Full-color Micro-LED micro display device based on vertical stacking and preparation method thereof

Abstract

The invention discloses a full-color Micro-LED micro display device based on vertical stacking and a preparation method of the full-color Micro-LED micro display device, and relates to the technical field of display devices. The micro display device comprises a CMOS driving substrate and a three-color epitaxial layer which are sequentially arranged from bottom to top, the three-color epitaxial layer is arranged in a vertical stacking mode, a P electrode is further arranged between the CMOS driving substrate and the three-color epitaxial layer, and a common N electrode is further arranged at the top end of the three-color epitaxial layer. Through the vertical stacking structural design, the limitation that three pixels are arranged side by side in the traditional horizontal direction is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of display devices, and in particular to a full-color Micro-LED micro display device based on vertical stacking and a preparation method thereof. Background Art

[0002] Micro-LED micro-display is a self-luminous display technology that integrates arrayed micron-level LED light-emitting devices on an actively addressed silicon substrate to achieve individual control and lighting of the output display image. Compared with liquid crystal display (LCD) and organic light-emitting diode display (OLED), Micro-LED micro-display has the advantages of high resolution, high brightness, low power consumption and fast response speed. It can be widely used in display fields such as vehicle-mounted display, AR / VR e-sports and military helmet wearables. It is a new subversive micro-display technology.

[0003] Despite the obvious advantages, with the increasing demand for colorization, high brightness and miniaturization, the main means to achieve full colorization are currently mass transfer or color conversion technology. The former has high precision and repair costs, and cannot achieve small pitch; the latter only requires monochrome pixels, but the quantum dots used as color conversion face life problems, and quantum dots are not stable enough at high temperatures and humidity. Therefore, how to achieve high-density integration and high-reliability stacking interconnection within a small size scale is a challenge in the current preparation of Micro-LED colorization. Summary of the invention

[0004] The purpose of the present invention is to provide a full-color Micro-LED micro display device based on vertical stacking and a preparation method thereof, which can avoid the limitation of the traditional three-pixel side-by-side layout in the horizontal direction through the vertical stacking structural design.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A full-color Micro-LED micro-display device based on vertical stacking includes: a CMOS driving substrate and three-color epitaxial layers arranged in a vertical stack from bottom to top, a P electrode is also provided between the CMOS driving substrate and the three-color epitaxial layers, and a common N electrode is also provided on the top of the three-color epitaxial layers.

[0007] Optionally, the three-color epitaxial layers are arranged from bottom to top as a P-GaP layer of a red epitaxial layer, an MQW layer of a red epitaxial layer, an N-GaAs layer of a red epitaxial layer, an SU-8 layer, a P-GaN layer of a blue epitaxial layer, an MQW layer of a blue epitaxial layer, an N-GaN layer of a blue epitaxial layer, a silica gel / epoxy layer, a P-GaN layer of a green epitaxial layer, an MQW layer of a green epitaxial layer, and an N-GaN layer of a green epitaxial layer.

[0008] Optionally, the lengths of the red epitaxial layer, the blue epitaxial layer and the green epitaxial layer in the three-color epitaxial layers decrease in sequence.

[0009] The present invention also provides a method for preparing a full-color Micro-LED micro-display device based on vertical stacking, comprising:

[0010] Step 101: transferring the red epitaxial layer to a temporary substrate;

[0011] Step 102: Etching TSV through holes on the red epitaxial layer and the blue-green epitaxial layer respectively;

[0012] Step 103: Filling metal materials at the TSVs of the two epitaxial layers respectively;

[0013] Step 104: bonding the red epitaxial layer to the blue-green epitaxial layer according to the through-hole position, and removing the temporary substrate of the red epitaxial layer;

[0014] Step 105: Evaporating metal on the surface of the through hole as a P electrode to obtain a Mciro-LED chip;

[0015] Step 106: Bonding the Micro-LED chip to the CMOS driver substrate;

[0016] Step 107: Peeling off the substrate of the Micro-LED chip;

[0017] Step 108: etching the blue-green epitaxial layer until the red epitaxial layer is exposed;

[0018] Step 109: etching the green epitaxial layer until the blue epitaxial layer is exposed;

[0019] Step 110: Prepare a common n-electrode on top of the three-color epitaxial layer, and wire the n-electrodes to form a common cathode.

[0020] Optionally, the through hole of the red epitaxial layer in step 102 needs to be etched through, one of the through holes of the blue epitaxial layer and the green epitaxial layer is etched to the p-GaN layer of the green epitaxial layer, and the other through hole is etched to the p-GaN layer of the blue epitaxial layer.

[0021] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0022] The present invention discloses a full-color Micro-LED micro-display device based on vertical stacking and a preparation method thereof, wherein the micro-display device comprises: a CMOS driving substrate arranged in sequence from bottom to top and three-color epitaxial layers arranged in a vertical stacking form, a P electrode is further provided between the CMOS driving substrate and the three-color epitaxial layers, and a common N electrode is further provided at the top of the three-color epitaxial layers. The present invention can avoid the limitation of the traditional three-pixel side-by-side layout in the horizontal direction through the vertical stacking structural design, reduce the pixel size and the spacing between the pixels, thereby achieving an improvement in display resolution, and further reduce the manufacturing cost by optimizing the layout strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 Schematic diagram of a partial preparation process of a full-color Micro-LED micro-display device based on vertical stacking in this embodiment;

[0025] Figure 2 This is a schematic diagram of another part of the preparation process of the vertically stacked full-color Micro-LED microdisplay device in this embodiment. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The purpose of the present invention is to provide a full-color Micro-LED micro display device based on vertical stacking and a preparation method thereof, which can avoid the limitation of the traditional three-pixel side-by-side layout in the horizontal direction through the vertical stacking structural design.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figure 1-Figure 2As shown, the present invention provides a full-color Micro-LED micro display device based on vertical stacking, including: a CMOS driving substrate and three-color epitaxial layers arranged in a vertical stacking form, a P electrode is also provided between the CMOS driving substrate and the three-color epitaxial layer, and a common N electrode is also provided on the top of the three-color epitaxial layer.

[0030] As a specific implementation, the three-color epitaxial layers are arranged from bottom to top in order as a P-GaP layer of a red epitaxial layer, an MQW layer of a red epitaxial layer, an N-GaAs layer of a red epitaxial layer, a SU-8 layer, a P-GaN layer of a blue epitaxial layer, an MQW layer of a blue epitaxial layer, an N-GaN layer of a blue epitaxial layer, a silica gel / epoxy glue layer, a P-GaN layer of a green epitaxial layer, an MQW layer of a green epitaxial layer, and an N-GaN layer of a green epitaxial layer. Among the three-color epitaxial layers, the lengths of the red epitaxial layer, the blue epitaxial layer, and the green epitaxial layer decrease in order.

[0031] In addition, this embodiment also provides a preparation method for preparing the vertically stacked full-color Micro-LED micro display device as described above, comprising:

[0032] Step 101: transferring the red epitaxy onto a temporary substrate;

[0033] Step 102: Etch TSV through holes on the red epitaxy and the blue-green epitaxy, respectively. The through hole of the red epitaxy needs to be etched through, and one through hole of the blue-green epitaxy is etched to the P-GaN layer of the green epitaxy, and the other is etched to the P-GaN layer of the blue epitaxy;

[0034] Step 103: Filling metal materials at the TSVs of the two epitaxial wafers respectively;

[0035] Step 104: bonding the red epitaxy onto the blue-green epitaxy according to the through-hole position, and removing the temporary substrate of the red epitaxy;

[0036] Step 105: Evaporating metal on the surface of the through hole as a P electrode to produce a Micro-LED chip;

[0037] Step 106: Bonding the Micro-LED chip to the CMOS driver substrate;

[0038] Step 107: Peeling off the substrate of the Micro-LED chip;

[0039] Step 108: Etching the blue-green epitaxy until the red epitaxy is exposed;

[0040] Step 109: Etching the green epitaxial layer until the blue epitaxial layer is exposed;

[0041] Step 110: Prepare a common N electrode on the top of the three-color epitaxy, and wire the N electrodes to connect them into a common cathode.

[0042] Therefore, the full-color Micro-LED micro display device of the present invention is implemented on the same epitaxy, and there is no need to combine different epitaxies; the present invention stacks RGB epitaxies in the vertical direction, avoiding the limitation of the traditional three-pixel side-by-side layout in the horizontal direction, reducing the pixel size and the spacing between them, thereby achieving an improvement in display resolution.

[0043] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0044] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A full-color Micro-LED micro-display device based on vertical stacking, characterized in that: include: A CMOS driving substrate and three-color epitaxial layers arranged in a vertical stack are arranged in sequence from bottom to top, a P electrode is arranged between the CMOS driving substrate and the three-color epitaxial layers, and a common N electrode is arranged on the top of the three-color epitaxial layers.

2. The vertically stacked full-color Micro-LED micro-display device according to claim 1, characterized in that: The three-color epitaxial layers are arranged from bottom to top as a P-GaP layer of a red epitaxial layer, an MQW layer of a red epitaxial layer, an N-GaAs layer of a red epitaxial layer, an SU-8 layer, a P-GaN layer of a blue epitaxial layer, an MQW layer of a blue epitaxial layer, an N-GaN layer of a blue epitaxial layer, a silica gel / epoxy layer, a P-GaN layer of a green epitaxial layer, an MQW layer of a green epitaxial layer, and an N-GaN layer of a green epitaxial layer.

3. The vertically stacked full-color Micro-LED micro-display device according to claim 2, characterized in that: The lengths of the red epitaxial layer, the blue epitaxial layer and the green epitaxial layer in the three-color epitaxial layers decrease in sequence.

4. A method for preparing a full-color Micro-LED micro-display device based on vertical stacking, characterized in that: include: Step 101: transferring the red epitaxial layer to a temporary substrate; Step 102: Etching TSV through holes on the red epitaxial layer and the blue-green epitaxial layer respectively; Step 103: Filling metal materials at the TSVs of the two epitaxial layers respectively; Step 104: bonding the red epitaxial layer to the blue-green epitaxial layer according to the through-hole position, and removing the temporary substrate of the red epitaxial layer; Step 105: Evaporating metal on the surface of the through hole as a P electrode to obtain a Mciro-LED chip; Step 106: Bonding the Micro-LED chip to the CMOS driver substrate; Step 107: Peeling off the substrate of the Micro-LED chip; Step 108: etching the blue-green epitaxial layer until the red epitaxial layer is exposed; Step 109: etching the green epitaxial layer until the blue epitaxial layer is exposed; Step 110: Prepare a common n-electrode on top of the three-color epitaxial layer, and wire the n-electrodes to form a common cathode.

5. The method for preparing a full-color Micro-LED micro-display device based on vertical stacking according to claim 4, characterized in that: The through hole of the red epitaxial layer in step 102 needs to be etched through, one of the through holes of the blue epitaxial layer and the green epitaxial layer is etched to the p-GaN layer of the green epitaxial layer, and the other through hole is etched to the p-GaN layer of the blue epitaxial layer.

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