An LED chip, an LED chip assembly, a display backplane and a display screen
By introducing an aluminum metal reflective layer and a passivation layer into the MicroLED chip, the problems of light leakage and chip reliability in the distributed Bragg reflector structure were solved, resulting in improved brightness and reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHONGQING KONKA PHOTOELECTRIC TECH RES INST CO LTD
- Filing Date
- 2025-08-15
- Publication Date
- 2026-07-21
AI Technical Summary
The distributed Bragg reflector structure of existing MicroLED chips is limited by the aperture size and cannot be as thick as that of traditional LEDs. As a result, thin-layer distributed Bragg reflectors cannot achieve high reflectivity at all angles, and thin-layer reflectors have light leakage problems. At the same time, the chips have short circuit and leakage problems.
The chip structure incorporates a metal reflective layer and a passivation layer. The metal reflective layer is an aluminum metal layer, and the passivation layer covers the chip sidewalls and extends to the sidewalls to prevent short circuits. The metal reflective layer reflects leaked light, increasing the amount of light emitted and improving brightness. The passivation layer design does not extend the structure outward to prevent debris generation and solve the leakage problem.
By adding a metal reflective layer and a passivation layer, the chip brightness was improved, reliability was enhanced, short circuits and leakage were prevented, achieving a balance between high reflectivity and reliability.
Smart Images
Figure CN224538660U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor technology, and in particular to an LED chip, an LED chip assembly, a display backplane, and a display screen. Background Technology
[0002] Currently, LED chips (such as MicroLED) mainly adopt the flip-chip DBR (distributed Bragg reflector) structure. Due to the limitation of the aperture size of the distributed Bragg reflector, it is not possible to perform optical aperture etching. It is also impossible to make the distributed Bragg reflector as thick as that of traditional LEDs. Only a thin stacked distributed Bragg reflector structure can be adopted. However, the thin stacked distributed Bragg reflector cannot achieve high reflectivity at all angles. Utility Model Content
[0003] In view of the shortcomings of the above-mentioned related technologies, the purpose of this utility model is to provide an LED chip, an LED chip assembly, a display backplane and a display screen, which can increase chip light output, improve chip brightness and enhance reliability.
[0004] This utility model provides an LED chip, including a chip structure, a distributed Bragg reflector layer, a metal reflective layer, a passivation layer, a first pad and a second pad. The chip structure includes a first semiconductor layer, an active layer, a second semiconductor layer, a transparent electrode layer, a first electrode and a second electrode. The first electrode and the active layer are respectively stacked on the first semiconductor layer, and the second semiconductor layer, the transparent electrode layer and the second electrode are sequentially stacked on the active layer.
[0005] The distributed Bragg reflector layer and the metal reflector layer are sequentially disposed on the side of the chip structure away from the first semiconductor layer. The passivation layer extends from the surface of the metal reflector layer toward the sidewall of the chip structure to cover the sidewall of the chip structure. The first pad is disposed on the passivation layer and is connected to the first electrode through a first via via a first conductor. The first via passes through the passivation layer, the metal reflector layer, and the distributed Bragg reflector layer sequentially to the first electrode. The first conductor and the metal reflector layer are spaced apart, and the passivation layer is disposed between the first conductor and the metal reflector layer. The second pad is disposed on the passivation layer and is connected to the second electrode through a second via a second conductor. The second via passes through the passivation layer, the metal reflector layer, and the distributed Bragg reflector layer sequentially to the second electrode. The second conductor and the metal reflector layer are spaced apart, and the passivation layer is disposed between the second conductor and the metal reflector layer.
[0006] Optionally, the metal reflective layer is an aluminum metal layer.
[0007] Optionally, the thickness of the distributed Bragg reflector layer is 0.6 μm to 1.5 μm.
[0008] Optionally, the LED chip is a MiniLED or MicroLED.
[0009] Optionally, the first pad is integrally formed with the first conductor, and the second pad is integrally formed with the second conductor.
[0010] This utility model also provides an LED chip assembly, including a substrate and the aforementioned LED chip, wherein the substrate is disposed on the side of the LED chip near the first semiconductor layer.
[0011] This utility model also provides a display backplate, including a driving backplate and the aforementioned LED chip, wherein the LED chip is bonded to the driving backplate.
[0012] This utility model also provides a display screen, including a housing and the aforementioned display back panel, wherein the display back panel is disposed on the housing.
[0013] This invention relates to an LED chip, LED chip assembly, display backplane, and display screen. The addition of a metal reflective layer reflects light leaking through the distributed Bragg reflector layer, increasing chip light output and improving chip brightness. A passivation layer on the sidewall of the LED chip prevents short circuits, ensuring high reliability. Furthermore, the passivation layer's non-outward-expanding design facilitates laser transfer and prevents debris generation. The aluminum metal reflective layer combines high reflectivity with high reliability, effectively solving the chip leakage problem. Attached Figure Description
[0014] Figure 1 A schematic diagram of an LED chip assembly is provided for an embodiment of this utility model;
[0015] Explanation of reference numerals in the attached figures: 1-Distributed Bragg reflector layer; 2-Metallic reflective layer; 3-Passivation layer; 4-First pad; 5-Second pad; 6-Substrate; 7-Transparent electrode layer; 8-First electrode; 9-Second electrode. Detailed Implementation
[0016] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.
[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0018] In the description of this utility model, the terms "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "upper," "lower," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0019] It should be noted that the illustrations provided in the embodiments of this utility model are only schematic representations of the basic concept of this utility model. The illustrations only show the components related to this utility model and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0020] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings.
[0021] See Figure 1 As shown in the figure, this utility model embodiment discloses an LED chip, including a chip structure, a distributed Bragg reflector layer 1, a metal reflective layer 2, a passivation layer 3, a first pad 4 and a second pad 5. The chip structure includes a first semiconductor layer, an active layer, a second semiconductor layer, a transparent electrode layer 7, a first electrode 8 and a second electrode 9. The first electrode 8 and the active layer are respectively stacked on the first semiconductor layer, and the second semiconductor layer, the transparent electrode layer 7 and the second electrode 9 are sequentially stacked on the active layer.
[0022] The distributed Bragg reflector layer 1 and the metal reflector layer 2 are sequentially disposed on the side of the chip structure away from the first semiconductor layer. The passivation layer 3 extends from the surface of the metal reflector layer 2 toward the sidewall of the chip structure to cover the sidewall of the chip structure. The first pad 4 is disposed on the passivation layer 3. The first pad 4 is connected to the first electrode 8 through a first via via a first wire. The first via passes through the passivation layer 3, the metal reflector layer 2, and the distributed Bragg reflector layer 1 sequentially to the first electrode 8. The first wire and the metal reflector layer 2 are spaced apart. The passivation layer 3 is disposed between the first wire and the metal reflector layer 2. The second pad 5 is disposed on the passivation layer 3. The second pad 5 is connected to the second electrode 9 through a second via a second wire. The second via passes through the passivation layer 3, the metal reflector layer 2, and the distributed Bragg reflector layer 1 sequentially to the second electrode 9. The second wire and the metal reflector layer 2 are spaced apart. The passivation layer 3 is disposed between the second wire and the metal reflector layer 2. For example, in MicroLEDs, the distributed Bragg reflector layer 1 is limited by size and aperture constraints, requiring a thin stack of distributed Bragg reflector layers 1. This distributed Bragg reflector layer 1 system exhibits light leakage under different incident angles. The metal reflective layer 2 can reflect the light leaking out of the distributed Bragg reflector layer 1, increasing chip light output and improving chip brightness. The passivation layer 3 on the sidewalls of the LED chip prevents short circuits. Without the passivation layer 3, the LED chip would be unusable at the packaging end. During AuSn soldering, Sn would flow to the sidewalls, causing the pads to conduct to the semiconductor layer, resulting in a short circuit. The passivation layer 3 is designed with a non-outward expansion structure, meaning that the passivation layer 3 does not extend towards the surface of the substrate 6 when extending along the sidewalls of the LED chip. This facilitates laser transfer and prevents debris generation.
[0023] In this embodiment, the metal reflective layer 2 is a silver metal layer, an aluminum metal layer, or other types of metal layers, and is not limited thereto. Optionally, the metal reflective layer 2 is an aluminum metal layer. Traditional metal reflective layers using silver metal layers have higher reflectivity but are chemically active, which can easily cause chip leakage and lead to reliability issues. This application uses an aluminum metal layer, which simultaneously achieves both high reflectivity and high reliability, thus solving the chip leakage problem.
[0024] In this embodiment, the thickness of the distributed Bragg reflector layer 1 is 0.6 μm to 1.5 μm.
[0025] In this embodiment, the LED chip is a MiniLED or a MicroLED.
[0026] In this embodiment, the first pad 4 is integrally formed with the first conductor, and the second pad 5 is integrally formed with the second conductor.
[0027] See Figure 1 As shown, this embodiment of the invention also discloses an LED chip assembly, including a substrate 6 and the aforementioned LED chip. The substrate 6 is disposed on the side of the LED chip near the first semiconductor layer. The passivation layer 3 is designed with a non-outward expansion structure, meaning that the passivation layer 3 does not extend towards the surface of the substrate 6 when it extends along the sidewall of the LED chip, which is beneficial for laser transfer and prevents the generation of debris.
[0028] This utility model embodiment also discloses a display backplate, including a driving backplate and the above-mentioned LED chip, wherein the LED chip is bonded to the driving backplate.
[0029] In this embodiment, the driving backplane can be a circuit board, an array substrate, a glass driving backplane, a flexible driving backplane, a lamp board, a semiconductor driving backplane, or other types of driving backplanes, and is not specifically limited in this embodiment; the material of the driving backplane can be glass, transparent plastic, acrylic, quartz, sapphire, semiconductor materials, etc., and can be selected according to the actual situation, and is not specifically limited in this embodiment.
[0030] This utility model embodiment also discloses a display screen, including a housing and the aforementioned display back panel, wherein the display back panel is disposed on the housing.
[0031] As one implementation method, the display screen can be a television, VR / AR device, smart wearable device, mobile phone, vehicle display, etc.
[0032] This invention relates to an LED chip, LED chip assembly, display backplane, and display screen. The addition of a metal reflective layer reflects light leaking through the distributed Bragg reflector layer, increasing chip light output and improving chip brightness. A passivation layer on the sidewall of the LED chip prevents short circuits, ensuring high reliability. Furthermore, the passivation layer's non-outward-expanding design facilitates laser transfer and prevents debris generation. The aluminum metal reflective layer combines high reflectivity with high reliability, effectively solving the chip leakage problem.
[0033] It should be understood that the application of this utility model is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. An LED chip, characterized in that, The chip includes a chip structure, a distributed Bragg mirror layer, a metal reflective layer, a passivation layer, a first pad, and a second pad. The chip structure includes a first semiconductor layer, an active layer, a second semiconductor layer, a transparent electrode layer, a first electrode, and a second electrode. The first electrode and the active layer are respectively stacked on the first semiconductor layer, and the second semiconductor layer, the transparent electrode layer, and the second electrode are sequentially stacked on the active layer. The distributed Bragg reflector layer and the metal reflector layer are sequentially disposed on the side of the chip structure away from the first semiconductor layer. The passivation layer extends from the surface of the metal reflector layer toward the sidewall of the chip structure to cover the sidewall of the chip structure. The first pad is disposed on the passivation layer and is connected to the first electrode through a first via via a first conductor. The first via passes through the passivation layer, the metal reflector layer, and the distributed Bragg reflector layer sequentially to the first electrode. The first conductor and the metal reflector layer are spaced apart, and the passivation layer is disposed between the first conductor and the metal reflector layer. The second pad is disposed on the passivation layer and is connected to the second electrode through a second via a second conductor. The second via passes through the passivation layer, the metal reflector layer, and the distributed Bragg reflector layer sequentially to the second electrode. The second conductor and the metal reflector layer are spaced apart, and the passivation layer is disposed between the second conductor and the metal reflector layer.
2. The LED chip as described in claim 1, characterized in that, The metal reflective layer is an aluminum metal layer.
3. The LED chip as described in claim 1, characterized in that, The thickness of the distributed Bragg reflector layer is 0.6 μm to 1.5 μm.
4. The LED chip as described in claim 1, characterized in that, The LED chip is either a MiniLED or a MicroLED.
5. The LED chip according to any one of claims 1 to 4, characterized in that, The first pad is integrally formed with the first conductor, and the second pad is integrally formed with the second conductor.
6. An LED chip assembly, characterized in that, It includes a substrate and an LED chip as described in any one of claims 1 to 5, wherein the substrate is disposed on the side of the LED chip near the first semiconductor layer.
7. A display back panel, characterized in that, It includes a driver backplane and an LED chip as described in any one of claims 1 to 5, wherein the LED chip is bonded to the driver backplane.
8. A display screen, characterized in that, It includes a housing and a display back panel as described in claim 7, wherein the display back panel is disposed on the housing.