Micro display panel, manufacturing method thereof and pixelated projection lamp

Abstract

The invention discloses a micro display panel. The micro display panel comprises a substrate, a micro light emitting diode display chip, a fluorescent layer and a packaging layer, wherein the micro-light-emitting diode display chip is located on the substrate, the edge of the micro-light-emitting diode display chip is provided with a metal pad, the metal pad is electrically connected with the area, not covered by the micro-light-emitting diode display chip, of the substrate, and the fluorescent layer is located on the surface of the micro-light-emitting diode display chip. The packaging layer covers the exposed area of the substrate and the area where the micro light-emitting diode display chip is electrically connected with the substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of micro light emitting diodes, and in particular to a micro display panel and a manufacturing method thereof, and a pixelated projection lamp. Background Art

[0002] Micro Light Emitting Diode (MicroLED) is a new type of LED structure obtained by thinning, miniaturizing and arraying the original LED structure. It integrates arrayed micron-level LED units on an active addressing drive panel to achieve the lighting and individual control of the LED units, thereby outputting the desired display image. Micro LED can achieve precise control at the pixel level, has high photoelectric conversion efficiency, excellent brightness and contrast, and fast response time, so it has been applied to the automotive display and lighting fields.

[0003] In pixelated projection lamps such as pixelated car lights, white light is usually required, but the MicroLED chip itself can only emit monochromatic light. Therefore, it is often necessary to set fluorescent materials on the surface of the MicroLED chip to convert the monochromatic light such as blue light emitted by the MicroLED into white light. At the same time, as mentioned above, the pixelated projection lamp package has high compactness requirements. The more compact the package, the higher the precision of pixel control. Therefore, how to accurately set fluorescent materials on the surface of the MicroLED chip while avoiding the peripheral structure covering the fluorescent orange and / or light-emitting area is a technical difficulty that needs to be solved urgently in the research and development of pixelated projection lamps. Summary of the invention

[0004] In view of some or all of the problems in the prior art, the present invention provides a non-display panel in a first aspect, comprising:

[0005] substrate;

[0006] A micro-LED display chip is located on the substrate, and the edge of the micro-LED display chip has a metal pad, and the metal pad is electrically connected to the area of ​​the substrate not covered by the micro-LED display chip;

[0007] A fluorescent layer, located on the surface of the micro-LED display chip;

[0008] The encapsulation layer covers the exposed area of ​​the substrate and the area where the micro-LED display chip is electrically connected to the substrate.

[0009] Furthermore, a dam is provided on the surface of the micro-LED display chip around the side wall of the fluorescent layer.

[0010] Furthermore, the micro LED display chip has a light emitting area, the fluorescent layer is located on the surface of the light emitting area, and the dam is located on the surface of the micro LED display chip outside the light emitting area.

[0011] Furthermore, the top of the dam is higher than the top of the fluorescent layer.

[0012] Furthermore, the outer edge of the dam does not exceed the edge of the micro light emitting diode display chip.

[0013] Furthermore, the material of the dam includes silicone and / or resin.

[0014] Furthermore, the dam further comprises a colored material doped in the silica gel and / or resin, so that the dam is non-transparent, thereby positioning and protecting the light-emitting area.

[0015] Furthermore, the colored material includes titanium dioxide and / or zirconium dioxide, or carbon black.

[0016] Furthermore, the metal pad is electrically connected to the surface of the substrate not covered by the micro light emitting diode display chip through a metal bonding wire.

[0017] Furthermore, the top of the dam is not lower than the highest point of the metal bonding wire.

[0018] Furthermore, the encapsulation layer covers the area between the outer side wall of the dam and the outer side wall of the substrate.

[0019] Furthermore, the surface of the encapsulation layer includes at least one protrusion.

[0020] Furthermore, the material of the packaging layer includes silica gel and / or resin.

[0021] Furthermore, a transparent covering layer is provided on the encapsulation layer, and the transparent covering layer covers the encapsulation layer.

[0022] Furthermore, the transparent covering layer also covers the surface of the fluorescent layer.

[0023] Furthermore, the top of the transparent covering layer is higher than the top of the dam, and the top of the transparent covering layer is flat.

[0024] Furthermore, the top of the transparent cover layer has a rough structure.

[0025] Furthermore, the material of the transparent covering layer includes silicone and / or resin.

[0026] Furthermore, the transparent covering layer also includes a diffusing agent and / or a surface roughening agent doped in the silica gel and / or the resin.

[0027] Furthermore, the bottom of the substrate also has an external solder pad, and the upper surface of the substrate has an upper metal pad, wherein the upper metal pad is electrically connected to the metal pad of the micro light emitting diode display chip.

[0028] Furthermore, the material of the substrate includes ceramic or metal.

[0029] Furthermore, the substrate includes at least one circuit structure layer, and the circuit structure layer is electrically connected to the micro light emitting diode display chip and is electrically connected to an external module via an external soldering pad.

[0030] Furthermore, the micro light emitting diode display chip is bonded to the surface of the substrate.

[0031] Furthermore, the micro light emitting diode display chip is bonded to the surface of the substrate by silver glue or silicone glue.

[0032] Furthermore, the micro light emitting diode display chip includes a driving backplane and a micro light emitting diode array, and the micro light emitting diode array is arranged on the surface of the driving backplane.

[0033] Furthermore, the micro light emitting diode array includes a plurality of light emitting mesas.

[0034] Furthermore, the micro light emitting diode array further includes a passivation layer, and the passivation layer covers the side surfaces of the light emitting mesa.

[0035] Furthermore, the passivation layer also covers the top edge of the light-emitting mesa.

[0036] Furthermore, the micro-LED array further comprises a top conductive layer, wherein the continuous top conductive layer is disposed above the micro-LED array and contacts and covers the top of each light-emitting mesa.

[0037] Furthermore, top electrodes are arranged between adjacent light-emitting mesas, and the top electrodes are connected to each other.

[0038] Furthermore, the top electrode is a ring-shaped reflective electrode, which is arranged around the light-emitting table.

[0039] Furthermore, the micro-LED display chip also includes a micro-lens array, which is located above the micro-LED array area and includes a plurality of micro-lenses, and the micro-lenses correspond to the light-emitting mesas one by one.

[0040] Furthermore, the material of the fluorescent layer includes silica gel and / or resin, and the fluorescent layer also includes fluorescent powder doped in the silica gel and / or resin.

[0041] Furthermore, the fluorescent layer also includes a diffusing agent and an anti-precipitation agent doped in the silica gel and / or resin.

[0042] Furthermore, the diffusing agent includes inorganic light diffusing agents such as nano barium sulfate, calcium carbonate, silicon dioxide, etc., or organic nano micro-pearl light diffusing agents.

[0043] Furthermore, the anti-precipitation agent includes organic polymer compounds such as polycarboxylates or polyvinyl alcohol.

[0044] Furthermore, the thickness of the fluorescent layer is greater than the particle size of the fluorescent powder.

[0045] Furthermore, the particle size of the phosphor is 1 to 5 microns, and the thickness of the phosphor layer is 10 to 50 microns.

[0046] A second aspect of the present invention provides a method for manufacturing the micro display panel as described above, comprising:

[0047] Provide micro-light emitting diode display chips;

[0048] forming a dam around the light emitting area of ​​the micro light emitting diode display chip;

[0049] forming a packaging layer around the micro light emitting diode display chip and the dam; and

[0050] A fluorescent layer is formed on the surface of the light emitting area.

[0051] A third aspect of the present invention provides another method for manufacturing the micro display panel as described above, comprising:

[0052] Provide micro-light emitting diode display chips;

[0053] forming a dam around the light emitting area of ​​the micro light emitting diode display chip;

[0054] forming a fluorescent layer on the surface of the light emitting area; and

[0055] A windshield layer is formed around the micro-LED display chip and the dam.

[0056] Furthermore, the manufacturing method further comprises:

[0057] Before forming the dam, the micro-LED display chip is first fixed on the substrate, and the micro-LED display chip is electrically connected to the substrate through metal bonding wires, wherein the metal bonding wires are coated in the packaging layer.

[0058] Furthermore, the micro light emitting diode display chip is fixed on the substrate by high pressure and high temperature bonding or SMT patch process.

[0059] Furthermore, the dam is a silicone sheet adhered to the surface of the micro light emitting diode display chip.

[0060] Furthermore, the dam is formed by a silicone injection molding process.

[0061] Furthermore, the packaging layer at least covers the metal bonding wire.

[0062] Furthermore, the encapsulation layer is formed by a plastic encapsulation process.

[0063] Further, forming a fluorescent layer on the surface of the light-emitting area includes:

[0064] Adding fluorescent powder, diffusing agent and anti-precipitation agent into liquid silica gel or resin and stirring them to form fluorescent glue;

[0065] Placing a baffle on the surface of the micro-LED display chip, wherein the baffle comprises a through hole, and the through hole is aligned with the light-emitting area; and

[0066] The fluorescent glue is evenly sprayed onto the surface of the light-emitting area through a glue dispensing process.

[0067] Furthermore, the manufacturing method further comprises:

[0068] A transparent covering layer is formed on the surface of the micro light emitting diode display chip.

[0069] A fourth aspect of the present invention provides a pixelated projection lamp, which comprises the micro display panel as described above.

[0070] The present invention provides a micro display panel and a manufacturing method thereof. On the one hand, a fluorescent glue structure is used to replace the traditional fluorescent body, further reducing the overall volume of the packaging structure. On the other hand, a dam is provided around the fluorescent layer, which can effectively prevent the peripheral glue from flowing to the light-emitting area and the fluorescent layer, shielding the fluorescent layer, thereby improving the light extraction efficiency. At the same time, the dam can also be used as a mark to facilitate the identification and positioning of the light-emitting area in subsequent processes or client assembly processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] To further illustrate the above and other advantages and features of various embodiments of the present invention, a more specific description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It will be understood that these drawings only depict typical embodiments of the present invention and are therefore not to be considered as limiting the scope thereof. In the accompanying drawings, for clarity, identical or corresponding parts will be represented by identical or similar reference numerals.

[0072] Figure 1 A schematic structural diagram of a micro display panel according to an embodiment of the present invention is shown;

[0073] Figure 2 A schematic diagram showing the structure of a micro light emitting diode display chip according to an embodiment of the present invention;

[0074] Figure 3 A schematic structural diagram of a micro display panel according to another embodiment of the present invention is shown;

[0075] Figure 4 A schematic structural diagram of a micro display panel according to another embodiment of the present invention is shown;

[0076] Figure 5 A schematic flow chart showing a method for manufacturing a micro display panel according to an embodiment of the present invention;

[0077] Figures 6a to 6f A schematic diagram showing a process of a method for manufacturing a micro display panel according to an embodiment of the present invention;

[0078] Figure 7 A schematic flow chart showing a method for manufacturing a micro display panel according to another embodiment of the present invention; and

[0079] Figures 8a to 8f A schematic diagram showing a process of a method for manufacturing a micro display panel according to yet another embodiment of the present invention. DETAILED DESCRIPTION

[0080] In the following description, the present invention is described with reference to various embodiments. However, those skilled in the art will recognize that various embodiments can be implemented without one or more specific details or with other replacement and / or additional methods, materials or components. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid blurring the inventive point of the present invention. Similarly, for the purpose of explanation, specific quantities, materials and configurations are set forth to provide a comprehensive understanding of embodiments of the present invention. However, the present invention is not limited to these specific details. In addition, it should be understood that the various embodiments shown in the drawings are illustrative representations and are not necessarily drawn in correct proportions.

[0081] In this specification, reference to "one embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. The phrase "in one embodiment" appearing in various places in this specification does not necessarily all refer to the same embodiment.

[0082] It should be noted that the embodiments of the present invention describe the process steps in a specific order, but this is only for the purpose of illustrating the specific embodiment, rather than limiting the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to the adjustment of the process.

[0083] In order to solve the compact packaging problem of high-power Micro LED pixelated projection lamps, the present invention uses fluorescent glue instead of traditional phosphors, wherein the fluorescent glue includes fluorescent powder and a transparent adhesive with high light transmittance, such as silicone, resin, etc. In addition, in order to avoid damage to the bonding wire, a protective glue needs to be provided during the manufacturing process. In order to prevent the protective glue from flowing into the light-emitting area and reducing the light-emitting area, the present invention further provides a dam around the light-emitting area to prevent the glue on the periphery from flowing to the middle light-emitting area or the fluorescent glue during the powder spraying process.

[0084] The technical solution of the present invention is further described below in conjunction with the accompanying drawings of the embodiments.

[0085] Figure 1 FIG. 2 is a schematic diagram showing the structure of a micro display panel according to an embodiment of the present invention. Figure 1 As shown, a micro display panel includes a substrate 101, a micro LED display chip 102, a fluorescent layer 103, a dam 104, and a packaging layer 105. The micro LED display chip 102 is arranged on the surface of the substrate 101 and is electrically connected to the substrate 101 by means such as metal bonding wires 106. The micro LED display chip 102 includes a light-emitting area 121. The fluorescent layer 103 is arranged on the surface of the light-emitting area 121. The dam 104 is arranged on the surface of the micro LED display chip outside the light-emitting area 121. The packaging layer 105 is arranged on the substrate 101, covering the exposed area of ​​the substrate 101 and the area where the micro LED display chip 102 is electrically connected to the substrate. The first protective layer 105 at least completely covers the metal bonding wires 106, and the surface of the first protective layer 105 is not higher than the surface of the dam 104.

[0086] In one embodiment of the present invention, the material of the substrate 101 includes ceramic or metal. The substrate 101 includes at least one layer of circuit structure and an external pad 111. In one embodiment of the present invention, the circuit structure and the external pad 111 are made of metal such as copper or aluminum. The circuit structure is used to realize the electrical connection between the micro-LED display chip 102 and the external module. Specifically, the metal pad of the micro-LED display chip 102 is connected to the upper metal pad provided on the first surface of the substrate 101 through the metal bonding wire 106, and the upper metal pad is further electrically connected to the external pad 111 on its second surface through the multi-layer circuit structure, and is electrically connected to the external module through the external pad 111. The external module can be used to provide power and / or control signals for the micro-LED display chip 102.

[0087] In one embodiment of the present invention, the fluorescent glue packaging structure further includes an adhesive layer 107, that is, the micro-LED display chip 102 is bonded to the surface of the substrate 101 through the adhesive layer 107. In one embodiment of the present invention, the adhesive layer 107 is made of silver glue and / or silicone, that is, the micro-LED display chip 102 is bonded to the surface of the substrate 101 through silver glue and / or silicone.

[0088] Figure 2 FIG. 1 is a schematic diagram showing the structure of a micro-LED display chip 102 according to an embodiment of the present invention. Figure 2 As shown, in one embodiment of the present invention, the micro LED display chip 102 includes a driving backplane 122 and a micro LED array, wherein the micro LED array is bonded to the driving backplane 122 to form a light emitting area.

[0089] like Figure 2 As shown, the micro-LED is bonded to the surface of the driving backplane 122 through the bottom stack 212, and the bottom stack includes a bonding layer, a barrier layer, a reflective layer and an adhesion layer from bottom to top. The bonding layer is made of AuSn alloy, the barrier layer is made of metals such as Ti and Pt to prevent the alloy from diffusing when it is melted during the bonding process, and the adhesion layer is made of metals with good adhesion such as Cr to increase the adhesion between the epitaxial layer and the IC metal layer. In one embodiment of the present invention, the reflective layer is made of a metal with a high reflectivity, such as Au, Sn, etc., to improve the reflectivity of the light emitted from the bottom of the multi-quantum well MQW.

[0090] In some embodiments of the present invention, the driving backplane 122 may be electrically connected to each micro-LED in the micro-LED array via a separate metal interconnect. In still other embodiments of the present invention, each micro-LED may be electrically controlled individually by the driving backplane. In some embodiments of the present invention, the driving backplane may be electrically connected to electrodes of a micro-LED display chip via a metal interconnect. In some embodiments of the present invention, a dielectric layer may be formed in the gaps between the micro-LEDs. In some embodiments of the present invention, a dielectric layer may also be formed in the gaps between the metal interconnects.

[0091] In one embodiment of the present invention, the micro-LED array includes a plurality of micro-LEDs. Each micro-LED may form at least a portion of a pixel element on a micro-LED display chip. The micro-LED structure is formed in an array in a micro-LED display chip, and the resolution includes but is not limited to 720*480, 640*480, 1920*1080, 1280*720, 2K or 4K. The diameter of the micro-LED structure is at the nanometer level, for example, 20nm to 100nm. In one embodiment of the present invention, the pitch of the micro-LED array, that is, the minimum center-to-center distance between the micro-LEDs, may be between about 2 microns and about 50 microns. In one embodiment of the present invention, the number of pixels on a micro-LED display chip may be between thousands and millions.

[0092] Specifically, if Figure 2 As shown, the micro-LED array includes a plurality of light-emitting mesas 202 and a continuous top conductive layer 203. The continuous top conductive layer 203 is disposed above the micro-LED array and contacts and covers the top of each light-emitting mesas 202, and is in electrical contact with the top surface of the light-emitting mesas, so as to connect the top surfaces of the semiconductor light-emitting mesas 202, i.e., the second type epitaxial layer, in series, which is a transparent conductive layer. In one embodiment of the present invention, the light-emitting mesas 202 can be arranged on the driving panel 122 in a regular or irregular manner as pixels of a micro-LED display chip.

[0093] like Figure 2As shown, the light-emitting mesa 202 includes a first type epitaxial layer, a second type epitaxial layer and a light-emitting layer located therebetween. In one embodiment of the present invention, the light-emitting mesa of each micro-light-emitting diode in the micro-light-emitting diode array may be a micron-sized light-emitting mesa. In one embodiment of the present invention, the micron-sized light-emitting mesa may include a first type epitaxial layer, a light-emitting layer and a second type epitaxial layer from bottom to top. That is, in the three-layer structure, the first type epitaxial layer is closest to the driving backplane; the light-emitting layer is located above the first type epitaxial layer and is further away from the driving backplane; the second type epitaxial layer is located above the light-emitting layer and is farthest away from the driving backplane. In one embodiment of the present invention, the light-emitting layer is formed by a plurality of stacked quantum well layers, in particular, quantum well layers stacked in a superlattice. Preferably, the quantum well layers stacked in a superlattice include a plurality of pairs of quantum well layers stacked with quantum barrier layers. In one embodiment of the present invention, the first type epitaxial layer is a semiconductor material having a first conductivity type and includes a plurality of semiconductor layers. The main matrix material of the first type of light-emitting mesa may be, but is not limited to, Ga, N, As, P, In or Al. In addition, the first type epitaxial layer may include, from top to bottom, but is not limited to, a waveguide layer, a confinement layer, a transition layer, and a window layer; in addition, an ohmic contact layer may be formed below the window layer. In one embodiment of the present invention, the second type epitaxial layer is a semiconductor material having a second conductivity type and includes a plurality of semiconductor layers. The main matrix material of the second type epitaxial layer may be, but is not limited to, Ga, N, As, P, In, or Al. In addition, the first type epitaxial layer may include, from top to bottom, but is not limited to, a confinement layer and a waveguide layer; in addition, in one embodiment of the present invention, an ohmic contact layer may be formed on the confinement layer. In one embodiment, the first conductivity type is different from the second conductivity type.

[0094] In one embodiment, the first type epitaxial layer is an N-type GaN layer or an N-type AlGaN layer, and the second type epitaxial layer is a P-type GaN layer or a P-type AlGaN layer, that is, the material of the second type epitaxial layer can be a material layer of the second conductivity type containing at least two or more elements of Ga, N, As, Al, In, and P, and the first type epitaxial layer can be a material layer of the first conductivity type containing at least two or more elements of Ga, N, As, Al, In, and P. In one embodiment, the light-emitting layer includes a multi-quantum well layer and an electron blocking layer, and the multi-quantum well layer is an InGaN / GaN multi-quantum well layer or an InGaN / AlGaN multi-quantum well layer or an InGaAs / AlGaAs multi-quantum well layer. In another embodiment, the first type epitaxial layer can also be a P-type GaN layer or a P-type AlGaN layer, and the second type epitaxial layer can be an N-type GaN layer or an N-type AlGaN layer.

[0095] In one embodiment of the present invention, the light emitting layer includes at least one quantum well layer. The thickness of the quantum well layer is between 20nm and 40nm, for example, the thickness is 30nm. In one embodiment of the present invention, the material of the quantum well layer is GaInP / (Al x Ga 1-x ) y In 1-y P, wherein x ranges from 0.5 to 0.9 and y ranges from 0.3 to 0.5. For example, x is 0.8 and y is 0.5. In one embodiment of the present invention, the relationship between x and y is that x is 1 to 2 times greater than y. In some embodiments, the light emitting layer is a multiple quantum well (MQW).

[0096] In an embodiment of the present invention, one of the first type epitaxial layer and the second type epitaxial layer is an N-type semiconductor layer, and the other is a P-type semiconductor layer. In an embodiment of the present invention, the N-type semiconductor layer further includes a doped N-type contact layer and an N-type cladding layer. The doped N-type contact layer is configured to bond with the bonding layer, and the N-type cladding layer is formed on the doped N-type contact layer. The material of the N-type cladding layer is Al x In 1-x P, wherein x ranges from 0.1 to 0.5, for example, x is 0.5. In addition, in these embodiments, the thickness of the N-type cladding layer is not greater than 350 nm, for example, the thickness of the N-type cladding layer is 320 nm. The doping concentration of the N-type cladding layer is 5e 17 cm -3 To 1e 18 cm -3 In one embodiment of the present invention, the N-type semiconductor layer further includes a doped N-type contact layer and an N-type cladding layer formed on the doped N-type contact layer. The doped N-type contact layer is configured to bond with the bonding layer. The material of the doped N-type contact layer is Si-doped GaN. In one embodiment of the present invention, the thickness of the doped N-type contact layer is 10nm to 30nm. In one embodiment of the present invention, the doping concentration of the doped N-type contact layer is 2e 18 cm -3 To 1e 19 cm -3 In one embodiment of the present invention, the N-type semiconductor layer further includes an N-type spacer layer formed on the N-type cladding layer. The material of the N-type spacer layer is (Al x Ga 1-x ) y In 1-yP, wherein x ranges from 0.5 to 0.9 and y ranges from 0.1 to 0.5. For example, x is 0.8 and y is 0.5. In one embodiment of the present invention, the relationship between x and y is that x is 1 to 2 times of y. The thickness of the N-type spacer layer is 50nm to 75nm, for example 65nm. In one embodiment of the present invention, the P-type semiconductor layer includes a P-type cladding layer and a doped P-type contact layer. The P-type cladding layer is formed on the light-emitting layer, and the doped P-type contact layer is formed on the P-type cladding layer.

[0097] In one embodiment of the present invention, the material of the P-type cladding layer is Al x In 1-x P, wherein x is 0.3 to 0.5, for example, x is 0.5. In such an embodiment, the thickness of the P-type cladding layer is not greater than 380 nm, for example, the thickness of the P-type cladding layer is 360 nm.

[0098] In one embodiment of the present invention, the material of the doped P-type contact layer is GaAs, and the thickness of the doped P-type contact layer is 10 nm to 30 nm, for example, 20 nm.

[0099] In one embodiment of the present invention, the P-type semiconductor layer further includes a P-type spacer layer formed under the P-type cladding layer, a first doped P-type transition layer formed on the P-type cladding layer, and a second doped P-type transition layer formed on the first doped P-type transition layer. In one embodiment of the present invention, the material of the P-type spacer layer is (Al x Ga 1-x ) y In 1-y P, wherein x ranges from 0.5 to 0.9 and y ranges from 0.3 to 0.5. For example, x is 0.8 and y is 0.5. In one embodiment of the present invention, the relationship between x and y is that x is 1 to 2 times greater than y. In some embodiments, the thickness of the P-type spacer layer is 50 nm to 70 nm, for example 65 nm.

[0100] In one embodiment of the present invention, the material of the first doped P-type transition layer is (Al x Ga 1-x ) y In 1-y P, wherein x ranges from 0.1 to 0.3, and y ranges from 0.3 to 0.5. For example, x is 0.17 and y is 0.5. In one embodiment of the present invention, the relationship between x and y is that y is 1 to 5 times x. In some embodiments, the thickness of the first doped P-type transition layer is 20 nm to 40 nm, for example 30 nm.

[0101] In one embodiment of the present invention, the material of the second doped P-type transition layer is Al x Ga1-x As, wherein x ranges from 0.5 to 0.9, for example, x is 0.6. In one embodiment of the present invention, the thickness of the second doped P-type transition layer is 10 nm to 30 nm, for example, 20 nm.

[0102] In one embodiment of the present invention, the doping concentration of the second doped P-type transition layer is greater than the doping density of the first doped P-type transition layer. The doping concentration of the doped P-type contact layer is 1 to 10 times the doping concentration of the second doped P-type transition layer.

[0103] In one embodiment of the present invention, the doping concentration of the doped P-type contact layer is greater than the doping concentration of the second doped P-type transition layer. In addition, in one embodiment of the present invention, the doping concentration of the second doped P-type transition layer is 2 to 4 times the doping concentration of the first doped P-type transition layer.

[0104] For example, the doping concentration of the first doped P-type transition layer is greater than 1e 18 cm -3 The doping density of the second doped P-type transition layer is 2e 18 cm -3 -4e 18 cm -3 In the range of 5e 18 cm -3 .

[0105] like Figure 2 As shown, there are partitions between the pixels formed by each semiconductor light-emitting mesa 202, and a top electrode 204 is arranged at the partition, and the top electrode 204 is arranged on the surface of the continuous top conductive layer 203. In one embodiment of the present invention, the top electrode 204 is a ring-shaped reflective electrode, which is arranged around the light-emitting mesa 202, and is formed by magnetron sputtering or evaporation. For example, the material can use Al or Al alloy metal as the side wall reflective mirror, and the electrode stack metal can be Ni, Al, Ti, Ni, Pt, Au and other metal materials. In one embodiment of the present invention, each top electrode is connected to each other.

[0106] In some embodiments of the present invention, a deep groove is provided at the partition between two adjacent light-emitting mesas 202, and the deep groove penetrates the micro-LED array, specifically, penetrates the bottom stack at the partition, and the top electrode 204 is provided at the deep groove. In one embodiment of the present invention, the top electrode between adjacent light-emitting mesas has at least two peaks. In some embodiments of the present invention, a deep groove is not provided at the partition between two adjacent light-emitting mesas 202, but a passivation isolation layer and a continuous top conductive layer are directly formed, so that the surface of the continuous top conductive layer between two adjacent light-emitting mesas 202 is a horizontal or substantially horizontal plane, the top electrode is formed therein, and its morphological interface is a trapezoid or approximately a trapezoid, and the surface of the top electrode is not higher than the highest point of the continuous top conductive layer.

[0107] As shown in the figure, in one embodiment of the present invention, the micro-LED display chip further includes a passivation layer 205. The passivation layer 205 is coated on the surface and side of the light-emitting mesa 202, but exposes at least a portion of the top surface of the light-emitting mesa, and the top conductive layer 203 is disposed on the surface of the passivation layer 205. In one embodiment of the present invention, the passivation layer 205 can be formed by CVD deposition of SiO2 or ALD deposition of Al2O3 film to effectively reduce the chip leakage rate. In some embodiments of the present invention, the passivation layer only covers the side of the light-emitting mesa, but not the top surface of the light-emitting mesa, and the highest point of the passivation layer is flush with the top surface of the light-emitting mesa. In these embodiments, the continuous top conductive layer covering the top of the light-emitting mesa is in a horizontal or substantially horizontal plane. In some embodiments of the present invention, the passivation layer not only covers the side surfaces of the light-emitting mesa, but also covers the edge portion of the top surface of the light-emitting mesa, so that there is a bulge at the top edge of the light-emitting mesa, so that the top conductive layer 203 covering it also forms a bulge at the top edge of the light-emitting mesa.

[0108] In one embodiment of the present invention, the driving backplane 122 includes a substrate, a driving circuit and an IC copper pillar 211 connected to the driving circuit, and the micro light emitting diode array is electrically connected to the IC copper pillar 211. The substrate can be a transparent substrate, such as a glass substrate. Examples of other substrates include GaAs, GaP, InP, SiC, ZnO and sapphire substrates. In one embodiment of the present invention, the substrate is about 700 microns thick. The driving circuit includes, for example, a complementary metal oxide semiconductor (CMOS) device or a TFT device. As shown in the figure, the IC copper pillar 211 includes a first IC copper pillar and a second IC copper pillar, wherein the first IC copper pillar is electrically connected to the N-type semiconductor layer of the semiconductor light emitting module in a one-to-one correspondence, and the second IC copper pillar is electrically connected to the first electrode 206. The first electrode 206 can be used as an external pad of the micro light emitting diode display chip, for example. In one embodiment of the present invention, the polarity of the first electrode is opposite to that of the second electrode. In one embodiment of the present invention, each semiconductor light emitting module has a common first electrode. The first electrode may be, for example, a P electrode or an anode electrode, and the second electrode may be an electrode with a polarity opposite to that of the first electrode, such as an N electrode or a cathode electrode. In one embodiment of the present invention, the first and second electrodes and their connecting parts may be made of materials such as graphene, ITO, aluminum-doped zinc oxide (AZO) or fluorine-doped tin oxide (FTO) or any combination of the above materials. In another embodiment of the present invention, the first and second electrodes and their connecting parts may be made of non-transparent or transparent conductive materials, such as indium tin oxide (ITO).

[0109] As shown in the figure, in one embodiment of the present invention, the micro-LED display chip further includes a micro-lens array. The micro-lens array is arranged above the micro-LED array, wherein at least one micro-lens 207 is arranged on the surface of the conductive layer on the top of the micro-LED, and the horizontal profile of the micro-lens is greater than the maximum horizontal profile of the micro-LED. The micro-lens is mainly used to converge and / or collimate the optical fiber, for example, the focus of the micro-lens can be located in the light-emitting table of the micro-LED by adjusting the thickness, curvature and other parameters of the micro-lens.

[0110] As shown in the figure, in one embodiment of the present invention, the microlenses of the microlens array correspond to the light-emitting mesas one by one. At the same time, in some embodiments of the present invention, there is a gap between adjacent microlenses and their bottoms are connected to each other. The bottom of the gap may be lower than the top of the light-emitting mesas of the micro-light-emitting diode, or lower than the bottom of the light-emitting layer of the light-emitting mesas, or located above the second electrode, or located between the two peaks of the second electrode. In some other embodiments of the present invention, adjacent microlenses are completely connected, but there is a gap in the connecting portion. And the bottom of the connecting portion may be lower than the top of the light-emitting mesas of the micro-light-emitting diode, or lower than the bottom of the light-emitting layer of the light-emitting mesas, or located above the second electrode, or located between the two peaks of the second electrode. In addition, in one embodiment of the present invention, there is an air gap inside the microlens.

[0111] In an embodiment of the present invention, the microlens can be formed by multiple depositions. In the process of forming the microlens, a SiO2 film layer needs to be deposited first, and then ion etching is performed. The microlens is formed on the surface of the passivation isolation layer at the position corresponding to each light-emitting table.

[0112] Back to Figure 1 ,like Figure 1 As shown, the driving backplane 122 also includes a non-luminous area, the non-luminous area surrounds the luminous area, and a metal pad 123 is provided on the non-luminous area. As mentioned above, the metal pad 123 is electrically connected to the upper metal pad 112 on the substrate 101 through the metal bonding wire 106. The material of the metal bonding wire 106 is, for example, one or more of the following materials: gold, silver, aluminum, etc.

[0113] like Figure 1As shown, the fluorescent layer 103 completely covers the light-emitting area 121. As mentioned above, in one embodiment of the present invention, the material of the fluorescent layer 103 is fluorescent glue, that is, a transparent adhesive with high light transmittance doped with fluorescent powder, and the transparent adhesive can be, for example, silica gel and / or resin. The fluorescent powder can cooperate with the blue light LED chip to produce white light. The specific principle is as follows: the blue light of the blue light chip is irradiated into the fluorescent powder, a part of which is absorbed by the fluorescent powder and excited to produce yellow light, green light or red light, and the other part of the blue light penetrates the fluorescent powder, and the penetrated blue light is mixed with the light excited by the fluorescent powder to form white light. In one embodiment of the present invention, in order to improve the luminous effect, a diffusing agent and an anti-precipitation agent can also be added to the transparent adhesive for preparing the fluorescent layer 103. The diffusing agent can improve the optical fiber dispersion effect, so that the distribution of light is more uniform. For example, it can be an inorganic light diffusing agent such as nano barium sulfate, calcium carbonate, silicon dioxide, or an organic nano micro-pearl light diffusing agent. The anti-precipitation agent can keep the particles of the fluorescent powder, diffusing agent and the like in the transparent adhesive in a suspended state and slow down precipitation, and the anti-precipitation agent includes, for example, organic polymer compounds such as polycarboxylate or polyvinyl alcohol.

[0114] In one embodiment of the present invention, the thickness of the fluorescent layer 103 is determined according to the particle size of the fluorescent powder. The lower the spraying thickness, the better the effect of preventing light crosstalk. The lower the spraying thickness, the smaller the particle size of the fluorescent powder is required. In one embodiment of the present invention, the particle size of the fluorescent powder in the fluorescent layer 103 is 2 to 5 um, preferably about 2.5 um, and the thickness of the fluorescent layer 103 is 10 to 15 um, which can be formed by multiple spraying. In one embodiment of the present invention, the fluorescent layer 103 is formed by 1 to 7 layers of spraying.

[0115] like Figure 1The dam 104 is arranged around the light-emitting area 121. On the one hand, it can block the glue on the periphery from flowing to the middle light-emitting area 121 during the powder spraying process, and block the glue on the outside from flowing to the fluorescent layer. On the other hand, it can also facilitate positioning and identification in subsequent processes or client assembly processes. In the actual manufacturing process, the formation order of the fluorescent layer 103 and the encapsulation layer 105 can be interchanged. If the fluorescent layer 103 is formed first and the encapsulation layer 105 is formed later, then if the height of the dam 104 is lower than the fluorescent layer 103, when the encapsulation layer 105 is formed, the glue used to form the encapsulation layer will not be intercepted and will flow to the fluorescent layer. Based on this, in one embodiment of the present invention, the height of the dam 104 is higher than the expected height of the fluorescent layer 103. In addition, since the encapsulation layer 105 needs to cover the entire metal bonding wire 106, but should not be higher than the dam 104, in the embodiment of the present invention, the height of the dam 104 should not be lower than the highest point of the metal bonding wire 106 to ensure that the encapsulation layer can cover the metal bonding wire 106. In one embodiment of the present invention, the inner edge of the dam 104 is aligned with the outer edge of the light emitting area 121, and the outer edge of the dam 104 may be flush with the edge of the micro-LED display chip 102, or may not exceed the edge of the micro-LED display chip 102, that is, the dam 104 may not cover (such as Figure 1 ), or partially covers, or completely covers the metal pad 123 on the surface of the micro LED display chip 102 (as shown in Figure 3 As shown), it can also cover part of the metal bonding wire 106. In one embodiment of the present invention, the dam 104 is made of a transparent adhesive with high light transmittance such as silicone and / or resin. In one embodiment of the present invention, the transparent adhesive forming the dam 104 can also be doped with colored materials, such as white or black materials, such as titanium dioxide, zirconium dioxide, carbon black, etc., so that the dam 104 will have color, so that the dam 104 can also be positioned and identified in subsequent processes or customer assembly processes. In one embodiment of the present invention, the dam 104 can also directly use a prefabricated silicone sheet (frame), which is directly adhered to the surface of the micro-light-emitting diode display chip 102 through a silicone sheet bonding process (frame attach).

[0116] like Figure 1As shown, the encapsulation layer 105 is arranged on the surface of the substrate 101, covering the exposed area of ​​the substrate and the area where the micro-LED display chip is electrically connected to the substrate, and completely covering the metal bonding wire 106. The encapsulation layer 105 is mainly used to protect the metal bonding wire 106 to prevent the metal bonding wire 106 from being damaged or deformed by external forces. At the same time, the encapsulation layer 105 can also serve as a supporting structure to play a supporting role. In order to prevent the material used from flowing onto the light-emitting area 121 or the fluorescent layer 103 when forming the encapsulation layer 105, in one embodiment of the present invention, the surface of the encapsulation layer 105 is not higher than the surface of the dam 104. In one embodiment of the present invention, the encapsulation layer 105 is made of a transparent adhesive with high light transmittance such as silicone or resin. In one embodiment of the present invention, a colored material, such as a white or black material, such as titanium dioxide, zirconium dioxide, carbon black, etc., can also be doped in the transparent adhesive. In the dispensing process, due to the characteristics of the liquid, the liquid transparent adhesive will flow as flat as possible, but there may be a slight bulge in the middle, or a slight bulge around the edges, or a slightly uneven surface.

[0117] Figure 4 FIG. 2 is a schematic diagram showing the structure of a micro display panel according to another embodiment of the present invention. Figure 4 The micro display panel shown is Figure 1 The micro display panels shown are substantially the same except that Figure 4 The micro display panel shown also includes a transparent cover layer 108. The transparent cover layer 108 is arranged on the surface of the encapsulation layer, the dam and the fluorescent layer, and is used to protect the Micro LED of the light-emitting layer, and can also serve as a structural support. In one embodiment of the present invention, the transparent cover layer 108 is made of a transparent adhesive with high light transmittance such as silicone and / or resin. In one embodiment of the present invention, in order to improve the light extraction efficiency, the transparent adhesive can also be doped with materials such as a diffusant and a surface roughening agent. The diffusant can enhance the light extraction dispersion effect and make the distribution of light more uniform. For example, it can be an inorganic light diffusor such as nano barium sulfate, calcium carbonate, silicon dioxide, or an organic nano-micro-pearl light diffusor. The surface roughening agent can increase the surface roughness of the second protective layer to improve its adhesion. For example, it can include polyetheretherketone.

[0118] Figure 5 A schematic diagram showing a process of manufacturing a micro display panel according to an embodiment of the present invention, and Figures 6a to 6f A schematic diagram of a process of manufacturing a micro display panel according to an embodiment of the present invention is shown. As shown in the figure, a method for manufacturing a micro display panel includes:

[0119] First, in step 501, Figure 6aAs shown, a micro-LED display chip is provided. A metal layer, a micro-LED array and a microlens array are formed on the driving backplane to form a micro-LED display chip 102. The micro-LED array is electrically connected to the metal layer to form a light-emitting area 121 of the micro-LED display chip. Specifically, first, a second type of epitaxial layer, an electron blocking layer, a multi-layer quantum well and a first type of epitaxial layer are sequentially deposited on the substrate, and then the substrate is thinned to form a semiconductor light-emitting module. At the same time, an adhesion layer, a reflective layer, a blocking layer and a bonding metal layer can also be sequentially deposited on the surface of the first type of epitaxial layer. Then, the semiconductor light-emitting module is bonded to the driving backplane through the bonding metal layer, so that the IC copper column on the driving backplane forms an electrical connection with the semiconductor light-emitting module. In one embodiment of the present invention, after the chip is bonded, the substrate can also be ground and thinned to remove, or the substrate can be removed by laser stripping to further thin the buffer layer structure, so as to facilitate the subsequent PN step structure. In an embodiment of the present invention, the bonding process can be, for example, a hot pressing bonding process, a eutectic bonding process, etc. Then, step etching is performed, and the semiconductor light-emitting module is ion-etched to form a positive trapezoidal structure pixel by adjusting the photolithography morphology. In one embodiment of the present invention, the horizontal angle of the positive trapezoidal structure pixel can be, for example, 65° to 85°. Then, a passivation isolation layer is formed on the side wall and surface of each pixel. In one embodiment of the present invention, the passivation isolation layer is formed by CVD deposition of SiO2 film layer and / or ALD deposition of Al2O3 film layer to reduce the chip leakage rate. After the deposition is completed, photolithography is performed above the corresponding pixel to open a hole to expose at least a part of the surface of the second type semiconductor layer. A top conductive layer is further formed on the surface of the passivation isolation layer to realize the shared series connection of the second type epitaxial layer of each pixel. An annular reflective electrode is formed at the partition of each pixel as a top electrode. In one embodiment of the present invention, the annular reflective electrode is realized by magnetron sputtering or evaporation process. In one embodiment of the present invention, the top electrode uses Al or Al alloy metal as the side wall reflective mirror, and the electrode stack metal uses Ni, Al, Ti, Pt, Au and other metal materials. In one embodiment of the present invention, before forming the passivation isolation layer, deep groove etching can be performed at the partition of each pixel point, for example, by using photolithography and IBE inert gas physical etching process, and the top electrode is subsequently formed at the deep groove. Subsequently, a first electrode is formed on the driving backplane, and the first electrode is connected to the IC copper column to play a protective pad height role and facilitate subsequent wiring. Finally, SiO2 is deposited, and the photolithography morphology is adjusted to form a microlens.In one embodiment of the present invention, a SiO2 film layer, i.e., a first transmission layer, is deposited by PECVD, and the thickness of the film layer is about 2.5 to 3.5 um. Subsequently, the photolithography array morphology corresponding to the pixel position is completed by adjusting the microlens photolithography morphology, such as the glue thickness, exposure energy, and hardening temperature, and the microlens passivation protection layer SiO2 material is ion-etched to form a hemispherical SiO2 microlens with a lens-like morphology, which can improve the light extraction efficiency to a certain extent. At this point, the initial structure of the micro-light-emitting diode display chip is formed. Since the step coverage of the PECVD deposited SiO2 is not good, microcracks are easily formed at the deep grooves of the pixel points, causing the quantum well light source to form diffuse reflection here, reducing the light extraction efficiency of the microlens. In addition, due to the photolithography size of the microlens and ion etching, the overall microlens curvature radius, the lower spacer height, the ball height, and the lens ball width are all small, and the optimal conditions of the lens are not achieved. Therefore, in some embodiments of the present invention, secondary deposition can also be performed to increase the microlens curvature radius, the lower spacer height, the ball height, and the lens ball width. In one embodiment of the present invention, the thickness of the secondary SiO2 deposition needs to be determined according to the thickness of the SiO2 deposited by the previous microlens and the microlens etching morphology. In one embodiment of the present invention, the thickness of the secondary deposition is preferably 0.2 to 1um, and the deposition operation can be single or multiple times. In one embodiment of the present invention, the secondary deposition of SiO2 uses a mixed gas of SiH4 and N2O, and the ratio of SiH4 to N2O is 1:5. At the same time, the gas flow rate is controlled at a low level so that the deposition rate is much lower than the previous microlens deposition. The secondary deposition uses a high vacuum environment process condition and a large flow of inert gas N2 to further improve the step coverage effect of the secondary deposition SiO2, which is not easy to produce defects, and can even repair the micro defects of the previous microlens deposition to obtain a better brightness improvement effect.

[0120] Next, in step 502, if Figure 6b As shown, chip bonding. The micro-LED display chip 102 is fixed on the substrate 101, and the micro-LED display chip is electrically connected to the substrate through a metal bonding wire 106. In one embodiment of the present invention, the micro-LED display chip is solid-crystal-bonded to the substrate as a whole. For example, the micro-LED display chip can be fixed to the substrate by high-pressure and high-temperature bonding (HBH), SMT patch and other processes, and an adhesive layer 107 is formed between the micro-LED display chip and the substrate. After the bonding is completed, the metal pad of the micro-LED display chip driving backplane, or the first electrode is bonded to the upper metal pad on the first surface of the substrate through a metal bonding wire. It should be understood that in some other embodiments of the present invention, the first electrode of the micro-LED display chip is arranged at its bottom, and can also be directly electrically connected to the substrate without the need to arrange a metal bonding wire;

[0121] Next, in step 503, if Figure 6c As shown, a dam is formed. A dam 104 is formed around the light-emitting area of ​​the micro-LED display chip, and the height of the dam 104 should not be lower than the highest point of the metal bonding wire 106. In one embodiment of the present invention, the dam 104 is made by a dispensing process. Specifically, a transparent adhesive doped with a colored material is sprayed at a designated position, i.e., around the light-emitting area, by a dispensing process, and then solidified by high-temperature baking to form a dam. In some embodiments, the colored material doped in the dam 104 may be a black or white material. In order to prevent the transparent adhesive from flowing to the light-emitting area when forming the dam, in another embodiment of the present invention, a silicone sheet may be prepared in advance, and the silicone sheet may be bonded to the designated position by a silicone sheet bonding process. In another embodiment of the present invention, the dam may also be formed by silicone injection molding. It should be understood that the dam mainly serves as a barrier, so there is no specific requirement for its width, and it may cover part of the metal bonding wire;

[0122] Next, in step 504, if Figure 6d As shown, an encapsulation layer is formed. An encapsulation layer 105 is formed around the micro-LED display chip and the dam, and the encapsulation layer must at least completely cover the metal bonding wire. At the same time, in order to prevent the material from flowing to the light-emitting area during the formation of the encapsulation layer, the height of the encapsulation layer 105 is not higher than the height of the dam 104. In one embodiment of the present invention, the encapsulation layer is made by a dispensing process. Specifically, a transparent adhesive doped with a colored material is sprayed at a specified position by a dispensing process, and then solidified by high-temperature baking to form an encapsulation layer. Due to the large dispensing area and the characteristics of the liquid, the liquid transparent adhesive itself will flow as flat as possible, but the surface of the encapsulation layer may still be slightly convex in the middle, or slightly convex around, or the surface may be slightly uneven. In another embodiment of the present invention, the encapsulation layer can also be formed by silicone injection molding;

[0123] Next, in step 505, if Figure 6eAs shown, a fluorescent layer is formed. A fluorescent layer 103 is formed on the surface of the light-emitting area. In one embodiment of the present invention, it is first necessary to add fluorescent powder and the like into a liquid transparent adhesive, such as silica gel, resin, etc., and stir it thoroughly. For example, it can be stirred as evenly as possible by a mixer and other equipment to reduce the generation of bubbles. After the stirring is completed, the fluorescent glue obtained by stirring is evenly sprayed onto the surface of the light-emitting area at room temperature. In one embodiment of the present invention, in order to prevent the non-luminous area from being sprayed with fluorescent glue, a baffle can be placed on the surface of the micro-light-emitting diode display chip before spraying, wherein the baffle includes a through hole, and the through hole is aligned with the light-emitting area. In one embodiment of the present invention, a fluorescent powder with a particle size of 2 to 5 microns is used, and 1 to 7 layers are sprayed to obtain a fluorescent layer with a thickness of about 10 to 15 microns. The lower the spraying thickness, the better the effect of preventing light crosstalk, and the lower the spraying thickness, the smaller the particle size of the fluorescent powder is required. In another embodiment of the present invention, the fluorescent layer can also be made by a dispensing process;

[0124] Next, in step 506, if Figure 6f As shown, a transparent covering layer is formed. A transparent covering layer 108 is formed on the surface of the micro-LED display chip to protect the light-emitting area, the fluorescent layer, etc. In one embodiment of the present invention, the transparent covering layer is made by a plastic encapsulation process. Specifically, a liquid adhesive is squeezed into a mold cavity in a manner similar to injection molding or extrusion, and then cured to form. The adhesive is usually transparent, and materials such as diffusing agents may be added to improve the light extraction efficiency. In another embodiment of the present invention, the transparent covering layer may also be made by a dispensing process. It should be understood that in some embodiments of the present invention, this step may be omitted and the process may be directly to step 507, encapsulation and cutting;

[0125] Next, in step 507, the package is cut into individual packages; and

[0126] Finally, in step 508, the optical separation and taping are performed. Each single package obtained by cutting is tested, each single package is classified according to brightness, and / or wavelength, and / or voltage, and taping is performed based on each type of single package.

[0127] Figure 7 and Figures 8a to 8f 1 and 2 respectively show a process flow and a process schematic diagram of a method for manufacturing a micro display panel according to another embodiment of the present invention. The manufacturing method in this embodiment is basically the same as that in the above embodiment, except that Figure 7 In the embodiment shown, step 505 is performed first to form a fluorescent layer, and then step 504 is performed to form an encapsulation layer. It should be noted that, as mentioned above, in this manufacturing method, the height of the dam should be higher than the fluorescent layer to prevent glue from flowing onto the fluorescent layer when forming the encapsulation layer.

[0128] The present invention also provides a pixelated projection lamp, which comprises the micro display panel as described above.

[0129] Although various embodiments of the present invention are described above, it should be understood that they are presented as examples only and not as limitations. It is obvious to those skilled in the relevant art that various combinations, modifications and changes can be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should only be defined according to the attached claims and their equivalents.

Claims

1. A micro display panel, characterized in that: include: substrate; A micro-LED display chip is located on the substrate, and the edge of the micro-LED display chip has a metal pad, and the metal pad is electrically connected to the area of ​​the substrate not covered by the micro-LED display chip; A fluorescent layer, located on the surface of the micro-LED display chip; The encapsulation layer covers the exposed area of ​​the substrate and the area where the micro-LED display chip is electrically connected to the substrate.

2. The micro display panel according to claim 1, characterized in that: The surface of the micro-LED display chip around the side wall of the fluorescent layer has a dam.

3. The micro display panel according to claim 2, characterized in that: The micro-LED display chip has a light-emitting area, the fluorescent layer is located on the surface of the light-emitting area, and the dam is located on the surface of the micro-LED display chip outside the light-emitting area.

4. The micro display panel according to claim 2, characterized in that: The top of the dam is higher than the top of the fluorescent layer.

5. The micro display panel according to claim 2, characterized in that: The outer edge of the dam does not exceed the edge of the micro light emitting diode display chip.

6. The micro display panel according to claim 2, characterized in that: The material of the dam includes silica gel and / or resin.

7. The micro display panel according to claim 6, characterized in that: The dam further comprises a colored material doped in the silica gel and / or resin, so that the dam is non-transparent, thereby positioning and protecting the light-emitting area.

8. The micro display panel according to claim 7, characterized in that: The colored material includes titanium dioxide and / or zirconium dioxide, or carbon black.

9. The micro display panel according to claim 2, characterized in that: The metal pad is electrically connected to the surface of the substrate not covered by the micro light emitting diode display chip through a metal bonding wire.

10. The micro display panel according to claim 9, characterized in that: The top of the dam is not lower than the highest point of the metal bonding line.

11. The micro display panel according to claim 2, characterized in that: The packaging layer covers the area between the outer wall of the dam and the outer wall of the substrate.

12. The micro display panel according to claim 1, characterized in that: The surface of the packaging layer includes at least one protrusion.

13. The micro display panel according to claim 1, characterized in that: The material of the packaging layer includes silica gel and / or resin.

14. The micro display panel according to claim 11, characterized in that: A transparent covering layer is also provided on the encapsulation layer, and the transparent covering layer covers the encapsulation layer.

15. The micro display panel according to claim 14, characterized in that: The transparent covering layer also covers the surface of the fluorescent layer.

16. The micro display panel according to claim 14, characterized in that: The top of the transparent covering layer is higher than the top of the dam, and the top of the transparent covering layer is flat.

17. The micro display panel according to claim 14, characterized in that: The top of the transparent cover layer has a rough structure.

18. The micro display panel according to claim 14, characterized in that: The material of the transparent covering layer includes silica gel and / or resin.

19. The micro display panel according to claim 18, characterized in that: The transparent covering layer further includes a diffusing agent and / or a surface roughening agent doped in the silica gel and / or the resin.

20. The micro display panel according to claim 1, characterized in that: The bottom of the substrate is also provided with an external solder pad, and the upper surface of the substrate is provided with an upper metal pad, wherein the upper metal pad is electrically connected to the metal pad of the micro light emitting diode display chip.

21. The micro display panel according to claim 1, characterized in that: The substrate is made of ceramic and metal.

22. The micro display panel according to claim 20, characterized in that: The substrate comprises at least one circuit structure layer, the circuit structure layer is electrically connected to the micro light emitting diode display chip, and is electrically connected to an external module through the external bonding pad.

23. The micro display panel according to claim 1, characterized in that: The micro light emitting diode display chip is bonded to the surface of the substrate.

24. The micro display panel according to claim 23, characterized in that: The micro light emitting diode display chip is bonded to the surface of the substrate through silver glue or silica gel.

25. The micro display panel according to claim 1, characterized in that: The micro-LED display chip includes a driving backplane and a micro-LED array, wherein the micro-LED array is arranged on the surface of the driving backplane; the micro-LED array includes a plurality of light-emitting mesas; the micro-LED array also includes a passivation layer, wherein the passivation layer at least covers the side surfaces of the light-emitting mesas; The micro-LED array also includes a top conductive layer, which is arranged above the micro-LED array; top electrodes are arranged between adjacent light-emitting mesas, and the top electrodes are interconnected; the micro-LED display chip also includes a micro-lens array, which is located above the micro-LED array area and includes a plurality of micro-lenses.

26. The micro display panel according to claim 1, characterized in that: The material of the fluorescent layer includes silica gel and / or resin, and the fluorescent layer also includes fluorescent powder doped in the silica gel and / or resin; the fluorescent layer also includes a diffusant and / or an anti-precipitation agent and / or a surface roughening agent doped in the silica gel and / or resin, the material of the diffusant includes an inorganic light diffusant, or an organic nano-micro-pearl light diffusant, and the material of the anti-precipitation agent includes an organic polymer compound.

27. The micro display panel according to claim 26, characterized in that: The thickness of the fluorescent layer is greater than the particle size of the fluorescent powder; the particle size of the fluorescent powder is 1 to 5 microns, and the thickness of the fluorescent layer is 10 to 50 microns.

28. A method for manufacturing a micro display panel, characterized in that: Includes steps: Provide micro-light emitting diode display chips; forming a dam around the light emitting area of ​​the micro light emitting diode display chip; forming a packaging layer around the micro light emitting diode display chip and the dam; as well as A fluorescent layer is formed on the surface of the light emitting area.

29. A method for manufacturing a micro display panel, characterized in that: Includes steps: Provide micro-light emitting diode display chips; forming a dam around the light emitting area of ​​the micro light emitting diode display chip; forming a fluorescent layer on the surface of the light-emitting area; as well as A packaging layer is formed around the micro light emitting diode display chip and the dam.

30. The manufacturing method according to claim 28 or 29, characterized in that: Also includes the steps: Before forming the dam, the micro-LED display chip is first fixed on a substrate, and the micro-LED display chip is electrically connected to the substrate through metal bonding wires, wherein the metal bonding wires are coated in the packaging layer.

31. The manufacturing method according to claim 30, characterized in that: The micro light emitting diode display chip is fixed on the substrate through high pressure and high temperature bonding or SMT patch process.

32. The manufacturing method according to claim 28 or 29, characterized in that: The dam is a silicone sheet, which is bonded to the surface of the micro light emitting diode display chip through a bonding process.

33. The manufacturing method according to claim 28 or 29, characterized in that: The dam is formed by glue dispensing or silicone injection molding process.

34. The manufacturing method according to claim 28 or 29, characterized in that: The encapsulation layer is formed by dispensing or silicone injection molding process.

35. The manufacturing method according to claim 28 or 29, characterized in that: Forming a fluorescent layer on the surface of the light-emitting area comprises the following steps: Adding fluorescent powder, diffusing agent and anti-precipitation agent into liquid silica gel or resin and stirring them to form fluorescent glue; Placing a baffle on the surface of the micro-LED display chip, wherein the baffle comprises a through hole, and the through hole is aligned with the light-emitting area; as well as The fluorescent glue is evenly sprayed onto the surface of the light-emitting area by a dispensing or spraying process.

36. The manufacturing method according to claim 28 or 29, characterized in that: Forming a fluorescent layer on the surface of the light-emitting area comprises the following steps: Adding fluorescent powder, diffusing agent and anti-precipitation agent into liquid silica gel or resin and stirring them to form fluorescent glue; as well as The fluorescent glue is disposed on the surface of the light-emitting area through a dispensing process and then baked to be cured and formed.

37. The manufacturing method according to claim 28 or 29, characterized in that: Also includes the steps: A transparent covering layer is formed on the surfaces of the encapsulation layer and the fluorescent layer.

38. The manufacturing method according to claim 37, characterized in that: The transparent covering layer is formed by a dispensing or silicone injection molding process.

39. The manufacturing method according to claim 28 or 29, characterized in that: Also includes the steps: Cutting to separate individual packages, and then perform optical splitting and taping.

40. A pixelated projection lamp, characterized in that Comprising the micro display panel as described in any one of claims 1 to 27.

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