A Micro OLED display structure and preparation method thereof

Abstract

A Micro OLED display structure and a preparation method thereof, belonging to the field of micro OLED display technology, the display structure comprises a circuit substrate and a multi-film layer structure covered thereon, the multi-film layer structure is formed by multiple mask plates covering the circuit substrate and sequentially vapor-deposited, a plurality of annular walls are arranged on the circuit substrate, an annular wall is arranged on both sides of the outer edge of the mask hole of each mask plate, and an annular groove for accommodating particles is formed between the two annular walls, the beneficial effect of the present invention is that the overall structure of the display structure is simple, the processing technology is simple, the particles at the edge of the mask plate in the vapor deposition process can be centrally stored, the particles are prevented from floating around in the vapor deposition process, and the reliability of the package, the quality of the product and the structural strength are improved.

Description

Technical Field

[0001] The present invention relates to the field of micro OLED display technology, and in particular to a Micro OLED display structure and a preparation method thereof. Background Art

[0002] Micro OLED (Organic Light Emitting Display) is a micro OLED display technology, which is mainly used in special military displays (gun scopes, individual combat helmet displays, pilot helmets, etc.) and civilian consumer electronics (AR, VR, micro projectors, aerial photography, etc.). Micro OLED has the advantages of small size, light weight, low power consumption, high contrast, and high resolution. It is expected to usher in explosive growth in the next few years.

[0003] In the process of Micro OLED, TFE (Thin Film Encapsulation) technology is needed, mainly to isolate water and oxygen and protect the luminescent material from corrosion. However, in the current industry, particles are easily generated at the edge of the mask during the evaporation process, and the particles fall onto the substrate. During the evaporation process and the back-end process, the particles may float around. The presence of particles will pierce the encapsulation film layer, providing a path for water and oxygen to invade, reducing the reliability of the encapsulation. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a Micro OLED display structure. By appropriately adjusting the preparation process and adjusting the structure of the circuit substrate, particles at the edge of the mask plate in the evaporation process can be centrally stored, which can prevent particles from floating around in the evaporation process and improve the reliability of packaging.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention to solve its technical problem is: the Micro OLED display structure includes a circuit substrate and a multi-film layer structure covered thereon, the multi-film layer structure is formed by multiple mask plates covering the circuit substrate and sequentially evaporated, the circuit substrate is provided with multiple annular walls, and one annular wall is respectively provided on both sides of the outer edge of the mask hole of each mask plate, and an annular groove for accommodating particles is formed between the two annular walls.

[0006] Furthermore, the distances between the two annular walls and the outer edge of the mask hole are equal, and the distance between the two annular walls is set to 10-100 μm.

[0007] Furthermore, the cross-sectional shape of the annular enclosure is set to be a trapezoid that is narrow at the top and wide at the bottom, the height of the annular enclosure is set to 0.5-2 μm, the top width of the annular enclosure is set to 5-40 μm, and the bottom width of the annular enclosure is set to 15-50 μm.

[0008] Furthermore, the annular wall is fixed on the circuit substrate by coating, exposure, development, etching, inkjet printing or dispensing of metal, inorganic or organic materials.

[0009] Furthermore, the multi-layer structure includes an organic light-emitting layer, a cathode metal layer, a light extraction layer and a packaging layer which are sequentially covered on a circuit substrate, and the organic light-emitting layer, the cathode metal layer, the light extraction layer and the packaging layer are each covered by a mask plate and vapor-deposited on the circuit substrate, and the annular wall is arranged on both sides of the intersections of the organic light-emitting layer and the cathode metal layer, the cathode metal layer and the light extraction layer, and the light extraction layer and the packaging layer along the circumferential direction.

[0010] Furthermore, a plurality of anode metal layers and pixel definition layers are also arranged on the circuit substrate, a sub-pixel pit is formed between two pixel definition layers, and the anode metal layer is arranged at the bottom of the sub-pixel pit.

[0011] Furthermore, the anode metal layer and the pixel definition layer are covered with the organic light emitting layer.

[0012] Furthermore, the film layer of the encapsulation layer is formed by a combination of one or more of Al2O3, TiO2, ATO, SiN, SiON, SiO, acrylic-based organic matter, and epoxy resin-based organic matter.

[0013] A method for preparing the Micro OLED display structure comprises the following steps:

[0014] 1) preparing a driving circuit on a silicon substrate to form the circuit substrate;

[0015] 2) preparing an anode metal layer and a pixel definition layer on the circuit substrate, and preparing two annular walls at the edge of the circuit substrate where the mask plate is placed;

[0016] 3) placing the corresponding mask plates on the circuit substrate in sequence, so that the outer edges of the mask plates are clamped in the two annular walls, and sequentially evaporating and preparing the organic light-emitting layer, the cathode metal layer and the light extraction layer;

[0017] 4) Prepare the encapsulation layer outside the light extraction layer to complete the subsequent yellow light and module processes.

[0018] The beneficial effects of the present invention are:

[0019] 1. The present invention arranges two annular walls at the outer edge of the mask plate placed on the circuit substrate, so that an annular groove is formed between the two annular walls, so that particles at the edge of the mask plate in the evaporation process can be stored in a centralized manner, thereby preventing particles from scattering everywhere, reducing the risk of particles piercing a multi-layer structure, improving the reliability of packaging, improving the quality of the product, and improving the strength of the entire display structure.

[0020] 2. The present invention can prepare the anode metal layer, the pixel definition layer and the annular wall at the same time without affecting the processing efficiency of the entire display structure; when a multi-layer structure is prepared by vapor deposition on a circuit substrate, the two annular walls arranged in pairs can be snap-fitted and positioned with the outer edge of the mask plate, making the positioning of the mask plate more stable and reducing the defective rate caused by the movement of the mask plate during the vapor deposition process.

[0021] 3. The present invention sets the cross section of the annular wall to be trapezoidal, which plays a role in guiding particles, and increases the space between the two annular walls, providing a space for accommodating more particles, further preventing particles from scattering.

[0022] In summary, the display structure has a simple overall structure and a simple processing technology. It can centrally store particles at the edge of the mask plate in the evaporation process, prevent particles from floating around in the evaporation process, and improve the reliability of packaging, product quality and structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0024] Figure 1 A top view of the present invention;

[0025] Figure 2 for Figure 1 AA section view;

[0026] The markings in the above figures are: 1. circuit substrate, 2. annular wall, 3. annular groove, 4. organic light-emitting layer, 5. cathode metal layer, 6. light extraction layer, 7. encapsulation layer, 8. anode metal layer, 9. pixel definition layer. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0028] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The specific implementation scheme of the present invention is: Figure 1 and Figure 2 As shown, a Micro OLED display structure includes a circuit substrate 1 and a multi-film layer structure covered thereon, wherein the multi-film layer structure is formed by sequentially vapor-depositing a plurality of mask plates covering the circuit substrate 1, wherein a plurality of annular walls 2 are arranged on the circuit substrate 1, and an annular wall 2 is arranged on both sides of the outer edge of the mask hole of each mask plate, and an annular groove 3 for accommodating particles is formed between the two annular walls 2, thereby preventing particles from scattering around, reducing the risk of particles piercing the multi-film layer structure, improving the reliability of packaging, improving the quality of the product, and improving the strength of the entire display structure.

[0031] Specifically, the distances between the two annular walls 2 and the outer edge of the mask hole are equal, and the distance between the two annular walls 2 is set to 10-100 μm, which can effectively accommodate particles on the edge of the mask plate between the two annular walls 2, providing space for more particles.

[0032] Specifically, the cross-sectional shape of the annular wall 2 is set to a trapezoid that is narrow at the top and wide at the bottom, the height of the annular wall 2 is set to 0.5-2 μm, the top width of the annular wall 2 is set to 5-40 μm, and the bottom width of the annular wall 2 is set to 15-50 μm. The annular wall 2 of this size can be more firmly fixed on the circuit substrate, and the inclined side of the annular wall 2 guides the particles, further preventing the particles from floating around, and increases the space between the two annular walls 2, providing accommodation space for more particles, further reducing the risk of particles piercing the multi-layer structure.

[0033] Specifically, the annular wall 2 can be made of metal, inorganic or organic material and fixed on the circuit substrate 1 by coating, exposure, development, etching, inkjet printing or dispensing.

[0034] Specifically, the multi-film layer structure includes an organic light-emitting layer 4, a cathode metal layer 5, a light extraction layer 6 and a packaging layer 7 which are sequentially covered on a circuit substrate 1. The organic light-emitting layer 4, the cathode metal layer 5, the light extraction layer 6 and the packaging layer 7 are each covered by a mask plate on the circuit substrate 1 and vapor-deposited to make the vapor deposition efficiency higher. Annular walls 2 are arranged on both sides of the intersections of the organic light-emitting layer 4 and the cathode metal layer 5, the cathode metal layer 5 and the light extraction layer 6, and the light extraction layer 6 and the packaging layer 7 along the circumferential direction, thereby improving the structural strength and stability of the multi-film layer structure.

[0035] In addition, a plurality of anode metal layers 8 and pixel definition layers 9 are provided on the circuit substrate 1, a sub-pixel pit is formed between two pixel definition layers 9, an anode metal layer 8 is provided at the bottom of the sub-pixel pit, and an organic light-emitting layer 4 is covered on the anode metal layer 8 and the pixel definition layer 9, so that holes in the anode metal layer 8 and electrons in the cathode metal layer 5 can be effectively transmitted, thereby ensuring that there are enough electrons and holes to recombine and emit light.

[0036] In addition, the film layer of the above-mentioned encapsulation layer 7 includes a combination of one or more of Al2O3, TiO2, ATO, SiN, SiON, SiO, acrylic-based materials, and epoxy resin-based organic materials, and is encapsulated by ALD (atomic layer deposition), PECVD (plasma enhanced chemical vapor deposition) or IJP (inkjet printing) and the like.

[0037] A method for preparing the above-mentioned Micro OLED display structure comprises the following steps:

[0038] 1) etching a driving circuit on a silicon substrate to form a circuit substrate 1;

[0039] 2) preparing an anode metal layer 8 and a pixel definition layer 9 on the circuit substrate 1, and simultaneously symmetrically preparing two annular walls 2 at the edge positions of the circuit substrate 1 where the mask plate is placed;

[0040] 3) placing a mask plate at the center of the circuit substrate 1 so that the outer edge of the mask plate is clamped in the two annular walls 2, vapor-depositing an organic light-emitting layer 4 in the mask hole of the mask plate at the center of the circuit substrate 1, taking out the mask plate at the center of the circuit substrate 1 and placing a corresponding mask plate at a corresponding position of the circuit substrate 1, and vapor-depositing a cathode metal layer 5 and a light extraction layer 6 in sequence;

[0041] 4) Outside the light extraction layer 6, a combination of one or more of Al2O3, TiO2, ATO, SiN, SiON, SiO, acrylic-based materials, and epoxy resin-based organic materials are encapsulated by ALD (atomic layer deposition), PECVD (plasma enhanced chemical vapor deposition) or IJP (inkjet printing) to prepare an encapsulation layer 7, and then subsequent yellow light and module processes including OC glue coating, cover plate bonding, and cutting are completed.

[0042] In summary, the display structure has a simple overall structure and a simple processing technology. It can centrally store particles at the edge of the mask plate in the evaporation process, prevent particles from floating around in the evaporation process, and improve the reliability of packaging, product quality and structural strength.

[0043] The above description is only used to illustrate some principles of the present invention. This specification is not intended to limit the present invention to the specific structure and application scope shown and described. Therefore, all corresponding modifications and equivalents that may be used belong to the patent scope applied for by the present invention.

Claims

1. A Micro OLED display structure, characterized in that: It comprises a circuit substrate (1) and a multi-layer structure covering it, wherein the multi-layer structure is formed by sequentially vapor-depositing a plurality of mask plates covering the circuit substrate (1), wherein a plurality of annular walls (2) are arranged on the circuit substrate (1), and an annular wall (2) is arranged on both sides of the outer edge of the mask hole of each mask plate, and an annular groove (3) for accommodating foreign matter is formed between the two annular walls (2); The multi-layer structure comprises an organic light-emitting layer (4), a cathode metal layer (5), a light extraction layer (6) and a packaging layer (7) which are sequentially covered on a circuit substrate (1); the organic light-emitting layer (4), the cathode metal layer (5), the light extraction layer (6) and the packaging layer (7) are each formed by vapor deposition on the circuit substrate (1) by covering the organic light-emitting layer (4), the cathode metal layer (5), the light extraction layer (6) and the packaging layer (7) with a mask plate; the annular enclosure (2) is provided on both sides of the intersections of the organic light-emitting layer (4) and the cathode metal layer (5), the cathode metal layer (5) and the light extraction layer (6), and the light extraction layer (6) and the packaging layer (7) along the peripheral direction; The circuit substrate (1) is also provided with a plurality of anode metal layers (8) and pixel definition layers (9); a sub-pixel pit is formed between two pixel definition layers (9); the anode metal layer (8) is provided at the bottom of the sub-pixel pit; the organic light-emitting layer (4) is covered on the anode metal layer (8) and the pixel definition layer (9); The film layer of the encapsulation layer (7) is formed by a combination of one or more of Al2O3, TiO2, ATO, SiN, SiON, SiO, acrylic-based organic matter, and epoxy resin-based organic matter.

2. The Micro OLED display structure according to claim 1, characterized in that: The distances between the two annular walls (2) and the outer edge of the mask hole are equal, and the distance between the two annular walls (2) is set to 10-100 um.

3. The Micro OLED display structure according to claim 1, characterized in that: The cross-sectional shape of the annular enclosure (2) is set to be a trapezoid that is narrow at the top and wide at the bottom, the height of the annular enclosure (2) is set to be 0.5-2 um, the top width of the annular enclosure (2) is set to be 5-40 um, and the bottom width of the annular enclosure (2) is set to be 15-50 um.

4. The Micro OLED display structure according to claim 1, characterized in that: The annular enclosure (2) is made of metal, inorganic or organic material and fixed on the circuit substrate (1) by coating, exposure, development, etching, inkjet printing or dispensing.

5. A method for preparing a Micro OLED display structure according to any one of claims 1 to 4, characterized in that: The following steps are involved: 1) preparing a driving circuit on a silicon substrate to form the circuit substrate (1); 2) preparing an anode metal layer (8) and a pixel definition layer (9) on the circuit substrate (1), and simultaneously preparing two annular walls (2) at the edge of the circuit substrate (1) where the mask plate is placed; 3) placing the corresponding mask plates on the circuit substrate (1) in sequence, so that the outer edges of the mask plates are locked in the two annular walls (2), and sequentially evaporating and preparing the organic light-emitting layer (4), the cathode metal layer (5) and the light extraction layer (6); 4) preparing the encapsulation layer (7) outside the light extraction layer (6) and completing the subsequent yellow light and module manufacturing process.

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