High-contrast MicroLED matrix light source

Abstract

The utility model relates to the technical field of LED display, in particular to a high-contrast MicroLED matrix light source. The high-contrast MicroLED matrix light source is provided with a sapphire substrate, an epitaxial layer is arranged on one side of the sapphire substrate, a plurality of pixel units are distributed on the outer side of the epitaxial layer in an array mode, an insulating buried layer is arranged on the outer side of each pixel unit, and the outer side of each insulating buried layer is connected with a CMOS backboard through a bonding layer. Micro lenses distributed in an array mode are machined on the other side face of the sapphire substrate, and the micro lenses and the pixel units are arranged in a one-to-one correspondence mode. The micro-lens array is simple in structure and reasonable in design, each micro-lens in the micro-lens array corresponds to one pixel unit, light emitted by each pixel unit is collimated, light crosstalk between pixels can be effectively prevented, and the contrast ratio of light source illumination and projection imaging is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of LED display, in particular to a high-contrast MicroLED matrix light source. Background Art

[0002] LED chips have dominated the lighting market, especially in the automotive lighting field, due to their excellent self-luminous properties, high energy efficiency, low energy consumption and excellent stability. In automotive lighting systems, smart high beams are usually composed of multiple LED chips, which can be individually controlled by the driving circuit to achieve brightness adjustment and switching.

[0003] With the development of technology and the increase in market demand, in-vehicle intelligent high beams are developing in a more intelligent and multifunctional direction. For example, high-precision local dimming technology can finely control the brightness of LED chips with extremely high resolution according to real-time traffic conditions, and automatically adjust the intensity of the light beam to reduce glare to oncoming drivers. In addition, with intelligent light projection technology, vehicles can project high-definition images, symbols or information onto the road to provide additional auxiliary information for drivers. These technologies not only improve driving safety, but also increase the personalized experience of the vehicle. These technologies are inseparable from MicroLED chips.

[0004] MicroLED is LED miniaturization technology, which pre-integrates a matrix CMOS control circuit in the silicon substrate of the chip, and performs matrix microstructure processing on the chip to achieve individual control of each microstructure area, forming independent pixels in the headlight. Each tiny LED light source of Micro LED directly emits light, achieving direct high-definition imaging of tens of thousands of pixels without the need for an additional pixel generation system. The main advantages of Micro LED are low system cost, small system size, and high luminous efficiency, and it is expected to be gradually applied on a large scale in mid-to-high-end models.

[0005] In the prior art, since the light-emitting angle of each pixel of the MicroLED light source module is large and there is no isolation wall between pixels, light crosstalk between pixels is very likely to occur, resulting in poor contrast between lighting and projection and poor effect. Utility Model Content

[0006] The technical problem to be solved by the utility model is: to overcome the deficiencies in the prior art, to provide a high-contrast MicroLED matrix light source, to perform graphic processing on a sapphire substrate to form a microlens array, to use the microlens array to collimate the emitted light from each pixel unit, and to prevent light crosstalk between pixels.

[0007] The technical solution adopted by the utility model to solve its technical problems is:

[0008] A high-contrast MicroLED matrix light source, comprising a sapphire substrate, an epitaxial layer on one side of the sapphire substrate, a plurality of pixel units arranged in an array on the outer side of the epitaxial layer, an insulating buried layer on the outer side of the pixel unit, and a CMOS backplane connected to the outer side of the insulating buried layer via a bonding layer;

[0009] An array of micro lenses is processed on the other side of the sapphire substrate, and the micro lenses are arranged in a one-to-one correspondence with the pixel units.

[0010] Furthermore, the epitaxial layer includes an N-type semiconductor layer, a quantum well layer and a P-type semiconductor layer which are arranged in sequence, and the N-type semiconductor layer is arranged close to the sapphire substrate.

[0011] Furthermore, a mounting groove for mounting the pixel unit is etched on the epitaxial layer, and the mounting groove extends from the P-type semiconductor layer to the N-type semiconductor layer.

[0012] Furthermore, the height of the portion of the mounting groove extending into the N-type semiconductor layer is 1 / 5 to 1 / 4 of the thickness of the N-type semiconductor layer.

[0013] Furthermore, the pixel unit includes a first insulating layer covering the mounting groove and the P-type semiconductor layer, a contact electrode layer and an extended electrode layer are arranged on the first insulating layer, an insulating isolation layer is arranged outside the extended electrode layer, and an insulating buried layer covers the insulating isolation layer.

[0014] Furthermore, the contact electrode layer is arranged close to the first insulating layer, and the extended electrode layer is located outside the contact electrode layer.

[0015] The beneficial effects of the utility model are as follows: the utility model has a simple structure and a reasonable design. Each microlens in the microlens array corresponds to a pixel unit, and the light emitted by each pixel unit is collimated, which can effectively prevent light crosstalk between pixels and greatly improve the contrast of light source illumination and projection imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] In the figure: 10. sapphire substrate, 20. epitaxial layer, 21. N-type semiconductor layer, 22. quantum well layer, 23. P-type semiconductor layer, 31. first insulating layer, 32. insulating isolation layer, 33. insulating buried layer, 41. contact electrode layer, 42. extended electrode layer, 51. bonding layer, 52. CMOS backplane, 60. outgoing light. DETAILED DESCRIPTION

[0019] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0021] The technical solution of the utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] like Figure 1 A high-contrast MicroLED matrix light source is shown, which has a sapphire substrate 10, an epitaxial layer 20 is provided on one side of the sapphire substrate 10, a plurality of pixel units are arrayed on the outer side of the epitaxial layer 20, an insulating buried layer 33 is provided on the outer side of the pixel unit, and a CMOS backplane 52 is connected to the outer side of the insulating buried layer 33 through a bonding layer 51;

[0023] An array of micro lenses is processed on the other side of the sapphire substrate 10 , that is, the micro lenses are formed on the outer surface of the sapphire substrate 10 by patterning, and the micro lenses are arranged in a one-to-one correspondence with the pixel units.

[0024] The epitaxial layer 20 includes an N-type semiconductor layer 21 , a quantum well layer 22 , and a P-type semiconductor layer 23 which are sequentially arranged. The N-type semiconductor layer 21 is arranged close to the sapphire substrate 10 .

[0025] A mounting groove for mounting the pixel unit is etched on the epitaxial layer 20 , and the mounting groove extends from the P-type semiconductor layer 23 to the N-type semiconductor layer 21 .

[0026] The height of the portion of the mounting groove extending into the N-type semiconductor layer 21 is 1 / 5 of the thickness of the N-type semiconductor layer 21 .

[0027] The pixel unit includes a first insulating layer 31 covering the mounting groove and the P-type semiconductor layer 23; a contact electrode layer 41 and an extended electrode layer 42 are arranged on the first insulating layer 31; an insulating isolation layer 32 is arranged outside the extended electrode layer 42; an insulating buried layer 33 covers the insulating isolation layer 32; the contact electrode layer 41 is arranged close to the first insulating layer 31, and the extended electrode layer 42 is located outside the contact electrode layer 41.

[0028] Each microlens in the microlens array corresponds to a pixel unit, and the light emitted by each pixel unit is corrected by the corresponding microlens to obtain collimated output light 60, which can effectively prevent light crosstalk between pixels and greatly improve the contrast of light source illumination and projection imaging.

[0029] In addition, this high-contrast MicroLED matrix light source is produced by the following steps:

[0030] Step (1), sequentially growing an N-type semiconductor layer 21, a quantum well layer 22, and a P-type semiconductor layer 23 on one side of a sapphire substrate 10 to form an epitaxial layer 20;

[0031] Step (2), etching the epitaxial layer 20, and stopping after penetrating the P-type semiconductor layer 21 and the quantum well layer 22;

[0032] Step (3), performing current spreading layer processing and passivation layer processing on the epitaxial layer 20, and preparing the first insulating layer 31, the insulating isolation layer 32, the insulating buried layer 33, the contact electrode layer 41 and the extended electrode layer 42;

[0033] Step (4), a CMOS backplane 52 is connected to the insulating buried layer 33 via a bonding layer 51;

[0034] Step (5), patterning the other side of the sapphire substrate 10 to etch out a microlens array to obtain a chip;

[0035] Step (6), performing thin film packaging and module packaging on the chip obtained in step (5).

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A high-contrast MicroLED matrix light source, characterized in that: A sapphire substrate (10) is provided, one side of the sapphire substrate (10) is provided with an epitaxial layer (20), a plurality of pixel units are arrayed on the outer side of the epitaxial layer (20), an insulating buried layer (33) is provided on the outer side of the pixel unit, and a CMOS backplane (52) is connected to the outer side of the insulating buried layer (33) via a bonding layer (51); The other side surface of the sapphire substrate (10) is processed with micro lenses distributed in an array, and the micro lenses are arranged in a one-to-one correspondence with the pixel units.

2. A high contrast MicroLED matrix light source according to claim 1, characterized in that: The epitaxial layer (20) comprises an N-type semiconductor layer (21), a quantum well layer (22) and a P-type semiconductor layer (23) which are arranged in sequence, and the N-type semiconductor layer (21) is arranged close to the sapphire substrate (10).

3. The high-contrast MicroLED matrix light source according to claim 2, characterized in that: A mounting groove for mounting a pixel unit is etched on the epitaxial layer (20), and the mounting groove extends from the P-type semiconductor layer (23) to the N-type semiconductor layer (21).

4. The high-contrast MicroLED matrix light source according to claim 3, characterized in that: The height of the portion of the mounting groove extending into the N-type semiconductor layer (21) is 1 / 5 to 1 / 4 of the thickness of the N-type semiconductor layer (21).

5. The high-contrast MicroLED matrix light source according to claim 3, characterized in that: The pixel unit comprises a first insulating layer (31) covering the mounting groove and the P-type semiconductor layer (23); a contact electrode layer (41) and an extended electrode layer (42) are arranged on the first insulating layer (31); an insulating isolation layer (32) is arranged outside the extended electrode layer (42); and an insulating buried layer (33) covers the insulating isolation layer (32).

6. The high-contrast MicroLED matrix light source according to claim 5, characterized in that: The contact electrode layer (41) is arranged close to the first insulating layer (31), and the extended electrode layer (42) is located outside the contact electrode layer (41).

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