Light emitting diode and packaging structure of light emitting diode

Abstract

The utility model discloses a light-emitting diode and a packaging structure of the light-emitting diode, and relates to the technical field of semiconductor light-emitting devices. A light emitting diode includes; the device comprises a substrate, an epitaxial laminated layer and an optical reflecting layer, the surface of one side of the substrate is provided with a first area and a second area, and the second area is distributed around the first area; the epitaxial laminated layer is arranged in the first region and comprises a first semiconductor layer, a light-emitting layer and a second semiconductor layer which are sequentially laminated on the substrate; the optical reflection layer is arranged in the second area and comprises a metal mirror reflection layer and a DBR reflection layer which are sequentially arranged in a stacked mode. According to the technical scheme, the light extraction efficiency of the light-emitting diode can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor light-emitting devices, and in particular to a light-emitting diode and a packaging structure of the light-emitting diode. Background Art

[0002] Existing LED (light emitting diode) chips can be divided into upright structure, flip-chip structure and vertical structure according to different packaging structures. In upright structure and flip-chip structure, the P and N electrodes in the LED chip are arranged horizontally on the same side. When the current expands horizontally, it is easy to produce current crowding, which makes the local heat of the LED chip too high, hindering the flow of current and not easy to dissipate heat quickly. Compared with upright structure and flip-chip structure, the current expansion distance in the vertical structure LED chip is shorter and the heat dissipation is better. It is suitable for carrying large currents. The luminous performance of the LED chip is better and it is often used in light-emitting devices for different lighting scenes.

[0003] However, with the development of the industry, consumers have an increasingly higher demand for the external quantum effect of light-emitting diodes. Therefore, how to improve the external quantum effect of light-emitting diodes is still a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0004] In view of this, in order to solve the above technical problems, the present application provides a light emitting diode and a packaging structure of the light emitting diode.

[0005] To achieve the above object, the present application provides a light emitting diode, which includes:

[0006] A substrate, wherein a first area and a second area are provided on one side surface of the substrate, and the second area is distributed around the first area;

[0007] An epitaxial stack is disposed in the first region and includes a first semiconductor layer, a light emitting layer, and a second semiconductor layer sequentially stacked on a substrate;

[0008] and an optical reflection layer, which is arranged in the second area, and the optical reflection layer comprises a metal mirror reflection layer and a DBR reflection layer which are stacked in sequence.

[0009] Optionally, the thickness of the DBR reflective layer is a first thickness, which is

[0010] Optionally, the thickness of the metal mirror reflection layer is a second thickness, and the second thickness is

[0011] Optionally, the light emitting diode comprises:

[0012] A current spreading layer is continuously distributed in the first area and the second area, and the optical reflection layer and the epitaxial stack are arranged on a side of the current spreading layer away from the substrate;

[0013] and a first electrode, disposed in the second region and located on a side of the current spreading layer away from the substrate;

[0014] The first semiconductor layer is electrically connected to the current spreading layer; the metal mirror reflection layer is electrically connected to the current spreading layer; and the first electrode penetrates the DBR reflection layer to be electrically connected to the metal mirror reflection layer.

[0015] Optionally, looking down at the light-emitting diode from a side of the current spreading layer facing away from the substrate, the first electrode is located inside the edge of the metal mirror reflection layer.

[0016] Optionally, the DBR reflective layer includes a plurality of material layers stacked in sequence, and the plurality of material layers cooperate with each other to form the DBR reflective layer; the material of the material layer belongs to a first material set, and the elements of the first material set include SiO2, SiN, SiO x N y , TiO2, Si3N4, Al2O3, TiN, AlN, ZrO, TiAlN, TiSiN, HfO2, TaO2 and MgF2.

[0017] Optionally, the reflectivity of the material of the metal mirror reflection layer is not less than 95%.

[0018] Optionally, looking down at the light-emitting diode from the side of the current spreading layer facing away from the substrate, the area of ​​the substrate, the area of ​​the epitaxial stack, the area of ​​the first electrode and the area of ​​the DBR reflective layer satisfy the following relationship:

[0019] S4=k×(S1-S2-N×S3)

[0020] Among them, k is a proportionality coefficient and k is 0.5-1, S1 is the area of ​​the substrate, S2 is the area of ​​the epitaxial stack, N is the number of first electrodes, S3 is the area of ​​the first electrode, and S4 is the area of ​​the DBR reflective layer.

[0021] Optionally, the light emitting diode is provided with a current contact hole, and the current contact hole penetrates the current spreading layer, the first semiconductor layer, the light emitting layer and extends to the second semiconductor layer; the light emitting diode comprises:

[0022] A first insulating layer, covering the current spreading layer and extending into the current contact hole to cover the side wall of the current contact hole;

[0023] and a bonding metal layer, covering the first insulating layer and extending into the current contact hole to be electrically connected to the second semiconductor layer;

[0024] The first insulating layer is continuously distributed in the first region and the second region, and at least part of the material layer in the DBR reflective layer is formed by the first insulating layer.

[0025] In order to solve the above-mentioned technical problems, another technical solution adopted in the present application is to provide a packaging structure of a light-emitting diode, which packaging structure includes a packaging substrate, a lens structure and a light-emitting diode, and the light-emitting diode is the above-mentioned light-emitting diode; wherein, the lens structure is arranged on the packaging substrate, and the light-emitting diode is packaged between the lens structure and the packaging substrate; the side of the second semiconductor layer away from the base substrate faces the lens structure.

[0026] Beneficial effect: Different from the prior art, in the technical solution of the present application, the light emitted from the epitaxial stack in the first region is reflected by the lens structure to form a primary reflected light, and when the primary reflected light enters the second region, the metal mirror reflection layer and the DBR reflection layer in the second region can cooperate with each other to reflect the primary reflected light to form a secondary reflected light, and the secondary reflected light enters the lens structure, so that at least part of the secondary reflected light is emitted through the lens structure. Based on this, the above technical solution of the present application can improve the extraction rate of the secondary reflected light, thereby improving the light extraction efficiency of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the light emitted by the existing vertical structure LED chip;

[0028] Figure 2 It is a schematic diagram of the packaging structure of the light emitting diode of the present application;

[0029] Figure 3 It is a schematic diagram of the structure of the light emitting diode of the present application;

[0030] Figure 4 is a schematic diagram of the first and second regions of the light emitting diode of the present application;

[0031] Figure 5 yes Figure 3 A magnified schematic diagram of the middle area A;

[0032] Figure 6 It is a schematic diagram of the light emitted by the light emitting diode of the present application;

[0033] Figure 7 yes Figure 5 Dimensioning diagram of

[0034] Figure 8 It is a schematic diagram of the relative distribution relationship between the DBR reflective layer and the first electrode in the light emitting diode of the present application;

[0035] Fig. 9 is a schematic diagram of the structure of the light emitting diode of the present application, Figure 8 The viewing angle is a top view of the light emitting diode from the side of the second semiconductor layer facing away from the substrate.

[0036] Description of reference numerals:

[0037] Vertical structure LED chip 11; lens structure 12; package substrate 13; primary reflected light S1; light emitting diode 23; package structure 20; package substrate 21; lens structure 22; light emitting diode 23; connection layer 24; substrate 100; epitaxial stack 200; first semiconductor layer 210; light emitting layer 220; second semiconductor layer 230; optical reflective layer 300; metal mirror reflective layer 310; DBR reflective layer 320; material layer 321; current spreading layer 400; first electrode 500; current contact hole 610; groove 620; first insulating layer 700; bonding metal layer 800; through hole 900; second insulating layer 1000; transparent conductive layer 1100; first region P1; second region P2; primary reflected light K1; secondary reflected light K2; first thickness H1; second thickness H2. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described implementation methods are only part of the implementation methods of the present application, rather than all the implementation methods. Based on the implementation methods in the present application, all other implementation methods obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0039] See also Figure 1 ,like Figure 1 As shown, when the vertical structure LED chip 11 is used, the vertical structure LED chip 11 is generally packaged between the lens structure 12 and the packaging substrate 13, and the light emitted from the vertical structure LED chip 11 passes through the lens structure 12 to form a transmitted light. In this process, the inventor found that the lens structure 12 easily reflects the light emitted by the vertical structure LED chip 11 to form a primary reflected light S1. When the primary reflected light S1 enters the non-EPI (epitaxial stack, referred to as EPI) area of ​​the vertical structure LED chip 11, the primary reflected light S1 is absorbed by the non-EPI area to cause light loss, thereby resulting in a decrease in the external quantum effect of the light emitting diode 23. In order to improve the external quantum efficiency of the light emitting diode, the inventor proposes the following embodiments.

[0040] like Figure 2 As shown, the packaging structure 20 of the light emitting diode 23 of the present application includes a packaging substrate 21, a lens structure 22 and a light emitting diode 23. The lens structure 22 is disposed on the packaging substrate 21, and the light emitting diode 23 is packaged between the lens structure 22 and the packaging substrate 21. Optionally, the light emitting diode 23 is connected and fixed to the packaging substrate 21 through a connecting layer 24. The connecting layer 24 includes, but is not limited to, one or more of a eutectic layer, an adhesive layer and a metal layer.

[0041] Combination Figure 2 See also Figure 3-Figure 5 The light emitting diode 23 includes a substrate 100 , an epitaxial stack 200 and an optical reflective layer 300 .

[0042] The surface of one side of the base substrate 100 has a first region P1 and a second region P2, and the second region P2 is distributed around the first region P1. The epitaxial stack 200 is arranged in the first region P1 and includes a first semiconductor layer 210, a light emitting layer 220, and a second semiconductor layer 230 sequentially stacked on the base substrate 100. The optical reflective layer 300 is arranged in the second region P2, and the optical reflective layer 300 includes a metal mirror reflective layer 310 and a DBR reflective layer 320 stacked. Among them, the second semiconductor layer 230 faces the lens structure 22 away from the side of the base substrate 100.

[0043] By combining the above methods Figure 2 and Figure 3 See also Figure 6 , the light emitted from the epitaxial stack 200 in the first region P1 is reflected by the lens structure 22 to form a primary reflected light K1, and when the primary reflected light K1 enters the second region P2, the metal mirror reflection layer 310 and the DBR reflection layer 320 in the second region P2 can cooperate with each other to reflect the primary reflected light K1 to form a secondary reflected light K2, and the secondary reflected light K2 enters the lens structure 22, so that at least part of the secondary reflected light K2 is emitted through the lens structure 22. Based on this, the above technical solution of the present application can improve the extraction rate of the secondary reflected light K2, thereby improving the light extraction efficiency of the light emitting diode 23.

[0044] In one example, the first semiconductor layer 210 may be a P-type semiconductor layer, and the second semiconductor layer 230 may be an N-type semiconductor layer, but is not limited thereto. In another example, the second semiconductor layer 230 may be an N-type semiconductor layer, and the second semiconductor layer 230 may be a P-type semiconductor layer, but is not limited thereto.

[0045] Furthermore, combined with Figure 2-Figure 4 See also Figure 6 , the metal mirror reflection layer 310 and the DBR reflection layer 320 are sequentially stacked in the second region P2. In this way, the DBR reflection layer 320 can reflect the primary reflected light K1 before the metal mirror reflection layer 310 to form a part of the secondary reflected light K2, and the metal mirror reflection layer 310 can reflect the primary reflected light K1 passing through the DBR reflection layer 320 to form another part of the secondary reflected light K2. Therefore, the light extraction efficiency of the secondary reflected light K2 can be improved by the DBR reflection layer 320 and the metal mirror reflection layer 310.

[0046] Optionally, combined Figure 5 See also Figure 7 , the thickness of the DBR reflective layer 320 is a first thickness H1, and the first thickness H1 is (For example, including but not limited to ). Optionally, the thickness of the metal mirror reflection layer 310 is a second thickness H2, and the second thickness H2 is (For example, including but not limited to ).

[0047] Combination Figure 5 See also Figure 8 The DBR reflective layer 320 may include a plurality of sequentially stacked material layers 321, and the plurality of material layers 321 cooperate with each other to form the DBR reflective layer 320. Optionally, the material of the material layer 321 belongs to a first material set, and the elements of the first material set include SiO2, SiN, SiO x N y , TiO2, Si3N4, Al2O3, TiN, AlN, ZrO, TiAlN, TiSiN, HfO2, TaO2 and MgF2, but are not limited thereto.

[0048] like Figure 5 As shown, the reflectivity of the material of the metal mirror reflection layer 310 may be not less than 95%. By way of example and not limitation, the material of the metal mirror reflection layer 310 belongs to the second material set, and the elements of the second material set include Ag and Al, but are not limited thereto. In other examples, the metal mirror reflection layer 310 may be other metal materials with a reflectivity of not less than 95%.

[0049] Furthermore, combined with Figure 4 and Figure 5 See also Figure 3 , the light emitting diode 23 includes a current spreading layer 400 and a first electrode 500 .

[0050] The current spreading layer 400 is continuously distributed in the first region P1 and the second region P2, and the optical reflective layer 300 and the epitaxial stack 200 are arranged on the side of the current spreading layer 400 away from the substrate 100. The first electrode 500 is arranged in the second region P2 and is located on the side of the current spreading layer 400 away from the substrate 100. Among them, the first semiconductor layer 210 is electrically connected to the current spreading layer 400. The metal mirror reflection layer 310 is electrically connected to the current spreading layer 400. The first electrode 500 penetrates the DBR reflection layer 320 to be electrically connected to the metal mirror reflection layer 310.

[0051] In the above manner, without damaging the normal use of the first electrode 500, the metal mirror reflection layer 310 can be used to reflect the primary reflected light K1 incident on the area where the first electrode 500 is located to form a part of the secondary reflected light K2, and the secondary reflected light K2 is incident on the lens structure 22, so that at least a part of the secondary reflected light K2 is emitted through the lens structure 22. In this way, the light loss caused by the absorption of the primary reflected light K1 by the area where the first electrode 500 is located can be reduced.

[0052] By way of example but not limitation, the material of the current spreading layer 400 belongs to a third material set, and the elements of the third material set include Au and Pt.

[0053] Optionally, looking down at the light emitting diode 23 from the side of the current spreading layer 400 away from the substrate 100, the first electrode 500 is located inside the edge of the metal mirror reflection layer 310. In this way, the metal mirror reflection layer 310 can more comprehensively reflect the primary reflected light K1 incident on the area where the first electrode 500 is located.

[0054] Alternatively, if Figure 3 As shown, a groove 620 is formed in the portion of the current spreading layer 400 corresponding to the epitaxial stack 200 . Looking down at the light emitting diode 23 from the side of the current spreading layer 400 away from the substrate 100 , the epitaxial stack 200 is located inside the edge of the groove 620 .

[0055] In this way, due to the presence of the groove 620 , the vertical distance between the surface of the second semiconductor layer 230 facing away from the base substrate 100 and the surface of the base substrate 100 facing away from the second semiconductor layer 230 can be reduced, which is beneficial to the miniaturization of the light-emitting diode 23 .

[0056] Alternatively, if Fig. 9 As shown, when looking down at the light-emitting diode 23 from the side of the current spreading layer 400 away from the substrate 100, the area of ​​the substrate 100, the area of ​​the epitaxial stack 200, the area of ​​the first electrode 500 and the area of ​​the DBR reflective layer 320 satisfy the following relationship (1):

[0057] S4=k×(S1-S2-N×S3)·························(1)

[0058] Among them, k is a proportionality coefficient and k is 0.5 to 1 (for example, including but not limited to 0.5, 0.75, 1), S1 is the area of ​​the substrate 100, S2 is the area of ​​the epitaxial stack 200, N is the number of first electrodes 500, S3 is the area of ​​the first electrode 500, and S4 is the area of ​​the DBR reflective layer 320.

[0059] For example, but not limitation, looking down at the light emitting diode 23 from the side of the current spreading layer 400 away from the substrate 100, the substrate 100 is rectangular, the epitaxial stack 200 is circular, and the first electrode 500 is circular. Let the length of the substrate 100 be L, and the width of the substrate 100 be W, then S1 = L×W. Let the radius of the epitaxial stack 200 be a, then S2 = π×a 2 . Let the radius of the first electrode 500 be b, then S3 = π × b 2 .

[0060] Optionally, combined Figure 4 and Figure 5 See also Figure 3 , the light emitting diode 23 may also be provided with a current contact hole 610, which penetrates the current spreading layer 400, the first semiconductor layer 210, and the light emitting layer 220 and extends into part of the second semiconductor layer 230. The light emitting diode 23 may also include a first insulating layer 700 and a bonding metal layer 800. The first insulating layer 700 covers the current spreading layer 400 and extends into the current contact hole 610 to cover the sidewall of the current contact hole 610. The bonding metal layer 800 covers the first insulating layer 700 and extends into the current contact hole 610 to be electrically connected to the second semiconductor layer 230. Among them, the first insulating layer 700 is continuously distributed in the first region P1 and the second region P2, and at least part of the material layer 321 in the DBR reflective layer 320 is formed by the first insulating layer 700.

[0061] Furthermore, combined with Figure 3 See also Figure 5 The light emitting diode 23 includes a second insulating layer 1000 and a transparent conductive layer 1100. The second insulating layer 1000 is disposed on a side of the current spreading layer 400 facing the first semiconductor layer 210 corresponding to the first semiconductor layer 210, and the transparent conductive layer 1100 is disposed on a side of the second insulating layer 1000 facing the first semiconductor layer 210 corresponding to the first semiconductor layer 210. The second insulating layer 1000 is provided with a through hole 900, and the current spreading layer 400 extends into and fills the through hole 900 to be electrically connected to the first semiconductor layer 210. The circuit expansion layer 400 includes but is not limited to a metal conductive layer.

[0062] Optionally, the second insulating layer 1000 extends along the bottom wall and side walls of the groove 620, and the portion of the second insulating layer 1000 extending along the side walls of the groove 620 can cover the side walls of the first semiconductor layer 210 to insulate and separate the electrical connection caused by direct contact between the metal mirror reflection layer 310 and the side walls of the first semiconductor layer 210.

[0063] The above are only implementation methods of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A light emitting diode, characterized in that: The light emitting diode comprises: A substrate, wherein a surface of one side of the substrate has a first area and a second area, and the second area is distributed around the first area; An epitaxial stack, disposed in the first region and comprising a first semiconductor layer, a light emitting layer, and a second semiconductor layer sequentially stacked on the base substrate; and an optical reflection layer, which is arranged in the second region, wherein the optical reflection layer comprises a metal mirror reflection layer and a DBR reflection layer which are stacked in sequence.

2. The light emitting diode according to claim 1, characterized in that: The thickness of the DBR reflective layer is a first thickness, and the first thickness is 3. The light emitting diode according to claim 1, characterized in that: The thickness of the metal mirror reflection layer is a second thickness.

4. The light emitting diode according to claim 1, characterized in that: The light emitting diode comprises: A current spreading layer is continuously distributed in the first region and the second region, and the optical reflective layer and the epitaxial stack are arranged on a side of the current spreading layer away from the substrate; and a first electrode, disposed in the second region and located on a side of the current spreading layer away from the substrate; The first semiconductor layer is electrically connected to the current spreading layer; the metal mirror reflection layer is electrically connected to the current spreading layer; and the first electrode penetrates the DBR reflection layer to be electrically connected to the metal mirror reflection layer.

5. The light emitting diode according to claim 4, characterized in that: Looking down at the light-emitting diode from a side of the current spreading layer away from the base substrate, the first electrode is located inside the edge of the metal mirror reflection layer.

6. The light emitting diode according to claim 4, characterized in that: Looking down at the light-emitting diode from the side of the current spreading layer away from the substrate, the area of ​​the substrate, the area of ​​the epitaxial stack, the area of ​​the first electrode and the area of ​​the DBR reflective layer satisfy the following relationship: S4=k×(S1-S2-N×S3) Among them, k is a proportionality coefficient and k is 0.5-1, S1 is the area of ​​the substrate, S2 is the area of ​​the epitaxial stack, N is the number of the first electrodes, S3 is the area of ​​the first electrode, and S4 is the area of ​​the DBR reflective layer.

7. The light emitting diode according to claim 4, characterized in that: The light emitting diode is provided with a current contact hole, and the current contact hole penetrates the current spreading layer, the first semiconductor layer, the light emitting layer and extends to a part of the second semiconductor layer; The light emitting diode comprises: A first insulating layer, covering the current spreading layer and extending into the current contact hole to cover the sidewall of the current contact hole; and a bonding metal layer, covering the first insulating layer and extending into the current contact hole to be electrically connected to the second semiconductor layer; Wherein, the first insulating layer is continuously distributed in the first area and the second area.

8. The light emitting diode according to claim 1, characterized in that: The DBR reflective layer includes a plurality of sequentially stacked material layers, and the plurality of material layers cooperate with each other to form the DBR reflective layer; the material of the material layer belongs to a first material set, and the elements of the first material set include SiO2, SiN, SiO x N y , TiO2, Si3N4, Al2O3, TiN, AlN, ZrO, TiAlN, TiSiN, HfO2, TaO2 and MgF2.

9. The light emitting diode according to claim 1, characterized in that: The reflectivity of the material of the metal mirror reflection layer is not less than 95%.

10. A packaging structure of a light emitting diode, characterized in that: The packaging structure comprises a packaging substrate, a lens structure and a light-emitting diode, and the light-emitting diode is the light-emitting diode according to any one of claims 1 to 9; The lens structure is arranged on the packaging substrate, and the light-emitting diode is packaged between the lens structure and the packaging substrate; and the side of the second semiconductor layer away from the base substrate faces the lens structure.

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