Light-emitting element and light-emitting device
By moving the Zener diode into the substrate in the LED package structure, the problem of waste of substrate area is solved, the maximum utilization of substrate area is achieved, and the luminous energy efficiency is improved.
Patent Information
- Application Number
- CN202421649571.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-07-12
AI Technical Summary
In the existing LED packaging structure, the Zener diode and LED chip are arranged in parallel with solid crystals through silver glue or eutectic processes, resulting in wasted substrate area, limiting the area of the solid crystal area, and the maximum utilization of the substrate area cannot be achieved.
By optimizing the design of the light emitting element, the Zener diode is arranged at the corner between the circular light emitting surface of the light emitting epitaxial layer and the edge of the substrate to avoid occupying the external area and thereby expanding the solid crystal area.
Maximized utilization of the packaging substrate is achieved, the area of the solid crystal region is increased, and the luminous energy efficiency is improved, including a smaller luminous angle, stronger axial light intensity and a longer projection distance.
Smart Images
Figure CN223040521U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of light-emitting semiconductors, in particular to a semiconductor light-emitting element and a light-emitting device. Background Art
[0002] An LED (light-emitting diode) is a light-emitting device that can directly convert electrical energy into visible light. It has the characteristics of high luminous efficiency, long lifespan, small volume, etc., and is widely used in various fields such as production and daily life. However, during daily use, electrostatic damage may occur. When the static electricity accumulates to a certain extent, discharge will occur, damaging the internal chip structure and causing irreversible damage to the LED device, thereby affecting the quality of the LED chip.
[0003] In the existing LED packaging structure, a Zener diode is reversely connected in parallel with the LED chip to provide reverse protection for the LED chip. The static charge is released through the Zener diode, thereby achieving the effect of protecting the LED chip and improving the anti-static ability of the LED chip. However, in the prior art, the Zener diode and the LED chip are fixedly arranged on the substrate in parallel through silver glue or eutectic process. The Zener diode is fixed on one side of the LED chip, and a certain substrate area is required to isolate the materials and electrical properties. This wastes a certain amount of substrate area, limits the area of the die bonding region for placing the LED chip, and cannot maximize the utilization of the substrate area. Summary of the Utility Model
[0004] The utility model provides a light-emitting element and a light-emitting device, which maximize the utilization of the substrate area through the optimized design of the light-emitting diode and the Zener diode.
[0005] To achieve the above object, the utility model provides a light-emitting element, which includes a substrate, a light-emitting epitaxial layer, and a Zener diode; the light-emitting epitaxial layer and the Zener diode are located on the same surface of the substrate. The light-emitting epitaxial layer has a circular light-emitting surface, the substrate is square, and the Zener diode is located at the corner between the circular light-emitting surface and the edge of the substrate.
[0006] The utility model also provides a light-emitting device, which includes a circuit board and the light-emitting element disposed on the circuit board.
[0007] As described above, the present utility model provides a light-emitting element and a light-emitting device. The light-emitting element includes a substrate, a light-emitting epitaxial layer, and a Zener diode. The light-emitting epitaxial layer and the Zener diode are bonded to the same surface of the substrate. The light-emitting epitaxial layer has a circular light-emitting surface, the substrate is square, and the Zener diode is located at the corner between the circular light-emitting surface and the edge of the substrate. In the present utility model, the epitaxial layer at the corner of the square light-emitting diode in the prior art is etched and removed, and the contour of the light-emitting epitaxial layer is designed as a circle, so that the Zener diode can be arranged at the corner outside the light-emitting epitaxial layer, that is, the Zener diode is moved inward to the inside of the substrate, avoiding occupying the external area. The original area for placing the Zener diode can be used to place the light-emitting epitaxial layer, so that the die bonding area can be expanded as much as possible, and a larger area of the substrate and the light-emitting epitaxial layer can be placed, realizing the maximum utilization of the packaging substrate and making the design more flexible. At the same time, when the light-emitting area of the chip is the same, the circular light-emitting surface has a smaller light-emitting angle, stronger axial light intensity, and farther projection distance compared with the square light-emitting surface, further improving the light-emitting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 It shows a top view structural schematic diagram of the light-emitting element in the embodiment of the present utility model.
[0009] Figure 2 It shows a schematic diagram of the arrangement of the light-emitting epitaxial layer and the Zener diode in the prior art.
[0010] Figure 3 It shows Figure 1 a cross-sectional view along the A-B direction in
[0011] Figure 4 It shows a comparison of the light illumination data between the light-emitting element in the present utility model and the light-emitting element in the prior art.
[0012] Description of Component Labels
[0013] Light-emitting epitaxial layer - 10; Semiconductor stack layer - 11; Zener diode - 30; Substrate - 20; Packaging substrate - 22; First conductive region - 221; Second conductive region - 222; Substrate insulating layer - 223; First semiconductor layer - 101; Active layer - 102; Second semiconductor layer - 103; Current blocking layer - 12; First metal reflection layer - 13; First through hole - 121; Second through hole - 111; First insulating layer - 14; Second metal reflection layer - 15; Second electrode - 16; Chip insulating layer - 31; Wavelength conversion layer - 17. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] The structures, proportions, sizes, etc. shown in the accompanying drawings of the specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the implementation conditions of the present utility model. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model. At the same time, terms such as "upper" and "lower" cited in this specification are only for the convenience of clear description and are not used to limit the implementation scope of the present utility model. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the implementable scope of the present utility model.
[0015] The present utility model provides a light-emitting element, and the light-emitting element includes a substrate, a light-emitting epitaxial layer, and a Zener diode.
[0016] The light-emitting epitaxial layer and the Zener diode are located on the same surface of the substrate. The light-emitting epitaxial layer has a circular light-emitting surface. The substrate is square, and the Zener diode is located at the corner between the circular light-emitting surface and the edge of the substrate.
[0017] Optionally, the light-emitting element includes a plurality of light-emitting epitaxial layers and a plurality of corresponding Zener diodes.
[0018] Optionally, the light-emitting element includes a packaging substrate on the surface of the substrate away from the light-emitting epitaxial layer. The packaging substrate includes a first conductive region and a second conductive region. The substrate is located within the first conductive region. The first electrodes of the light-emitting epitaxial layer and the Zener diode are electrically connected to the first conductive region, and the second electrodes of the light-emitting epitaxial layer and the Zener diode are electrically connected to the second conductive region.
[0019] Optionally, at least part of the second conductive region surrounds the first conductive region.
[0020] Optionally, the light-emitting epitaxial layer includes a semiconductor stack layer, and the semiconductor stack layer includes a first semiconductor layer, an active layer, and a second semiconductor layer arranged in sequence.
[0021] A current blocking layer and a first metal reflection layer are sequentially covered on the surface of the second semiconductor layer away from the active layer. At least one first through hole is formed in the current blocking layer, and the first metal reflection layer also fills into the first through hole to achieve electrical connection with the second semiconductor layer.
[0022] Optionally, at least one second through hole is formed in the semiconductor stack layer. The second through hole penetrates the second semiconductor layer and the active layer, and the current blocking layer also extends to cover the inner wall of the second through hole.
[0023] Optionally, a first insulating layer covers the surface of the first metal reflective layer away from the current blocking layer, and the first insulating layer also covers the sidewalls of the first metal reflective layer and the surface of the current blocking layer located on the inner wall of the second through hole.
[0024] Optionally, a second metal reflective layer covers the surface of the first insulating layer away from the metal reflective layer and fills into the second through hole to achieve electrical connection with the first semiconductor layer.
[0025] Optionally, a second electrode is formed on the periphery of the semiconductor stack layer, and penetrates through the current blocking layer located on the periphery of the semiconductor stack layer and contacts the first metal reflective layer to achieve electrical connection with the second semiconductor layer.
[0026] Optionally, a wavelength conversion layer is formed on the light-emitting surface of the first semiconductor layer away from the active layer and on the sidewalls of the semiconductor stack layer.
[0027] Optionally, the substrate is a conductive substrate.
[0028] Optionally, the Zener diode and the light-emitting epitaxial layer are separated by a chip insulating layer located on the surface of the substrate.
[0029] Optionally, the Zener diode and the light-emitting epitaxial layer are connected in parallel, and the Zener diode is a unidirectional Zener diode or a bidirectional Zener diode.
[0030] An embodiment of the present invention further provides a light-emitting device, including a circuit board and the light-emitting element disposed on the circuit board.
[0031] The following is a further detailed description through specific embodiments.
[0032] Embodiment 1
[0033] This embodiment provides a semiconductor light-emitting element, as Figure 1 shown, the semiconductor light-emitting element includes a substrate 20, a light-emitting epitaxial layer 10, and a Zener diode 30.
[0034] The light-emitting epitaxial layer 10 and the Zener diode 30 are bonded to the same surface of the substrate 20. The light-emitting epitaxial layer 10 has a circular contour and a circular light-emitting surface. The substrate is square, and the Zener diode 30 is located at the corner between the circular light-emitting surface and the edge of the substrate. The surface of the substrate 20 away from the light-emitting epitaxial layer 10 is bonded to a packaging substrate 22. The packaging substrate 22 includes a first conductive region 221 and a second conductive region 222 located outside the first conductive region 221. The first conductive region 221 and the second conductive region 222 are separated by a substrate insulating layer 223.
[0035] The substrate 20 is located within the first conductive region 221. The first electrodes of the light-emitting epitaxial layer 10 and the Zener diode 30 are electrically connected to the first conductive region 221 through the substrate 20, and the second electrodes of the light-emitting epitaxial layer 10 and the Zener diode 30 are electrically connected to the second conductive region 222 through bonding wires.
[0036] Specifically, as Figure 2 shown, the light-emitting epitaxial layer 10 in the prior art has a square structure. The epitaxial layer 10 has a quasi-square light-emitting surface, and the light-emitting epitaxial layer 10 almost occupies the entire surface of the substrate 20. The Zener diode can only be arranged on the substrate surface outside the substrate 20, and the Zener diode needs to maintain a certain interval from the light-emitting epitaxial layer. It is difficult to expand the die bonding area of the substrate and the light-emitting epitaxial layer on the limited packaging substrate. In contrast, in the present application, the regions at the four corners of the original square light-emitting epitaxial layer are etched away, and the contour of the light-emitting epitaxial layer is designed as a circle, so that the Zener diode can be arranged at the corner between the circular light-emitting surface and the substrate edge, that is, the Zener diode is moved inward to the inside of the substrate, avoiding the occupation of external area, and the original area for placing the Zener diode can be used to place the substrate, so that the die bonding area can be expanded as much as possible, and a larger area of the substrate and the light-emitting epitaxial layer can be placed, realizing the maximum utilization of the packaging substrate. It should be understood that the Zener diode and the light-emitting epitaxial layer are connected in parallel to use the Zener diode to provide reverse protection for the light-emitting epitaxial layer and improve the reverse electrostatic discharge resistance of the light-emitting epitaxial layer. The Zener diode can be a unidirectional Zener or a bidirectional Zener, and a bidirectional Zener diode is preferably used in this embodiment.
[0037] Furthermore, as Figure 3 shown, the light-emitting epitaxial layer includes a semiconductor stack layer 11. The semiconductor stack layer 11 may include a first semiconductor layer 101 (which may be an N-type semiconductor layer), an active layer 102, and a second semiconductor layer 103 (which may be a P-type semiconductor layer) arranged in sequence. The first semiconductor layer 101, the active layer 102, and the second semiconductor layer 103 are only the basic constituent units of the semiconductor stack layer. In addition, other epitaxial layer structures, such as superlattice stress buffer layers and electron blocking layers, may be included to optimize the light-emitting performance. The semiconductor stack layer can be obtained by epitaxial deposition, and its specific materials include but are not limited to aluminum gallium arsenide, gallium arsenide phosphide, aluminum gallium indium phosphide, gallium nitride, indium gallium nitride, zinc selenide, or gallium phosphide.
[0038] Further, a current blocking layer 12 and a first metal reflective layer 13 are sequentially covered on the surface of the second semiconductor layer 103 away from the active layer 102. At least one first through hole 121 is formed in the current blocking layer 12, and the first metal reflective layer 13 is also filled into the first through hole 121 to achieve electrical connection with the second semiconductor layer 103. Here, the material of the current blocking layer 12 is a transparent insulating layer, including at least one of transparent inorganic insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, titanium oxide or aluminum oxide. In this embodiment, it is preferably a silicon oxide layer. In addition to being used for conduction, the first metal reflective layer 13 also functions as a light reflector, reflecting as much light as possible emitted from the active layer to the light-emitting surface side, that is, emitting from the surface of the first semiconductor layer 101. In this embodiment, the first metal reflective layer 13 is formed as a multi-layer structure, which can be a two-layer or three-layer or more-layer structure.
[0039] Further, at least one second through hole 111 is formed in the semiconductor stack layer. The second through hole 111 penetrates through the second semiconductor layer 103 and the active layer 102, or continues to penetrate through part of the first semiconductor layer 101. Subsequently, a metal material is deposited in the second through hole 111 to achieve electrical connection with the first semiconductor layer. The current blocking layer 12 also covers the inner wall surface of the second through hole 111 to achieve electrical insulation.
[0040] Further, a first insulating layer 14 is covered on the surface of the first metal reflective layer 13 away from the current blocking layer 12. The first insulating layer 14 also covers the side wall of the first metal reflective layer 13 and the surface of the current blocking layer 12 located on the inner wall of the second through hole 111. A second metal reflective layer 15 covers the surface of the first insulating layer 14 away from the metal reflective layer 13 and is filled into the second through hole 111 to achieve electrical connection with the first semiconductor layer 101. Similar to the first metal reflective layer 13, the second metal reflective layer 15 not only functions as a conductor but also functions as a light reflector to reflect more light.
[0041] Further, the surface of the second metal reflective layer 15 away from the first insulating layer 14 is bonded to the substrate 20. The substrate 20 is a conductive substrate, which can serve as the first electrode electrically connected to the first semiconductor layer 101.
[0042] Further, a second electrode 16 is formed on the periphery of the semiconductor stack layer 11 and is electrically connected to the first metal reflective layer 13 through the current blocking layer 12 located on the periphery of the semiconductor stack layer, so as to achieve electrical connection with the second semiconductor layer 103.
[0043] Further, the Zener diode and the light-emitting epitaxial layer are located on the same surface of the substrate 20, and the Zener diode 30 and the light-emitting epitaxial layer 10 are electrically separated by a chip insulating layer 31 located on the surface of the substrate 20.
[0044] Further, a wavelength conversion layer 17 is formed on the light-emitting surface of the first semiconductor layer 101 away from the active layer and on the side walls of the semiconductor stack layer. The wavelength conversion layer 17 is used to protect the entire semiconductor stack layer and perform wavelength conversion. Its main component is an organic silicone doped with phosphor powder to play a role in wavelength conversion. In addition, a small amount of micron-sized or nano-sized reflective material powder formed by any one or a combination of SiO2, CaO, Na2O, TiO2, and BaO can be doped inside to enhance reflection and improve the light extraction efficiency.
[0045] As a comparison, as Figure 4 shown, it is a comparison of the light-emitting data of the square light-emitting epitaxial layer of the prior art and the circular light-emitting epitaxial layer of the present application. When the light-emitting area of the chip is the same, for example, both are 1.2 mm 2 , at this time, the substrate area corresponding to the circular light-emitting epitaxial layer is larger than the substrate area corresponding to the square light-emitting epitaxial layer in the prior art. Thanks to the inward movement of the Zener diode in the present application, a larger square area can be vacated to place a circular light-emitting epitaxial layer with the same area. This makes the LED structure more compact, and a chip with a larger light-emitting surface size can be placed within a fixed package size, making the design more flexible.
[0046] According to the data measured in the figure, when the lumen value is the same, the circular light-emitting surface has a smaller light-emitting angle, stronger axial light intensity, and a longer projection distance. Specifically, when the LED flux is set to 500 lm and under the same secondary optical lens, the circular light-emitting chip has a more circular and smaller light spot; at the same time, compared with the square chip, the circular chip has an approximately 0.8% increase in lumen extraction efficiency, a 0.36° decrease in angle, a 34% increase in axial light intensity, a 33% increase in optical efficiency, and a 16% increase in irradiation distance. It can be seen that by moving the Zener diode inward in the present application, a larger square area for placing the substrate and the light-emitting epitaxial layer can be vacated, and combined with the shape of the circular light-emitting surface, the luminous energy efficiency is further improved.
[0047] Embodiment 2
[0048] This embodiment provides a light-emitting device, including a circuit board and a light-emitting element disposed on the circuit board. The light-emitting element includes the light-emitting element in Embodiment 1, and the light-emitting element is electrically connected to the circuit board. The light-emitting element can be single or multiple; when there are multiple light-emitting elements, the multiple light-emitting elements are arranged in an array, such as in a circular arrangement or a rectangular arrangement.
[0049] In summary, the present utility model provides a light-emitting element and a light-emitting device. The light-emitting element includes a substrate, a light-emitting epitaxial layer, and a Zener diode. The light-emitting epitaxial layer and the Zener diode are bonded to the same surface of the substrate. The light-emitting epitaxial layer has a circular light-emitting surface, the substrate is square, the Zener diode is located at the corner between the circular light-emitting surface and the edge of the substrate, and the substrate is bonded to the packaging substrate to supply power to the diode. In the present utility model, the epitaxial layer at the corner of the square light-emitting diode in the prior art is etched away, and the contour of the light-emitting epitaxial layer is designed to be circular, so that the Zener diode can be arranged at the corner outside the light-emitting epitaxial layer, that is, the Zener diode is moved inside the substrate, avoiding occupying the external area. The original area for placing the Zener diode can be used to place the light-emitting epitaxial layer, so that the die bonding area can be expanded as much as possible, and a larger area of the substrate and the light-emitting epitaxial layer can be placed, realizing the maximum utilization of the packaging substrate and making the design more flexible. At the same time, when the light-emitting area of the chip is the same, the circular light-emitting surface has a smaller light-emitting angle, stronger axial light intensity, and a farther projection distance compared with the square light-emitting surface, further improving the light-emitting efficiency.
[0050] The above embodiments are only illustrative of the principles and effects of the present utility model, and are not used to limit the present utility model. There are many aspects of the present utility model that can be improved without departing from the overall idea. Those familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present utility model. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present utility model should still be covered by the claims of the present utility model.
Claims
1. A light emitting element, characterized in that: The light emitting element comprises a substrate, a light emitting epitaxial layer and a Zener diode; The light-emitting epitaxial layer and the Zener diode are located on the same surface of the substrate. The light-emitting epitaxial layer has a circular light-emitting surface. The substrate is square. The Zener diode is located at the corner between the circular light-emitting surface and the edge of the substrate.
2. The light emitting element according to claim 1, characterized in that: A packaging substrate is provided on a surface of the substrate away from the light-emitting epitaxial layer, wherein the packaging substrate comprises a first conductive region and a second conductive region, wherein the second conductive region at least partially surrounds the first conductive region; The substrate is located in the first conductive region, the first electrode of the light emitting epitaxial layer and the first electrode of the Zener diode are electrically connected to the first conductive region, and the second electrode of the light emitting epitaxial layer and the second electrode of the Zener diode are electrically connected to the second conductive region.
3. The light emitting element according to claim 1, wherein: The light-emitting epitaxial layer includes a semiconductor stack layer, and the semiconductor stack layer includes a first semiconductor layer, an active layer, and a second semiconductor layer arranged in sequence; The surface of the second semiconductor layer away from the active layer is sequentially covered with a current blocking layer and a first metal reflective layer, the current blocking layer is formed with at least one first through hole, and the first metal reflective layer is also filled into the first through hole to achieve electrical connection with the second semiconductor layer.
4. The light emitting element according to claim 3, characterized in that: At least one second through hole is formed in the semiconductor stacking layer, the second through hole penetrates the second semiconductor layer and the active layer, and the current blocking layer also extends to cover the inner wall of the second through hole.
5. The light emitting element according to claim 4, characterized in that: The surface of the first metal reflective layer away from the current blocking layer is covered with a first insulating layer, and the first insulating layer also covers the sidewalls of the first metal reflective layer and the surface of the current blocking layer located on the inner wall of the second through hole.
6. The light emitting element according to claim 5, characterized in that: The second metal reflective layer covers the surface of the first insulating layer away from the metal reflective layer and fills into the second through hole to achieve electrical connection with the first semiconductor layer.
7. The light emitting element according to claim 3, characterized in that: The second electrode is formed at the periphery of the semiconductor stack layer, penetrates the current blocking layer at the periphery of the semiconductor stack layer and contacts the first metal reflective layer to achieve electrical connection with the second semiconductor layer.
8. The light emitting element according to claim 3, characterized in that: A wavelength conversion layer is formed on a light emitting surface of the first semiconductor layer away from the active layer and on a side wall of the semiconductor stacked layer.
9. The light emitting element according to claim 1, characterized in that: The Zener diode is connected in parallel with the light-emitting epitaxial layer, and the Zener diode is a unidirectional Zener diode or a bidirectional Zener diode.
10. A light emitting device, characterized in that: The invention comprises a circuit substrate and the light emitting element according to any one of claims 1 to 9 provided on the circuit substrate.