Light-emitting screen body and light-emitting device
By applying heat-degraded protective agent and setting a barrier structure on the auxiliary electrode surface of the OLED screen body, the problem of lead pad corrosion is solved, the storage time and reliability of the screen body are improved, and the stability of electrical conduction is ensured.
Patent Information
- Application Number
- CN202411352648.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2024-12-27
AI Technical Summary
The lead pad of the OLED screen is susceptible to water and oxygen erosion when exposed to the air for a long time, resulting in electrochemical reactions and corrosion, which leads to poor connection or failure of the screen.
Coating the auxiliary electrode surface with heat degradation properties to form a first protective layer, and a barrier structure is provided in the Bundestag area to limit the protective agent coating range, avoid corrosion, and degrading the protective agent by high temperature treatment when needed to ensure electrical conduction.
It effectively avoids corrosion of auxiliary electrodes, improves the storage time of the light-emitting screen, prevents poor connections and failures, and ensures the reliability of the screen.
Smart Images
Figure CN119212451A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of light-emitting semiconductor technology, and in particular to a light-emitting screen and a light-emitting device. Background Art
[0002] OLED (Organic Lighting Emitting Display) has the advantages of active light emission, wide color gamut, fast response, wide viewing angle, high contrast, and planarization. The structure of the OLED screen includes a substrate layer, a light-emitting functional layer, and a packaging layer. One end of the substrate layer extends from the packaging layer and forms a bonding area on its surface. The lead of the light-emitting functional layer extends from between the substrate layer and the packaging layer, and the lead pad is located in the bonding area. The lead pad is generally made of Al, Mo, Ti and other materials. If it is exposed to the air for a long time, it is corroded by water and oxygen in the air, and electrochemical reactions are likely to occur, resulting in corrosion, which will lead to poor connection of the screen or even failure of the screen. Summary of the invention
[0003] The purpose of the present application is to address the above problems and to provide a light-emitting screen and a light-emitting device that can increase the storage time of the light-emitting screen and avoid corrosion of the lead pad.
[0004] In a first aspect, the present application provides a light-emitting screen having a first bonding area thereon; the first bonding area is provided with an auxiliary electrode for electrical conduction; the surface of the auxiliary electrode is coated with a first protective layer formed by a protective agent, and the protective agent has the property of being degraded by heat.
[0005] According to the technical solutions provided in certain embodiments of the present application, the protective agent degrades when heated to a first temperature, and the first temperature is lower than the bonding temperature of the auxiliary electrode; preferably, the bonding temperature is at least 185°C.
[0006] According to the technical solutions provided in some embodiments of the present application, the first protective layer is formed by coating the liquid protective agent on the surface of the auxiliary electrode and then solidifying it.
[0007] According to the technical solutions provided in certain embodiments of the present application, the protective agent is a thioether compound, a thiol compound or an organic amine compound.
[0008] According to the technical solutions provided in some embodiments of the present application, the first bonding area is further provided with a blocking structure, and the blocking structure forms a limiting space on the surface of the auxiliary electrode to limit the coating range of the protective agent.
[0009] According to the technical solution provided in some embodiments of the present application, the blocking structure includes a coating portion; the coating portion coats the edges around the surface of the auxiliary electrode; preferably, the coating width of the coating portion is 2μm-100μm, and the coating height is 100nm-500nm.
[0010] According to the technical solution provided in certain embodiments of the present application, the blocking structure also includes a supporting portion; the supporting portion is formed by bending from the edge of the coating portion toward the side close to the first bonding area, and the supporting portion is arranged closely against the outer periphery of the auxiliary electrode; preferably, the coating portion and the supporting portion are made of different materials, and the coating portion uses a solidified protective agent.
[0011] According to the technical solutions provided in certain embodiments of the present application, the blocking structure is made of inorganic dielectric material. Preferably, the material of the blocking structure is silicon oxide or silicon nitride.
[0012] In a second aspect, the present application provides a light-emitting device, comprising the light-emitting screen as described above, and also comprising an FPC; a second bonding area is provided on the FPC corresponding to the first bonding area, and an electrode gold finger is provided on the second bonding area; when the first bonding area and the second bonding area are bonded, the first protective layer is degraded by heat, and the electrode gold finger is electrically connected to the auxiliary electrode.
[0013] According to the technical solution provided in certain embodiments of the present application, a functional area is also provided on the light-emitting screen, and a light-emitting functional layer electrically connected to the auxiliary electrode and a packaging cover plate that encapsulates the light-emitting functional layer are provided on the functional area. When the first bonding area and the second bonding area are bonded, a gap is formed between the packaging cover plate and the FPC; the gap is filled with the protective agent.
[0014] Compared with the prior art, the beneficial effects of the present application are as follows: the light-emitting screen provided by the present application has a first protective layer arranged on the surface of the auxiliary electrode on the first bonding area, and the protective agent forming the first protective layer has the property of being degraded by heat. When not bonded to the FPC, the protective agent can form a dense organic insulating film layer on the surface of the auxiliary electrode, and is bonded to the surface of the auxiliary electrode by a mating key, which can, to a certain extent, prevent the auxiliary electrode from being corroded by water and oxygen in the air and causing corrosion, thereby increasing the storage time of the light-emitting screen and effectively avoiding the occurrence of poor connection and failure of the screen. When it is necessary to bond to the FPC, the first protective layer can be heated by a certain high-temperature treatment method, so that the protective agent is degraded by heat to avoid affecting the electrical conduction between the light-emitting screen and the FPC.
[0015] It should be understood that the description of technical features, technical solutions, beneficial effects or similar language in this application does not imply that all features and advantages can be realized in any single embodiment. On the contrary, it is understood that the description of features or beneficial effects means that specific technical features, technical solutions or beneficial effects are included in at least one embodiment. Therefore, the description of technical features, technical solutions or beneficial effects in this specification does not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions and beneficial effects described in the present embodiment can also be combined in any appropriate manner. Those skilled in the art will understand that the embodiment can be realized without one or more specific technical features, technical solutions or beneficial effects of a specific embodiment. In other embodiments, additional technical features and beneficial effects can also be identified in a specific embodiment that does not embody all embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0017] Figure 1 A schematic diagram of a top view of the light-emitting screen (excluding the packaging cover plate) provided in an embodiment of the present application;
[0018] Figure 2 A schematic diagram of the side structure of the light-emitting screen (including the packaging cover plate) provided in an embodiment of the present application;
[0019] Figure 3 A schematic diagram of a partial top view of the first bonding area (including the blocking structure) of the light-emitting screen provided in an embodiment of the present application;
[0020] Figure 4 for Figure 3 AA section view;
[0021] Figure 5 A schematic diagram of the structure of the blocking structure of the light-emitting screen provided in an embodiment of the present application;
[0022] Figure 6 A schematic diagram of the structure of a light-emitting device provided in an embodiment of the present application.
[0023] The text annotations in the figure represent:
[0024] 11. Substrate; 12. Light-emitting functional layer; 13. Packaging cover; 14. Functional area; 15. First bonding area; 16. Auxiliary electrode; 17. First protective layer; 18. Blocking structure; 2. FPC; 3. Second protective layer. DETAILED DESCRIPTION
[0025] In order to enable those skilled in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings. The description in this section is only exemplary and explanatory and should not have any limiting effect on the protection scope of the present application. Specifically, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work should fall within the scope of protection of the present application.
[0026] It should be noted that similar reference numerals and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. 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 necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0027] The light-emitting screen is usually powered by an external power supply through an FPC (Flexible Printed Circuit Board). Before the light-emitting screen is bonded to the FPC, the lead pad (hereinafter referred to as the "auxiliary electrode") used for bonding to the FPC is directly exposed to the air. The lead pad is generally made of metal material, which is easily corroded by water and oxygen in the air and undergoes electrochemical reactions, that is, it is easy to cause corrosion of the lead pad, which can easily lead to poor connection of the light-emitting screen or even failure of the light-emitting screen.
[0028] Please refer to Figure 1 and Figure 2 This embodiment provides a light-emitting screen, on which a first bonding area 15 is provided. The first bonding area 15 is provided with an auxiliary electrode 16 for electrical conduction. The surface of the auxiliary electrode 16 is coated with a first protective layer 17 formed by a protective agent, and the protective agent has the property of being degraded by heat.
[0029] Specifically, the light-emitting screen can be an LCD screen, an LED screen, an OLED screen, etc. In this embodiment, the light-emitting screen is an OLED screen; the light-emitting screen includes a substrate 11, on which a functional area 14 and a first bonding area 15 are provided, and the functional area 14 is Figure 1In the middle triangular area, a light-emitting functional layer 12 is provided on the functional area 14, and the light-emitting functional layer 12 is encapsulated in the functional area 14 of the substrate 11 through the encapsulation cover plate 13, and the light-emitting functional layer 12 includes a plurality of light-emitting units; the first bonding area 15 is located on one side of the functional area 14, and a plurality of auxiliary electrodes 16 are provided on the first bonding area 15 on the side close to the functional area 14, and the plurality of auxiliary electrodes 16 are arranged in a row in sequence, and each auxiliary electrode 16 is electrically connected to the corresponding light-emitting unit through an electrode lead; the thickness of the auxiliary electrode 16 is 100nm to 1000nm, and the auxiliary electrode 16 can be a single-layer structure, such as a single-layer Al, Mo, Ti, Cu, Ag or ITO, or a double-layer structure, such as an Al-Mo double-layer structure or an Al-Ti double-layer structure, or a three-layer structure, such as a Mo-Al-Mo three-layer structure or a Ti-Al-Ti three-layer structure.
[0030] The surface of each auxiliary electrode 16 away from the substrate 11 is provided with a removable first protective layer 17. The first protective layer 17 is an organic insulating protective layer, which can isolate water and oxygen in the air. The first protective layer 17 is formed by a protective agent, which has the property of degrading and evaporating when heated. When the electrical conduction function needs to be realized, the first protective layer 17 needs to be removed. The removal method is simple and convenient. Specifically, a certain high-temperature treatment method can be adopted, such as a plasma treatment method, a hot pressing process in bonding, etc.
[0031] The light-emitting screen provided in this embodiment has a first protective layer 17 arranged on the surface of the auxiliary electrode 16 on the first bonding area 15, and the protective agent forming the first protective layer 17 has the property of being degraded and evaporated by heat. When it is not bonded to FPC2, the protective agent can form a dense organic insulating film layer on the surface of the auxiliary electrode 16. By bonding to the surface of the auxiliary electrode 16 with a matching key, the auxiliary electrode 16 can be prevented from being corroded by water and oxygen in the air, thereby increasing the storage time of the light-emitting screen and effectively avoiding the occurrence of poor connection and failure of the screen. When it is necessary to bond to FPC2, the first protective layer 17 can be heated by a certain high-temperature treatment method, so that the protective agent is degraded and evaporated by heat, thereby avoiding affecting the electrical conduction between the light-emitting screen and FPC2. It should be noted that the above technical solution is suitable for both glass-encapsulated screens and thin-film-encapsulated screens.
[0032] Preferably, the protective agent degrades when heated to a first temperature, and the first temperature is lower than the bonding temperature of the auxiliary electrode 16 .
[0033] Specifically, when the light-emitting screen is bonded to FPC2, a hot pressing process is usually used to bond the auxiliary electrode 16 of the light-emitting screen to the electrode gold finger of FPC2 through ACF (Anisotropic Conductive Film). The temperature of the hot pressing process is the bonding temperature, which is at least 185°C. The thermal degradation temperature of the protective agent is lower than the bonding temperature. The purpose of this setting is that before bonding, there is no need for an additional process step to remove the first protective layer 17. The heat generated by the hot pressing process during the bonding process can degrade the protective agent, which is convenient and quick. It should be noted that the value of the first temperature is above 85°C, and can be 90°C, 100°C, 110°C, 120°C, etc.
[0034] Preferably, the first protective layer 17 is formed by coating a liquid protective agent on the surface of the auxiliary electrode 16 and then curing it. Specifically, the coating method is not specifically limited, and it can be brushing or spraying. The protective agent can be cured by room temperature, heating, UV (Ultraviolet) irradiation, etc.
[0035] In this embodiment, the protective agent is preferably a platinum protective agent, which can be a sulfide compound, such as dithiothiomethane, dithiothiopropane, etc., which can form stable complexes with the surfaces of platinum, gold, and copper through the thiol group to provide protection; the protective agent can also be a thiol compound, such as mercaptoethanol, mercaptopropanol, etc., which can also form sulfur-metal bonds with the surfaces of platinum, gold, and copper to play a protective role; the protective agent can also be an organic amine compound, such as ethylenediamine and its derivatives, etc., the organic amine molecules in this type of compound can form stable complexes with the surfaces of platinum, gold, and copper through the amino group to provide a protective effect.
[0036] Preferably, reference Figure 3 and Figure 4 The first bonding area 15 is further provided with a blocking structure 18 , and the blocking structure 18 forms a limiting space on the surface of the auxiliary electrode 16 to limit the coating range of the protective agent.
[0037] Specifically, the material of the blocking structure 18 is silicon oxide or silicon nitride. The blocking structure 18 forms a rectangular limiting space on the surface of the auxiliary electrode 16. The setting of the limiting space facilitates the coating of the protective agent on the surface of the auxiliary electrode 16 and can prevent the protective agent from overflowing from the surface of the auxiliary electrode 16, making the process easier to implement.
[0038] Preferably, the blocking structure 18 includes a coating portion; the coating portion coats the edges around the surface of the auxiliary electrode 16; the coating width of the coating portion is 2μm-100μm, which can be 2μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, and the coating height is 100-500nm, which can be 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm.
[0039] Specifically, in this embodiment, the surface of the auxiliary electrode 16 is a rectangular structure, so there are four covering parts in total, and the four covering parts together enclose a rectangular confined space, and the covering parts can be directly deposited on the surface of the auxiliary electrode 16, or can only be in close contact with the surface of the auxiliary electrode 16 without a direct connection relationship, such as being supported by other components. Figure 5 The coating width l refers to the width of the coating portion, that is, the distance between the edge of the first protective layer 17 and the edge of the surface of the auxiliary electrode 16 ; the coating height h refers to the height of the coating portion, that is, the vertical distance between the upper surface of the coating portion and the upper surface of the auxiliary electrode 16 .
[0040] Preferably, the blocking structure 18 further includes a supporting portion, which is formed by bending from the edge of the covering portion toward the side close to the first bonding area 15 , and is disposed closely to the outer periphery of the auxiliary electrode 16 .
[0041] Specifically, in the present embodiment, since the auxiliary electrode 16 is electrically connected to the light-emitting unit through the electrode lead on one side close to the light-emitting functional layer 12, the auxiliary electrode 16 has three exposed side surfaces. Therefore, the coating portion close to the light-emitting functional layer 12 is directly deposited on the surface of the auxiliary electrode 16, and the remaining three coating portions respectively correspond to supporting portions. A corresponding group of coating portions and supporting portions together form an inverted "L"-shaped structure. The coating portion and the supporting portion are perpendicular to each other. The supporting portion is vertically arranged on the substrate 11, and specifically can be deposited on the first bonding area 15 of the substrate 11 by CVD (Chemical Vapor Deposition), and the side surface of the supporting portion is in close contact with the side surface of the auxiliary electrode 16. By adopting the above technical solution, it is possible to achieve stable support for the coating portion, and avoid exposing the side surface of the auxiliary electrode 16 to the air, so as to better protect the auxiliary electrode 16.
[0042] It should be noted that when bonding the light-emitting screen to the FPC 2 , the ACF glue will be filled in the limiting space formed by the blocking structure 18 to bond the auxiliary electrode 16 to the electrode gold finger.
[0043] Optionally, the coating part and the supporting part of the blocking structure 18 are made of different materials. The supporting part is made of silicon oxide or silicon nitride, and the coating part is made of a solidified protective agent. The blocking structure 18 is prefabricated first, and then the prefabricated blocking structure 18 is installed on the substrate 11. When the light-emitting screen is bonded to the FPC2, the coating part and the first protective layer 17 are degraded by heat. On the one hand, it is beneficial to the full fitting of the electrode gold finger and the auxiliary electrode 16, and on the other hand, it can also save the amount of ACF glue.
[0044] In order to verify the reliability of the light-emitting screen provided by the embodiment of the present invention, a test screen was made and a performance test was performed. The auxiliary electrode 16 of the test screen adopts an Al-Mo double-layer structure, wherein the thickness of the Al layer is 500nm, the thickness of the Mo layer is 50nm, the width of the auxiliary electrode 16 is 100μm, and the blocking structure 18 is made of silicon oxide as a whole, and the coating width of the auxiliary electrode 16 is 10μm, and the coating height is 300nm. The surface of the auxiliary electrode 16 is coated with a first protective layer 17 formed by a dithiothiomethane protective agent. In addition, a comparative screen was also made. The difference between the comparative screen and the test screen is that there is no blocking structure 18 and the first protective layer 17, and the auxiliary electrode 16 is completely exposed.
[0045] The above test screen and comparison screen were subjected to salt spray test. The specific method was as follows: first, ensure that the test chamber meets the following conditions: the temperature is stable at 35±5℃, the pressure is stable at 1.0±0.2mpa, and the pH value is stable at 6.5-7.2. The type and concentration of the spray solution in the test chamber are 5% sodium chloride solution; then the two screens were placed in the test chamber for a set time. In this test, the comparison screen was placed in the test chamber for 8 hours, and the test screen was placed in the test chamber for 24 hours. After the test, the appearance of the two screens was observed, and the test results were shown in Table 1.
[0046] Table 1
[0047] Screen type Appearance Salt spray test duration Comparison screen There is mass corrosion 8h Test screen No change 24h
[0048] It can be seen from Table 1 that, compared with the light-emitting screen in the prior art, the anti-oxidation performance of the light-emitting screen coated with the first protective layer provided by the present invention is greatly improved.
[0049] refer to Figure 6This embodiment also provides a light-emitting device, including the above-mentioned light-emitting screen and FPC2, a second bonding area is provided on the FPC2 corresponding to the first bonding area 15, and an electrode gold finger is provided on the second bonding area; when the first bonding area 15 and the second bonding area are bonded, the first protective layer 17 is degraded by heat, and the electrode gold finger is electrically connected to the auxiliary electrode 16; one end of the FPC2 away from the auxiliary electrode 16 is connected to an external power supply, which supplies power to the light-emitting unit through a conductive path formed by the electrode gold finger, the auxiliary electrode 16 and the electrode lead, so that the OLED screen works.
[0050] Specifically, in order to ensure the reliability of the entire light-emitting device, before bonding, that is, when the light-emitting screen and FPC2 are stored separately, a protective agent can be coated on the surface of the electrode gold finger of FPC2, so that the protective agent can be solidified on the surface of the electrode gold finger to form an insulating protective layer, thereby preventing the electrode gold finger from being corroded by water and oxygen in the air and causing corrosion, thereby increasing the storage time of FPC2 and thus improving the reliability of the entire OLED module.
[0051] Preferably, a functional area 14 is also provided on the light-emitting screen, and a light-emitting functional layer 12 electrically connected to the auxiliary electrode 16 and a packaging cover 13 that encapsulates the light-emitting functional layer 12 are provided on the functional area 14. When the first bonding area 15 and the second bonding area are bonded, a gap is formed between the packaging cover 13 and the FPC2; the gap is filled with a protective agent.
[0052] Specifically, after the light-emitting screen and FPC2 are bonded, a gap is likely to exist between the end faces of the packaging cover plate 13 and FPC2 that are close to each other, which will cause part of the auxiliary electrode 16 to be exposed and easily corroded by water and oxygen in the air. To avoid this phenomenon, after the light-emitting screen and FPC2 are bonded, a protective agent is applied to the gap between the packaging cover plate 13 and FPC2. After the protective agent is cured, a second protective layer 3 is formed to ensure the reliability of the entire light-emitting device.
[0053] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.
Claims
1. A light-emitting screen, characterized in that: The light-emitting screen is provided with a first bonding area; the first bonding area is provided with an auxiliary electrode for electrical conduction; the surface of the auxiliary electrode is coated with a first protective layer formed by a protective agent, and the protective agent has the property of being degraded by heat.
2. The light-emitting screen according to claim 1, characterized in that: The protective agent degrades when heated to a first temperature, and the first temperature is lower than the bonding temperature of the auxiliary electrode; preferably, the bonding temperature is at least 185°C.
3. The light-emitting screen according to claim 2, characterized in that: The first protective layer is formed by coating the liquid protective agent on the surface of the auxiliary electrode and then solidifying it.
4. The light-emitting screen according to claim 3, characterized in that: The protective agent is a thioether compound, a thiol compound or an organic amine compound.
5. The light-emitting screen according to claim 3, characterized in that: The first bonding area is further provided with a blocking structure, and the blocking structure forms a limiting space on the surface of the auxiliary electrode to limit the coating range of the protective agent.
6. The light-emitting screen according to claim 5, characterized in that: The blocking structure includes a coating portion; the coating portion coats the edges around the surface of the auxiliary electrode; preferably, the coating width of the coating portion is 2 μm-100 μm, and the coating height is 100 nm-500 nm.
7. The light-emitting screen according to claim 6, characterized in that: The blocking structure also includes a supporting portion; the supporting portion is formed by bending from the edge of the coating portion toward the first bonding area, and the supporting portion is arranged close to the outer periphery of the auxiliary electrode; preferably, the coating portion and the supporting portion are made of different materials, and the coating portion uses a solidified protective agent.
8. The light-emitting screen according to claim 5, characterized in that: The blocking structure is made of inorganic dielectric material. Preferably, the material of the blocking structure is silicon oxide or silicon nitride.
9. A light emitting device, characterized in that: It includes the light-emitting screen body as described in any one of claims 1 to 8, and also includes an FPC; a second bonding area is provided on the FPC corresponding to the first bonding area, and an electrode gold finger is provided on the second bonding area; when the first bonding area and the second bonding area are bonded, the first protective layer is degraded by heat, and the electrode gold finger is electrically connected to the auxiliary electrode.
10. The light emitting device according to claim 9, characterized in that: The light-emitting screen is also provided with a functional area, on which is provided a light-emitting functional layer electrically connected to the auxiliary electrode and a packaging cover plate that encapsulates the light-emitting functional layer. When the first bonding area and the second bonding area are bonded, a gap is formed between the packaging cover plate and the FPC; the gap is filled with the protective agent.