Display device and manufacturing method thereof

Abstract

The invention discloses a display device and a manufacturing method thereof. The display device comprises a driving substrate and a plurality of light-emitting units located on the driving substrate. The light-emitting unit is arranged to be of a concave structure bent towards one side of the driving substrate, so that compared with an LED epitaxy of a plane structure, the LED epitaxy has a larger light-emitting area and high light-emitting brightness. The light-emitting units of the concave structures can occupy smaller space under the condition that the light-emitting areas are the same, so that the number of the light-emitting units can be increased, the distribution density of the light-emitting units can be improved, and the resolution of the display device can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a display device and a manufacturing method thereof. BACKGROUND

[0002] In recent years, near-eye display technology has developed rapidly in the fields of augmented reality (AR) and virtual reality (VR). Near-eye display is a special head-mounted device that directly observes virtual images in the field of view, thereby creating an immersive experience. The core of near-eye display technology is how to accurately project high-quality images to the user's eyes while maintaining a lightweight and comfortable wearing experience.

[0003] In near-eye display technology, micro light emitting diodes (Micro LED) have attracted much attention due to their high brightness, high contrast, low power consumption, and fast response time. X-cube technology is a method of combining three primary colors of Micro LED to achieve full-color display, which has important application value in the field of near-eye display.

[0004] As the market demands higher quality of near-eye display, the demand for pixel density and display screen brightness is also increasing. SUMMARY

[0005] In a first aspect of the embodiments of the present application, a display device is provided, comprising:

[0006] a driving substrate for providing a driving signal; a surface of the driving substrate comprising a plurality of electrical connection portions; and

[0007] a plurality of light emitting units on the driving substrate, electrically connected to the electrical connection portions on the surface of the driving substrate;

[0008] wherein the light emitting unit is a recessed structure curved towards the side of the driving substrate.

[0009] In some embodiments of the present application, the shape of the recessed structure is one of a hemisphere, a semicircle, a cone, or a circular truncated cone.

[0010] In some embodiments of the present application, the plurality of electrical connection portions comprises a plurality of first electrical connection portions.

[0011] The light emitting unit comprises:

[0012] a first semiconductor layer electrically connected to the corresponding first electrical connection portion on the driving substrate;

[0013] a light emitting layer on the side of the first semiconductor layer away from the driving substrate.

[0014] a second semiconductor layer located on a side of the light-emitting layer away from the first semiconductor layer.

[0015] In some embodiments of the present application, the plurality of electrical connection portions further comprises a second electrical connection portion.

[0016] The display device further comprises:

[0017] a barrier layer located between each of the light-emitting units; the barrier layer is used to isolate the emitted light of each of the light-emitting units;

[0018] a first insulating layer covering the surface of the barrier layer and each of the light-emitting units;

[0019] a conductive portion located on the first insulating layer; the conductive portion electrically connects the second semiconductor layer of each of the light-emitting units and the second electrical connection portion through a via hole of the first insulating layer;

[0020] a second insulating layer covering the surface of the first insulating layer and the conductive portion.

[0021] In some embodiments of the present application, the display device further comprises:

[0022] a plurality of microlenses located on the second insulating layer; the plurality of microlenses are arranged one-to-one with each of the light-emitting units; the microlenses are used to converge the emitted light of the light-emitting units.

[0023] In some embodiments of the present application, the emitted light of each of the light-emitting units is of the same color.

[0024] The display device further comprises:

[0025] a plurality of color conversion units filled in the recessed structures of at least part of the light-emitting units; the color conversion units are used to emit light of other colors under the excitation of the emitted light of the light-emitting units.

[0026] In some embodiments of the present application, the emitted light of the light-emitting units is blue light; three adjacent light-emitting units constitute a display unit.

[0027] The color conversion units comprise red conversion units and green conversion units; the red conversion units are used to emit red light under the excitation of blue light, and the green conversion units are used to emit green light under the excitation of blue light.

[0028] Each of the display units comprises one red conversion unit and one green conversion unit, and the red conversion unit and the green conversion unit are respectively filled in the recessed structures of any two light-emitting units in the display unit.

[0029] In a second aspect, the present application provides a manufacturing method of a display device, comprising:

[0030] providing a substrate, etching the substrate to form a plurality of protruding structures;

[0031] forming an epitaxial layer on the substrate;

[0032] etching the epitaxial layer according to the interval positions of the plurality of protruding structures to form a plurality of light emitting units;

[0033] forming a barrier layer between each of the light emitting units; the barrier layer exposes a partial area of each of the light emitting units;

[0034] bonding each of the exposed light emitting units to a driving substrate; the light emitting unit is a concave structure curved towards the driving substrate;

[0035] peeling off the substrate;

[0036] forming a first insulating layer on each of the light emitting units;

[0037] forming a conductive part on the first insulating layer; the conductive part electrically connects each of the light emitting units to the driving substrate;

[0038] forming a second insulating layer on the first insulating layer and the conductive part.

[0039] In some embodiments of the present application, the colors of the light emitted by each of the light emitting units are the same, and after the substrate is peeled off, before the first insulating layer is formed on each of the light emitting units, the manufacturing method further comprises:

[0040] filling a color conversion unit in the concave structure of at least part of the light emitting units.

[0041] In some embodiments of the present application, the manufacturing method further comprises:

[0042] forming a plurality of microlenses on the second insulating layer; the plurality of microlenses are arranged one-to-one corresponding to each of the light emitting units.

[0043] The display device and the manufacturing method thereof provided by the embodiments of the present application, the display device comprises a driving substrate and a plurality of light emitting units on the driving substrate. The light emitting units are arranged as a concave structure curved towards the driving substrate, so that compared with an LED epitaxial layer of a planar structure, the light emitting unit has a larger light emitting area and a higher light emitting brightness. The light emitting unit of the concave structure can occupy a smaller space under the condition of the same light emitting area, so that the number of light emitting units can be increased, the distribution density of the light emitting units is improved, and the resolution of the display device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. Obviously, the drawings to be introduced below are only some of the embodiments of the present application, and other drawings can also be obtained by those of ordinary skill in the art without any creative effort on the basis of these drawings.

[0045] Figure 1 One of the cross-sectional structure schematic diagrams of the display device provided by the embodiments of the present application;

[0046] Figure 2 The second cross-sectional structure schematic diagram of the display device provided by the embodiments of the present application;

[0047] Figure 3 The third cross-sectional structure schematic diagram of the display device provided by the embodiments of the present application;

[0048] Figure 4 The flow chart of the manufacturing method of the display device provided by the embodiments of the present application;

[0049] Figure 5 One of the cross-sectional structure schematic diagrams of the intermediate state of the display device in the manufacturing process provided by the embodiments of the present application;

[0050] Figure 6 The second cross-sectional structure schematic diagram of the intermediate state of the display device in the manufacturing process provided by the embodiments of the present application;

[0051] Figure 7 The third cross-sectional structure schematic diagram of the intermediate state of the display device in the manufacturing process provided by the embodiments of the present application;

[0052] Figure 8 The fourth cross-sectional structure schematic diagram of the intermediate state of the display device in the manufacturing process provided by the embodiments of the present application;

[0053] Figure 9 The fifth cross-sectional structure schematic diagram of the intermediate state of the display device in the manufacturing process provided by the embodiments of the present application;

[0054] Figure 10 The sixth cross-sectional structure schematic diagram of the intermediate state of the display device in the manufacturing process provided by the embodiments of the present application;

[0055] Figure 11 The seventh cross-sectional structure schematic diagram of the intermediate state of the display device in the manufacturing process provided by the embodiments of the present application;

[0056] Figure 12 The eighth cross-sectional structure schematic diagram of the intermediate state of the display device in the manufacturing process provided by the embodiments of the present application;

[0057] Figure 13 Fig. 9 is a cross-sectional view of an intermediate state of a display device in a manufacturing process according to an embodiment of the present application;

[0058] Figure 14 Fig. 10 is a cross-sectional view of an intermediate state of a display device in a manufacturing process according to an embodiment of the present application;

[0059] Figure 15 Fig. 11 is a cross-sectional view of an intermediate state of a display device in a manufacturing process according to an embodiment of the present application;

[0060] Figure 16 Fig. 12 is a cross-sectional view of an intermediate state of a display device in a manufacturing process according to an embodiment of the present application. DETAILED DESCRIPTION

[0061] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the following will further describe the present application with reference to the accompanying drawings and embodiments. However, the example embodiments can be implemented in various forms, and should not be understood as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present application more comprehensive and complete, and to fully convey the ideas of the example embodiments to those skilled in the art. The same reference numerals in the drawings represent the same or similar structures, and thus repeated description thereof will be omitted. The expressions of position and direction described in the present application are described with reference to the drawings, but can be changed as needed, and the changes made are included in the scope of protection of the present application. The drawings of the present application are only used to illustrate the relative positional relationship and do not represent the true proportions.

[0062] Light emitting diode (LED) display technology refers to using LED as a light emitting device for direct image display. In a display device based on LED technology, the size of an LED chip can be reduced to the micron level, which is called Micro LED. Since the size of Micro LED is very small, it can be directly used as a pixel or sub-pixel for image display. Micro LED has the characteristics of high integration density, low power consumption, long service life, self-luminous without backlight, etc., and has broad application prospects in public display, TV, vehicle display, commercial display, mobile phone, etc.

[0063] Micro LED display technology is particularly suitable for near-eye display field. Near-eye display is to directly observe virtual images in the field of view through special head-mounted equipment, thereby creating an immersive experience. The core of near-eye display technology is how to accurately project high-quality images to the user's eyes while maintaining a light and comfortable wearing experience, so the size of the display device needs to be small, and at the same time the display device also needs to have high enough resolution and brightness.

[0064] Therefore, the display device provided by the embodiments of the present application can help to improve the pixel density and display brightness.

[0065] Figure 1 A cross-sectional structure diagram of the display device provided by the embodiments of the present application.

[0066] As shown in Figure 1 The display device includes a driving substrate 11 and a plurality of light-emitting units 12 located on the driving substrate 11.

[0067] The driving substrate 11 can include a substrate and a driving circuit formed on the substrate.

[0068] The substrate can be a hard substrate with a clean surface, such as SiO2 / p-Si, SiO2 / n-Si, transparent glass, quartz, etc., or a flexible substrate such as polyimide (PI), polyether sulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), and polyethylene terephthalate (PET).

[0069] The driving circuit is formed on the substrate and can be a thin film transistor (TFT) driving circuit, which can specifically include a low-temperature polysilicon TFT, an oxide TFT, a low-temperature polysilicon oxide TFT, etc. The driving circuit can also be a complementary metal oxide semiconductor (CMOS) driving circuit or a micro-electro-mechanical system (MEMS) driving circuit, etc. The driving circuit can provide a driving signal.

[0070] The surface of the driving substrate 11 is also provided with a plurality of electrical connection parts, which are connected to the driving circuit inside the driving substrate 11, and the light-emitting units 12 are connected to the electrical connection parts, thereby realizing electrical communication between the light-emitting units 12 and the driving substrate 11, and driving the light-emitting units 12 to emit light by the driving substrate 11.

[0071] The plurality of light emitting units 12 are located on the driving substrate 11 and are electrically connected with the electrical connection portions on the surface of the driving substrate 11. The light emitting unit 12 can adopt an LED chip, and in the embodiment of the present application, the light emitting unit 12 specifically refers to the epitaxial part of the LED. The light emitting unit 12 is made into a concave structure A that is bent towards the side of the driving substrate 11, so that compared with the LED epitaxial part of the planar structure, it has a larger light emitting area and a high light emitting brightness. The light emitting unit 12 of the concave structure can occupy a smaller space under the condition of the same light emitting area, so that the number of light emitting units can be increased in the limited space, the distribution density of the light emitting units is improved, and the resolution of the display device is improved.

[0072] The light emitting unit 12 of the concave structure A is obtained by patterning the epitaxial substrate to form a plurality of convex structures, and then forming an epitaxial layer on the substrate with the convex structures. Therefore, the concave structure A and the convex structure on the substrate are complementary shapes. In some embodiments, the shape of the concave structure A can be one of a hemisphere, a semicircle, a cone or a circular truncated cone. The embodiment of the present application takes the example of the concave structure A adopting a hemispherical shape.

[0073] As shown in Figure 1 The electrical connection portions on the surface of the driving substrate 11 can be divided into first electrical connection portions 111 and second electrical connection portions 112. The number of the first electrical connection portions 111 and the second electrical connection portions 112 can be multiple. In the embodiment of the present application, each light emitting unit 12 corresponds to a first electrical connection portion 111, the light emitting unit 12 is electrically connected with the corresponding first electrical connection portion 111, and each light emitting unit 12 is connected to the second electrical connection portion 112 through a common electrode. By applying an electrical signal to the second electrical connection portion and the first electrical connection portion, the light emitting brightness of the light emitting unit 12 can be controlled.

[0074] It is worth noting that the common electrode means that the one side electrode of each light emitting unit 12 applies the same signal, and does not mean that all the light emitting units 12 need to be connected to the same second electrical connection portion 112. If the size of the display device is small, only one second electrical connection portion 112 can be provided, and the one side electrodes of all the light emitting units 12 are connected to the second electrical connection portion 112. If the size of the display device is large, connecting all the light emitting units 12 to the same second electrical connection portion 112 can cause a large voltage drop in the light emitting units located at the far end. At this time, a plurality of second electrical connection portions 112 can be provided, the light emitting units 12 are connected to the adjacent second electrical connection portions 112 in a partitioned manner, and the same electrical signal is applied to each second electrical connection portion 112 through the driving circuit, so that the common electrode of each light emitting unit 12 is realized.

[0075] Specifically, as shown in Figure 1As shown, the light emitting unit 12 comprises a first semiconductor layer 121, a light emitting layer 122 and a second semiconductor layer 123. The first semiconductor layer 121 is electrically connected with the corresponding first electrical connection part 111 on the driving substrate 11; the light emitting layer 122 is located on the side of the first semiconductor layer 121 away from the driving substrate 11; and the second semiconductor layer 123 is located on the side of the light emitting layer 122 away from the first semiconductor layer 121.

[0076] The film layer close to the driving substrate 11 in the light emitting unit 12 is the first semiconductor layer 121, and the film layer on the top of the light emitting unit is the second semiconductor layer 123. Considering the manufacturing sequence of the epitaxial structure of the light emitting unit and the fact that the light emitting unit needs to be reversely bonded to the driving substrate, the first semiconductor layer 121 can be a P-type doped semiconductor layer, the second semiconductor layer 123 can be an N-type doped semiconductor layer, and the light emitting unit 12 can adopt a common cathode structure.

[0077] As shown, Figure 1 The display device can further comprise a barrier layer 13, a first insulating layer 14, a conductive part e and a second insulating layer 15.

[0078] The barrier layer 13 is located between each light emitting unit 12 and is used to isolate the emitted light of each light emitting unit 12. As shown, Figure 1 The barrier layer 13 exposes part of the first semiconductor layer 121 of the light emitting unit 12, and the height does not exceed the second semiconductor layer 123. The barrier layer 13 can be made of a material with good fluidity, strong light reflection performance and good heat dissipation, for example, one of resin, black glue and other materials.

[0079] The first electrical connection part 111 electrically connected with the light emitting unit 12 can be made of a metal material with good light reflection and small resistance, so as to block the light emitted from the bottom of the light emitting unit 12. The cooperation of the first electrical connection part 111 and the barrier layer 13 makes the light emitting of the light emitting unit 12 all emitted from the top, thereby increasing the top light emitting brightness of the light emitting unit 12.

[0080] The first insulating layer 14 covers the surface of the barrier layer 13 and each light emitting unit 12, and insulates and protects each light emitting unit 12. The conductive part e is located on the first insulating layer 14, the first insulating layer 14 comprises a via hole exposing part of the second semiconductor layer 123 of each light emitting unit 12 and the second electrical connection part 112, and the conductive part e electrically connects the second semiconductor layer 123 of each light emitting unit 12 with the second electrical connection part 112 through the via hole of the first insulating layer 14. The second insulating layer 15 covers the surface of the first insulating layer 14 and the conductive part e, and insulates and protects the whole device.

[0081] As shown, Figure 1It can be seen that the conductive part e includes a part on the surface of the insulating layer and a part in the through hole of the insulating layer. The part on the surface of the insulating layer can be made of one of transparent conductive materials such as indium tin oxide, indium zinc oxide, indium gallium zinc oxide, indium aluminum zinc oxide, and indium gallium tin oxide, or a laminated structure of multiple materials. Meanwhile, the conductive parts connecting different light emitting units can use the same or different materials. The part in the through hole of the insulating layer can be made of one or more of metal materials with small resistance such as tungsten, aluminum, copper, gold, and indium, or materials with excellent conductivity such as indium zinc oxide and indium tin oxide.

[0082] The first insulating layer 14 and the second insulating layer 15 can be made of high-transmittance wide-bandgap materials, for example, one or more of materials such as aluminum oxide, silicon oxide, hafnium oxide, tantalum oxide, and silicon nitride. Meanwhile, the first insulating layer 14 and the second insulating layer 15 can use the same or different materials.

[0083] Figure 2 A cross-sectional structure diagram of a display device provided by an embodiment of the present application.

[0084] In some embodiments, as shown in Figure 2 The display device further includes a plurality of microlenses 16 on the second insulating layer 15, and the microlenses 16 are arranged one-to-one with the light emitting units 12. The microlenses can be hemispherical, can converge the light emitted by the light emitting units 12, and constrain the divergence angle of the light emitted from the top of the light emitting units 12, especially optimal for improving the central light emission brightness of the light emitting units.

[0085] The microlenses 16 can be made of organic glue materials such as PMMA and SU8, or high-refractive inorganic materials with excellent light transmittance such as silicon oxide and silicon nitride, without limitation.

[0086] Figure 3 A cross-sectional structure diagram of a display device provided by an embodiment of the present application.

[0087] In order to realize full display, in some embodiments, the light emitting units can include multiple types, for example, three types of light emitting units for emitting red, green, and blue three primary colors of light. In some embodiments, the light emitting units can also emit light of the same color, and full-color display can be realized by combining color conversion materials. Using the color conversion scheme can reduce the manufacturing difficulty of the display device and improve the production efficiency. The embodiments of the present application take the scheme of light emitting units emitting light of the same color and color conversion materials as an example for specific description.

[0088] As shown in Figure 3As shown, the display device further comprises a plurality of color conversion units 17 filled in the recessed structures A of at least part of the light emitting units 12, and the color conversion units 17 are configured to emit light of other colors under excitation of the emitted light of the light emitting units 12.

[0089] In some embodiments, the emitted light of the light emitting units 12 is blue light, and the light emitting layer of the light emitting units 12 can be made of compound materials such as gallium nitride (GaN), indium gallium nitride (InGaN), zinc arsenide (ZnSe), etc. Three adjacent light emitting units 12 form a display unit, and the color conversion units 17 include a red conversion unit 17r and a green conversion unit 17g; the red conversion unit 17r is configured to emit red light under excitation of the blue light, and the green conversion unit 17g is configured to emit green light under excitation of the blue light. Each display unit includes a red conversion unit 17r and a green conversion unit 17g, and the red conversion unit 17r and the green conversion unit 17g are respectively filled in the recessed structures A of any two light emitting units in the display unit.

[0090] The color conversion units 17 can be made of fluorescent materials or quantum dot materials and filled in the recessed structures of the corresponding light emitting units 12 by using processes such as inkjet printing. Due to the recessed structures A of the light emitting units 12, the filling of the color conversion materials is more favorable, and the color conversion materials have a certain self-limiting effect.

[0091] In some embodiments, the sizes of the light emitting units 12 can be the same or different, for example, the size of the light emitting unit for filling the red conversion unit 17r can be the largest, and the size of the light emitting unit for filling the green conversion unit 17g can be the smallest.

[0092] In some embodiments, the thicknesses of the color conversion materials can also be different. For example, when the color conversion materials are quantum dot materials, the thickness of the red quantum dot material for converting red light can be slightly thicker than the thickness of the green quantum dot for converting green light.

[0093] Based on the same inventive concept, the embodiments of the present application also provide a manufacturing method of a display device, Figure 4 The manufacturing method of the display device provided by the embodiments of the present application is shown in a flowchart.

[0094] As shown in the flowchart, the manufacturing method of the display device includes the following steps. Figure 4 As shown in the flowchart, the manufacturing method of the display device includes the following steps.

[0095] S10, providing a substrate, etching the substrate to form a plurality of protruding structures;

[0096] S20, forming an epitaxial layer on the substrate;

[0097] S30, etching the epitaxial layer according to interval positions of the plurality of protruding structures to form a plurality of light emitting units;

[0098] S40, forming a barrier layer between the light emitting units;

[0099] S50, bonding the exposed light emitting units to a driving substrate;

[0100] S60, peeling off the substrate;

[0101] S70, forming a first insulating layer on the light emitting units;

[0102] S80, forming a conductive part on the first insulating layer;

[0103] S90, forming a second insulating layer on the first insulating layer and the conductive part.

[0104] The driving substrate can be manufactured by using a manufacturing process in the related art, which will not be described herein. The surface of the driving substrate includes a plurality of first electrical connection parts and second electrical connection parts, and one first electrical connection part corresponds to one light emitting unit.

[0105] Figures 5-16 The cross-sectional structure of the display device in an intermediate state during manufacturing is shown.

[0106] As shown in Figure 5 , a substrate C is provided first, which needs to be matched with the epitaxial growth.

[0107] As shown in Figure 6 , the substrate C is etched to form a plurality of protruding structures T, and the positions of the plurality of protruding structures T correspond to the positions of the light emitting units, so the size and interval of the protruding structures T can be set according to the pixel density of the display device.

[0108] The protruding structure T can be one of a hemisphere, a semicircular body (a three-dimensional structure obtained by cutting a cylindrical body along the axial direction), a cone or a circular truncated cone, which will not be limited herein.

[0109] As shown in Figure 7 , an epitaxial layer 12w is grown on the substrate C with the plurality of protruding structures T, and the epitaxial layer can include a first semiconductor layer 121, a light emitting layer 122 and a second semiconductor layer 123. The manufacturing sequence of each film layer is: forming the second semiconductor layer 123 on the substrate C, forming the light emitting layer 122 on the second semiconductor layer 123, and forming the first semiconductor layer 121 on the light emitting layer 122.

[0110] According to the light emitting color of the light emitting unit 12, the substrate C and the epitaxial layer can adopt different materials, and the epitaxial layer can further include other film layers in addition to the first semiconductor layer 121, the light emitting layer 122 and the second semiconductor layer 123, so as to optimize the performance of the light emitting unit, which is not limited herein.

[0111] As shown in FIG. 12, the epitaxial layer 12w is etched according to the interval positions of the plurality of protruding structures T, so as to form a plurality of discrete light emitting units 12. The shape of the protruding structure T determines the shape of the light emitting unit 12, and the light emitting unit 12 is no longer a planar structure, so that the light emitting area can be increased in the same size, and the brightness of the light emitting unit can be improved. Figure 8 As shown in FIG. 13, a barrier layer 13 is filled between the light emitting units 12. The material of the barrier layer 13 needs to have good fluidity, strong light reflection performance and good heat dissipation, and the material can be one of resin, black glue and the like, and different regions of the barrier can adopt different materials. The barrier layer 13 can be made by one of dispensing, spraying, inkjet and the like.

[0112] Figure 9 Since the light emitting unit 12 is formed on the protruding structure T and has the same shape as the protruding structure T, the filling of the barrier layer material is more favorable, and the formed barrier layer is also patterned.

[0113] As shown in FIG. 14, the barrier layer 13 is etched to expose the top of the first semiconductor layer 121 of each light emitting unit 12, and the surface is planarized.

[0114] As shown in FIG. 15, each light emitting unit 12 is bonded with each first electrical connection part 111 of the driving substrate 11. Each first electrical connection part 111 on the surface of the driving substrate can adopt a metal material with good light reflection and small resistance, so as to block the light emitted from the bottom of the light emitting unit 12 and improve the light utilization efficiency. The light emitting unit 12 is covered by the barrier layer 13 except the region bonded with the first electrical connection part 111, so that the emitted light of the light emitting unit 12 is emitted from the top. Figure 10 As shown in FIG. 16, the substrate C is peeled off, so that the light emitting unit 12 forms a concave structure A bending to the side of the driving substrate 11.

[0115] Figure 11 In some embodiments, the light emitting unit 12 can adopt a blue light LED epitaxial layer for emitting blue light, and a color conversion material can be used to convert the blue light into light of other colors for full-color display.

[0116] As shown in FIG. 17, the substrate C is peeled off, so that the light emitting unit 12 forms a concave structure A bending to the side of the driving substrate 11. Figure 12 In some embodiments, the light emitting unit 12 can adopt a blue light LED epitaxial layer for emitting blue light, and a color conversion material can be used to convert the blue light into light of other colors for full-color display.

[0117] As shown in FIG. 18, the substrate C is peeled off, so that the light emitting unit 12 forms a concave structure A bending to the side of the driving substrate 11.

[0118] Figure 13 ​​​As shown, a color conversion material can be filled into the recessed structure of at least part of the light-emitting unit 12 to form a color conversion unit. Since the light-emitting unit 12 has a recessed structure, it is more conducive to filling the color conversion material. The color conversion material can be a fluorescent material or a quantum dot material; there is no limitation here.

[0119] When the light-emitting unit 12 is used to emit blue light, the color conversion unit 17 includes a red conversion unit 17r and a green conversion unit 17g. The red conversion unit 17r can emit red light when excited by blue light, and the green conversion unit 17g can emit green light when excited by blue light.

[0120] like Figure 14 As shown, a first insulating layer 14 is covered on the surface of each light-emitting unit 12 to provide insulation protection for each light-emitting unit. The first insulating layer 14 is etched to form vias that expose a portion of the second semiconductor layer 123 and the second electrical connection portion 112 in each light-emitting unit 12.

[0121] like Figure 15 As shown, a conductive portion e is formed on the surface of the first insulating layer 14, so that the conductive portion conducts through the through hole of the first insulating layer 14 to each light-emitting unit 12 and the second electrical connection portion 112.

[0122] The portion of the conductive part e located on the surface of the first insulating layer 14 can be made of a transparent conductive material with excellent conductivity, such as indium tin oxide, indium zinc oxide, indium gallium zinc oxide, indium aluminum zinc oxide, or indium gallium tin oxide. The portion of the conductive part e located in the through-hole can be made of a metal material with low resistance, such as tungsten, aluminum, copper, gold, or indium, or a semiconductor material with excellent conductivity, such as InSnO or InZnO. The conductive part e can be fabricated using one of the following methods: magnetron sputtering, electron beam evaporation, thermal evaporation, pulsed laser deposition, chemical vapor deposition, or sol-gel method; no limitation is made here.

[0123] like Figure 16 As shown, a second insulating layer 15 is formed on the surface of the first insulating layer 14 and the conductive part e. The first insulating layer 14 and the second insulating layer 15 can be made of a high-transmittance, wide-bandgap material, such as alumina, silicon oxide, hafnium oxide, tantalum oxide, silicon nitride, etc. The first insulating layer 14 and the second insulating layer 15 can be fabricated using one of the following methods: magnetron sputtering, electron beam evaporation, thermal evaporation, pulsed laser deposition, chemical vapor deposition, and sol-gel. Different insulating layers can be made of the same or different materials and using the same or different processes, which is not limited here.

[0124] Finally, as Figure 3As shown, a plurality of microlenses 16 can also be formed on the second insulating layer 15, the microlenses 16 are arranged one-to-one with the light emitting units 12, and the microlenses 16 can converge the light emitted by the light emitting units 12 to improve the central brightness of the light emitting units 12.

[0125] The microlenses 16 can be made of PMMA, SU8 or other organic glue materials, or high refractive index inorganic materials with excellent light transmittance such as silicon oxide and silicon nitride. The microlenses 16 can be made by sol-gel method, vapor deposition method or physical deposition method, which are not limited here.

[0126] Thus, the display device is completed, and the manufacturing method of the display device provided by the embodiment of the present application only needs to etch the epitaxial layer once, each light emitting unit adopts a common electrode structure, which can reduce the subsequent etching steps of the light emitting unit, simplify the preparation process, and also can avoid the yield problem caused by the etching thickness and precision problem in the etching process.

[0127] In the manufacturing method of the display device provided by the embodiment of the present application, photoresist spin coating, photolithography, stripping, etching, chemical mechanical planarization and other common patterning processes are used multiple times, which are not described here. Heat annealing treatment can be added after each step is prepared. After each film layer is formed, surface planarization processes such as chemical mechanical polishing (CMP), spin coating, grinding, etc. can be used.

[0128] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to these embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the present application.

[0129] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A display device, characterized by comprising: The display device comprises: a driving substrate for providing driving signals; a surface of the driving substrate comprises a plurality of electrical connection portions; and a plurality of light emitting units on the driving substrate, electrically connected to the electrical connection portions on the surface of the driving substrate; wherein the light emitting units are concave structures curved towards the driving substrate.

2. The display device of claim 1, wherein, The concave structures are in one of the shapes of a hemisphere, a semicircle, a cone or a truncated cone.

3. The display device of claim 1, wherein The plurality of electrical connection portions comprises a plurality of first electrical connection portions; The light emitting units comprise: a first semiconductor layer electrically connected to the corresponding first electrical connection portion on the driving substrate; a light emitting layer on the side of the first semiconductor layer away from the driving substrate; a second semiconductor layer on the side of the light emitting layer away from the first semiconductor layer.

4. The display device of claim 3, wherein The plurality of electrical connection portions further comprises a second electrical connection portion; The display device further comprises: a barrier layer between the light emitting units, for isolating the light emitting units; a first insulating layer covering the barrier layer and the surfaces of the light emitting units; a conductive portion on the first insulating layer, electrically connecting the second semiconductor layer of each light emitting unit to the second electrical connection portion through a via hole of the first insulating layer; a second insulating layer covering the surfaces of the first insulating layer and the conductive portion.

5. The display device of claim 4, wherein, The display device further comprises: a plurality of microlenses on the second insulating layer, one-to-one corresponding to the light emitting units, for converging the light emitted by the light emitting units.

6. The display device according to any one of claims 1 to 5, wherein The light emitted by each light emitting unit is of the same color; The display device further comprises: a plurality of color conversion units filled in the concave structures of at least some of the light emitting units, for emitting light of other colors under the excitation of the light emitted by the light emitting units.

7. The display device of claim 6, wherein, The light emitted by the light emitting units is blue light; three adjacent light emitting units constitute a display unit; The color conversion units comprise red conversion units and green conversion units; the red conversion units are for emitting red light under the excitation of blue light, and the green conversion units are for emitting green light under the excitation of blue light; Each display unit comprises a red conversion unit and a green conversion unit, which are respectively filled in the concave structures of any two light emitting units in the display unit.

8. A method for manufacturing a display device, comprising: The display device comprises: providing a substrate, etching the substrate to form a plurality of convex structures; forming an epitaxial layer on the substrate; etching the epitaxial layer according to the interval positions of the convex structures to form a plurality of light emitting units; forming a barrier layer between the light emitting units, exposing part of the light emitting units; bonding the exposed light emitting units to a driving substrate; the light emitting units are concave structures curved towards the driving substrate; stripping the substrate; forming a first insulating layer on each light emitting unit; forming a conductive portion on the first insulating layer, electrically connecting each light emitting unit to the driving substrate; forming a second insulating layer on the first insulating layer and the conductive portion.

9. The manufacturing method as described in claim 8, characterized in that, The colors of the outgoing light of each of the light emitting units are the same, and after the substrate is peeled off, before a first insulating layer is formed on each of the light emitting units, the method further comprises: filling a color conversion unit in the recessed structure of at least part of the light emitting unit.

10. The manufacturing method as described in claim 8, characterized in that, The method further comprises: forming a plurality of microlenses on the second insulating layer; The plurality of microlenses are arranged one-to-one corresponding to each of the light emitting units.

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