Preparation method of OLED display screen and OLED display screen

Abstract

The present application provides an OLED display screen and a preparation method thereof. The method includes: providing a carrier substrate, the carrier substrate includes a display area and a non-display area, and a cathode signal line is arranged in the non-display area; forming a photoresist layer covering the cathode signal line, the photoresist layer having a first surface away from the cathode signal line and a first side surface adjacent to the display area; forming a sacrificial layer, wherein the sacrificial layer covers the first surface of the photoresist layer and avoids at least part of the first side surface, and the sacrificial layer is connected to the surface of the carrier substrate away from the display area; removing the photoresist layer to form a gap between the sacrificial layer and the cathode signal line; forming a first functional film layer in the display area and the non-display area, and the first functional film layer in the non-display area is arranged on the sacrificial layer; removing the part of the sacrificial layer corresponding to the gap to expose the cathode signal line; and forming a cathode layer, the cathode layer covers and is electrically connected to the cathode signal line.

Description

Technical Field

[0001] The present application relates to the field of display, and in particular to a method for preparing an OLED display and an OLED display. Background Art

[0002] With the rapid development of optoelectronic display technology and semiconductor manufacturing technology, organic light-emitting diode (OLED) display screens have been widely used. OLED display screens have the advantages of high color gamut, high contrast, wide viewing angle, etc., and the market is becoming more and more extensive. However, the resistance between the cathode signal line and the cathode layer in the OLED display screen in the related art is large, resulting in high power consumption of the OLED display screen. Summary of the invention

[0003] In a first aspect, an embodiment of the present application provides a method for preparing an OLED display screen, and the method for preparing an OLED display screen comprises:

[0004] Providing a carrier substrate, the carrier substrate comprising a display area and a non-display area, the non-display area being provided with a cathode signal line;

[0005] forming a photoresist layer covering the cathode signal line, wherein the photoresist layer has a first surface away from the cathode signal line and a first side surface adjacent to the display area;

[0006] forming a sacrificial layer, wherein the sacrificial layer covers the first surface of the photoresist layer and avoids at least a portion of the first side surface, and the sacrificial layer is connected to a surface of the carrier substrate away from the display area;

[0007] removing the photoresist layer to form a gap between the sacrificial layer and the cathode signal line;

[0008] forming a first functional film layer in the display area and the non-display area, wherein the first functional film layer in the non-display area is disposed on the sacrificial layer;

[0009] removing a portion of the sacrificial layer corresponding to the gap to expose the cathode signal line; and

[0010] A cathode layer is formed, the cathode layer covering and electrically connecting the cathode signal line.

[0011] In a second aspect, an embodiment of the present application provides an OLED display screen, wherein the OLED display screen includes a plurality of OLED light-emitting units, and the OLED display screen includes:

[0012] A carrier substrate, the carrier substrate comprising a display area and a non-display area;

[0013] A cathode signal line, wherein the cathode signal line is arranged in the non-display area;

[0014] a first functional film layer, the first functional film layer is located in the display area and avoids the cathode signal line, wherein the OLED light-emitting unit includes the first functional film layer; and

[0015] A cathode layer covers and is electrically connected to the cathode signal line.

[0016] In summary, the method for preparing an OLED display screen provided in the embodiment of the present application forms a photoresist layer covering the cathode signal line; and forms a sacrificial layer 130 covering the first surface of the photoresist layer and avoiding the first side surface of the photoresist layer; after the photoresist layer is removed, a gap is formed between the sacrificial layer and the cathode signal line; when forming the first functional film layer, the first functional film layer located in the non-display area is set on the sacrificial layer; after the portion of the sacrificial layer corresponding to the gap is removed, the portion of the first functional film layer located on the sacrificial layer is also removed; therefore, the cathode layer can be directly connected to the cathode signal line. There is no first functional film layer between the cathode layer and the cathode signal line, therefore, the resistance between the cathode layer and the cathode signal line is small, thereby enabling the cathode layer to be better electrically connected to the cathode signal line, so that the OLED display screen has a smaller power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the implementation will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A flowchart of a method for preparing an OLED display screen provided in one embodiment;

[0019] Figure 2 for Figure 1 A schematic diagram of the structures corresponding to each step in the method for preparing an OLED display screen;

[0020] Figure 3 An implementation method Figure 1 A schematic diagram of the process included in S120;

[0021] Figure 4 A schematic diagram of the process included in S160 in 1 is provided for an implementation manner;

[0022] Figure 5 A schematic diagram of a process for preparing an OLED display screen provided in one embodiment of the present application;

[0023] Figure 6 for Figure 5 A schematic diagram of the process included in S180 in the method for preparing an OLED display screen shown in ;

[0024] Figure 7 It is a schematic diagram of the corresponding structure after S183;

[0025] Figure 8 A schematic diagram of the structure of an OLED display screen provided in one embodiment of the present application;

[0026] Fig. 9 A schematic structural diagram of an OLED display screen provided in another embodiment of the present application.

[0027] Main component numbers:

[0028] OLED display screen 1, OLED light emitting unit 10a, carrier substrate 110, display area 110a, non-display area 110b, gap 110c;

[0029] Cathode signal line 120, sacrificial layer 130, sacrificial layer residual portion 131, first functional film layer 140, second functional film layer 160, encapsulation layer 170, first inorganic layer 171, organic layer 172, second inorganic layer 173;

[0030] Photoresist layer 310, first surface 311, first side surface 312, second side surface 313;

[0031] Auxiliary workpiece 320 , auxiliary substrate 321 , carrying surface 3211 , adhesive member 322 . DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0034] Reference to "embodiment" or "implementation" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment or implementation may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] Before introducing the organic light-emitting diode (OLED) display screen provided in the embodiments of the present application, an OLED display screen in the related art (not the prior art) is first introduced.

[0036] When preparing an OLED display, not all functional film layers use a fine metal mask (Fine Metal Mask, FMM) to accurately evaporate the materials required for the corresponding functional film layer (named as the first functional film layer) to the pixel area of ​​the OLED display. When some functional film layers (for example, one or more of the electron transport layer, electron blocking layer, hole transport layer, and hole blocking layer) are formed using an open mask (Open Mask), the corresponding materials are evaporated onto the entire substrate to form the functional film layer. These functional film layers will be in the cathode overlap area, sandwiched between the cathode signal line (also called anode metal like the anode material in the OLED display) and the cathode layer. These functional film layers are generally organic and have a large resistance, which causes a large resistance between the cathode layer and the cathode signal line, which in turn causes poor overlap between the cathode layer and the cathode signal line or a large resistance between the cathode layer and the cathode signal line, resulting in high power consumption of the OLED display.

[0037] An embodiment of the present application provides a method for preparing an organic light-emitting diode (OLED) display screen to solve the related problems in the related art. The following is a detailed introduction to the method for preparing the OLED display screen 1 provided in an embodiment of the present application.

[0038] See also Figure 1 and Figure 2 , Figure 1 A flowchart of a method for preparing an OLED display screen provided in one embodiment; Figure 2 for Figure 1 Schematic diagram of the corresponding structures in each step of the method for preparing an OLED display screen. The OLED display screen 1 (see Figure 8 and Fig. 9) include but are not limited to S110, S120, S130, S140, S150, S160 and S170, S110, S120, S130, S140, S150, S160 and S170 are described in detail as follows.

[0039] S110, providing a carrier substrate 110, the carrier substrate 110 includes a display area 110a and a non-display area 110b, the non-display area 110b is provided with a cathode signal line 120. For the corresponding structure, please refer to Figure 2 (a) in .

[0040] The carrier substrate 110 may be, but is not limited to, a transparent substrate such as glass or plastic. The display area 110a of the carrier substrate 110 is an area in the OLED display screen 1 for display. The non-display area 110b is an area in the OLED display screen 1 that is not for display. The non-display area 110b is usually used to lay out conductive traces, which are electrically connected to each transmission line in the display area 110a to transmit the signal of the transmission line to the chip or circuit board in the OLED display screen 1; or transmit the signal from the chip or circuit board to the display area 110a of the OLED display screen 1.

[0041] The non-display area 110b is located at least partially around the display area 110a. In this embodiment, the non-display area 110b is located on the left side of the display area 110a. It is understandable that this should not be construed as a limitation on the carrier substrate 110 provided in the embodiment of the present application.

[0042] The cathode signal line 120 may be made of, but not limited to, metal. Therefore, the cathode signal line 120 is also called a cathode signal metal line or cathode metal line. The cathode signal line 120 may be made of, but not limited to, aluminum, silver, gold, copper, or an alloy of gold and copper.

[0043] In this embodiment, there is a bottom film layer 12a between the carrier substrate 110 and the cathode signal line 120. The bottom film layer 12a can be a single but not limited to an insulating layer, or a flat layer, etc. In other embodiments, the cathode signal line 120 can be directly disposed on the carrier substrate 110. The embodiment of the present application does not limit whether there is a bottom film layer 12a between the cathode signal line 120 and the carrier substrate 110.

[0044] In this embodiment, the cathode signal line 120 is spaced apart from the display area 110a by a gap. The cathode signal line 120 is spaced apart from the display area 110a by a gap, which can facilitate subsequent processing steps.

[0045] S120, forming a photoresist layer 310 covering the cathode signal line 120, wherein the photoresist layer 310 has a first surface 311 away from the cathode signal line 120 and a first side surface 312 adjacent to the display area 110a. For the corresponding structure, please refer to Figure 2 (b) in .

[0046] In this embodiment, the photoresist layer 310 covers the upper surface of the cathode signal line 120 away from the carrier substrate 110, and also covers the side of the cathode signal line 120 adjacent to the display area 110a and the side of the cathode signal line 120 away from the display area 110a.

[0047] The photoresist layer 310 can be formed by, but not limited to, coating, etc. The photoresist layer 310 can be, but not limited to, a positive photoresist layer 310 or a negative photoresist layer 310 .

[0048] When forming the photoresist layer 310 , a whole layer of photoresist material layer may be formed corresponding to the display area 110 a and the non-display area 110 b , and the photoresist material layer may be patterned by photolithography or other processes to form the photoresist layer 310 corresponding to the non-display area 110 b .

[0049] Since the cathode signal line 120 is located in the non-display area 110 b , the cathode layer 150 formed subsequently overlaps with the cathode signal line 120 , and therefore, the non-display area 110 b is also referred to as an overlapping area.

[0050] The surface of the photoresist layer 310 facing away from the cathode signal line 120 is called the first surface 311. The side surface of the photoresist layer 310 adjacent to the display area 110a is called the first side surface 312. The first side surface 312 is connected to the first surface 311 by bending.

[0051] In this embodiment, the photoresist layer 310 further includes a second side surface 313. The second side surface 313 is a side surface of the photoresist layer 310 that is away from the display area 110a. The second side surface 313 is disposed opposite to the first side surface 312, and the second side surface 313 is connected to the first side surface 312 by bending.

[0052] In this embodiment, the photoresist layer 310 covers the surface of the cathode signal line 120 away from the carrier substrate 110. In addition, the photoresist layer 310 covers the side of the cathode signal line 120 adjacent to the display area 110a. Further, the photoresist layer 310 also covers the side of the cathode signal line 120 away from the display area 110a, so that the size of the remaining sacrificial layer residue 131 is smaller, and the remaining sacrificial layer residue 131 is further away from the display area 110a. This will be described in detail later.

[0053] It can be understood that in other embodiments, the photoresist layer 310 may only cover the surface of the cathode signal line 120 away from the carrier substrate 110, cover the side of the cathode signal line 120 close to the display area 110a, and avoid the side of the cathode signal line 120 away from the display area 110a.

[0054] In this embodiment, the first side surface 312 of the photoresist layer 310 is spaced apart from the display area 110 a by a gap 110 c , so that a photoresist stripping liquid capable of removing the photoresist layer 310 can be dropped into the photoresist layer 310 when the photoresist layer 310 is subsequently removed.

[0055] Please also read Figure 1 , Figure 2 and Figure 3 , Figure 3 An implementation method Figure 1 Schematic diagram of the process included in S120. Figure 2 In (b), the display area 110a of the carrier substrate 110 further has a second functional film layer 160. S120, forming a photoresist layer 310 covering the cathode signal line 120, including: S121. S121 is described in detail as follows.

[0056] S121 , forming a photoresist layer 310 covering the cathode signal line 120 , wherein a surface of the photoresist layer 310 facing away from the carrier substrate 110 protrudes beyond a surface of the second functional film layer 160 facing away from the carrier substrate 110 .

[0057] S130, forming a sacrificial layer 130, wherein the sacrificial layer 130 covers the first surface 311 of the photoresist layer 310 and avoids at least a portion of the first side surface 312, and the sacrificial layer 130 is connected to the surface of the carrier substrate 110 away from the display area 110a. For the corresponding structure, please refer to Figure 2 (c) in .

[0058] The sacrificial layer 130 may be formed by, but is not limited to, chemical vapor deposition (CVD) and photolithography.

[0059] The material of the sacrificial layer 130 may be, but is not limited to, at least one of silicon nitride (SiNx) and silicon oxide (SiOx), and the thickness of the sacrificial layer 130 is 0.1 μm to 3 μm.

[0060] Generally speaking, the material of the sacrificial layer 130 may be but is not limited to at least one of silicon nitride (SiNx) and silicon oxide (SiOx). Therefore, the sacrificial layer 130 is relatively brittle and has poor ductility, and is easy to be disconnected and removed in subsequent processes.

[0061] The thickness of the sacrificial layer 130 may be, but is not limited to, 0.1 μm, 0.5 μm, 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm, or 3 μm.

[0062] When the thickness of the sacrificial layer 130 is small, the sacrificial layer 130 is not easy to be formed; when the thickness of the sacrificial layer 130 is large, the sacrificial layer 130 is relatively strong and not easy to be broken in subsequent processes. In the preparation method of the OLED display screen 1 provided in the embodiment of the present application, the thickness of the sacrificial layer 130 is 0.1 μm to 3 μm, which can facilitate the formation of the sacrificial layer 130 on the one hand, and make the sacrificial layer 130 easy to be broken in subsequent processes on the other hand.

[0063] The sacrificial layer 130 partially covers the first surface 311 of the photoresist layer 310. The sacrificial layer 130 avoids at least a portion of the first side surface 312 of the photoresist layer 310, so that the photoresist layer 310 can be subsequently removed through the first side surface 312. In this embodiment, the sacrificial layer 130 is connected to a portion of the non-display area 110b of the carrier substrate 110 away from the display area 110a.

[0064] S140, removing the photoresist layer 310, so that a gap 110c is formed between the sacrificial layer 130 and the cathode signal line 120. For the corresponding structure, please refer to Figure 2 (d) in.

[0065] The method of removing the photoresist layer 310 may be, but is not limited to, passing a photoresist stripping liquid through the first side surface 312 of the photoresist layer 310 to dissolve the photoresist layer 310 .

[0066] After the photoresist layer 310 is removed, a gap 110 c is formed between the sacrificial layer 130 and the cathode signal line 120 . In other words, after the photoresist layer 310 is removed, a gap 110 c is formed between the sacrificial layer 130 and the cathode layer 150 .

[0067] As can be seen from the above description of the photoresist layer 310, the photoresist layer 310 covers the cathode signal line 120. Therefore, after the photoresist layer 310 is removed, the area between the sacrificial layer 130 and the cathode signal line 120 is the same as or slightly larger than the area of ​​the cathode signal line 120.

[0068] S150, forming a first functional film layer 140 in the display area 110a and the non-display area 110b, wherein the first functional film layer 140 in the non-display area 110b is disposed on the sacrificial layer 130. For the corresponding structure, please refer to Figure 2 (e) in .

[0069] The first functional film layer 140 refers to a film layer in the OLED light-emitting unit 10a that realizes the light-emitting function of the OLED light-emitting unit 10a except for the anode and the cathode. For example, the first functional film layer 140 can be, but is not limited to, one or more of a hole blocking layer, an electron transport layer, a light-emitting layer, a hole transport layer, and an electron blocking layer.

[0070] The first functional film layer 140 is usually formed by evaporation using an open mask. The first functional film layer 140 is evaporated onto the sacrificial layer 130 .

[0071] The first functional film layer 140 includes a portion (labeled as 141 ) located in the display area 110 a and a portion (labeled as 142 ) located in the non-display area 110 b .

[0072] S160 , removing the portion of the sacrificial layer 130 corresponding to the gap 110 c to expose the cathode signal line 120 .

[0073] The portion of the sacrificial layer 130 corresponding to the gap 110c is removed, and thus the first functional film layer 140 on the sacrificial layer 130 is also removed. S160 will be described in detail later.

[0074] In this embodiment, the portion of the sacrificial layer 130 corresponding to the gap 110 c is removed, and the portion of the sacrificial layer 130 located on the side of the cathode signal line 120 away from the display area 110 a is left to form a sacrificial layer residual portion 131 .

[0075] See also Figure 4 , Figure 4 A schematic diagram of the process included in S160 in 1 is provided as an embodiment. The removing of the portion of the sacrificial layer 130 corresponding to the gap 110c to expose the cathode signal line 120 includes: S161 and S162. S161 and S162 are described in detail as follows.

[0076] S161 , providing an auxiliary workpiece 320 , wherein the auxiliary workpiece 320 includes an auxiliary substrate 321 and an adhesive member 322 carried on the auxiliary substrate 321 .

[0077] The adhesive member 322 in the auxiliary workpiece 320 is also referred to as an adhesive material. The auxiliary substrate 321 has a carrying surface 3211. The adhesive member 322 may cover the entire carrying surface 3211 of the carrying substrate 110, or a portion of the carrying surface 3211.

[0078] S162, attach the adhesive member 322 in the auxiliary workpiece 320 to the first functional film layer 140, and disconnect the sacrificial layer 130 and the first functional film layer 140 corresponding to the gap 110c through the auxiliary workpiece 320, and leave the sacrificial layer 130 located on the side of the cathode signal line 120 away from the display area 110a to form a sacrificial layer residual portion 131. For the corresponding structural diagram, please refer to Figure 2 (f) and Figure 2 (g) in.

[0079] When the auxiliary workpiece 320 is used to remove the portion of the sacrificial layer 130 corresponding to the gap 110c, the adhesive member 322 in the auxiliary workpiece 320 and the first functional film layer 140 can be separated, so that the portion of the sacrificial layer 130 corresponding to the gap 110c is pressed or torn off by the auxiliary workpiece 320. The portion of the sacrificial layer 130 corresponding to the gap 110c is also referred to as the weak connection portion of the sacrificial layer 130. The portion of the sacrificial layer 130 corresponding to the gap 110c is pressed or torn off by the auxiliary workpiece 320, that is, the weak connection portion of the sacrificial layer 130 is pressed or torn off by the auxiliary workpiece 320.

[0080] In one embodiment, since the surface of the photoresist layer 310 away from the carrier substrate 110 protrudes from the surface of the second functional film layer 160 away from the carrier substrate 110, when the sacrificial layer 130 is disposed on the photoresist layer 310, the surface of the sacrificial layer 130 away from the carrier substrate 110 protrudes from the second functional film layer 160 of the carrier substrate 110 located in the display area 110a. After the first functional film layer 140 is formed, part of the first functional film layer 140 is located on the sacrificial layer 130, and part of the first functional film layer 140 is located in the second functional film layer 160 of the display area 110a away from the surface of the carrier substrate 110. As can be seen from the above description, the surface of the sacrificial layer 130 facing away from the carrier substrate 110 protrudes from the second functional film layer 160 of the carrier substrate 110 located in the display area 110a. Therefore, after the first functional film layer 140 is formed, the portion of the first functional film layer 140 located in the sacrificial layer 130 also protrudes from the portion of the first functional film layer 140 located in the second functional film layer 160. Therefore, when the sacrificial layer 130 is removed by using the auxiliary workpiece 320, the sacrificial layer 130 and the first functional film layer 140 located on the sacrificial layer 130 are located at the highest point of the carrier substrate 110. The adhesive member 322 on the auxiliary workpiece 320 contacts the first functional film layer 140 located in the sacrificial layer 130, and the distance between the adhesive member 322 on the auxiliary workpiece 320 and the portion of the first functional film layer 140 on the carrier substrate 110 located in the display area 110a is large, and the first functional film layer 140 in the display area 110a of the carrier substrate 110 will not be contacted. Thus, the influence of the adhesive member 322 on the first functional film layer 140 in the display area 110 a of the carrier substrate 110 is reduced or even avoided.

[0081] After S162, please refer to the corresponding structure Figure 2 When the portion of the sacrificial layer 130 corresponding to the gap 110c is removed, the portion of the sacrificial layer 130 located on the side of the cathode signal line 120 away from the display area 110a is left to form a sacrificial layer residual portion 131, the sacrificial layer residual portion 131 is located on the side of the cathode signal line 120 away from the display area 110a.

[0082] S170, forming a cathode layer 150, wherein the cathode layer 150 covers and is electrically connected to the cathode signal line 120. For the corresponding structure, please refer to Figure 2 (h) in.

[0083] The cathode layer 150 may be formed by, but is not limited to, evaporation. Since the cathode signal line 120 is exposed after S160 , the cathode layer 150 directly covers and is electrically connected to the cathode signal line 120 .

[0084] Specifically, a portion of the cathode layer 150 is located in the display area 110 a , and another portion of the cathode layer 150 directly contacts the surface of the cathode signal line 120 away from the carrier substrate 110 , so as to be electrically connected to the cathode signal line 120 .

[0085] Since the other part of the cathode layer 150 directly contacts the surface of the cathode signal line 120 away from the carrier substrate 110 to be electrically connected to the cathode signal line 120, there is no first functional film layer 140 between the cathode layer 150 and the cathode signal line 120. Therefore, the resistance between the cathode layer 150 and the cathode signal line 120 is small, so that the cathode layer 150 can be better electrically connected to the cathode signal line 120, so that the OLED display screen 1 has lower power consumption.

[0086] In addition, when the portion of the sacrificial layer 130 corresponding to the gap 110c is removed, the portion of the sacrificial layer 130 located on the side of the cathode signal line 120 away from the display area 110a is left to form a sacrificial layer residual portion 131, the sacrificial layer residual portion 131 is located on the side of the cathode signal line 120 away from the display area 110a, so the sacrificial layer residual portion 131 has no or almost no effect on the electrical connection between the cathode layer 150 and the cathode signal line 120. If the sacrificial layer residual portion 131 is located on the side of the cathode signal line 120 close to the display area 110a, the existence of the sacrificial layer residual portion 131 may cause a break between the cathode layer 150 and the cathode signal line 120.

[0087] The cathode layer 150 may be, but is not limited to, three layers of sub-conductive layers stacked in layers. In one embodiment, the three layers of sub-conductive layers, from the direction close to the carrier substrate 110 to the direction away from the carrier substrate 110, are an indium tin oxide layer, a silver layer, and an indium tin oxide layer.

[0088] In summary, the method for preparing the OLED display screen 1 provided in the embodiment of the present application forms a photoresist layer 310 covering the cathode signal line 120; and forms a sacrificial layer 130 covering the first surface 311 of the photoresist layer 310 and avoiding the first side surface 312 of the photoresist layer 310; after the photoresist layer 310 is removed, the sacrificial layer 130 and the cathode signal line 120 form a gap 110c; when forming the first functional film layer 140, the first functional film layer 140 located in the non-display area 110b is set on the sacrificial layer 130; after the portion of the sacrificial layer 130 corresponding to the gap 110c is removed, the portion of the first functional film layer 140 located on the sacrificial layer 130 is also removed; therefore, the cathode layer 150 can be directly connected to the cathode signal line 120. There is no first functional film layer 140 between the cathode layer 150 and the cathode signal line 120, so the resistance between the cathode layer 150 and the cathode signal line 120 is small, so that the cathode layer 150 can be better electrically connected to the cathode signal line 120, so that the OLED display screen 1 has lower power consumption.

[0089] See also Figure 5 , Figure 5 A schematic flow chart of a method for preparing an OLED display screen provided in one embodiment of the present application. The method for preparing the OLED display screen 1 includes S110, S120, S130, S140, S150, S160, S170 and S180. Among them, S160 includes S161 and S162. S110, S120, S130, S140, S150, S160 and S170; S161 and S162 refer to the previous description and will not be repeated here. S180 is described in detail as follows.

[0090] S180 , forming a packaging layer 170 , wherein the packaging layer 170 is used to package the cathode layer 150 and the sacrificial layer residual portion 131 .

[0091] The encapsulation layer 170 encapsulates the cathode layer 150 and the sacrificial layer residue 131 to protect the cathode layer 150 , and can reduce or even avoid the influence of the sacrificial layer residue 131 on other components in the OLED display screen 1 .

[0092] See also Figure 6 and Figure 7 , Figure 6 for Figure 5 A schematic diagram of the process included in S180 in the method for preparing an OLED display screen shown in ; Figure 7The schematic diagram of the structure after S183 is shown. S180, forming the encapsulation layer 170, the encapsulation layer 170 is used to encapsulate the cathode layer 150, including S181, S182 and S183. S181, S182 and S183 are described in detail as follows.

[0093] S181 , providing a first inorganic layer 171 , wherein the first inorganic layer 171 covers the cathode layer 150 and the sacrificial layer residual portion 131 .

[0094] The first inorganic layer 171 may be, but is not limited to, at least one of silicon nitride (SiNx) and silicon oxide (SiO). In this embodiment, the first inorganic layer 171 may be silicon nitride (SiNx).

[0095] S182 , providing an organic layer 172 , wherein the organic layer 172 covers a surface of the first inorganic layer 171 facing away from the carrier substrate 110 .

[0096] The organic layer 172 may be, but is not limited to, organic siloxane or polyimide. The organic layer 172 covers the surface of the first inorganic layer 171 away from the carrier substrate 110. The thickness of the organic layer 172 may be, but is not limited to, 4 μm to 8 μm, so as to effectively cover the sacrificial layer residue 131. For example, the thickness of the organic layer 172 may be 6 μm. In this embodiment, the surface of the organic layer 172 away from the first inorganic layer 171 is a plane. The organic layer 172 is used to planarize the various film layers on the carrier substrate 110.

[0097] S183 , providing a second inorganic layer 173 , wherein the second inorganic layer 173 covers the organic layer 172 and is away from the first inorganic layer 171 .

[0098] The second inorganic layer 173 may be, but is not limited to, at least one of silicon nitride (SiNx) and silicon oxide (SiO). In this embodiment, the second inorganic layer 173 may be silicon nitride (SiNx).

[0099] The embodiment of the present application also provides an OLED display screen 1. The OLED display screen 1 can be prepared by the preparation method of the OLED display screen 1 provided in any of the previous embodiments. Accordingly, the preparation method of the OLED display screen 1 provided in the previous embodiments can prepare the OLED display screen 1 provided in the embodiment of the present application.

[0100] See also Figure 8 , Figure 8A schematic diagram of the structure of an OLED display screen provided in one embodiment of the present application. The OLED display screen 1 includes a plurality of OLED light-emitting units 10a. The OLED display screen 1 includes a carrier substrate 110, a cathode signal line 120, a first functional film layer 140, and a cathode layer 150. The carrier substrate 110 includes a display area 110a and a non-display area 110b. The cathode signal line 120 is disposed in the non-display area 110b. The first functional film layer 140 is located in the display area 110a and avoids the cathode signal line 120, wherein the OLED light-emitting unit 10a includes the first functional film layer 140. The cathode layer 150 covers and is electrically connected to the cathode signal line 120.

[0101] The carrier substrate 110 may be, but is not limited to, a transparent substrate such as glass or plastic. The display area 110a of the carrier substrate 110 is an area in the OLED display screen 1 for display. The non-display area 110b is an area in the OLED display screen 1 that is not for display. The non-display area 110b is usually used to lay out conductive traces, which are electrically connected to each transmission line in the display area 110a to transmit the signal of the transmission line to the chip or circuit board in the OLED display screen 1; or transmit the signal from the chip or circuit board to the display area 110a of the OLED display screen 1.

[0102] The non-display area 110b is located at least partially around the display area 110a. In this embodiment, the non-display area 110b is located on the left side of the display area 110a. It is understandable that this should not be construed as a limitation on the carrier substrate 110 provided in the embodiment of the present application.

[0103] The cathode signal line 120 may be made of, but not limited to, metal. Therefore, the cathode signal line 120 is also called a cathode signal metal line or cathode metal line. The cathode signal line 120 may be made of, but not limited to, aluminum, silver, gold, copper, or an alloy of gold and copper.

[0104] In this embodiment, there is a bottom film layer 12a between the carrier substrate 110 and the cathode signal line 120. The bottom film layer 12a can be a single but not limited to an insulating layer, or a flat layer, etc. In other embodiments, the cathode signal line 120 can be directly disposed on the carrier substrate 110. The embodiment of the present application does not limit whether there is a bottom film layer 12a between the cathode signal line 120 and the carrier substrate 110.

[0105] The first functional film layer 140 refers to a film layer in the OLED light-emitting unit 10a that realizes the light-emitting function of the OLED light-emitting unit 10a except for the anode and the cathode. For example, the first functional film layer 140 can be, but is not limited to, one or more of a hole blocking layer, an electron transport layer, a light-emitting layer, a hole transport layer, and an electron blocking layer.

[0106] The first functional film layer 140 is usually formed by evaporation using an open mask.

[0107] The cathode layer 150 may be formed by, but is not limited to, evaporation. The cathode layer 150 may be formed by, but is not limited to, three layers of sub-conductive layers stacked in layers. In one embodiment, the three layers of sub-conductive layers are, from the direction close to the carrier substrate 110 to the direction away from the carrier substrate 110, an indium tin oxide layer, a silver layer, and an indium tin oxide layer. The cathode layer 150 may be directly connected to the cathode signal line 120. There is no first functional film layer 140 between the cathode layer 150 and the cathode signal line 120, so the resistance between the cathode layer 150 and the cathode signal line 120 is small, so that the cathode layer 150 can be better electrically connected to the cathode signal line 120, so that the OLED display screen 1 has a smaller power consumption.

[0108] For further information, see Figure 8 In one embodiment, the OLED display screen 1 further includes a sacrificial layer residual portion 131. The sacrificial layer residual portion 131 is located at a side of the cathode signal line 120 away from the display area 110a.

[0109] It can be seen from the above-mentioned method for preparing the OLED display screen 1 that the finally prepared OLED display screen 1 includes a sacrificial layer residue 131. The sacrificial layer residue 131 is located on the side of the cathode signal line 120 away from the display area 110a, so the sacrificial layer residue 131 has no or almost no effect on the electrical connection between the cathode layer 150 and the cathode signal line 120. If the sacrificial layer residue 131 is located on the side of the cathode signal line 120 close to the display area 110a, the existence of the sacrificial layer residue 131 may cause a break between the cathode layer 150 and the cathode signal line 120.

[0110] Furthermore, in one embodiment, the sacrificial layer 130 includes at least one of silicon nitride and silicon oxide, and the thickness of the sacrificial layer residual portion 131 is 0.1 μm to 3 μm.

[0111] The thickness of the sacrificial layer residual portion 131 may be, but is not limited to, 0.1 μm, 0.5 μm, 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm, or 3 μm.

[0112] It can be seen from the above-mentioned method for preparing the OLED display screen 1 that the thickness of the sacrificial layer residue 131 is consistent with the thickness of the sacrificial layer 130. When the thickness of the sacrificial layer 130 is small, the sacrificial layer 130 is not easy to be formed; when the thickness of the sacrificial layer 130 is large, the sacrificial layer 130 is relatively strong and not easy to be disconnected in subsequent processes. In the method for preparing the OLED display screen 1 provided in the embodiment of the present application, the thickness of the sacrificial layer 130 is 0.1μm to 3μm, which can facilitate the formation of the sacrificial layer 130 on the one hand, and make the sacrificial layer 130 easy to be disconnected in subsequent processes on the other hand.

[0113] For further information, see Fig. 9 , Fig. 9 A schematic diagram of the structure of an OLED display screen provided in another embodiment of the present application. In one embodiment, the OLED display screen 1 further includes an encapsulation layer 170. The encapsulation layer 170 is disposed on a side of the cathode signal line 120 away from the carrier substrate 110 and the sacrificial layer residual portion 131.

[0114] The encapsulation layer 170 encapsulates the cathode layer 150 and the sacrificial layer residue 131 to protect the cathode layer 150 , and can reduce or even avoid the influence of the sacrificial layer residue 131 on other components in the OLED display screen 1 .

[0115] In one embodiment, the encapsulation layer 170 includes a first inorganic layer 171, an organic layer 172, and a second inorganic layer 173. The first inorganic layer 171 covers the cathode layer 150 and the sacrificial layer residue 131. The organic layer 172 covers the surface of the first inorganic layer 171 away from the carrier substrate 110. The second inorganic layer 173 covers the surface of the organic layer 172 away from the first inorganic layer 171.

[0116] The first inorganic layer 171 may be, but is not limited to, at least one of silicon nitride (SiNx) and silicon oxide (SiO). In this embodiment, the first inorganic layer 171 may be silicon nitride (SiNx).

[0117] The organic layer 172 covers the surface of the first inorganic layer 171 away from the carrier substrate 110. The organic layer 172 may be, but is not limited to, organic siloxane or polyimide. The organic layer 172 covers the surface of the first inorganic layer 171 away from the carrier substrate 110. The thickness of the organic layer 172 may be, but is not limited to, 4 μm to 8 μm, so as to effectively cover the sacrificial layer residue 131. For example, the thickness of the organic layer 172 may be 6 μm. In this embodiment, the surface of the organic layer 172 away from the first inorganic layer 171 is a plane. The organic layer 172 is used to planarize the various film layers on the carrier substrate 110.

[0118] The second inorganic layer 173 may be, but is not limited to, at least one of silicon nitride (SiNx) and silicon oxide (SiO). In this embodiment, the second inorganic layer 173 may be silicon nitride (SiNx).

[0119] On the one hand, the structure of the encapsulation layer 170 can make the encapsulation layer 170 stronger to protect the cathode layer 150 ; on the other hand, the encapsulation layer 170 can flatten the sacrificial layer residue 131 , thereby reducing or even avoiding the influence of the sacrificial layer residue 131 on other components in the OLED display 1 .

[0120] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application, and these improvements and modifications are also regarded as the scope of protection of the present application.

Claims

1. A method for preparing an OLED display screen, characterized in that: The method for preparing the OLED display screen comprises: Providing a carrier substrate, the carrier substrate comprising a display area and a non-display area, the non-display area being provided with a cathode signal line; forming a photoresist layer covering the cathode signal line, wherein the photoresist layer has a first surface away from the cathode signal line and a first side surface adjacent to the display area; forming a sacrificial layer, wherein the sacrificial layer covers the first surface of the photoresist layer and avoids at least a portion of the first side surface, and the sacrificial layer is connected to a surface of the carrier substrate away from the display area; removing the photoresist layer to form a gap between the sacrificial layer and the cathode signal line; forming a first functional film layer in the display area and the non-display area, wherein the first functional film layer in the non-display area is disposed on the sacrificial layer; removing a portion of the sacrificial layer corresponding to the gap to expose the cathode signal line; and A cathode layer is formed, the cathode layer covering and electrically connecting the cathode signal line.

2. The method for preparing an OLED display screen according to claim 1, wherein: The display area of ​​the carrier substrate also has a second functional film layer; forming a photoresist layer covering the cathode signal line, including: A photoresist layer covering the cathode signal line is formed, wherein a surface of the photoresist layer away from the carrier substrate protrudes beyond a surface of the second functional film layer away from the carrier substrate.

3. The method for preparing an OLED display screen according to claim 2, wherein: The step of removing a portion of the sacrificial layer corresponding to the gap to expose the cathode signal line comprises: Providing an auxiliary workpiece, wherein the auxiliary workpiece comprises an auxiliary substrate and an adhesive member carried on the auxiliary substrate; and The adhesive member in the auxiliary workpiece is attached to the first functional film layer, and the sacrificial layer and the first functional film layer corresponding to the gap are disconnected by the auxiliary workpiece, and the sacrificial layer portion located on the cathode signal line away from the display area is left to form a sacrificial layer residue.

4. The method for preparing an OLED display screen according to claim 3, wherein: The method for preparing the OLED display screen further includes: A packaging layer is formed, wherein the packaging layer is used to package the cathode layer and the remaining portion of the sacrificial layer.

5. The method for preparing an OLED display screen according to claim 4, wherein: The forming of the encapsulation layer, wherein the encapsulation layer is used to encapsulate the cathode layer, comprises: Providing a first inorganic layer, wherein the first inorganic layer covers the cathode layer and the remaining portion of the sacrificial layer; providing an organic layer, the organic layer covering a surface of the first inorganic layer facing away from the carrier substrate; and A second inorganic layer is provided, the second inorganic layer covering the organic layer facing away from the first inorganic layer.

6. An OLED display screen, characterized in that: The OLED display screen includes a plurality of OLED light-emitting units, and the OLED display screen includes: A carrier substrate, the carrier substrate comprising a display area and a non-display area; A cathode signal line, wherein the cathode signal line is arranged in the non-display area; A first functional film layer, the first functional film layer is located in the display area and avoids the cathode signal line, wherein the OLED light-emitting unit includes the first functional film layer; a cathode layer covering and electrically connected to the cathode signal line; and A sacrificial layer residual portion, wherein the sacrificial layer residual portion is located at a side of the cathode signal line away from the display area.

7. The OLED display screen according to claim 6, characterized in that: The sacrificial layer includes at least one of silicon nitride and silicon oxide, and the thickness of the remaining portion of the sacrificial layer is 0.1 μm to 3 μm.

8. The OLED display screen according to claim 6, wherein: The OLED display screen also includes: The packaging layer is arranged on a side of the cathode signal line away from the carrier substrate and on a residual portion of the sacrificial layer.

9. The OLED display screen according to claim 8, characterized in that: The encapsulation layer comprises: a first inorganic layer, the first inorganic layer covering the cathode layer and the remaining portion of the sacrificial layer; an organic layer, the organic layer covering a surface of the first inorganic layer facing away from the carrier substrate; and A second inorganic layer covers the organic layer and is away from the first inorganic layer.

Images