Micro LED display panel applied to naked eye 3D and manufacturing method thereof

Abstract

The invention relates to a Micro LED display panel applied to naked eye 3D and a manufacturing method thereof, and relates to the technical field of semiconductor display. According to the manufacturing method of the Micro LED display panel applied to the naked eye 3D, packaging processing is performed on Micro LED chips in advance to form a plurality of Micro LED chip packaging modules, so that each Micro LED chip packaging module comprises a plurality of Micro LED chips arranged in an array, and when a magnetic structure is prepared, the micro LED chips are arranged in the array to form a plurality of micro LED chip packaging modules. Precise adsorption of the first magnetic structure and the corresponding second magnetic structure can be realized only by preparing the magnetic structures on the circle of Micro LED chips on the outermost periphery of the Micro LED chip packaging module and arranging the corresponding magnetic structures on the transfer substrate.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor light emitting technology, and in particular to a Micro LED display panel for naked-eye 3D and a manufacturing method thereof. Background Art

[0002] Glasses-free 3D display technology produces realistic stereoscopic images with space and depth without the need for any auxiliary equipment. This technology exploits the parallax of the human eye. Through specialized optical techniques and algorithms, each eye sees different images, thereby synthesizing a three-dimensional visual effect in the brain. Micro LED display panels are based on an array of micron-scale semiconductor light-emitting units. Each unit is typically less than 50 microns in size and can be densely integrated on a chip. This technology combines the advantages of new display technologies with light-emitting diode (LED) technology, offering self-luminescence, high efficiency, low power consumption, high integration, high stability, and all-weather operation. Displays based on Micro LED display technology are well-suited for glasses-free 3D. Micro LED display technology can be combined with lenticular lens technology. By placing a lenticular lens array in front of the display, the image is divided into multiple sub-pixels and projected to the viewer's eyes from different directions. Because the sub-pixels seen by each eye vary slightly from different angles, the illusion of three-dimensionality is created. Therefore, how to improve the preparation process of Micro-LED chips has become a hot topic widely discussed and deeply researched in the industry, aiming to further promote the popularization and application of Micro-LED technology in the naked-eye 3D field through technological breakthroughs. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a Micro LED display panel for naked-eye 3D and a manufacturing method thereof.

[0004] To achieve the above objectives, the present invention proposes a method for manufacturing a Micro LED display panel for naked-eye 3D, the method comprising the following steps: A semiconductor light-emitting wafer is provided, and the light-emitting wafer is diced to form a plurality of Micro LED chips. Each of the Micro LED chips includes a substrate and a functional layer located on the substrate.

[0005] Then, the plurality of Micro LED chips are subjected to a crystal expansion process.

[0006] A carrier substrate is provided, and the plurality of expanded Micro LED chips are disposed on the carrier substrate.

[0007] Then, an encapsulation layer is formed on the carrier substrate, the encapsulation layer wraps each of the Micro LED chips, and then the encapsulation layer is planarized to expose the substrate of each of the Micro LED chips.

[0008] The packaging layer is then cut to form a plurality of Micro LED chip packaging modules, each of which includes Micro LED chips arranged in an M×M array, where M≥10, and each of which includes a peripheral area and a middle area.

[0009] Then, the substrate of each Micro LED chip in the peripheral area of ​​the Micro LED chip packaging module is etched to form a groove in the substrate of each Micro LED chip in the peripheral area.

[0010] Then, a first magnetic structure is formed in each of the grooves.

[0011] A transfer substrate is provided, which has a plurality of second magnetic structures and a plurality of positioning posts. The Micro LED chip packaging module is transferred to the transfer substrate so that each first magnetic structure is magnetically adsorbed to a corresponding second magnetic structure.

[0012] A driving substrate is provided, wherein the driving substrate has multiple conductive pads and multiple positioning cavities, and the multiple positioning posts correspond one-to-one to the multiple positioning cavities. The Micro LED chip packaging module on the transfer substrate is then transferred to the driving substrate, so that each Micro LED chip is fixedly electrically connected to the corresponding conductive pad.

[0013] Then, the Micro LED chip packaging module on the driving substrate is etched to remove the first magnetic structure in each of the grooves.

[0014] As a preferred technical solution, the substrate is a sapphire substrate or a gallium nitride substrate, and the functional layer includes a first semiconductor layer, a light-emitting quantum well layer, a second semiconductor layer, a first electrode, and a second electrode.

[0015] As a preferred technical solution, the first electrode is electrically connected to the first semiconductor layer, and the second electrode is electrically connected to the second semiconductor layer.

[0016] As a preferred technical solution, before placing the multiple Micro LED chips after crystal expansion on the carrier substrate, a temporary protective layer is provided on the carrier substrate, and the first electrode and the second electrode of each Micro LED chip are buried in the temporary protective layer.

[0017] As a preferred technical solution, the outer area is an annular area, which includes a circle of MicroLED chips, and the middle area includes MicroLED chips arranged in an (M-2)×(M-2) array, where M≥10.

[0018] As a preferred technical solution, the first magnetic structure includes a resin material containing magnetic filler, wherein the magnetic filler is ferroferric oxide powder, iron-cobalt powder or iron-nickel powder, and the first magnetic structure is formed by a dispensing process, a slit coating process or a spraying process.

[0019] As a preferred technical solution, a plurality of the positioning posts surround a plurality of the second magnetic structures.

[0020] As a preferred technical solution, after removing the first magnetic structure in each of the grooves, an organic protection layer is formed on the driving substrate.

[0021] The present invention also proposes a Micro LED display panel for naked-eye 3D display, which is manufactured using the above-mentioned manufacturing method.

[0022] The beneficial effects of the present invention are: In the existing Micro LED chip transfer process, when using magnetic components for adsorption transfer, a magnetic block needs to be set on the back of each Micro LED chip. This makes the Micro LED chip transfer process more complicated, which in turn easily leads to a decrease in the Micro LED chip transfer yield, greatly increasing production costs. In the manufacturing method of the Micro LED display panel for naked-eye 3D of the present application, the Micro LED chips are pre-packaged to form a plurality of Micro LED chip packaging modules, so that each of the Micro LED chip packaging modules includes a plurality of Micro LED chips arranged in an array. When preparing the magnetic structure, it is only necessary to prepare the magnetic structure on the outermost circle of Micro LED chips of the Micro LED chip packaging module and set the corresponding magnetic structure on the transfer substrate, so as to achieve precise adsorption of the first magnetic structure and the corresponding second magnetic structure. The setting of the positioning column can, on the one hand, assist the Micro LED chip packaging module in being precisely set at the corresponding position of the transfer substrate. On the other hand, by setting a positioning cavity that cooperates with the positioning column, the Micro LED chip packaging module can be precisely transferred to the driving substrate. The present invention optimizes the manufacturing method of the Micro LED display panel, which greatly improves the transfer accuracy and patent yield, and greatly reduces the process complexity, thereby reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It shows a structural schematic diagram of scribing a light-emitting wafer to form multiple Micro LED chips in an embodiment of the present invention.

[0024] Figure 2 It shows a structural schematic diagram of placing a Micro LED chip on a carrier substrate and forming an encapsulation layer in an embodiment of the present invention.

[0025] Figure 3 It shows a schematic diagram of the structure of forming multiple Micro LED chip packaging modules in an embodiment of the present invention.

[0026] Figure 4 It is a schematic structural diagram of forming a groove and forming a first magnetic structure in an embodiment of the present invention.

[0027] Figure 5 It shows a schematic structural diagram of transferring a Micro LED chip packaging module to a transfer substrate in an embodiment of the present invention.

[0028] Figure 6 It shows a structural schematic diagram of transferring the Micro LED chip packaging module on the transfer substrate to the driving substrate in an embodiment of the present invention.

[0029] Figure 7 Shown is a schematic diagram of the structure of forming an encapsulation layer in an embodiment of the present invention DETAILED DESCRIPTION

[0030] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0031] like Figures 1 to 7 As shown, this embodiment provides a method for manufacturing a Micro LED display panel for naked-eye 3D, and the method for manufacturing a Micro LED display panel for naked-eye 3D includes the following steps: like Figure 1 , providing a semiconductor light-emitting wafer, and performing a dicing process on the light-emitting wafer to form a plurality of Micro LED chips 100, each of the Micro LED chips 100 includes a substrate 101 and a functional layer 102 located on the substrate.

[0032] In a specific embodiment, the substrate 101 is a sapphire substrate or a gallium nitride substrate, and the functional layer 102 includes a first semiconductor layer, a light-emitting quantum well layer, a second semiconductor layer, a first electrode and a second electrode (not shown), wherein the first electrode is electrically connected to the first semiconductor layer, and the second electrode is electrically connected to the second semiconductor layer.

[0033] In a specific embodiment, the first semiconductor layer, the light-emitting quantum well layer and the second semiconductor layer are prepared by metal organic chemical vapor deposition, wherein the first semiconductor layer and the second semiconductor layer are n-type gallium nitride layers and p-type gallium nitride layers, respectively, and the light-emitting quantum well layer is an alternately grown InGaN quantum well layer and a GaN quantum barrier layer.

[0034] In a specific embodiment, the first electrode and the second electrode are metal electrodes, and the material of the metal electrodes is any suitable single metal layer or alloy metal layer such as copper, aluminum, silver, titanium, gold, palladium, etc., and the metal electrodes are formed by thermal evaporation, magnetron sputtering, electroplating or chemical plating process.

[0035] Then, the plurality of Micro LED chips are subjected to a crystal expansion process to increase the spacing between adjacent Micro LED chips, thereby facilitating the subsequent transfer process.

[0036] like Figure 2As shown, a carrier substrate 200 is provided, and the plurality of expanded Micro LED chips 100 are placed on the carrier substrate 200 .

[0037] In a specific embodiment, an encapsulation layer 300 is then formed on the carrier substrate 200 , and the encapsulation layer 300 wraps each of the Micro LED chips 100 . The encapsulation layer is then planarized to expose the substrate 101 of each of the Micro LED chips 100 .

[0038] In a specific embodiment, before the expanded plurality of Micro LED chips 100 are disposed on the carrier substrate 200 , a temporary protective layer 201 is disposed on the carrier substrate 200 , and the first electrode and the second electrode of each Micro LED chip 100 are embedded in the temporary protective layer 201 .

[0039] In a specific embodiment, the carrier substrate 200 is any suitable rigid substrate such as glass, ceramic, metal, etc., and the temporary protective layer 201 can be an adhesive layer that loses its stickiness under light or heating, thereby facilitating the peeling of the MicroLED chip 100.

[0040] In a specific embodiment, the encapsulation layer 300 is made of any suitable polymer material such as epoxy resin, and is formed by any process such as slit coating, molding, hot pressing, etc.

[0041] like Figure 3 As shown, the encapsulation layer 300 is then cut to form a plurality of Micro LED chip encapsulation modules 400. Each of the Micro LED chip encapsulation modules 400 includes Micro LED chips arranged in an M×M array, where M is greater than or equal to 10. Each of the Micro LED chip encapsulation modules 400 includes a peripheral region and a middle region. Figure 3 Only a portion of the Micro LED chips are shown schematically, and the actual number of Micro LED chips in each Micro LED chip packaging module 400 shall be subject to the written description of the specific embodiment.

[0042] In a specific embodiment, a plurality of Micro LED chip packaging modules 400 are formed by a laser cutting process.

[0043] In a specific embodiment, the carrier substrate 200 is removed, and then the encapsulation layer 300 is cut.

[0044] In a specific embodiment, each of the Micro LED chip packaging modules 400 includes Micro LED chips 100 arranged in an M×M array, where M ≥ 10 and M ≤ 30. Thus, by adjusting the specific number of Micro LED chips 100 in each of the Micro LED chip packaging modules 400, the manufacturing complexity and transfer efficiency of the Micro LED chip packaging modules 400 can be balanced.

[0045] In a specific embodiment, the outer region is an annular region comprising a ring of Micro LED chips, and the central region comprises Micro LED chips arranged in an (M-2)×(M-2) array, where M≥10. In a more preferred embodiment, the central region comprises Micro LED chips arranged in an (M-2)×(M-2) array, where M≥10 and M≤30.

[0046] In other embodiments, the annular area may include two circles of Micro LED chips, and the two circles of Micro LED chips are the outermost circles of the Micro LED chip packaging module 400.

[0047] like Figure 4 As shown, Figure 4 FIG4 is a top view of a Micro LED chip packaging module 400. The substrate 101 of each Micro LED chip 100 located in the peripheral area of ​​the Micro LED chip packaging module 400 is then etched to form a groove 1011 in the substrate 101 of each Micro LED chip 100 in the peripheral area. A first magnetic structure 500 is then formed in each groove 1011.

[0048] In a specific embodiment, the groove 1011 is formed by a wet etching process or a dry etching process.

[0049] In a specific embodiment, the first magnetic structure 500 includes a resin material containing magnetic filler, wherein the magnetic filler is ferroferric oxide powder, iron-cobalt powder or iron-nickel powder, and the resin material is any suitable resin material such as polyethylene, polypropylene, EVA, PVB, etc. The first magnetic structure 500 is formed by a dispensing process, a slit coating process or a spraying process.

[0050] In a specific embodiment, the content of the magnetic filler in the first magnetic structure 500 is 1-5 wt %.

[0051] like Figure 5As shown, a transfer substrate 600 is provided, and the transfer substrate 600 has a plurality of second magnetic structures 601 and a plurality of positioning posts 602. The Micro LED chip packaging module 500 is transferred to the transfer substrate 600 so that each of the first magnetic structures 500 is magnetically adsorbed with a corresponding second magnetic structure 602.

[0052] In a specific embodiment, the plurality of positioning posts 602 surround the plurality of second magnetic structures 601 .

[0053] In a specific embodiment, it is necessary to form multiple grooves on the transfer substrate 600, and then form a second magnetic structure 601 in the grooves. More specifically, the second magnetic structure 601 includes a resin material containing magnetic filler, and the magnetic filler is ferroferric oxide powder, iron cobalt powder or iron nickel powder. The resin material is any suitable resin material such as polyethylene, polypropylene, EVA, PVB, etc. The second magnetic structure 601 is formed by a dispensing process, a slit coating process or a spraying process. The content of magnetic filler in the second magnetic structure 601 is 8-15 wt%. Through the above-mentioned setting method, the magnetic adsorption strength of the first magnetic structure 500 and the second magnetic structure 601 can be greatly improved, and by setting a large amount of magnetic filler in the second magnetic structure 601, the reuse rate of the transfer substrate 600 can be improved.

[0054] like Figure 6 As shown, a driving substrate 700 is provided, and the driving substrate 700 has a plurality of conductive pads (not shown) and a plurality of positioning cavities 702. The plurality of positioning posts 602 correspond one-to-one to the plurality of positioning cavities 702. Then, the Micro LED chip packaging module 400 on the transfer substrate 600 is transferred to the driving substrate 700, so that each Micro LED chip 100 is fixedly electrically connected to the corresponding conductive pad.

[0055] like Figure 7 As shown, the transfer substrate 600 is then removed, and the MicroLED chip packaging module 400 on the driving substrate 700 is then etched to remove the first magnetic structure 500 in each of the grooves 1011. After removing the first magnetic structure 500 in each of the grooves 1011, an organic protective layer 800 is formed on the driving substrate 700.

[0056] In a specific embodiment, the material of the organic protection layer 800 is epoxy resin.

[0057] like Figure 7 As shown, the present invention also proposes a Micro LED display panel for naked-eye 3D, which is manufactured using the above-mentioned manufacturing method.

[0058] In other preferred technical solutions, the present invention proposes a method for manufacturing a Micro LED display panel for naked-eye 3D, which comprises the following steps: A semiconductor light-emitting wafer is provided, and the light-emitting wafer is diced to form a plurality of Micro LED chips. Each of the Micro LED chips includes a substrate and a functional layer located on the substrate.

[0059] Then, the plurality of Micro LED chips are subjected to a crystal expansion process.

[0060] A carrier substrate is provided, and the plurality of expanded Micro LED chips are disposed on the carrier substrate.

[0061] Then, an encapsulation layer is formed on the carrier substrate, the encapsulation layer wraps each of the Micro LED chips, and then the encapsulation layer is planarized to expose the substrate of each of the Micro LED chips.

[0062] The packaging layer is then cut to form a plurality of Micro LED chip packaging modules, each of which includes Micro LED chips arranged in an M×M array, where M≥10, and each of which includes a peripheral area and a middle area.

[0063] Then, the substrate of each Micro LED chip in the peripheral area of ​​the Micro LED chip packaging module is etched to form a groove in the substrate of each Micro LED chip in the peripheral area.

[0064] Then, a first magnetic structure is formed in each of the grooves.

[0065] A transfer substrate is provided, which has a plurality of second magnetic structures and a plurality of positioning posts. The Micro LED chip packaging module is transferred to the transfer substrate so that each first magnetic structure is magnetically adsorbed to a corresponding second magnetic structure.

[0066] A driving substrate is provided, wherein the driving substrate has multiple conductive pads and multiple positioning cavities, and the multiple positioning posts correspond one-to-one to the multiple positioning cavities. The Micro LED chip packaging module on the transfer substrate is then transferred to the driving substrate, so that each Micro LED chip is fixedly electrically connected to the corresponding conductive pad.

[0067] Then, the Micro LED chip packaging module on the driving substrate is etched to remove the first magnetic structure in each of the grooves.

[0068] In other preferred technical solutions, the substrate is a sapphire substrate or a gallium nitride substrate, and the functional layer includes a first semiconductor layer, a light-emitting quantum well layer, a second semiconductor layer, a first electrode, and a second electrode.

[0069] In other preferred technical solutions, the first electrode is electrically connected to the first semiconductor layer, and the second electrode is electrically connected to the second semiconductor layer.

[0070] In other preferred technical solutions, before placing the multiple Micro LED chips after crystal expansion on the carrier substrate, a temporary protective layer is provided on the carrier substrate, and the first electrode and the second electrode of each Micro LED chip are buried in the temporary protective layer.

[0071] In other preferred technical solutions, the outer area is an annular area, which includes a circle of Micro LED chips, and the middle area includes Micro LED chips arranged in an (M-2)×(M-2) array, where M≥10.

[0072] In other preferred technical solutions, the first magnetic structure includes a resin material containing magnetic filler, and the magnetic filler is ferroferric oxide powder, iron-cobalt powder or iron-nickel powder. The first magnetic structure is formed by a dispensing process, a slit coating process or a spraying process.

[0073] In other preferred technical solutions, a plurality of the positioning posts surround a plurality of the second magnetic structures.

[0074] In other preferred technical solutions, after removing the first magnetic structure in each of the grooves, an organic protection layer is formed on the driving substrate.

[0075] In other preferred technical solutions, the present invention also proposes a Micro LED display panel for naked-eye 3D, which is manufactured using the above-mentioned manufacturing method.

[0076] In the existing Micro LED chip transfer process, when using magnetic components for adsorption transfer, a magnetic block needs to be set on the back of each Micro LED chip. This makes the Micro LED chip transfer process more complicated, which in turn easily leads to a decrease in the Micro LED chip transfer yield, greatly increasing production costs. In the manufacturing method of the Micro LED display panel for naked-eye 3D of the present application, the Micro LED chips are pre-packaged to form a plurality of Micro LED chip packaging modules, so that each of the Micro LED chip packaging modules includes a plurality of Micro LED chips arranged in an array. When preparing the magnetic structure, it is only necessary to prepare the magnetic structure on the outermost circle of Micro LED chips of the Micro LED chip packaging module and set the corresponding magnetic structure on the transfer substrate, so as to achieve precise adsorption of the first magnetic structure and the corresponding second magnetic structure. The setting of the positioning column can, on the one hand, assist the Micro LED chip packaging module in being precisely set at the corresponding position of the transfer substrate. On the other hand, by setting a positioning cavity that cooperates with the positioning column, the Micro LED chip packaging module can be precisely transferred to the driving substrate. The present invention optimizes the manufacturing method of the Micro LED display panel, which greatly improves the transfer accuracy and patent yield, and greatly reduces the process complexity, thereby reducing the production cost.

[0077] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for manufacturing a Micro LED display panel for naked-eye 3D display, characterized by: The method for manufacturing a Micro LED display panel for naked-eye 3D includes the following steps: Providing a semiconductor light-emitting wafer, and scribing the light-emitting wafer to form a plurality of Micro LED chips, each of the Micro LED chips including a substrate and a functional layer located on the substrate; Then, performing a crystal expansion process on the plurality of Micro LED chips; Providing a carrier substrate, and placing the plurality of expanded Micro LED chips on the carrier substrate; Then, forming an encapsulation layer on the carrier substrate, the encapsulation layer wrapping each of the Micro LED chips, and then performing a planarization process on the encapsulation layer to expose the substrate of each of the Micro LED chips; Then, the packaging layer is cut to form a plurality of Micro LED chip packaging modules, each of which includes Micro LED chips arranged in an M×M array, where M is greater than or equal to 10, and each of which includes a peripheral region and a middle region; Then, etching the substrate of each Micro LED chip in the peripheral area of ​​the Micro LED chip packaging module to form a groove in the substrate of each Micro LED chip in the peripheral area; Then forming a first magnetic structure in each of the grooves; Providing a transfer substrate having a plurality of second magnetic structures and a plurality of positioning posts, transferring the MicroLED chip package module to the transfer substrate so that each first magnetic structure is magnetically attached to a corresponding second magnetic structure; Providing a driving substrate having a plurality of conductive pads and a plurality of positioning cavities, wherein the plurality of positioning posts correspond one-to-one to the plurality of positioning cavities. Then, transferring the Micro LED chip package module on the transfer substrate to the driving substrate, such that each Micro LED chip is fixedly electrically connected to a corresponding conductive pad; Then, the Micro LED chip packaging module on the driving substrate is etched to remove the first magnetic structure in each of the grooves.

2. The method for manufacturing a Micro LED display panel for naked-eye 3D display according to claim 1, wherein: The substrate is a sapphire substrate or a gallium nitride substrate, and the functional layer includes a first semiconductor layer, a light-emitting quantum well layer, a second semiconductor layer, a first electrode, and a second electrode.

3. The method for manufacturing a Micro LED display panel for naked-eye 3D display according to claim 2, wherein: The first electrode is electrically connected to the first semiconductor layer, and the second electrode is electrically connected to the second semiconductor layer.

4. The method for manufacturing a Micro LED display panel for naked-eye 3D display according to claim 2, wherein: Before placing the plurality of expanded Micro LED chips on the carrier substrate, a temporary protective layer is provided on the carrier substrate, and the first electrode and the second electrode of each Micro LED chip are buried in the temporary protective layer.

5. The method for manufacturing a Micro LED display panel for naked-eye 3D display according to claim 1, wherein: The outer area is an annular area, which includes a circle of Micro LED chips, and the middle area includes Micro LED chips arranged in an (M-2)×(M-2) array, where M≥10.

6. The method for manufacturing a Micro LED display panel for naked-eye 3D display according to claim 1, wherein: The first magnetic structure includes a resin material containing a magnetic filler, wherein the magnetic filler is ferroferric oxide powder, iron-cobalt powder or iron-nickel powder, and the first magnetic structure is formed by a dispensing process, a slit coating process or a spraying process.

7. The method for manufacturing a Micro LED display panel for naked-eye 3D display according to claim 1, wherein: The plurality of positioning posts surround the plurality of second magnetic structures.

8. The method for manufacturing a Micro LED display panel for naked-eye 3D display according to claim 1, wherein: After removing the first magnetic structure in each of the grooves, an organic protection layer is formed on the driving substrate.

9. A Micro LED display panel for naked-eye 3D, characterized in that: The display panel is manufactured by the method for manufacturing a Micro LED display panel for naked-eye 3D according to any one of claims 1 to 8.

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