Manufacturing method of micro LED light projection chip for vehicle

Abstract

The application discloses a manufacturing method of a vehicle Micro LED light projection chip. An integrated lens is made on a substrate based on a preset array pattern on one side of the substrate of a wafer far from a metal electrode, so that the chip can integrate the lens without using an additional lens or optical component; and the wafer is cut to obtain an integrated chip, and a high-integration, high-pixel density and small-volume chip can be obtained through a plurality of sub-pixels on the integrated chip; each pixel on the chip corresponds to a driving substrate, so that the effect of adjustable resolution and free pixel partitioning can be realized through driving design.

Description

[0001] The present application is a divisional application of the parent application with the application number 202210473461.5, the application date of April 29, 2022, and the name of 'Micro LED light projection chip and manufacturing method thereof'. TECHNICAL FIELD

[0002] The present application relates to the field of semiconductor electronics, in particular to a manufacturing method of a vehicle Micro LED light projection chip. BACKGROUND

[0003] At present, Micro LED has the following three advantages: 1. High brightness; 2. High life, high reliability, and high environmental tolerance. However, there is no case of Micro LED applied to vehicle projection display at present, and the existing projection light sources for vehicles mostly use single-point large-size LEDs, which have low integration, poor pixel density, large volume, and need to be equipped with more optical components such as lenses. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a manufacturing method of a vehicle Micro LED light projection chip, which can reduce the demand of the light projection chip for optical components and improve the resolution of vehicle projection.

[0005] In order to solve the above technical problems, the technical scheme adopted by the present application is:

[0006] A manufacturing method of a vehicle Micro LED light projection chip, comprising the steps of:

[0007] Preparing a conductive layer, a protective layer and a metal electrode on a wafer in a preset array pattern;

[0008] On the side of the substrate of the wafer away from the metal electrode, the substrate is made into a lens according to the preset array pattern;

[0009] The etched wafer is cut to obtain an integrated chip with a lens;

[0010] The electrodes of the integrated chip are welded to a driving substrate by a welding material to obtain a light projection chip.

[0011] In order to solve the above technical problems, another technical scheme adopted by the present application is:

[0012] A vehicle Micro LED light projection chip, comprising an integrated chip, a welding material and a driving substrate;

[0013] The integrated chip comprises a substrate and a plurality of sub-pixels on the surface of the substrate;

[0014] The substrate far from the sub-pixels is etched into a lens shape according to a preset array pattern;

[0015] The sub-pixels are arranged according to a preset array pattern, and a welding pad is arranged at the position of each sub-pixel on the surface of the substrate;

[0016] The welding pad is connected with the driving substrate through a welding material.

[0017] The beneficial effects of the present application are as follows: the substrate far from the metal electrode of the wafer is made into a lens according to a preset array pattern, so that the chip can be integrated with the lens without using an additional lens or optical component; and the wafer can be cut to obtain an integrated chip, and a high-integration, high-pixel density and small-volume chip can be obtained through the multiple sub-pixels on the integrated chip; each pixel on the chip corresponds to the driving substrate, so that the effects of adjustable resolution and free pixel partitioning can be achieved through driving design. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A flowchart of a manufacturing method of a vehicle Micro LED light projection chip according to an embodiment of the present application;

[0019] Figure 2 A structure diagram of a vehicle Micro LED light projection chip using a substrate to make a lens according to an embodiment of the present application;

[0020] Figure 3 A structure diagram of a vehicle Micro LED light projection chip using a substrate to make a lens according to an embodiment of the present application;

[0021] Figure 4 A structure diagram of a vehicle Micro LED light projection chip using a substrate and a silicon oxide layer to make a lens according to an embodiment of the present application;

[0022] Figure 5 An application scenario diagram of a vehicle Micro LED light projection chip according to an embodiment of the present application;

[0023] Figure 6 A driving effect diagram of a vehicle Micro LED light projection chip according to an embodiment of the present application;

[0024] REFERENCE NUMERALS:

[0025] 1, pixel array; 2, welding pad; 3, sub-pixel; 4, substrate; 5, lens; 6, integrated chip; 7, welding material; 8, driving substrate; 9, light projection chip mounting position; 10, projection area; 11, silicon oxide layer. DETAILED DESCRIPTION

[0026] In order to explain the technical content of the present application, the purposes and effects achieved, the following will be described in conjunction with the embodiments and the accompanying drawings.

[0027] Please refer to Figure 1 The embodiment of the present application provides a manufacturing method of a vehicle Micro LED light projection chip, comprising the following steps:

[0028] A conductive layer, a protective layer and a metal electrode are prepared on the wafer in a preset array pattern;

[0029] On the side of the substrate of the wafer away from the metal electrode, the substrate is made into a lens according to the preset array pattern;

[0030] The etched wafer is cut to obtain an integrated chip with a lens;

[0031] The electrodes of the integrated chip are welded to a driving substrate by a welding material to obtain a light projection chip.

[0032] From the above description, the beneficial effects of the present application are that on the side of the substrate of the wafer away from the metal electrode, the substrate is made into a lens according to the preset array pattern, so that the chip can be integrated with the lens without using an additional lens or optical component; and the wafer is cut to obtain an integrated chip, and a high-integration, high-pixel density and small-volume chip can be obtained through a plurality of sub-pixels on the integrated chip; each pixel on the chip corresponds to a driving substrate, which facilitates the realization of resolution adjustment and pixel free partitioning through driving design.

[0033] Further, before the conductive layer, the protective layer and the metal electrode are prepared on the wafer in the preset array pattern, the method comprises the following steps:

[0034] According to the arrangement of the driving substrate, a pixel array of the chip is arranged on the wafer, and a plurality of LED self-luminous pixels are integrated in the chip of the wafer according to the preset array pattern of the pixel array.

[0035] From the above description, the pixel array is directly integrated on the wafer, a plurality of high-brightness LED self-luminous pixels can be integrated in one chip, and the pixel density and integration can be improved without the need for separate welding of each chip.

[0036] Further, on the side of the substrate of the wafer away from the metal electrode, the substrate is made into a lens according to the preset array pattern, which comprises the following steps:

[0037] On the side of the substrate of the wafer away from the metal electrode, polishing is performed, and the substrate is etched according to the preset array pattern to make the substrate into a lens.

[0038] As can be seen from the above description, the lens is made of the substrate, so that the lens is integrated on the chip instead of being externally added or an optical component, thereby reducing the redundant connection lines, and meanwhile, the lens made of the substrate can improve the corrosion resistance and acid and alkali resistance of the lens.

[0039] Further, the substrate is made into the lens, and then the method further comprises:

[0040] A silicon oxide layer is deposited on the lens, and the silicon oxide layer is etched and the profile of the lens is adjusted.

[0041] As can be seen from the above description, the secondary deposition and the secondary etching of the lens can adjust the profile of the lens to the expected aspect ratio and tip angle.

[0042] Further, the substrate of the wafer is made into the lens on the side away from the metal electrode according to the preset array pattern, and the method further comprises:

[0043] A silicon oxide layer is deposited on the side of the substrate of the wafer away from the metal electrode, and the substrate and the silicon oxide layer are etched according to the preset array pattern, and the substrate and the silicon oxide layer are made into the lens.

[0044] As can be seen from the above description, the silicon oxide layer is deposited on the substrate, and the substrate and the silicon oxide layer are patterned and etched at the same time, so that the lens made of the composite substrate is obtained, thereby strengthening the projection structure of the chip.

[0045] Please refer to Figure 2 Another embodiment of the present application provides a Micro LED light projection chip for vehicles, comprising an integrated chip, a welding material and a driving substrate.

[0046] The integrated chip comprises a substrate and a plurality of sub-pixels on the surface of the substrate.

[0047] The side of the substrate away from the sub-pixels is in the shape of a lens etched according to a preset array pattern.

[0048] The sub-pixels are arranged according to the preset array pattern, and a welding pad is arranged at the position of each sub-pixel on the surface of the substrate.

[0049] The welding pad is connected to the driving substrate through the welding material.

[0050] As can be seen from the above description, the substrate of the wafer is made into a lens in a preset array pattern on the side of the substrate away from the metal electrode, so that the chip can be integrated with the lens without using an additional lens or optical component; and the integrated chip can be obtained by cutting the wafer, and a high-integration, high-pixel density and small-size chip can be obtained by the multiple sub-pixels on the integrated chip; each pixel on the chip corresponds to a driving substrate, so that the resolution can be adjusted and the effect of free partition of pixels can be achieved by driving design.

[0051] Further, the side of the substrate away from the sub-pixel is deposited with a silicon oxide layer, and the lens shape is obtained by etching the substrate and the silicon oxide layer in the preset array pattern.

[0052] As can be seen from the above description, the silicon oxide layer is deposited on the substrate, and the substrate and the silicon oxide layer are etched at the same time, so that the lens made of the composite substrate can be obtained, thereby strengthening the projection structure of the chip.

[0053] Further, the lens shape on the side of the substrate away from the sub-pixel is provided with a silicon oxide layer with a lens shape.

[0054] As can be seen from the above description, the lens is subjected to secondary deposition and secondary etching, so that the appearance of the lens can be adjusted to the expected aspect ratio and tip angle.

[0055] Further, the bottom width of the lens shape is 10-200μm, and the height is 50-500μm.

[0056] Further, the thickness of the silicon oxide layer is 10-300μm.

[0057] As can be seen from the above description, the appearance of the lens can be adjusted by depositing the silicon oxide layer, thereby improving the flexibility of lens manufacturing.

[0058] The manufacturing method of the vehicle Micro LED light projection chip described above is suitable for being used as a high-definition projection light source for vehicles, and the following will be described through specific embodiments:

[0059] Embodiment one

[0060] Please refer to Figure 1 A manufacturing method of a vehicle Micro LED light projection chip, comprising the steps of:

[0061] S1, according to the arrangement of the driving substrate 8, the pixel array 1 of the chip is arranged on the wafer, and multiple LED self-luminous pixels are integrated in the chip of the wafer according to the preset array pattern of the pixel array 1.

[0062] In which, 900,000 to 10 million high-brightness LED self-luminous pixels can be integrated in a chip, the chip volume depends on the number of pixels, and the pixel density can reach more than 1000ppi, and the corresponding size is between 20um and 2cm.

[0063] S2, a conductive layer, a protective layer and a metal electrode are prepared on the wafer in a preset array pattern.

[0064] S3, on the side of the substrate 4 of the wafer away from the metal electrode, the substrate 4 is made into a lens 5 according to the preset array pattern.

[0065] Among them, the lens 5 can be a convex lens for condensing light or a concave lens for scattering light, and the lens 5 is made by the following three methods:

[0066] 1. Use the substrate 4 to make the lens 5:

[0067] Grind and polish the side of the substrate 4 of the wafer away from the metal electrode, and etch the substrate 4 according to the preset array pattern, and make an integrated lens 5 based on the substrate 4.

[0068] 2. Adjust the topography of the lens 5 made of the substrate 4:

[0069] Grind and polish the side of the substrate 4 of the wafer away from the metal electrode, and etch the substrate 4 according to the preset array pattern, and make an integrated lens 5 based on the substrate 4; deposit a silicon oxide layer 11 on the integrated lens 5, and etch the silicon oxide layer 11 and adjust the topography of the lens 5.

[0070] 3. Use the substrate 4 and the silicon oxide layer 11 to make the lens 5:

[0071] Depositing a silicon oxide layer 11 on the side of the substrate 4 of the wafer away from the metal electrode, and etching the substrate 4 and the silicon oxide layer 11 according to the preset array pattern, and making an integrated lens 5 based on the substrate 4 and the silicon oxide layer 11.

[0072] S4, cut the etched wafer to obtain an integrated chip 6 with a lens 5.

[0073] S5, weld the electrodes of the integrated chip 6 with the driving substrate 8 through the welding material 7 to obtain a light projection chip.

[0074] Example two

[0075] This embodiment provides a specific manufacturing method of a Micro LED light projection chip for vehicles, in which the substrate 4 is used to make the lens 5, specifically:

[0076] Step 11, using the MOCVD device to grow the GaN epitaxial wafer on the sapphire substrate 4 as the base, using the photoetching machine and photoetching glue and other photoetching facilities and materials to transfer the pattern according to the designed chip pattern, and etching the GaN surface to make the N-type layer.

[0077] Step 12, evaporating a conductive layer on the above wafer, using a photoetching machine and photoetching glue and other photoetching facilities and materials to transfer the pattern according to the designed chip pattern, and etching to remove the current expansion layer film on the N-type layer.

[0078] Step 13, depositing an aluminum oxide and silicon oxide protective layer on the above wafer using an ALD device and a PECVD device, using a photoetching machine and photoetching glue and other photoetching facilities and materials to transfer the pattern according to the designed chip pattern, and etching to remove the protective layer and reserve the metal electrode position.

[0079] Step 14, performing glue coating and photoetching on the above wafer, and then evaporating a metal electrode using metal evaporation, and then performing metal stripping to leave a metal electrode at the predetermined position.

[0080] Step 15, please refer to Figure 2 Grinding and polishing the substrate 4 of the above wafer, using a photoetching machine and photoetching glue and other photoetching facilities and materials to transfer the pattern on the substrate 4 according to the designed microlens array pattern, and performing ICP etching to make an integrated lens 5, with a lens 5 bottom width range of 10-200 μm and a lens 5 height of 50-300 μm.

[0081] Step 16, cutting the above wafer to make an integrated Micro LED chip with a lens 5.

[0082] Step 17, welding the above chip to the driving substrate 8 through the welding material 7, with the chip welding surface being the chip electrode, the chip electrode surface being below after welding, combined with the driving substrate 8, and the lens 5 being above.

[0083] The above is the manufacturing method of the vehicle Micro LED light projection chip, please refer to Figure 5 The above is the manufacturing method of the vehicle Micro LED light projection chip, please refer to

[0084] Example Three

[0085] The embodiment provides a specific manufacturing method of a vehicle Micro LED light projection chip, wherein the lens 5 made of the substrate 4 is adjusted in appearance, specifically:

[0086] Step 21, using the MOCVD device to grow a GaN epitaxial wafer on the sapphire substrate 4 as the base, using photoetching machine and photoetching glue and other photoetching facilities and materials to transfer the designed chip pattern, and etching the GaN surface to make the N-type layer.

[0087] Step 22, evaporating a conductive layer on the above wafer, which can be indium tin oxide or NiAu alloy metal or molybdenum oxide, using photoetching machine and photoetching glue and other photoetching facilities and materials to transfer the designed chip pattern, removing the current expansion layer film on the N-type layer by etching, and only retaining the conductive layer on the P-GaN.

[0088] Step 23, depositing titanium oxide and silicon oxide protective layer on the above wafer using DBR device and PECVD device, using photoetching machine and photoetching glue and other photoetching facilities and materials to transfer the designed chip pattern, making conductive vias under the metal electrode by etching or corrosion, and reserving the metal electrode position.

[0089] Step 24, performing glue coating and photoetching on the above wafer, using electron beam evaporation metal or sputtering metal to make conductive pads 2, and then performing metal stripping to leave metal electrodes at the predetermined position.

[0090] Step 25, grinding and polishing the substrate 4 of the above wafer. Continue processing on the sapphire surface, and use photoetching machine and photoetching glue and other photoetching facilities and materials to transfer the designed microlens array pattern on the substrate 4.

[0091] Step 26, according to the pattern made in step 25, performing ICP etching to make an integrated lens 5, the lens 5 has a width range of 10-200 μm, and the lens 5 has a height of 50-500 μm.

[0092] Step 27, using ALD or PECVD device to continue secondary deposition on the surface of the above lens 5, depositing SiO2 material, and then using photoetching glue to make patterns by photoetching machine.

[0093] Step 28, please refer to Figure 3 Second etching is performed on the lens 5 to adjust the appearance of the lens 5 to obtain the desired aspect ratio and tip angle.

[0094] Step 29, cutting the above wafer to make an integrated Micro LED chip with lens 5, and welding the above chip to the driving substrate 8 through the welding material 7, the welding surface of the chip being the chip electrode, and the chip electrode surface being below after welding, combined with the driving substrate 8.

[0095] Please refer to Figure 5The driving and chip are pasted on the light projection chip mounting position 9 of the automobile, and the projection effect and control of the projection pattern can be realized in the projection area 10 by driving power supply and control.

[0096] Embodiment Four

[0097] The embodiment provides a specific manufacturing method of the Micro LED light projection chip for vehicles, wherein the substrate 4 and the silicon oxide layer 11 are used to manufacture the lens 5, and specifically:

[0098] Step 31, using a GaN epitaxial wafer grown on a sapphire substrate 4 as a base, using a photoetching machine and photoetching glue and other photoetching facilities and materials to perform pattern transfer according to a designed chip pattern, and removing a current expansion layer film on the N-type layer by etching to only reserve the conductive layer on the P-GaN.

[0099] Step 32, evaporating a conductive layer on the wafer, the conductive layer can be indium tin oxide or NiAu alloy metal or molybdenum oxide, using a photoetching machine and photoetching glue and other photoetching facilities and materials to perform pattern transfer according to a designed chip pattern, and removing the current expansion layer film on the N-type layer by etching to only reserve the conductive layer on the P-GaN.

[0100] Step 33, depositing a titanium oxide and silicon oxide protective layer on the wafer by using a DBR device and a PECVD device, using a photoetching machine and photoetching glue and other photoetching facilities and materials to perform pattern transfer according to a designed chip pattern, and making a conductive via under the metal electrode by etching or etching to reserve the metal electrode position.

[0101] Step 34, performing glue coating and photoetching on the wafer, using an electron beam evaporation metal or sputtering metal to make a conductive pad 2, and then performing metal stripping to leave the metal electrode at a predetermined position.

[0102] Step 35, please refer to Figure 4 The substrate 4 of the wafer is ground and polished, silicon oxide is deposited on the sapphire surface, the thickness ranges from 10 to 300 μm, the designed microlens array pattern is transferred to the silicon oxide film by using a photoetching machine and photoetching glue and other photoetching facilities and materials, and the silicon oxide film between the two lens patterns is removed by wet etching.

[0103] Step 36, performing ICP etching on the pattern to make an integrated lens 5, the bottom width of the lens 5 ranges from 10 to 200 μm, and the height of the lens 5 ranges from 50 to 500 μm.

[0104] Step 37, cutting the wafer to make an integrated Micro LED chip with the lens 5.

[0105] Step 38, the chip is welded to the driving substrate 8 through the welding material 7, the welding surface of the chip is the chip electrode, and the chip electrode surface is below after welding, combined with the driving substrate 8.

[0106] Please refer to Figure 5 The driving and chip are attached to the light projection chip mounting position 9 of the automobile, and the projection effect and control of the projection pattern can be realized in the projection area 10 by driving power supply and control.

[0107] Example five

[0108] Please refer to Figure 2 to Figure 6 A Micro LED light projection chip for vehicles, comprising an integrated chip 6, a welding material 7 and a driving substrate 8.

[0109] The integrated chip 6 comprises a substrate 4 and a plurality of sub-pixels 3 on the surface of the substrate 4.

[0110] The substrate surface is provided with a welding pad 2 at the position of each sub-pixel 3, and the pad 2 is connected with the driving substrate 8 through the welding material 7.

[0111] Please refer to Figure 2 The side of the substrate 4 away from the sub-pixel 3 is etched into a lens 5 shape according to a preset array pattern. Figure 3 Optionally, please refer to The side of the substrate 4 away from the sub-pixel 3 is deposited with a silicon oxide layer 11 with a lens shape.

[0112] Figure 4 In another embodiment, please refer to The side of the substrate 4 away from the sub-pixel 3 is deposited with a silicon oxide layer 11, and the side of the substrate 4 away from the sub-pixel 3 is etched into a lens shape by etching the substrate 4 and the silicon oxide layer 11 according to the preset array pattern.

[0113] The bottom width of the lens shape is 10-200μm, the height of the lens shape is 50-500μm, and the thickness of the silicon oxide layer 11 is 10-300μm.

[0114] The projection demonstration effect of the Micro LED light projection chip on the automobile is shown in Figure 5 And please refer to Figure 6 The resolution is adjustable and the pixel free partition light source effect is realized by driving design, realizing single-pixel display or multi-pixel display.

[0115] In summary, the application provides a manufacturing method of a vehicle Micro LED light projection chip, compared with a traditional chip structure, the application has the characteristics of performing semiconductor process on a wafer, compressing the projection light source to a very small range by integrating multiple sub-pixels on the chip, and having very high pixel density; in combination with a driving substrate, the size and shape of the light spot formed by the projection light source can be controlled more highly, and the light spot can be combined in real time through software without relying on hardware conditions. The gallium nitride and aluminum oxide, silicon oxide materials used in the manufacturing method of the application are materials with strong ability to resist environmental humidity, temperature, acid and alkali, etc. The chip can be directly placed on the outer surface of a basic object such as a car, without the need for other material protection or covering. Moreover, the integrated matrix chip in the application is provided with a lens, the chip and the lens are integrated on a substrate, the lens function can be customized in the chip processing stage, the light can be concentrated and scattered, and the lens can be composed of multiple components, the projection strengthening structure can be formed by the combination of two or more materials, the shape of the projection lens and the projection effect can be customized.

[0116] The above description is only an embodiment of the application, and does not limit the patent scope of the application, any equivalent transformation or direct or indirect application in the related technical field based on the content of the specification and drawings is also included in the patent protection scope of the application.

Claims

1.A method for manufacturing a Micro LED light projection chip for vehicles, characterized in that, The method comprises the steps of: preparing a conductive layer, a protective layer and a metal electrode on the wafer in sequence according to a preset array pattern; grinding and polishing the substrate surface of the wafer, performing pattern transfer on the substrate using a photoetching machine and photoresist according to a preset array pattern, and performing ICP etching to manufacture an integrated lens, wherein the lens has a width of 10-200 μm and a height of 50-500 μm; continuously depositing SiO2 material on the lens surface using an ALD or PECVD device, and etching the silicon oxide layer and adjusting the lens morphology using photoresist and a photoetching machine; cutting the etched wafer to obtain an integrated chip with lenses; welding the electrodes of the integrated chip to a driving substrate by using a welding material, wherein the welding surface of the integrated chip is the chip electrode, and the chip electrode surface is combined with the driving substrate after welding to obtain a light projection chip; supplying power and controlling by driving to realize projection effect and control of the projection pattern in the projection area. 2.The method of claim 1, wherein the method further comprises: forming a plurality of micro LED light emitting chips on the substrate; and forming a plurality of micro LED light emitting chips on the substrate. Before the step of preparing a conductive layer, a protective layer and a metal electrode on the wafer in sequence according to a preset array pattern, the method further comprises the steps of: arranging the pixel array of the chip on the wafer according to the arrangement of the driving substrate, and integrating a plurality of LED self-luminous pixels in the chip of the wafer according to the preset array pattern of the pixel array. 3.The method of claim 1, wherein the method further comprises: forming a plurality of micro LED light emitting chips on the substrate; and forming a plurality of micro LED light emitting chips on the substrate. The conductive layer comprises indium tin oxide or NiAu alloy metal or molybdenum oxide. 4.The method of claim 1, wherein the method further comprises: forming a plurality of micro-LEDs on the substrate; and forming a plurality of micro-LED light projection chips by cutting the substrate. Before the step of preparing a conductive layer on the wafer in sequence according to a preset array pattern, the method further comprises the steps of: using a GaN epitaxial wafer grown on a substrate as a substrate, performing pattern transfer using a photoetching machine and photoresist according to a preset array pattern, and manufacturing an N-type layer by etching the GaN surface. 5.The method of claim 4, wherein the method further comprises: The step of preparing a conductive layer comprises the steps of: removing the current spreading layer film on the N-type layer by etching, and only retaining the conductive layer on the P-GaN. 6.The method of claim 1, wherein the method further comprises: forming a plurality of micro-LEDs on the substrate; and forming a plurality of micro-LEDs on the substrate. The step of preparing a protective layer comprises the steps of: depositing a titanium oxide and silicon oxide protective layer on the wafer using a DBR device and a PECVD device, performing pattern transfer using a photoetching machine and photoresist according to a designed chip pattern, manufacturing a conductive via under the metal electrode by etching or etching, and reserving the position of the metal electrode. 7.The method of claim 6, wherein the method further comprises: forming a plurality of micro-LEDs on the substrate; and forming a plurality of micro-LEDs on the substrate. The step of evaporating a metal electrode comprises the steps of: performing glue coating and photoetching on the wafer, manufacturing a conductive pad by using an electron beam evaporation metal or sputtering metal, and then performing metal stripping to leave a metal electrode at a predetermined position.

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