WO2020248404A1

WO2020248404A1 - Micro light emitting diode and display panel

Info

Publication number: WO2020248404A1
Application number: PCT/CN2019/104615
Authority: WO
Inventors: 樊勇
Original assignee: 深圳市华星光电半导体显示技术有限公司
Priority date: 2019-06-14
Filing date: 2019-09-06
Publication date: 2020-12-17
Also published as: CN110265531B; CN110265531A

Abstract

A micro light emitting diode (101) and a display panel (300). The micro light emitting diode (101) comprises: a light conversion layer (120) used for converting blue light into white light; a black matrix (110) provided in the light conversion layer (120); a buffer layer (130) provided on the light conversion layer (120); a first semiconductor layer (140) provided on the buffer layer (130); an indium gallium nitride layer (150) provided on the first semiconductor layer (140); a second semiconductor layer (160) provided on the indium gallium nitride layer (150); a current spreading layer (170) provided on the second semiconductor layer (160) and used for widening the light-emitting area; a passivation layer (180) provided on the current spreading layer (170) and the buffer layer (130); a first pad (190); and a second pad (195).

Description

Miniature light emitting diode and display panel

Technical field

This application relates to the field of display, in particular to a miniature light emitting diode and a display panel.

Background technique

In order to pursue self-luminescence in order to increase the contrast, the current display is developing towards a flexible display. Therefore, the liquid crystal display (liquid-crystal display, abbreviation: LCD) is developing toward an organic electroluminescence display (OELD). The advantage of OLED is that it can self-illuminate to meet the display requirements, does not require liquid crystals and can make flexible and flexible displays. It is quite popular in the current stage of development. However, the disadvantages of OLED displays are that the manufacturing process is difficult, and the vapor deposition process and the packaging process have not yet been optimized. As a result, the process yield is low and the production cost increases.

Summary of the invention

technical problem

At present, the industry is trying to replace OLED with Micro Light Emitting Diode Display (Micro LED). Its main advantages are mature process, low power consumption, and high contrast requirements.

The micro-light-emitting diode is an array structure of miniaturized light-emitting diodes, which has self-luminous display characteristics. With active components, each pixel can be addressed and individually driven to emit light. The advantages include high brightness, low power consumption, small size, and ultra-high Resolution and color saturation, etc. Both micro-light-emitting diodes and organic light-emitting diodes are suitable for flexible and transparent displays. Compared with organic light-emitting diodes, which are also self-luminous displays, micro-light-emitting diodes not only have higher luminous efficiency, longer life, and materials that are not easily affected by the environment. It is relatively stable and can avoid the afterimage phenomenon.

Because the miniature light-emitting diodes are small in size, they can be arranged more densely to greatly improve the resolution. However, because organic light-emitting diodes are small in size and arranged more densely, it is more difficult for the traditional manufacturing process to use single-sided printing to make display devices with micro-LEDs. The process of printing and transposing is limited by the accuracy of the mechanism. , The material characteristics of the stamp and the accuracy of the pitch limit the resolution of the product. When single-sided printing is placed in a high-density arrangement, it is easy to cause interference from adjacent micro LEDs during placement. Transpose, thus causing misplacement.

In the active matrix drive display device (AM microLED), since the size of the micro light-emitting diode display is usually less than 100um; its size exceeds the size of the traditional grabbing tip, and the traditional sub-box cannot be used. (bin) The machine bins the brightness, chromaticity, wavelength and voltage of the micro-light-emitting diode display chip. As a result, the micro-light-emitting diode display applied on the same display panel may be due to voltage, brightness, wavelength, and color. There are big differences, resulting in quality problems such as brightness and darkness, color cast, and color spots.

Therefore, the main purpose of the patent of the present invention is to provide a miniature light emitting diode and a display panel to further optimize the above-mentioned problems.

The solution to the problem

Technical solutions

In order to solve the above technical problems, the purpose of the patent of the present invention is to provide a miniature light emitting diode, which includes: a light conversion layer for converting blue light into white light; a buffer layer arranged on the light conversion layer; The matrix is arranged in the light conversion layer; a first semiconductor layer is arranged on the buffer layer; an indium gallium nitride type layer is arranged on the first semiconductor layer; a second semiconductor layer is arranged On the indium gallium nitride type layer; a current spreading layer arranged on the second semiconductor layer to widen the light-emitting area; a passivation layer arranged on the current spreading layer and the buffer On the layer; a first pad, arranged on the second semiconductor layer and the current spreading layer, and connected to the passivation layer; and a second pad, arranged on the passivation layer.

The purpose of the patent of the invention and the solution of its technical problems are achieved by adopting the following technical solutions.

In an embodiment of the patent of the present invention, the first semiconductor layer is an N-type semiconductor layer, and the second semiconductor layer is a P-type semiconductor layer; both the first semiconductor layer and the second semiconductor layer contain The composition of gallium nitride.

In an embodiment of the patent of the present invention, the light conversion layer contains a composition of yellow phosphor or a fluorescent conversion material mixed with red and green.

In an embodiment of the patent of the present invention, the first cushion is a P-type cushion, and the second cushion is an N-type cushion

The purpose of the patent of the present invention and the solution of its technical problems can be further realized by the following technical measures.

Another object of the present patent is to provide a display panel, including: a first substrate; a plurality of pixels arranged on the first substrate and each of the pixels includes at least four sub-pixels; Light emitting diodes are arranged on the first substrate and the plurality of micro light emitting diodes are electrically connected to the first substrate, wherein each of the micro light emitting diodes includes: a light conversion layer for converting blue light into White light; a black matrix, arranged in the light conversion layer, respectively used to separate the first, second, third, and fourth pixels to avoid color interference; a buffer layer, arranged in On the light conversion layer; a first semiconductor layer, arranged on the buffer layer; an indium gallium nitride type layer, arranged on the first semiconductor layer; a second semiconductor layer, arranged on the nitrogen On the indium gallium type layer; a current spreading layer arranged on the second semiconductor layer to widen the light-emitting area; a passivation layer arranged on the current spreading layer and the buffer layer; A first pad is arranged on the second semiconductor layer and the current spreading layer, and is joined to the passivation layer; and a second pad is arranged on the passivation layer; and a second substrate, It is electrically connected to the plurality of micro light emitting diodes, and the plurality of micro light emitting diodes are located between the first substrate and the second substrate.

In an embodiment of the present invention patent, the first cushion is a P-type cushion, and the second cushion is an N-type cushion.

In an embodiment of the present invention patent, at least one of the micro light emitting diodes is located in one of the sub-pixels.

In an embodiment of the patent of the present invention, the second substrate further includes: a plurality of gate lines disposed on the second substrate; a gate cover layer disposed on the second substrate and covering The gate lines; a plurality of data lines are arranged on the gate cover layer, wherein a plurality of active switch arrays are arranged at the intersection of the data lines and the gate lines; an insulating layer is arranged on the Data line; an outer coating, arranged on the gate cover layer and the data line, and connected to the insulating layer; an anode electrode layer, arranged on the outer coating and the insulating layer And respectively connect the gate cover layer and the data line; a bank layer disposed on the outer coating layer and covering the anode electrode layer; and a cathode electrode layer disposed on the bank layer on.

The patent of the invention provides a full-color scheme that can carry out a new type of miniature light-emitting diode chip and its display panel, so that the miniature light-emitting diode chip can use the traditional way of binning to measure the brightness, chromaticity, wavelength, voltage and other photoelectric characteristics Carrying out binning, so that the same micro-LED display panel has a stable and reliable life, uniform brightness and chromaticity, and avoids the occurrence of panel display unevenness (mura).

The beneficial effects of the invention

Brief description of the drawings

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following briefly introduces the drawings that need to be used in the embodiments. The drawings in the following description are only part of the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

Fig. 1 is a schematic diagram of a miniature light emitting diode according to an embodiment of the present invention;

2 is a schematic diagram of a micro light emitting diode pixel array according to an embodiment of the invention;

FIG. 3 is a schematic diagram of a micro LED pixel design according to an embodiment of the invention;

4 is a schematic diagram of a display with micro light emitting diodes according to an embodiment of the invention.

Invention embodiment

Embodiments of the invention

Please refer to the drawings in the drawings, where the same component symbols represent the same components. The following description is based on the exemplified specific embodiments of the present application, which should not be regarded as limiting other specific embodiments that are not described in detail herein.

The description of the following embodiments refers to the attached drawings to illustrate specific embodiments that can be implemented by the patent of the present invention. The directional terms mentioned in the patent of this invention, such as "up", "down", "front", "rear", "left", "right", "inner", "outer", "side", etc., are only Refer to the direction of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the patent of the present invention, rather than to limit the patent of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, the thickness of some layers and regions are exaggerated for understanding and ease of description. It will be understood that when a component such as a layer, film, region, or substrate is referred to as being "on" another component, the component can be directly on the other component, or intervening components may also be present.

The drawings and descriptions are to be regarded as illustrative in nature and not restrictive. In the figure, units with similar structures are indicated by the same reference numerals. In addition, for understanding and ease of description, the size and thickness of each component shown in the drawings are arbitrarily shown, but the patent of the present invention is not limited thereto.

In addition, in the specification, unless expressly described to the contrary, the word "including" will be understood as meaning including the components, but does not exclude any other components. In addition, in the specification, "on" means to be located above or below the target component, and does not mean that it must be located on the top based on the direction of gravity.

In order to further explain the technical means and effects adopted by the patent of the present invention to achieve the intended purpose of the invention, the following, with reference to the drawings and specific embodiments, will describe the specific implementation and structure of the micro light emitting diode and display panel proposed in the patent of the present invention. , Characteristics and effects, detailed description is as follows.

FIG. 1 is a schematic diagram of a micro light emitting diode according to an embodiment of the present invention, FIG. 2 is a schematic diagram of a micro light emitting diode pixel array according to an embodiment of the present invention, and FIG. 3 is a schematic diagram of a micro light emitting diode pixel design according to an embodiment of the present invention. Please refer to FIG. 1 2 and 3, in an embodiment of the patent of the present invention, a miniature light-emitting diode 101 includes: a light conversion layer 120 for converting blue light into white light; a black matrix 110 arranged on the light In the conversion layer 120; a buffer layer 130 is disposed on the light conversion layer 120; a first semiconductor layer 140 is disposed on the buffer layer 130; an indium gallium nitride type layer 150 is disposed on the second A semiconductor layer 140; a second semiconductor layer 160 disposed on the indium gallium nitride type layer 150; a current spreading layer 170 disposed on the second semiconductor layer 160 to widen the light emitting area; A passivation layer 180 is disposed on the current spreading layer 170 and the buffer layer 130; a first pad 190 is disposed on the second semiconductor layer 160 and the current spreading layer 170 and connected The passivation layer 180; and a second pad 195 disposed on the passivation layer 180.

In an embodiment of the patent of the present invention, the first semiconductor layer 140 is an N-type semiconductor layer, and the second semiconductor layer 160 is a P-type semiconductor layer; the first semiconductor layer 140 and the second semiconductor layer The layers 160 all contain gallium nitride composition.

In an embodiment of the patent of the present invention, the light conversion layer 120 contains yellow phosphor or a composition of a fluorescent conversion material mixed with red and green, such as: Nitride, sulfide, and fluorine. Fluoride, quantum dots and other materials.

In an embodiment of the present patent, the first cushion 190 is a P-type cushion, and the second cushion 195 is an N-type cushion.

2 and 3, in an embodiment of the present invention patent, each group of micro light emitting diodes 101 corresponds to two rows of first sub-pixels 100R (for example: red sub-pixels), second sub-pixels 100G (for example: green Sub-pixel), third sub-pixel 100B (for example: blue sub-pixel), fourth sub-pixel 100W (for example: white sub-pixel) (total 8 sub-pixels).

2 and 3, in an embodiment of the patent of the present invention, each micro light emitting diode 101 on the group of micro light emitting diodes 101 corresponds to a sub pixel (for example: the first pixel 100R, the second sub pixel 100G, The third pixel 100B, the fourth pixel 100W); the second pixel (for example: the first pixel 100R, the second pixel 100G, the third pixel 100B, the fourth pixel 100W) are two groups of red, green, and blue Color and white sub-pixels.

4 is a schematic diagram of a display with micro light emitting diodes according to an embodiment of the invention. Please refer to FIG. 1, FIG. 2, FIG. 3, and FIG. 4. In an embodiment of the present invention, a display panel 300 includes: a first substrate 10; a plurality of pixels 100 are disposed on the first substrate 10 and each of the pixels 100 includes at least four sub-pixels 100R, 100G, 100B, 100W; a plurality of micro light-emitting diodes 101 are arranged on the first substrate 10 and the plurality of micro light-emitting diodes 101 and The first substrate 10 is electrically connected, and each of the micro light-emitting diodes 101 includes: a light conversion layer 120 for converting blue light into white light; a black matrix 110 arranged in the light conversion layer 120, Are used to separate the first sub-pixel 100R, the second sub-pixel 100G, the third sub-pixel 100B, and the fourth sub-pixel 100W to avoid color interference; a buffer layer 130 is disposed on the light conversion layer 120; A semiconductor layer 140 is disposed on the buffer layer 130; an indium gallium nitride type layer 150 is disposed on the first semiconductor layer 140; a second semiconductor layer 160 is disposed on the indium gallium nitride type On the layer 150; a current spreading layer 170 is provided on the second semiconductor layer 160 to widen the light-emitting area; a passivation layer 180 is provided on the current spreading layer 170 and the buffer layer 130 A first pad 190, disposed on the second semiconductor layer 160 and the current spreading layer 170, and connected to the passivation layer 180; and a second pad 195, disposed on the passivation layer 180 On; and a second substrate 20 electrically connected to the plurality of micro light emitting diodes 101, and the plurality of micro light emitting diodes 101 are located between the first substrate 10 and the second substrate 20.

In an embodiment of the present invention patent, at least one of the micro light emitting diodes 101 is located in one of the sub-pixels 100R, 100G, 100B, 100W.

Please refer to FIG. 4, in an embodiment of the present invention patent, the second substrate 20 further includes: a plurality of gate lines 210 disposed on the second substrate 20; a gate cover layer 220 disposed on On the second substrate 20 and covering the gate lines 210; a plurality of data lines 230 are disposed on the gate covering layer 220, and the part where the data lines 230 and the gate lines 210 intersect A plurality of active switch arrays 235 are disposed; an insulating layer 240 is disposed on the data line 230; an outer coating 250 is disposed on the gate cover layer 220 and the data line 230, and is connected to the Insulating layer 240; an anode electrode layer 260, disposed on the outer coating 250 and the insulating layer 240, and respectively connected to the gate cover layer 220 and the data line 230; a bank layer 270, disposed On the outer coating layer 250 and covering the anode electrode layer 260; and a cathode electrode layer 280 disposed on the bank layer 270.

2 and 3, in an embodiment of the patent of the present invention, in an embodiment of the patent of the present invention, each group of micro light emitting diodes 101 corresponds to two rows of first sub-pixels 100R (for example: red sub-pixels) , The second sub-pixel 100G (for example: green sub-pixel), the third sub-pixel 100B (for example: blue sub-pixel), the fourth sub-pixel 100W (for example: white sub-pixel) (a total of 8 sub-pixels).

2 and 3, in an embodiment of the patent of the present invention, in an embodiment of the patent of the present invention, each micro light emitting diode 101 on the group of micro light emitting diodes 101 corresponds to a sub-pixel (for example: the first Sub-pixel 100R, second sub-pixel 100G, third sub-pixel 100B, fourth sub-pixel 100W); second pixel (for example: first sub-pixel 100R, second sub-pixel 100G, third sub-pixel 100B, fourth sub-pixel 100 W) are two sets of red, green, blue, and white sub-pixels.

Referring to FIG. 4, in an embodiment of the present invention patent, the second substrate 20 is embodied as a thin film transistor (TFT) substrate. In other embodiments, the second substrate 20 may be a semiconductor (Semiconductor) substrate, a submount, a complementary metal-oxide semiconductor (Complementary Metal-Oxide-Semiconductor, CMOS) circuit substrate, a silicon-based substrate The liquid crystal (Crystal on Silicon, LCOS) substrate or other substrates with driving units are not limited in the present invention.

The terms "in some embodiments" and "in various embodiments" are used repeatedly. The term generally does not refer to the same embodiment; but it can also refer to the same embodiment. The terms "including", "having" and "including" are synonymous, unless the context indicates other meanings.

As mentioned above, for those of ordinary skill in the art, various other corresponding changes and modifications can be made according to the technical solutions and technical ideas of the present invention, and all these changes and modifications shall belong to the appended claims of the present invention. The scope of protection.

Industrial applicability

The subject of this application can be manufactured and used in industry and has industrial applicability.

Claims

A miniature light emitting diode, which includes:

A light conversion layer for converting blue light into white light;

A black matrix arranged in the light conversion layer;

A buffer layer arranged on the light conversion layer;

A first semiconductor layer disposed on the buffer layer;

An indium gallium nitride type layer disposed on the first semiconductor layer;

A second semiconductor layer disposed on the indium gallium nitride type layer;

A current spreading layer disposed on the second semiconductor layer to widen the light emitting area;

A passivation layer disposed on the current spreading layer and the buffer layer;

A first pad, arranged on the second semiconductor layer and on the current spreading layer, and connected to the passivation layer; and

A second cushion is arranged on the passivation layer.
3. The miniature light emitting diode of claim 1, wherein the first semiconductor layer is an N-type semiconductor layer, and the second semiconductor layer is a P-type semiconductor layer.
3. The miniature light emitting diode according to claim 2, wherein said first semiconductor layer and said second semiconductor layer both contain gallium nitride composition.
3. The miniature light emitting diode of claim 1, wherein the light conversion layer contains yellow phosphor.
The miniature light emitting diode of claim 1, wherein the light conversion layer contains a composition of a fluorescent conversion material mixed with red and green.
The miniature light emitting diode of claim 1, wherein the first cushion is a P-type cushion, and the second cushion is an N-type cushion.
A display panel, which includes:

A first substrate;

A plurality of pixels are arranged on the first substrate, and each of the pixels includes at least four sub-pixels;

A plurality of micro light emitting diodes are arranged on the first substrate and the plurality of micro light emitting diodes are electrically connected to the first substrate, wherein each of the micro light emitting diodes includes:

A light conversion layer for converting blue light into white light;

A black matrix is arranged in the light conversion layer to separate the first pixel, the second pixel, the third pixel, and the fourth pixel to avoid color interference;

A buffer layer arranged on the light conversion layer;

A first semiconductor layer disposed on the buffer layer;

An indium gallium nitride type layer disposed on the first semiconductor layer;

A second semiconductor layer disposed on the indium gallium nitride type layer;

A current spreading layer disposed on the second semiconductor layer to widen the light emitting area;

A passivation layer disposed on the current spreading layer and the buffer layer;

A first pad, disposed on the second semiconductor layer and on the current spreading layer, and joined with the passivation layer; and

A second cushion arranged on the passivation layer;

as well as

A second substrate is electrically connected to the plurality of micro light emitting diodes, and the plurality of micro light emitting diodes are located between the first substrate and the second substrate.
7. The display panel of claim 7, wherein the first semiconductor layer is an N-type semiconductor layer, and the second semiconductor layer is a P-type semiconductor layer.
8. The display panel of claim 8, wherein the first semiconductor layer and the second semiconductor layer both contain gallium nitride composition.
8. The display panel of claim 7, wherein the light conversion layer contains yellow phosphor.
8. The display panel of claim 7, wherein the light conversion layer contains a composition of a fluorescent conversion material mixed with red and green.
7. The display panel of claim 7, wherein the first cushion is a P-type cushion, and the second cushion is an N-type cushion.
7. The display panel of claim 7, wherein at least one of the micro light emitting diodes is located in one of the sub-pixels.
7. The display panel of claim 7, wherein the second substrate further comprises: a plurality of gate lines disposed on the second substrate; a gate cover layer disposed on the second substrate, and Cover the gate lines; a plurality of data lines are arranged on the gate cover layer, wherein a plurality of active switch arrays are arranged at the intersection of the data lines and the gate lines; an insulating layer is arranged on the The data line; an outer coating, disposed on the gate cover layer and the data line, and connected to the insulating layer; an anode electrode layer, disposed on the outer coating and the insulating Layer and respectively connected to the gate cover layer and the data line; a bank layer disposed on the outer coating layer and covering the anode electrode layer; and a cathode electrode layer disposed on the bank Layer up.