LED chip, display module and display screen

Abstract

The present invention provides an LED chip, a display screen module and a display screen, wherein the LED chip comprises: an N-type semiconductor; a light-emitting layer, located above the N-type semiconductor layer; a P-type semiconductor layer, located above the light-emitting layer; an anti-reflection layer, covering the P-type semiconductor layer, for absorbing light emitted from the light-emitting layer and finally emitted to the anti-reflection layer; a first electrode and a second electrode, respectively located above the P-type semiconductor layer and the N-type semiconductor layer and electrically connected to the P-type semiconductor layer and the N-type semiconductor layer. The present invention can effectively reduce the reflection of light from the back of the LED chip, thereby reducing the light emission, reducing the brightness of the LED chip, so that the LED chip can work in the linear region without the problem of excessive brightness; at the same time, the present invention can reduce the thickness of the black film layer when applied to the LED display screen module, so that the display screen module has better ink color consistency.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor display design and manufacturing, and in particular relates to an LED chip, a display screen module and a display screen. Background Art

[0002] In the application of LED chips, ordinary LED chips are mainly used in lighting and display backlight modules, while the rapidly developing Mini LED is mainly used in indoor and outdoor display screens.

[0003] Among the current LED chips, most of their designs are based on lighting applications, such as the use of graphic substrates, distributed Bragg reflection layers, etc. The currently used Mini LEDs also use similar designs. There is no problem with the application of this type of chip in the field of lighting or backlighting, but there is a major defect in the field of display: excessive brightness affects the comfort of the display. In order to make the brightness of the LED chip more appropriate, the existing solution is to use a small current to drive the LED chip. When displaying darker graphics, the LED chip tends to work in the small current density nonlinear area, and in this working area, the brightness of the LED chip is different, which brings great difficulties to the point measurement sorting and the correction of the display screen, such as large sorting workload, long correction time, and poor low brightness consistency of the display screen.

[0004] In addition, if the chip emits too bright light, when used in LED display modules, the chip surface needs to be covered with a thicker black film layer to keep the chip's light brightness within the human eye's comfort zone. Covering the black film layer not only increases the process complexity of the LED display module, but also causes problems with ink color consistency due to inconsistent black film thickness.

[0005] Therefore, the present application performs reverse design to address this defect, thereby reducing the chip's luminous brightness while making the chip work in a linear region, thereby simplifying the design and process complexity of the back-end display screen application. Summary of the invention

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide an LED chip, a display screen module and a display screen, which are used to solve the problems in the prior art of excessive brightness of LED chips, such as large sorting workload, long correction time, low brightness of the display screen and poor ink color consistency.

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention provides an LED chip, which is used for an LED display screen module. The LED chip includes: an N-type semiconductor; a light-emitting layer, which is located above the N-type semiconductor layer; a P-type semiconductor layer, which is located above the light-emitting layer; an anti-reflection layer, which covers the P-type semiconductor layer and is used to absorb light emitted from the light-emitting layer and finally emitted to the anti-reflection layer; a first electrode and a second electrode, which are respectively located above the P-type semiconductor layer and the N-type semiconductor layer and are respectively electrically connected to the P-type semiconductor layer and the N-type semiconductor layer.

[0008] Optionally, the anti-reflection layer comprises a low-reflectivity conductive material, and the anti-reflection layer absorbs most of the light incident thereon and reflects only a small amount of light.

[0009] Optionally, the anti-reflection layer forms an ohmic contact with the P-type semiconductor layer to simultaneously serve as a current spreading layer, and the first electrode is electrically connected to the P-type semiconductor layer through the anti-reflection layer.

[0010] Optionally, the low reflectivity conductive material comprises a Ni / Au / Ti stacked metal film, wherein a Ti layer in the Ni / Au / Ti stacked metal film is connected to the P-type semiconductor layer.

[0011] Optionally, in the Ni / Au / Ti stacked metal film, the thickness of the Ni layer is between 5 nanometers and 15 nanometers, the thickness of the Au layer is between 50 nanometers and 100 nanometers, and the thickness of the Ni layer is between 80 nanometers and 150 nanometers.

[0012] Optionally, the first electrode includes a first bottom electrode and a first outer electrode, the second electrode includes a second bottom electrode and a second outer electrode, the anti-reflection layer includes a low-reflectivity conductive material, and the anti-reflection layer forms an ohmic contact with the P-type semiconductor layer to simultaneously serve as the first bottom electrode and the current spreading layer.

[0013] Optionally, the LED chip further includes an ITO transparent conductive layer, the ITO transparent conductive layer forms an ohmic contact with the P-type semiconductor layer, the anti-reflection layer covers the surface of the ITO transparent conductive layer, and the first electrode is electrically connected to the P-type semiconductor layer through the anti-reflection layer and the ITO transparent conductive layer.

[0014] Optionally, the first electrode includes a first bottom electrode and a first outer electrode, the second electrode includes a second bottom electrode and a second outer electrode, and the anti-reflection layer serves as the first bottom electrode to connect the ITO transparent conductive layer and the first outer electrode.

[0015] Optionally, the first electrode includes a first bottom electrode and a first outer electrode, the second electrode includes a second bottom electrode and a second outer electrode, and the first bottom electrode is electrically connected to the P-type semiconductor layer through the anti-reflection layer and the ITO transparent conductive layer.

[0016] The present invention also provides a display screen module, comprising: a substrate, a plurality of electrode pairs are provided on the surface of the substrate, the electrode pairs include a plurality of positive electrodes and negative electrodes; a plurality of LED chips as described in any one of the above items are located on the substrate, the first electrode of the LED chip is connected to the positive electrode, and the second electrode is connected to the negative electrode.

[0017] Optionally, the substrate is a PCB substrate or a glass substrate.

[0018] The present invention further provides a display screen, which is formed by splicing a plurality of display screen modules as described in any one of the above items.

[0019] As described above, the LED chip, display screen module and display screen of the present invention have the following beneficial effects:

[0020] The present invention covers an anti-reflection layer on the P-type semiconductor layer to absorb most of the light directed thereto and reflect only a small amount of light. On the one hand, the anti-reflection layer can effectively reduce the reflection of light from the back of the LED chip, thereby reducing the light emission and reducing the brightness of the LED chip, so that the LED chip can operate in the linear region without the problem of excessive brightness; on the other hand, the anti-reflection layer can reduce the thickness of the black film layer when applied to the LED display screen module, so that the display screen module has better ink color consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of the LED chip of Example 1 of the present invention.

[0022] Figure 2 Shown is a schematic structural diagram of an LED chip according to Embodiment 2 of the present invention.

[0023] Figure 3 It is a schematic diagram showing the structure of the LED chip according to the third embodiment of the present invention.

[0024] Figure 4 Shown is a schematic structural diagram of an LED chip according to Embodiment 4 of the present invention.

[0025] Figure 5 Shown is a structural schematic diagram of a display screen module according to an embodiment of the present invention.

[0026] Component number description

[0027] 10 LED chips

[0028] 101 Substrate

[0029] 102 Buffer layer

[0030] 103 Intrinsic semiconductor layer

[0031] 104 N-type semiconductor layer

[0032] 105 Luminous Layer

[0033] 106 Electron blocking layer

[0034] 107 P-type semiconductor layer

[0035] 108 ITO transparent conductive layer

[0036] 109 second bottom electrode

[0037] 110 first bottom electrode

[0038] 111 Passivation layer

[0039] 112 Anti-reflection layer

[0040] 113 First outer electrode

[0041] 114 Second outer electrode

[0042] 201 substrate

[0043] 202 positive electrode

[0044] 203 Negative electrode DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0046] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general scale, and the schematic view is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional space dimensions of length, width and depth should be included.

[0047] For ease of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0048] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0049] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0050] Example 1

[0051] like Figure 1 As shown, this embodiment provides an LED chip, which is used for an LED display screen module. The LED chip includes a substrate 101, a buffer layer 102, an intrinsic semiconductor layer 103, an N-type semiconductor layer 104, a light-emitting layer 105, an electron blocking layer 106, a P-type semiconductor layer 107, an ITO transparent conductive layer 108, an anti-reflection layer 112, a step, a first electrode, a second electrode and a passivation layer 111, wherein the light-emitting layer 105 is located above the N-type semiconductor layer 104, the P-type semiconductor layer 107 is located above the light-emitting layer 105, and the step penetrates the P-type semiconductor layer 107 and the light-emitting layer 105, and exposes a portion of the surface of the N-type semiconductor layer 104.

[0052] For example, the substrate 101 may be a sapphire substrate, the N-type semiconductor may be an N-type gallium nitride layer, the light-emitting layer 105 may be a gallium nitride-based multi-quantum well layer, and the P-type semiconductor layer 107 may be a P-type gallium nitride layer.

[0053] like Figure 1As shown, in this embodiment, the ITO transparent conductive layer 108 forms an ohmic contact with the P-type semiconductor layer 107, the anti-reflection layer 112 covers the surface of the ITO transparent conductive layer 108, and the first electrode is electrically connected to the P-type semiconductor layer 107 through the anti-reflection layer 112 and the ITO transparent conductive layer 108. The anti-reflection layer 112 of the present invention is connected to the P-type semiconductor layer 107 through the ITO transparent conductive layer 108, and the anti-reflection layer 112 does not need to directly form an ohmic contact with the P-type semiconductor layer 107, which can greatly expand the material selection types of the anti-reflection layer 112.

[0054] like Figure 1 As shown, the first electrode includes a first bottom electrode 110 and a first outer electrode 113, and the second electrode includes a second bottom electrode 109 and a second outer electrode 114, wherein the first bottom electrode 110 and the second bottom electrode 109 are wrapped by a passivation layer 111, and the first bottom electrode 110 and the second bottom electrode 109 can effectively improve the electrical conductivity and mechanical properties of the electrodes, and the first outer electrode 113 and the second outer electrode 114 can facilitate the welding of the LED chip and the substrate. In this embodiment, the first bottom electrode 110 is electrically connected to the P-type semiconductor layer 107 through the anti-reflection layer 112 and the ITO transparent conductive layer 108.

[0055] The anti-reflection layer 112 is used to absorb most of the light directed to it and only reflect a small amount of light. Specifically, when the LED chip emits light, part of the light will be emitted toward the light-emitting surface (sapphire substrate), and the other part will reach the anti-reflection layer 112 toward the back. Since the emissivity of the anti-reflection layer 112 is low, most of the light reaching the anti-reflection layer 112 will not be reflected back into the LED chip but will be absorbed by the anti-reflection layer 112. Therefore, the LED chip with the anti-reflection layer 112 of the present invention, the light emitted from the light-emitting surface will be greatly reduced compared to the LED chip without the anti-reflection layer 112 on the back. For example, the brightness reduction range can be 20% to 60%. When the LED chip of the present invention is applied to an LED display screen, it can be operated in the current linear region without the problem of excessive brightness. Preferably, the reflectivity of the anti-reflection layer 112 is below 50%, and more preferably, the reflectivity of the anti-reflection layer 112 is below 20%.

[0056] In this embodiment, the low reflectivity conductive material includes a Ni / Au / Ti laminated metal film, wherein the Ti layer in the Ni / Au / Ti laminated metal film is connected to the P-type semiconductor layer 107. The thickness of the Ni layer in the Ni / Au / Ti laminated metal film is between 5 nanometers and 15 nanometers, the thickness of the Au layer is between 50 nanometers and 100 nanometers, and the thickness of the Ni layer is between 80 nanometers and 150 nanometers. For example, the thickness of the Ni layer can be 10 nanometers, the thickness of the Au layer can be 80 nanometers, and the thickness of the Ni layer can be 100 nanometers. The Ni / Au / Ti laminated metal film innovatively used in the present invention as the anti-reflection layer 112 has a lower emissivity and is equipped with an innovative thickness range, which can greatly reduce the reflection of light, thereby reducing the brightness of the LED chip.

[0057] like Figure 5 As shown, this embodiment further provides a display screen module, the display screen module comprising: a substrate 201, a plurality of electrode pairs are provided on the surface of the substrate 201, the electrode pairs include a positive electrode 202 and a negative electrode 203; a plurality of LED chips 10 as described above, located on the substrate 201, the first electrode of the LED chip 10 is connected to the positive electrode 202, and the second electrode is connected to the negative electrode 203. The substrate 201 can be a PCB substrate or a glass substrate.

[0058] In addition, this embodiment also provides a display screen, which is formed by splicing a plurality of display screen modules as described above.

[0059] The present invention covers an anti-reflection layer 112 above the P-type semiconductor layer 107 to reduce the light emitted from the LED chip and reflected back to the inside of the LED chip through the anti-reflection layer. On the one hand, the anti-reflection layer 112 can effectively reduce the reflection of light from the back of the LED chip, thereby reducing the emission of light and reducing the brightness of the LED chip, so that the LED chip can operate in the linear region (large current density) without the problem of excessive brightness; on the other hand, the anti-reflection layer 112 can reduce the thickness of the black film layer when applied to the LED display module, so that the display module has better ink color consistency.

[0060] Example 2

[0061] like Figure 2As shown, this embodiment provides an LED chip, which is used for an LED display screen module. The basic structure of the LED chip is as in Embodiment 1, wherein the difference from Embodiment 1 is that the first electrode includes a first bottom electrode 110 and a first outer electrode 113, the second electrode includes a second bottom electrode 109 and a second outer electrode 114, and the anti-reflection layer 112 is used as the first bottom electrode 110 to connect the ITO transparent conductive layer 108 and the first outer electrode 113. This embodiment uses the anti-reflection layer 112 as the first bottom electrode 110, which can effectively save process steps and reduce process costs.

[0062] Example 3

[0063] like Figure 3 As shown, this embodiment provides an LED chip, which is used for an LED display screen module. The basic structure of the LED chip is as in Embodiment 1, wherein the difference from Embodiment 1 is that the anti-reflection layer 112 includes a low-reflectivity conductive material, and the anti-reflection layer 112 forms an ohmic contact with the P-type semiconductor layer 107 to simultaneously serve as a current spreading layer, and the first electrode is electrically connected to the P-type semiconductor layer 107 through the anti-reflection layer 112. The LED chip of this embodiment does not require an additional ITO transparent conductive layer 108, and the anti-reflection layer 112 directly forms an ohmic contact with the P-type semiconductor layer 107, which not only plays a role in current diffusion, but also plays a role in reducing light reflection, which can effectively simplify the process flow and reduce the process cost.

[0064] Example 4

[0065] like Figure 4 As shown, this embodiment provides an LED chip, which is used for an LED display screen module. The basic structure of the LED chip is as in Embodiment 1, wherein the difference from Embodiment 1 is that: the first electrode includes a first bottom electrode 110 and a first outer electrode 113, the second electrode includes a second bottom electrode 109 and a second outer electrode 114, the anti-reflection layer 112 includes a low-reflectivity conductive material, and the anti-reflection layer 112 forms an ohmic contact with the P-type semiconductor layer 107 to simultaneously serve as the first bottom electrode 110 and the current spreading layer. The LED chip of this embodiment does not require the additional production of an ITO transparent conductive layer 108 and a first bottom electrode 110, and the anti-reflection layer 112 directly forms an ohmic contact with the P-type semiconductor layer 107, which not only plays a role in current diffusion, but also plays a role in reducing light reflection. At the same time, the anti-reflection layer 112 is directly connected to the first outer electrode 113 as the first bottom electrode 110, which can effectively simplify the process flow and reduce the process cost.

[0066] As described above, the LED chip, display screen module and display screen of the present invention have the following beneficial effects:

[0067] The present invention covers the P-type semiconductor layer 107 with an anti-reflection layer 112 to absorb most of the light directed thereto and reflect only a small amount of light. On the one hand, the anti-reflection layer 112 can effectively reduce the reflection of light from the back of the LED chip, thereby reducing the light emission and reducing the brightness of the LED chip, so that the LED chip can operate in the linear region (large current density) without the problem of excessive brightness. On the other hand, the anti-reflection layer 112 can reduce the thickness of the black film layer when applied to the LED display module, so that the display module has better ink color consistency.

[0068] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0069] 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 familiar with 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 a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An LED chip, characterized in that: The LED chip is used in an LED display screen module, and the LED chip includes: N-type semiconductor layer; A light emitting layer, located above the N-type semiconductor layer; A P-type semiconductor layer, located above the light-emitting layer; an anti-reflection layer, covering the P-type semiconductor layer, and used for absorbing the light emitted from the light-emitting layer and finally emitted to the anti-reflection layer; A first electrode and a second electrode, respectively located above the P-type semiconductor layer and the N-type semiconductor layer and respectively electrically connected to the P-type semiconductor layer and the N-type semiconductor layer; The anti-reflection layer comprises a low-reflectivity conductive material, and the anti-reflection layer forms an ohmic contact with the P-type semiconductor layer to simultaneously serve as a current spreading layer, and the first electrode is electrically connected to the P-type semiconductor layer through the anti-reflection layer; The low reflectivity conductive material comprises a Ni / Au / Ti stacked metal film, wherein the Ti layer in the Ni / Au / Ti stacked metal film is connected to the P-type semiconductor layer; The thickness of the Ni layer in the Ni / Au / Ti laminated metal film is between 5 nanometers and 15 nanometers, the thickness of the Au layer is between 50 nanometers and 100 nanometers, and the thickness of the Ni layer is between 80 nanometers and 150 nanometers; The first electrode includes a first bottom electrode and a first outer electrode, the second electrode includes a second bottom electrode and a second outer electrode, the anti-reflection layer includes a low-reflectivity conductive material, and the anti-reflection layer forms an ohmic contact with the P-type semiconductor layer to simultaneously serve as the first bottom electrode and the current spreading layer.

2. The LED chip according to claim 1, characterized in that: The LED chip also includes an ITO transparent conductive layer, which forms an ohmic contact with the P-type semiconductor layer. The anti-reflection layer covers the surface of the ITO transparent conductive layer. The first electrode is electrically connected to the P-type semiconductor layer through the anti-reflection layer and the ITO transparent conductive layer.

3. The LED chip according to claim 2, characterized in that: The first electrode includes a first bottom electrode and a first outer electrode, the second electrode includes a second bottom electrode and a second outer electrode, and the anti-reflection layer serves as the first bottom electrode to connect the ITO transparent conductive layer and the first outer electrode.

4. The LED chip according to claim 2, characterized in that: The first electrode includes a first bottom electrode and a first outer electrode, the second electrode includes a second bottom electrode and a second outer electrode, and the first bottom electrode is electrically connected to the P-type semiconductor layer through the anti-reflection layer and the ITO transparent conductive layer.

5. A display screen module, characterized in that: include: A substrate, wherein a plurality of electrode pairs are disposed on the surface of the substrate, wherein the electrode pairs include a positive electrode and a negative electrode; A plurality of LED chips according to any one of claims 1 to 4 are located on the substrate, the first electrode of the LED chip is connected to the positive electrode, and the second electrode is connected to the negative electrode.

6. A display screen, characterized in that: The display screen is formed by splicing a plurality of display screen modules as claimed in claim 5.

Images