Quantum dot-based composite light conversion structures, their fabrication methods and applications

Abstract

The present application discloses a composite light conversion structure based on quantum dots, its manufacturing method and application. The composite light conversion structure includes a light-transmitting substrate, multiple light conversion structures, a light-blocking layer, an inorganic encapsulation layer, an organic encapsulation layer, etc. The multiple light conversion structures are arranged at intervals, and each light conversion structure includes a filter layer and a light conversion layer stacked in sequence on the surface of the light-transmitting substrate, and at least one light conversion layer contains quantum dots. The light-blocking layer includes a light-blocking structure for preventing light from being transmitted between adjacent light conversion structures. The inorganic encapsulation layer is continuously coated on the light conversion layer and the light-blocking layer. The organic encapsulation layer is continuously coated on the inorganic encapsulation layer. By using the scheme of the present application, the influence of factors such as water and oxygen on the working performance of the quantum dot integrated micro-LED full-color display device can be further reduced, its working quality can be guaranteed and improved, its service life can be extended, and the difficulty of its manufacturing process can be reduced.

Description

Technical Field

[0001] The present application relates to a light conversion structure applied to a semiconductor light-emitting device, and in particular to a quantum dot-based composite light conversion structure, a manufacturing method and application thereof, such as application in the preparation of a micro-LED display device. Background Art

[0002] Micro LED display technology refers to a display technology that uses self-luminous micro-nano-scale Micro LED or Mini LED as the light-emitting pixel unit, which is assembled on a driving panel to form a high-density LED array. Compared with LCD, OLED display technology, etc., it has obvious advantages in brightness, resolution, contrast, energy consumption, service life, response speed and thermal stability.

[0003] In the development of micro-LED display technology, the initial research work focused on the structure, manufacturing process, device characteristics, etc. of monochrome display devices such as red light, blue-green light and ultraviolet light. With the increasing demand for the application of micro-LED display devices, full-color micro-LED display technology has gradually become a research hotspot.

[0004] At present, the full-color micro-LED display technologies mainly include three-color integrated full-color micro-LED display technology, quantum dot integrated micro-LED full-color display technology, and three-color synthesis micro-LED projection full-color display technology. Among them, quantum dot integrated micro-LED full-color display technology is to prepare a color conversion layer with quantum dots with different wavelength conversion capabilities, so that the color conversion layer contains quantum dot pixel units of different colors, and then integrate it with a monochrome micro-LED chip array to obtain a full-color micro-LED display device. Compared with the other two solutions, this solution can not only make the full-color micro-LED display device have a high color gamut and high color purity, but also only requires monochrome micro-LED chips, such as blue light LED chips, without the need for massive transfer of other color micro-LED chips, which reduces costs, simplifies circuit design, and improves production efficiency.

[0005] However, quantum dot integrated micro-LED full-color display technology still has some defects. For example, the quantum dots in the color conversion layer are not heat-resistant and not resistant to water and oxygen, which can easily lead to problems such as a decrease in luminous intensity or even failure of the full-color micro-LED display device during application. In this regard, the solution proposed by the researchers is mainly to add a packaging structure in the color conversion layer to isolate water and oxygen. However, the existing color conversion layer packaging structure has poor protection effect on the edges, especially in subsequent processes that may involve cutting, and no matter which cutting process is used, it is likely to cause cracks on the edges, which makes it easy for water and oxygen to enter the device through these gaps, causing packaging failure. Summary of the invention

[0006] The main purpose of the present application is to provide a composite light conversion structure based on quantum dots, a manufacturing method and application thereof, so as to overcome the deficiencies in the prior art.

[0007] In order to achieve the aforementioned invention objectives, the technical solutions adopted in this application include:

[0008] One aspect of the present application provides a quantum dot-based composite light conversion structure, comprising:

[0009] A light-transmitting substrate having a first area on its surface;

[0010] A plurality of light conversion structures, wherein the plurality of light conversion structures are spaced apart and distributed on a first area on the surface of the light-transmitting substrate, each light conversion structure comprises a filter layer and a light conversion layer sequentially stacked on the surface of the light-transmitting substrate, and at least one light conversion layer comprises quantum dots for performing wavelength conversion on incident light passing through the filter layer;

[0011] The light blocking layer comprises a first light blocking structure, wherein the first light blocking structure is at least arranged between adjacent light conversion structures and is at least used to block a transmission path of light between adjacent light conversion structures;

[0012] A first inorganic encapsulation layer, which is continuously coated on at least the light conversion layer and the light blocking layer;

[0013] The organic encapsulation layer is at least continuously disposed on the first inorganic encapsulation layer.

[0014] Another aspect of the present application provides a method for manufacturing a composite light conversion structure based on quantum dots, which comprises:

[0015] Providing a light-transmitting substrate, wherein a surface of the light-transmitting substrate has a first area;

[0016] A plurality of filter layers are arranged at intervals on a first area on the surface of the light-transmitting substrate;

[0017] A first light-blocking structure is arranged on a first area on the surface of the light-transmitting substrate to form a light-blocking layer, wherein the first light-blocking structure is at least arranged between adjacent light conversion structures;

[0018] A light conversion layer is disposed on each filter layer to form a plurality of light conversion structures, wherein at least one light conversion layer includes quantum dots for converting the wavelength of incident light passing through the filter layer, and the first light blocking structure is capable of at least blocking the transmission path of light between adjacent light conversion structures;

[0019] A first inorganic encapsulation layer is continuously provided at least on the light conversion layer and the light blocking layer;

[0020] And, an organic encapsulation layer is continuously coated on at least the first inorganic encapsulation layer.

[0021] Another aspect of the present application provides an application of the quantum dot-based composite light conversion structure in the preparation of a micro LED display device.

[0022] Compared with the prior art, the technical solution of the present application has at least the following beneficial effects:

[0023] (1) The provided quantum dot-based composite light conversion structure has a simple structure, which can not only protect the surface of the quantum dots in the light conversion layer, reduce the influence of factors such as water, oxygen, and heat on the working performance of the composite light conversion structure, but also prevent the side packaging from failing due to subsequent processes.

[0024] (2) The provided quantum dot-based composite light conversion structure can ensure a sufficiently low reflectivity. Due to the existence of the second light blocking structure, when observed from the light-emitting surface, the second light blocking structure is also black, which can also reduce the reflectivity.

[0025] (3) The provided quantum dot-based composite light conversion structure has a simple manufacturing process, is compatible with the manufacturing process of existing micro-LED full-color display devices, and is conducive to large-scale implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0027] Figure 1 is a process flow chart of a composite light conversion structure based on quantum dots in Example 1;

[0028] Figure 2 is a process flow chart of a composite light conversion structure based on quantum dots in Example 2;

[0029] Figure 3 is a top view of a product in Example 2;

[0030] Figure 4 This is a process flow chart for manufacturing a quantum dot-based composite light conversion structure in Example 3. DETAILED DESCRIPTION

[0031] In view of the defects of the prior art, the present application proposes a composite light conversion structure based on quantum dots and a method for manufacturing the same, so as to further reduce the impact of factors such as water and oxygen on the working performance of the quantum dot integrated micro-LED full-color display device, ensure and improve its working quality, extend its service life, and reduce the difficulty of its manufacturing process.

[0032] Some embodiments of the present invention provide a quantum dot-based composite light conversion structure, comprising:

[0033] A light-transmitting substrate having a first area on its surface;

[0034] A plurality of light conversion structures, wherein the plurality of light conversion structures are spaced apart and distributed on a first region of the surface of the light-transmitting substrate, each light conversion structure comprises a filter layer and a light conversion layer sequentially stacked on the surface of the light-transmitting substrate, and at least one light conversion layer comprises quantum dots for performing wavelength conversion on incident light passing through the filter layer, for example, converting incident blue light into red light, green light, etc. before emitting the light;

[0035] The light blocking layer comprises a first light blocking structure, wherein the first light blocking structure is at least arranged between adjacent light conversion structures and is at least used to block a transmission path of light between adjacent light conversion structures;

[0036] A first inorganic encapsulation layer, which is continuously coated on at least the light conversion layer and the light blocking layer;

[0037] The organic encapsulation layer is at least continuously disposed on the first inorganic encapsulation layer.

[0038] In one embodiment, the orthographic projection of the filter layer in the light conversion structure on the surface of the transparent substrate covers the orthographic projection of the light conversion layer on the surface of the transparent substrate to prevent part of the incident light from being directly emitted without passing through the light conversion layer after passing through the filter layer, that is, to prevent direct leakage of the incident light.

[0039] In one embodiment, the sidewall of each light conversion structure is closely attached to the first light blocking structure to avoid reducing the protection effect of the light conversion structure due to a gap between the light conversion structure and the first light blocking structure.

[0040] In one embodiment, the surface of the light blocking layer is flush with or higher than the surface of the light conversion layer to better eliminate problems such as light crosstalk caused by light transmission between adjacent light conversion structures and avoid light leakage at the edges of the composite light conversion structure.

[0041] In one embodiment, the filter layer can be made of materials commonly used in the art for making filter films, such as red, green, and blue light filter films, and the thickness can be 1-3 μm.

[0042] In one embodiment, the light conversion layer can be prepared in a variety of ways, such as coating a precursor liquid containing one or more quantum dots on the filter layer by blade coating, spin coating, printing, etc., and then drying or curing; or one or more quantum dots can be deposited on the filter layer by physical deposition or chemical deposition. The thickness of the light conversion layer can be determined according to actual needs, for example, it can be preferably 5-20 μm to obtain the best light efficiency. The quantum dots can be selected from a variety of types of quantum dots, such as CdSe, InP quantum dots, etc., but are not limited thereto.

[0043] In one embodiment, the surface of the light-transmitting substrate further has a second area, the second area is arranged around the first area, and the light-blocking layer further includes a second light-blocking structure, and the second light-blocking structure is distributed on the second area of ​​the surface of the light-transmitting substrate. By providing the second light-blocking structure, the damage to the material in the later cutting process of the composite light conversion structure can be reduced, and a buffering effect can be played.

[0044] The second light-blocking structure may be integrated with the first light-blocking structure. Also, the first light-blocking structure and the second light-blocking structure are mainly made of opaque organic material (such as black resin), inorganic material (such as Cr, chromium oxide) or their composite materials, and may be black, white or other colors.

[0045] In one embodiment, the light-blocking layer includes a black matrix (BM) layer, but is not limited thereto. Also, the thickness of the light-blocking layer can be determined according to actual needs and should be kept as level as possible with the quantum dot layer (i.e., the light conversion layer). For example, the thickness of the light-blocking layer can be preferably 5 to 20 μm.

[0046] In one embodiment, the first inorganic encapsulation layer continuously covers the light conversion layer, the light blocking layer, and the remaining area of ​​the surface of the light-transmitting substrate that is not covered by the light conversion layer and the light blocking layer. That is, the first inorganic encapsulation layer covers the entire surface of the light conversion layer, the light blocking layer, and the surface of the light-transmitting substrate to achieve a more comprehensive water-oxygen isolation effect.

[0047] In the present application, by providing the organic encapsulation layer, the first inorganic encapsulation layer can be flattened and the water and oxygen isolation effect can be further enhanced. In addition, by using the combination of the organic encapsulation layer and the first inorganic encapsulation layer, the heat transfer path from the micro LED chip to the light conversion layer can be extended, reducing the influence of the heat generated by the micro LED chip when it is working on the quantum dots.

[0048] In one embodiment, the organic encapsulation layer extends continuously and completely covers the light conversion layer and the first light blocking structure, but does not contact the second light blocking structure, so as to avoid damage to the edge area of ​​the encapsulation structure due to factors such as heat and vibration generated by cutting during the subsequent cutting process, thereby causing water, oxygen, etc. to penetrate. By making the organic encapsulation layer at least continuously cover the first inorganic encapsulation layer and the remaining area in the first area of ​​the surface of the light-transmitting substrate that is not covered by the light conversion layer and the light blocking layer, a more comprehensive water and oxygen isolation effect can be achieved. Moreover, in some cases, the organic encapsulation layer can also have the function of a bonding layer, which is conducive to simplifying the process flow and reducing costs.

[0049] In one embodiment, the material of the first inorganic encapsulation layer and the second inorganic encapsulation layer includes, but is not limited to, SiO2, Si3N4, Al2O3, AlN, TiO2 or HfO2, etc. Also, the thickness of the first inorganic encapsulation layer and the second inorganic encapsulation layer can be determined according to actual needs, for example, 0.01 to 2 μm.

[0050] In one embodiment, the material of the organic encapsulation layer is a light-transmitting organic material, including photoresist, UV, thermosetting adhesive, etc., but not limited thereto. The thickness of the organic encapsulation layer can also be determined according to actual needs, for example, it can be 2 to 10 μm. If it is too thin, it is not conducive to planarization, and if it is too thick, it will cause the distance between the LED and the light conversion layer to be too large, which may cause cross-light.

[0051] In one embodiment, the composite light conversion structure further includes a second inorganic encapsulation layer, which continuously covers the light conversion layer, the light blocking layer and the remaining area of ​​the surface of the light-transmitting substrate not covered by the light conversion layer and the light blocking layer.

[0052] In one embodiment, the composite light conversion structure further includes a bonding layer, and the bonding layer is coated on the organic encapsulation layer. The material of the bonding layer is a light-transmitting organic material, including photoresist, UV, thermosetting adhesive, etc., but not limited thereto. The thickness of the organic encapsulation layer can also be determined according to actual needs, for example, it can be 1 to 3 μm.

[0053] In one embodiment, the light-transmitting substrate includes a sapphire substrate or a glass substrate, but is not limited thereto.

[0054] Some embodiments of the present invention further provide a method for manufacturing a composite light conversion structure based on quantum dots, which is characterized by comprising:

[0055] Providing a light-transmitting substrate, wherein a surface of the light-transmitting substrate has a first area;

[0056] A plurality of filter layers are arranged at intervals on a first area on the surface of the light-transmitting substrate;

[0057] A first light-blocking structure is arranged on a first area on the surface of the light-transmitting substrate to form a light-blocking layer, wherein the first light-blocking structure is at least arranged between adjacent light conversion structures;

[0058] A light conversion layer is disposed on each filter layer to form a plurality of light conversion structures, wherein at least one light conversion layer includes quantum dots for converting the wavelength of incident light passing through the filter layer, and the first light blocking structure is capable of at least blocking the transmission path of light between adjacent light conversion structures;

[0059] A first inorganic encapsulation layer is continuously provided at least on the light conversion layer and the light blocking layer;

[0060] And, an organic encapsulation layer is continuously coated on at least the first inorganic encapsulation layer.

[0061] In one embodiment, the orthographic projection of the filter layer on the surface of the transparent substrate in the light conversion structure covers the orthographic projection of the light conversion layer on the surface of the transparent substrate.

[0062] In one embodiment, the sidewall of each light conversion structure is tightly fitted with the first light blocking structure.

[0063] In one embodiment, the surface of the light blocking layer is flush with or higher than the surface of the light conversion layer.

[0064] In one embodiment, the manufacturing method further includes: providing a second light blocking structure on a second area on the surface of the light-transmitting substrate, the second light blocking structure cooperates with the first light blocking structure to form the light blocking layer, and the second area is provided around the first area.

[0065] In one embodiment, the manufacturing method further comprises: making the first inorganic encapsulation layer continuously cover the light conversion layer, the light blocking layer and the remaining area of ​​the surface of the light-transmitting substrate not covered by the light conversion layer and the light blocking layer.

[0066] In one embodiment, the manufacturing method further comprises: extending the organic encapsulation layer continuously and completely covering the light conversion layer and the first light blocking structure, but not contacting the second light blocking structure. Exemplarily, the organic encapsulation layer can at least continuously cover the first inorganic encapsulation layer and the remaining area in the first area of ​​the surface of the light-transmitting substrate that is not covered by the light conversion layer and the light blocking layer.

[0067] In one embodiment, the manufacturing method further comprises: continuously covering the light conversion layer, the light blocking layer and the remaining area of ​​the surface of the light-transmitting substrate not covered by the light conversion layer and the light blocking layer with a second inorganic encapsulation layer.

[0068] In one embodiment, the manufacturing method further comprises: providing a bonding layer on the organic encapsulation layer.

[0069] Among them, the materials and sizes of the light-transmitting substrate, filter layer, light conversion layer, light-blocking layer, first inorganic encapsulation layer, second inorganic encapsulation layer, organic encapsulation layer, bonding layer, etc. are as described above and will not be repeated here.

[0070] Some embodiments of the present application also provide applications of the quantum dot-based composite light conversion structure in the preparation of a micro-LED display device.

[0071] For example, in one embodiment, a micro LED display device includes:

[0072] A micro LED array, comprising a plurality of micro LEDs arranged in an array, wherein the micro LEDs include Micro LEDs or Mini LEDs;

[0073] And, a color conversion film includes the quantum dot-based composite light conversion structure, the color conversion film is integrated with a micro LED array, and each light conversion structure corresponds to one or more micro LEDs.

[0074] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0075] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general scale, and the schematic view is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional space dimensions of length, width and depth should be included.

[0076] For ease of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0077] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0078] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0079] Example 1 Please refer to Figure 1 The present embodiment provides a method for manufacturing a composite light conversion structure based on quantum dots, comprising the following steps:

[0080] S1. Provide a sapphire or glass substrate 10, and define a first area 101 (also referred to as AA area) on the surface of the substrate.

[0081] S2. A filter structure is fabricated on the first area 101 on the surface of the substrate 10, including a red filter layer 111, a green filter layer 112 and a blue filter layer 113 spaced apart from each other. The thickness of these filter layers may be 1 to 3 μm. The spacing between adjacent filter layers may be determined according to the distance between each micro LED chip in the corresponding micro LED array.

[0082] S3. Using photolithography or other methods, a first light blocking structure 12 is fabricated on the first area 101 on the surface of the substrate 10 to form a light blocking layer. The first light blocking structure 12 may be a black matrix layer (BM), which covers the area of ​​the first area 101 on the surface of the substrate 10 that is not covered by the light filtering structure, and its height, i.e., its thickness, may be 5 to 20 μm and is higher than the light filtering structure.

[0083] S4. Use photolithography or inkjet printing to make a red quantum dot light conversion layer 131 and a green quantum dot light conversion layer 132 on the red filter layer 111 and the green filter layer 112, respectively, and make a transparent layer 133 on the blue filter layer 113, thereby forming a plurality of light conversion structures. The adjacent light conversion structures are blocked by the BM layer to prevent light from being transmitted between adjacent light conversion structures, thereby causing light crosstalk. Moreover, the orthographic projection of the filter layer on the substrate surface in each light conversion structure covers the orthographic projection of the light conversion layer on the substrate surface. And, the side walls of each light conversion structure are tightly fitted with the first light blocking structure. At the same time, the surface of the light blocking layer is preferably flush with the surface of each light conversion layer.

[0084] S5. Materials such as SiO2, Si3N4, Al2O3, AlN, TiO2 or HfO2 are deposited on the light conversion layer and the light blocking layer by ALD (atomic layer deposition) or PECVD (plasma enhanced chemical vapor deposition) to form a continuous first inorganic encapsulation layer 14, which can be 0.01 to 2 μm thick and is mainly used to reduce the water and oxygen transmittance to better protect each light conversion layer.

[0085] S6. A light-transmitting organic material such as photoresist, UV, thermosetting adhesive, etc. is coated on the first inorganic encapsulation layer 14 by scraping, spin coating, spraying, printing, etc. to form an organic encapsulation layer 15 to planarize and protect the first inorganic encapsulation layer 14. The thickness of the organic encapsulation layer 15 can be 2 to 10 μm.

[0086] S7, coating the organic encapsulation layer 15 with a light-transmitting organic material such as photoresist, UV, thermosetting adhesive, etc. by scraping, spin coating, spraying, printing, etc. to form a bonding layer 16, and finally obtain the composite light conversion structure. The bonding layer 16 may have a thickness of 1 to 3 μm, and is mainly used to bond the composite light conversion structure to the corresponding micro LED array. In some cases, the composite light conversion structure may also be named a color conversion film, etc.

[0087] The composite light conversion structure finally obtained in this embodiment, because it includes the aforementioned inorganic packaging layer and organic packaging layer, can better protect the quantum dots in the light conversion layer, reduce the influence of factors such as water, oxygen, and heat on its working performance, eliminate problems such as blue light leakage, and help reduce the process difficulty of integrating the composite light conversion structure with the micro LED chip array, thereby effectively ensuring the quality and working stability of the micro LED full-color display device and extending its service life.

[0088] Example 2 Please refer to Figure 2 The present embodiment provides a method for manufacturing a composite light conversion structure based on quantum dots, comprising the following steps:

[0089] S1. Provide a sapphire or glass substrate 20, and define a first area 201 (also referred to as an AA area) and a second area 202 (also referred to as a non-AA area) on the surface of the substrate.

[0090] S2. A filter structure is fabricated on the first area 201 on the surface of the substrate 20, including a red filter layer 211, a green filter layer 212 and a blue filter layer 213 spaced apart from each other. The thickness of these filter layers may be 1 to 3 μm. The spacing between adjacent filter layers may be determined according to the distance between each micro LED chip in the corresponding micro LED array.

[0091] S3. Use photolithography or other methods to respectively make a first light blocking structure 221 and a second light blocking structure 222 on the first area 201 and the second area 202 on the surface of the substrate 20 to form a light blocking layer 22. The light blocking layer can be a black matrix (BM) layer, which covers the area of ​​the first area 201 on the surface of the substrate 20 that is not covered by the filter structure and a part of the second area 202, and the height can be 5 to 20 μm, and is higher than the filter structure. The second light blocking structure set in the second area 202 can reduce the damage to the material in the later cutting process and play a buffering role.

[0092] S4. Use photolithography or inkjet printing to make a red quantum dot light conversion layer 231 and a green quantum dot light conversion layer 232 on the red filter layer 211 and the green filter layer 212, respectively, and make a transparent layer 233 on the blue filter layer 213, thereby forming a plurality of light conversion structures. The adjacent light conversion structures are blocked by the BM layer to prevent light from being transmitted between adjacent light conversion structures, thereby causing light crosstalk. Moreover, the orthographic projection of the filter layer on the substrate surface in each light conversion structure covers the orthographic projection of the light conversion layer on the substrate surface. And, the side walls of each light conversion structure are tightly fitted with the first light blocking structure. At the same time, the surface of the light blocking layer is preferably flush with the surface of each light conversion layer.

[0093] S5. Deposit SiO2, Si3N4, Al2O3, AlN, TiO2 or HfO2 or other materials on the light conversion layer and the light blocking layer by ALD (atomic layer deposition) or PECVD (plasma enhanced chemical vapor deposition) to form a continuous first inorganic encapsulation layer 24, which can be 0.01 to 2 μm thick and is mainly used to reduce the water and oxygen transmittance to better protect each light conversion layer.

[0094] S6. Photoresist, UV, thermosetting adhesive and other light-transmitting organic materials are coated on the surface of the first inorganic encapsulation layer 24 and the remaining area of ​​the first area 201 on the substrate surface that is not covered by the light conversion layer and the light blocking layer by scraping, spin coating, spraying, printing and other methods to form a continuous organic encapsulation layer 25, so that the first light blocking structure 221 and the light conversion layer are completely covered by the organic encapsulation layer 25, but the second light blocking structure 222 is not in contact with the organic encapsulation layer 25, so that the organic encapsulation layer 25 can be used to planarize and protect the first inorganic encapsulation layer 24, and it can also serve as a bonding layer. The thickness of the organic encapsulation layer 25 can be 2 to 10 μm.

[0095] The composite light conversion structure finally obtained in this embodiment not only has the advantages of the composite light conversion structure obtained in Example 1, but also can further enhance the protection effect of the quantum dots in the light conversion layer, and can also omit the process of additionally making a bonding layer, and reduce the probability of the composite light conversion structure being damaged in the subsequent cutting process.

[0096] See also Figure 3 A composite light conversion structure product in this embodiment is shown, wherein the first inorganic encapsulation layer and the organic encapsulation layer are not shown because of their thin thickness and good light transmittance.

[0097] Example 3, please refer to Figure 4 The present embodiment provides a method for manufacturing a composite light conversion structure based on quantum dots, comprising the following steps:

[0098] S1. Provide a sapphire or glass substrate 30, and define a first area 301 (also referred to as an AA area) and a second area 302 (also referred to as a non-AA area) on the surface of the substrate.

[0099] S2. A filter structure is fabricated on the first area 301 on the surface of the substrate 30, including a red filter layer 311, a green filter layer 312 and a blue filter layer 313 spaced apart from each other. The thickness of these filter layers may be 1 to 3 μm. The spacing between adjacent filter layers may be determined according to the distance between each micro LED chip in the corresponding micro LED array.

[0100] S3. Using photolithography or other methods, a first light blocking structure 321 and a second light blocking structure 322 are respectively formed on the first area 301 and the second area 302 on the surface of the substrate 30 to form a light blocking layer 32. The light blocking layer 32 may be a black matrix layer (BM), which covers the area of ​​the first area 301 on the surface of the substrate 30 that is not covered by the filter structure and a part of the second area 302, and the height may be 5 to 20 μm and is higher than the filter structure.

[0101] S4. Use photolithography or inkjet printing to make a red quantum dot light conversion layer 331 and a green quantum dot light conversion layer 332 on the red filter layer 311 and the green filter layer 312, respectively, and make a transparent layer 333 on the blue filter layer 313, thereby forming a plurality of light conversion structures, and adjacent light conversion structures are blocked by the BM layer to prevent light from being transmitted between adjacent light conversion structures, thereby causing light crosstalk. In addition, the orthographic projection of the filter layer on the substrate surface in each light conversion structure covers the orthographic projection of the light conversion layer on the substrate surface. In addition, the side walls of each light conversion structure are tightly fitted with the first light blocking structure. At the same time, the surface of the light blocking layer is preferably flush with the surface of each light conversion layer.

[0102] S5. Materials such as SiO2, Si3N4, Al2O3, AlN, TiO2 or HfO2 are deposited on the light conversion layer, the light blocking layer and the remaining areas of the substrate surface not covered by the light conversion layer and the light blocking layer by means of ALD (atomic layer deposition) or PECVD (plasma enhanced chemical vapor deposition), thereby forming a continuous first inorganic encapsulation layer 34, which can be 0.01 to 2 μm thick and is mainly used to reduce the water and oxygen transmittance to better protect each light conversion layer.

[0103] S6. Use scraping, spin coating, spraying, printing and other methods to coat the surface of the first inorganic encapsulation layer 34 and the remaining area of ​​the first area 301 on the substrate surface that is not covered by the light conversion layer and the light blocking layer with photoresist, UV, thermosetting adhesive and other light-transmitting organic materials to form a continuous organic encapsulation layer 35, so that the first light blocking structure 321 is completely covered by the light conversion layer and the organic encapsulation layer 35, but the second light blocking structure 322 is not in contact with the organic encapsulation layer 35, and the thickness of the organic encapsulation layer 35 can be 2 to 10 μm.

[0104] S7. Deposit SiO2, Si3N4, Al2O3, AlN, TiO2 or HfO2 or other materials on the first inorganic encapsulation layer 34 and the organic encapsulation layer 35 by ALD (atomic layer deposition) or PECVD (plasma enhanced chemical vapor deposition) to form a continuous second inorganic encapsulation layer 36, the thickness of which can be 0.01 to 2 μm.

[0105] S7, coating the second inorganic encapsulation layer 36 with a light-transmitting organic material such as photoresist, UV, thermosetting adhesive, etc. by scraping, spin coating, spraying, printing, etc. to form a bonding layer 37, and finally obtaining the composite light conversion structure.

[0106] The composite light conversion structure finally obtained in this embodiment not only has the advantages of the composite light conversion structure obtained in Example 1, but can also further enhance the protection effect on the quantum dots in the light conversion layer.

[0107] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A composite light conversion structure based on quantum dots, characterized in that: include: A light-transmitting substrate, a surface of which has a first area and a second area, wherein the second area is arranged around the first area; A plurality of light conversion structures, wherein the plurality of light conversion structures are spaced apart and distributed on a first area on the surface of the light-transmitting substrate, each light conversion structure comprises a filter layer and a light conversion layer sequentially stacked on the surface of the light-transmitting substrate, and at least one light conversion layer comprises quantum dots for performing wavelength conversion on incident light passing through the filter layer; A light blocking layer, comprising a first light blocking structure and a second light blocking structure, wherein the first light blocking structure is at least arranged between adjacent light conversion structures and is at least used to block the transmission path of light between the adjacent light conversion structures, and the second light blocking structure is distributed on a second area of ​​the surface of the light-transmitting substrate, and a spacing between the second light blocking structure and the first light blocking structure is greater than or equal to 5 μm; A first inorganic encapsulation layer, which is continuously coated on at least the light conversion layer and the light blocking layer; The organic encapsulation layer is continuously covered on the first inorganic encapsulation layer, and continuously extends to completely cover the light conversion layer and the first light blocking structure, but does not contact the second light blocking structure.

2. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: In the light conversion structure, the orthographic projection of the filter layer on the surface of the light-transmitting substrate covers the orthographic projection of the light conversion layer on the surface of the light-transmitting substrate.

3. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The thickness of the filter layer is 1-3 μm.

4. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The thickness of the light conversion layer is 5-20 μm.

5. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The side wall of each light conversion structure is tightly fitted with the first light blocking structure.

6. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The surface of the light blocking layer is flush with or higher than the surface of the light conversion layer.

7. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The light blocking layer includes a black matrix layer.

8. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The thickness of the light blocking layer is 5-20 μm.

9. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The first inorganic encapsulation layer continuously covers the light conversion layer, the light blocking layer and the remaining area of ​​the surface of the light-transmitting substrate that is not covered by the light conversion layer and the light blocking layer.

10. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The material of the first inorganic encapsulation layer includes SiO2, Si3N4, Al2O3, AlN, TiO2 or HfO2.

11. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The thickness of the first inorganic encapsulation layer is 0.01-2 μm.

12. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The composite light conversion structure further includes a second inorganic encapsulation layer, which continuously covers the light conversion layer, the light blocking layer and the remaining area of ​​the surface of the light-transmitting substrate not covered by the light conversion layer and the light blocking layer.

13. The quantum dot-based composite light conversion structure according to claim 12, characterized in that: The thickness of the second inorganic encapsulation layer is 0.01-2 μm.

14. The quantum dot-based composite light conversion structure according to claim 12, characterized in that: The material of the second inorganic encapsulation layer includes SiO2, Si3N4, Al2O3, AlN, TiO2 or HfO2.

15. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The composite light conversion structure further includes a bonding layer, and the bonding layer is coated on the organic encapsulation layer.

16. The quantum dot-based composite light conversion structure according to claim 15, characterized in that: The thickness of the bonding layer is 1-3 μm.

17. The quantum dot-based composite light conversion structure according to claim 15, characterized in that: The bonding layer and the organic encapsulation layer are made of materials selected from light-transmitting organic materials.

18. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The thickness of the organic encapsulation layer is 2-10 μm.

19. The quantum dot-based composite light conversion structure according to claim 1, characterized in that: The light-transmitting substrate includes a sapphire substrate or a glass substrate.

20. A method for manufacturing a quantum dot-based composite light conversion structure according to any one of claims 1 to 19, characterized in that: include: Providing a light-transmitting substrate, wherein a surface of the light-transmitting substrate has a first area and a second area, wherein the second area is arranged around the first area; A plurality of filter layers are arranged at intervals on a first area on the surface of the light-transmitting substrate; A first light-blocking structure and a second light-blocking structure are respectively arranged on the first area and the second area of ​​the surface of the light-transmitting substrate to form a light-blocking layer, wherein the first light-blocking structure is at least arranged between adjacent light conversion structures, and a distance between the second light-blocking structure and the first light-blocking structure is greater than or equal to 5 μm; A light conversion layer is disposed on each filter layer to form a plurality of light conversion structures, wherein at least one light conversion layer includes quantum dots for converting the wavelength of incident light passing through the filter layer, and the first light blocking structure is capable of at least blocking the transmission path of light between adjacent light conversion structures; A first inorganic encapsulation layer is continuously provided at least on the light conversion layer and the light blocking layer; Furthermore, an organic encapsulation layer is continuously covered on the first inorganic encapsulation layer, and the organic encapsulation layer is continuously extended to completely cover the light conversion layer and the first light blocking structure, but does not contact the second light blocking structure.

21. The manufacturing method according to claim 20, characterized in that: Also includes: The first inorganic encapsulation layer continuously covers the light conversion layer, the light blocking layer and the remaining area of ​​the surface of the light-transmitting substrate not covered by the light conversion layer and the light blocking layer.

22. The method according to claim 20, characterized in that: Also includes: A bonding layer is disposed on the organic encapsulation layer.

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