be described in detail herein. In addition, when two or more first holes are provided in the cathode layer, two or more first holes are provided in the thin film transistor layer, the anode layer, and the light-emitting layer, respectively, so that two or more transparent regions are formed.

As can be seen from the above description, in the embodiments of the present application, when the encapsulation film layer 60 encapsulates other devices of the display screen, the encapsulation film layer 60 encapsulates the above layers and covers the sidewalls of the first hole 71. The first hole 71 is a transparent area on the display screen, and as can be seen from the above description, the transparent area in this application includes layers including the substrate and the encapsulation film layer 60, and the cathode layer 50 is removed. For the cathode layer 50 that is removed, since the cathode layer 50 is a metal material, it has a strong reflection in this area, and thus has a large influence on the transmittance. Therefore, compared with the prior art in which the transparent region of the display screen includes the substrate and the encapsulation film layer 60 and also includes the structure of the cathode layer 50, the technical scheme disclosed in the application reduces the layer structure of the transparent region of the display screen, thereby improving the light penetration rate, reducing the loss of light when penetrating the transparent region, and improving the light transmission effect of the display screen. In the above solution, the encapsulation film 60 encapsulates the gaps between the layers on the sidewall of the second hole 70, so as to improve the water and oxygen corrosion resistance of the display screen.

In the above description, only the case where the display panel includes the transparent substrate, the thin film transistor layer, the anode layer, the light emitting layer, and the cathode layer is described. It should be understood that the display screen provided by the embodiment of the present application may also include other layer structures.

As shown in fig. 17, the display panel 1 shown in fig. 17 may include a polarizer (polarizer)11, an encapsulation film layer 12, an organic self-luminescent layer 13, and a transparent substrate 14. The polarizer 11 may be used to improve the contrast ratio and reduce the influence on the contrast ratio due to the reflection of the display screen when the external light irradiates the display screen; the encapsulation film layer 12 may be used to protect the organic self-luminescent layer 13 and has high light transmittance; the organic self-luminescent layer 13 is mainly used for self-luminescence of the display screen; the transparent substrate 14 may be used to carry the upper organic self-emissive layer 13. Specifically, referring to fig. 18, the organic self-light emitting layer 13 may include a common layer 131, a light emitting layer 132, an anode layer (anode)133, and a thin film transistor layer 134. Referring to fig. 18 and 19 together, the common layer 131 is usually made of an organic material, and thus may be referred to as an organic common layer (common organic layer). The common layer 131 may specifically include a cathode (cathode)1311, an Electron Injection Layer (EIL) 1312, an Electron Transport Layer (ETL) 1313, a Hole Transport Layer (HTL) 1314, and a Hole Injection Layer (HIL) 1315. The light emitting layer 132 may include a red light emitting pixel (R), a green light emitting pixel (G), and a blue light emitting pixel (B). Common layer 131 may be used to cooperate with anode layer 133 and thin-film-transistor layer 134 to drive the light-emitting pixels in light-emitting layer 132 to emit light. It should be noted that the above-mentioned structure is only an exemplary illustration of the OLED screen, and the OLED screen may have other structures, for example, a cover plate may be further included on the upper layer of the polarizer 11.

As can be seen from the above description, the cathode layer 1311, the electron injection layer 1312, the electron transport layer 1313, the hole transport layer 1314 and the hole injection layer 1315 may be referred to as a common layer 131, and a method of preparing the same as that of the cathode layer 1311, and thus, in preparing the other layers of the common layer 131, reference may be made to the above-described method of preparing the cathode layer. Of course, it should be understood that, in the case of the electron injection layer 1312, the electron transport layer 1313, the hole transport layer 1314 and the hole injection layer 1315, since the above layers have a certain light transmittance, a part of or all of the transparent region may be left when the transparent region is formed. In the specific preparation of the electron injection layer 1312, the electron transport layer 1313, the hole transport layer 1314 and the hole injection layer 1315, as shown in fig. 19, at least one of the electron injection layer 1312, the electron transport layer 1313, the hole transport layer 1314 and the hole injection layer 1315 is provided with a fourth hole 72, and a vertical projection of the fourth hole 72 on the first plane at least partially overlaps with the first holes 71 on the thin-film transistor layer, the anode layer, the light-emitting layer and the cathode layer. When the fourth hole 72 is formed in any one of the electron injection layer 1312, the electron transport layer 1313, the hole transport layer 1314 and the hole injection layer 1315, the mask corresponding to the cathode layer described above may be used for formation, and only the structure for blocking the first hole needs to be changed to the structure for blocking the fourth hole.

The hole structure on the display screen is illustrated in detail below with reference to the accompanying drawings. As shown in fig. 19, in the structure shown in fig. 19, fourth holes 72 are provided for each of the electron injection layer 1312, the electron transport layer 1313, the hole transport layer 1314 and the hole injection layer 1315. And the fourth hole 72 communicates with the first hole 71 when provided to form a fifth hole 73. It is to be understood that any one or more of the partially remaining electron injection layer 1312, the electron transport layer 1313, the hole transport layer 1314 and the hole injection layer 1315 may be employed in addition to the structure in which the layers of the common layer 131 are cut out in the transparent region as shown in fig. 19. When preparing each layer structure, if the lower layer is a suspended hole structure, the layer structures in the transparent region sink in sequence to form the structure shown in fig. 18. In fig. 18, a structure in which the first hole 71 is formed only on the cathode layer 1311 of the common layer 131 is shown, and at this time, the electron injection layer 1312, the electron transport layer 1313, the hole transport layer 1314, and the hole injection layer 1315 sink into the first hole 71 on the thin film transistor layer 134, the anode layer 133, and the light emitting layer 132, and one sink hole 74 is formed on the display screen. Among them, the oval lines in fig. 18 and 19 are auxiliary lines for indicating the positions of the holes.

Further, with continuing reference to fig. 5 and 19, it can be seen from fig. 5 and 19 that the transparent region only includes the transparent substrate 10 and the encapsulating film 60, and in order to further improve the light transmission effect of the transparent region, a third hole may be provided, and the third hole is communicated with the second hole and the fifth hole. Taking the structure shown in fig. 5 as an example, when the third hole is formed, the structure is as shown in fig. 20: the third hole 75 is communicated with the second hole 70, and the third hole 75 is formed through the encapsulation film 60 and the transparent substrate 10. In a specific arrangement, the center lines of the second hole 70 and the third hole 75 are the same center line, and the diameters of the second hole 70 and the third hole 75 may be the same or different, and as shown in fig. 20, the diameters of the second hole 70 and the third hole 75 are arranged in a different manner. However, in any of the above-described methods, as shown in fig. 21a, the first holes are formed in the thin film transistor layer 20, the anode layer 30, the light-emitting layer 40, and the cathode layer 50, the second holes 70 are formed so as to communicate with the first holes, and the sealing film layer 60 seals the side walls of the second holes 70. Then, as shown in fig. 21b, the transparent substrate 10 and the packaging film 60 in the transparent region are cut off, that is, a third hole 75 is opened on the packaging film 60, so as to form the structure shown in fig. 21 c. In the structure shown in fig. 20, it is clearly seen that there is no layer structure in the transparent region. Thus, compared to the display screen shown in fig. 3, a through hole is formed through the second hole 70 and the third hole 75, which is arranged to allow the entire display screen to pass through, without passing through the layer structure when light is applied to the device through the transparent area. Further reducing the light loss and improving the light transmission effect of the transparent area.

It should be understood that, in the above embodiments, only the layer structure of the common display screen is shown, and the display screen may further include other layer structures, such as a polarizer, a buffer layer, a heat dissipation layer or a cover plate, and the above listed several layer structures are the same as the layer structure in the prior art when being set, and when being specifically prepared, corresponding holes are also formed, and when specifically forming the holes, the holes may be formed by laser cutting, numerical control (CNC) grinding, cutter wheel processing, and the like, and the above processing manners are all processing manners common in the prior art and will not be described in detail here again

In order to facilitate understanding of the structure of the display screen provided in the embodiments of the present application, the following description will be made again with reference to the manufacturing method thereof.

The preparation method comprises the following steps:

step 001: preparing a thin film transistor layer, an anode layer and a light-emitting layer on a transparent substrate; and forming first holes respectively when evaporating the thin film transistor layer, the anode layer and the light-emitting layer;

when the thin film transistor layer, the anode layer and the light-emitting layer are prepared specifically, the thin film transistor layer, the anode layer and the light-emitting layer are formed on the transparent substrate in sequence through a third mask plate; and a plate-shaped structure for shielding the first hole is arranged on the third mask plate. The above-described methods for preparing the thin film transistor layer, the anode layer, and the light-emitting layer in the display structure may be combined. And the perpendicular projections of the first holes of the formed layers on the first side of the transparent substrate at least partially overlap.

Step 002: forming a cathode layer on the luminous layer by a process of twice evaporation; forming a first part of the cathode layer through first evaporation, forming a second part of the cathode layer through second evaporation, and forming a first hole at the splicing position of the first part and the second part;

specifically, when the structure of the cathode layer is prepared, the method for preparing the cathode layer described in the display screen structure above and in fig. 5 to fig. 20 can be combined. And the perpendicular projection of the first holes of the formed layers on the first surface of the transparent substrate is at least partially overlapped, so that the first holes of the layers are communicated to form second holes.

In addition, in order to improve the effect in the case of two times of vapor deposition, a first portion formed by the first time of vapor deposition and a second portion formed by the second time of vapor deposition are overlapped at a splice.

Step 003: and preparing a packaging film layer on the cathode layer, wherein the packaging film layer covers the side wall of the first hole on the cathode layer.

Specifically, when the packaging film layer is packaged, the packaging film layer wraps the thin film transistor layer, the anode layer, the light emitting layer and the cathode layer, and the packaging film layer covers the side wall of the second hole.

Step 004: a third hole is formed and communicates with the second hole.

When the display panel further includes an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer, after the anode layer in step 001 is formed, the hole injection layer and the hole transport layer are formed on the anode layer by preparation. And then preparing a light emitting layer, after the light emitting layer is formed, preparing an electron transport layer and an electron injection layer on the light emitting layer, and then preparing the cathode layer in the step 002 on the electron injection layer. And when the electron injection layer, the electron transport layer, the hole transport layer and the hole injection layer are specifically prepared, a fourth hole may be formed in at least one layer of the electron injection layer, the electron transport layer, the hole transport layer and the hole injection layer, so as to reduce the layer structure of the transparent region.

In the display screen after adopting above-mentioned technology to prepare to form, the layer that transparent region it includes only is base plate and encapsulation rete, compare with the transparent region of display screen among the prior art except that base plate and encapsulation rete still include other structures in the common layer outside, the transparent region of the display screen disclosed in this application has reduced the setting of layer structure, and then has improved the penetration rate of light, has reduced the loss of light when penetrating transparent region, has improved the printing opacity effect of display screen. In addition, in the scheme, the packaging film layer packages the gaps among all layers on the side wall of the hole, so that the waterproof oxygen corrosion effect of the display screen is improved.

In addition, an embodiment of the present application further provides a mobile terminal, as shown in fig. 22, where the mobile terminal includes the display screen of any one of the above. Wherein, this mobile terminal can be common mobile terminal such as cell-phone, panel computer, and the display screen that its adopted is in the display screen after adopting above-mentioned technology preparation to form, wherein, three first hole 71 has been set up on the cathode layer of this display screen, this first hole 71 is located the top of cathode layer, the top of display screen promptly, refer to the layer structure shown in fig. 5 together, the layer that this transparent region includes is only transparent substrate and encapsulation rete, compare with the transparent region of display screen among the prior art except that base plate and encapsulation rete still include other structures in the common layer, the transparent region of the display screen disclosed in this application has reduced the setting of layer structure, and then has improved the transmissivity of light, the loss of light when penetrating transparent region has been reduced, the printing opacity effect of display screen has been improved. In addition, in the scheme, the packaging film layer packages the gaps among all layers on the side wall of the hole, so that the waterproof oxygen corrosion effect of the display screen is improved.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

A display screen, comprising: the transparent substrate is provided with a thin film transistor layer, an anode layer, a light emitting layer and a cathode layer which are arranged on the transparent substrate and are stacked along the direction far away from the transparent substrate, and a packaging film layer covered on the cathode layer; the thin film transistor layer, the anode layer, the light emitting layer and the cathode layer are respectively provided with a first hole, and the vertical projections of the first holes on the thin film transistor layer, the anode layer, the light emitting layer and the cathode layer on a first plane are at least partially overlapped, wherein the first plane is the surface of the transparent substrate facing the thin film transistor layer;

the encapsulation film layer covers at least a sidewall of the first hole on the cathode layer.
The display screen of claim 1, wherein the number of first holes in the cathode layer is two or more.
A display screen as recited in claim 2, wherein the two or more first apertures of the cathode layer are different shapes and/or different sizes.
A display screen according to any one of claims 1 to 3, wherein the first holes in the cathode layer are located on top of the cathode layer.
The display screen of any one of claims 1 to 4, wherein the first holes on the thin film transistor layer, the anode layer, the light emitting layer and the cathode layer are communicated to form a second hole.
The display screen of claim 5, wherein a third hole is disposed on the transparent substrate and the encapsulation film layer and is in communication with the second hole.
The display panel according to any one of claims 1 to 4, further comprising a hole injection layer and a hole transport layer provided between the anode layer and the light-emitting layer, and an electron transport layer and an electron injection layer provided between the cathode layer and the light-emitting layer.
A display screen as recited in claim 7, wherein at least one of the hole transport layer, the hole injection layer, the electron transport layer, and the electron injection layer has a fourth hole disposed therein, and a perpendicular projection of the fourth hole onto the first plane at least partially overlaps the first holes in the thin-film transistor layer, the anode layer, the light-emitting layer, and the cathode layer.
The display screen of claim 8, wherein the hole transport layer, the hole injection layer, the electron transport layer, and the electron injection layer are respectively provided with fourth holes, and the fourth holes of the hole transport layer, the hole injection layer, the electron transport layer, and the electron injection layer are communicated with the first holes of the thin film transistor layer, the anode layer, the light emitting layer, and the cathode layer to form fifth holes.
The display screen of claim 9, wherein a third hole is disposed on the transparent substrate and the encapsulation film layer and is in communication with the fifth hole.
A display screen according to any one of claims 1 to 10, wherein the transparent substrate is a flexible transparent substrate or a glass substrate.
A method of manufacturing a display screen according to claim 1, comprising the steps of:

preparing a thin film transistor layer, an anode layer and a light-emitting layer on a transparent substrate; and forming first holes respectively when evaporating the thin film transistor layer, the anode layer and the light-emitting layer;

forming a cathode layer on the luminous layer by a process of twice evaporation; forming a first part of the cathode layer through first evaporation, forming a second part of the cathode layer through second evaporation, and forming a first hole at the splicing position of the first part and the second part;

and preparing a packaging film layer on the cathode layer, wherein the packaging film layer covers the side wall of the first hole on the cathode layer.
The method of claim 12, further comprising: forming a hole injection layer on the prepared anode layer by evaporation;

preparing and forming a hole transport layer on the prepared hole injection layer; the light-emitting layer is prepared on the hole transport layer;

forming an electron transport layer on the prepared luminescent layer by evaporation;

and an electron injection layer is formed on the prepared electron transport layer by evaporation, and the cathode layer is prepared on the electron injection layer.
The method according to claim 13, wherein at least one layer of the hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer is formed by two evaporation processes; and forming a first part of the layer structure by first evaporation, forming a second part of the layer structure by second evaporation, and forming a fourth hole at the joint of the first part and the second part.
The method according to claim 14, wherein the cathode layer or one of the hole injection layer, the hole transport layer, the electron injection layer and the electron transport layer is formed by a double evaporation process, and specifically comprises:

forming the first portion by a first mask evaporation; the first rectangular shielding plate is connected with a first bulge used for shielding the first hole or the fourth hole;

forming the second part by a second mask plate through evaporation; the second rectangular shielding plate is arranged on the second mask plate and used for shielding the first part, and a second protrusion used for shielding the first hole or the fourth hole is connected to the second rectangular shielding plate.
The method according to claim 14, wherein the cathode layer or one of the hole injection layer, the hole transport layer, the electron injection layer and the electron transport layer is formed by a double evaporation process, and specifically comprises:

forming the first portion by a first mask evaporation; the first rectangular shielding plate is connected with a first bulge used for shielding the first hole or the fourth hole;

forming the second part by a second mask plate through evaporation; and a second rectangular shielding plate for shielding the first part position and the first hole or the fourth hole position is arranged on the second mask plate.
The production method according to any one of claims 12 to 16, wherein a first portion formed by the first evaporation and a second portion formed by the second evaporation overlap at a joint.
The method according to any one of claims 12 to 16, wherein the thin film transistor layer, the anode layer and the light-emitting layer are formed on the transparent substrate; forming a first hole when the thin film transistor layer, the anode layer and the luminous layer are evaporated; the method specifically comprises the following steps:

sequentially forming the thin film transistor layer, the anode layer and the light-emitting layer on the transparent substrate through a third mask plate; and a plate-shaped structure for shielding the first hole is arranged on the third mask plate.
The method of any one of claims 12 to 18, further comprising: and forming a second through hole which is communicated with the first hole or the fourth hole on the transparent substrate and the packaging film layer.
A mobile terminal characterized by comprising a display screen according to any one of claims 1 to 11.