Flip-chip light emitting diode

Abstract

The utility model provides a flip light-emitting diode. The flip light-emitting diode comprises a substrate; the bonding layer is located on the substrate and comprises a second colloid layer and a first colloid layer which are sequentially stacked from bottom to top, and the first colloid layer and the second colloid layer comprise different fluorescent powder bodies; the epitaxial layer is located on the bonding layer, the epitaxial layer comprises a second semiconductor layer, a light-emitting layer and a first semiconductor layer which are sequentially stacked from bottom to top, and the edge of the epitaxial layer is provided with a step structure to expose part of the second semiconductor layer; a first electrode electrically connected to the second semiconductor layer; and a second electrode electrically connected to the first semiconductor layer. According to the embodiment of the invention, the first colloid layer and the second colloid layer with different fluorescent powder bodies are utilized to perform twice wavelength conversion on the light emitted by the light-emitting layer in different wave bands, so that the energy loss of the light emitted by the light-emitting layer is reduced, and the luminous efficiency of the flip-chip light-emitting diode is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and in particular to a flip-chip light emitting diode. Background Art

[0002] A light emitting diode (LED) is a commonly used light emitting device that emits light by releasing photons through the recombination of electrons and holes. In the related art, an LED chip is solidified on a bracket, and phosphor is added to a colloid, and the colloid is covered on the light emitting diode. The light radiated by the light emitting diode passes through the colloid with phosphor, is absorbed by the phosphor and converted into light of different wavelengths. Since the light emitted by the light emitting diode is absorbed and converted into light of other wavelengths after passing through the colloid with phosphor for the first time, it will continue to be absorbed and converted after passing through the colloid with phosphor for the second time. Multiple absorptions and conversions will cause energy loss of the light emitted by the light emitting layer of the light emitting diode, which reduces the light efficiency of the light emitting diode. Utility Model Content

[0003] In view of the above problems, the purpose of the present disclosure is to provide a flip-chip light emitting diode, which aims to utilize a first colloidal layer and a second colloidal layer with different phosphors to perform two wavelength conversions on the light emitted by the light-emitting layer in different bands, thereby reducing the energy loss of the light emitted by the light-emitting layer and improving the luminous efficiency of the flip-chip light-emitting diode.

[0004] According to a first aspect of an embodiment of the present disclosure, there is provided a flip-chip light emitting diode, comprising:

[0005] substrate;

[0006] A bonding layer, located on the substrate, comprising a second colloid layer and a first colloid layer stacked in sequence from bottom to top, wherein the first colloid layer and the second colloid layer comprise different fluorescent powders;

[0007] An epitaxial layer, located on the bonding layer, the epitaxial layer comprising a second semiconductor layer, a light emitting layer and a first semiconductor layer stacked in sequence from bottom to top, and an edge of the epitaxial layer having a step structure to expose a portion of the second semiconductor layer;

[0008] a first electrode electrically connected to the second semiconductor layer;

[0009] The second electrode is electrically connected to the first semiconductor layer.

[0010] Optionally, the first colloid layer and the second colloid layer include organic colloid layers.

[0011] Optionally, a peak wavelength range of the fluorescence radiated by the first colloidal layer when excited is within a wavelength range of the light radiated by the luminescent layer.

[0012] Optionally, a peak wavelength range of the fluorescence radiated by the second colloidal layer when excited is within a peak wavelength range of the fluorescence radiated by the first colloidal layer when excited.

[0013] Optionally, the first colloid layer includes one or more phosphors, and the second colloid layer includes one or more phosphors.

[0014] Optionally, the thickness of the first colloid layer is 1 μm to 50 μm, and the thickness of the second colloid layer is 1 μm to 50 μm.

[0015] Optionally, the organic colloid layer comprises: a combination of one or more layers of a b-stage bisbenzocyclobutene layer, a polyimide layer and a perfluorocyclobutane layer.

[0016] Optionally, the first semiconductor layer includes a first-type confinement layer, a first-type window layer and a first-type ohmic contact layer stacked in sequence from bottom to top, and the second electrode is electrically connected to the first-type ohmic contact layer;

[0017] The second semiconductor layer includes a second-type ohmic contact layer, a second-type window layer, and a second-type confinement layer stacked in sequence from bottom to top, the step structure of the epitaxial layer exposes the second-type ohmic contact layer, and the first electrode is electrically connected to the second-type ohmic contact layer.

[0018] Optionally, the flip-chip light emitting diode further comprises: an insulating layer,

[0019] The insulating layer covers the epitaxial layer, the insulating layer includes a first opening and a second opening, the first electrode and the second electrode are located on the insulating layer, the first electrode is electrically connected to the second semiconductor layer through the first opening, and the second electrode is electrically connected to the first semiconductor layer through the second opening.

[0020] Optionally, the flip-chip light emitting diode further comprises: a first metal layer and a second metal layer,

[0021] The first metal layer is located on the second semiconductor layer exposed by the step structure, the second metal layer is located on the first semiconductor layer, the first electrode is electrically connected to the first metal layer through the first opening, and the second electrode is electrically connected to the second metal layer through the second opening.

[0022] According to the flip-chip light-emitting diode provided by the embodiment of the present disclosure, the bonding layer located on the substrate includes a second colloidal layer and a first colloidal layer stacked in sequence from bottom to top, the light emitted by the light-emitting layer is absorbed by the first colloidal layer and converted into fluorescence in a first peak wavelength range, and the fluorescence in the first peak wavelength range is absorbed by the second colloidal layer and converted into fluorescence in a second peak wavelength range. In this way, by using the first colloidal layer and the second colloidal layer with different phosphors, the light emitted by the light-emitting layer is subjected to multiple wavelength conversions in different bands, thereby avoiding multiple absorption of the light emitted by the light-emitting layer in the same band, reducing the energy loss of the light emitted by the light-emitting layer, and improving the light efficiency of the flip-chip light-emitting diode.

[0023] Furthermore, by arranging different fluorescent powders in the first colloid layer and the second colloid layer, the first colloid layer and the second colloid layer can be designed to emit fluorescence with different peak wavelengths without the need to prepare fluorescent glue, thereby reducing the packaging cost of the flip-chip light emitting diode.

[0024] Furthermore, compared with the traditional dispensing packaging form, the bonding packaging of the first colloid layer and the second colloid layer can reduce the packaging thickness of the flip-chip light-emitting diode, thereby achieving an ultra-thin light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0026] Figure 1 A cross-sectional schematic diagram of a flip-chip light emitting diode according to an embodiment of the present disclosure is shown;

[0027] Figures 2 to 5 Schematic cross-sectional views of different stages of a method for manufacturing a flip-chip light-emitting diode according to an embodiment of the present disclosure are shown. DETAILED DESCRIPTION

[0028] Various embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0029] The specific implementation of the present disclosure is further described in detail below in conjunction with the drawings and examples.

[0030] Figure 1 FIG. 2 shows a cross-sectional schematic diagram of a flip-chip light-emitting diode according to an embodiment of the present disclosure. Figure 1As shown, the flip-chip light-emitting diode 1000 includes: a substrate 100, a bonding layer 700 located on the substrate 100, an epitaxial layer 800 located on the bonding layer 700, a first electrode 13 and a second electrode 14. In some embodiments, the material of the substrate 100 includes one of aluminum oxide, gallium arsenide, gallium nitride, gallium oxide, silicon and silicon carbide, but is not limited thereto. The thickness of the substrate 100 includes: 100μm to 500μm. In some embodiments, the bonding layer 700 includes a second colloidal layer 600 and a first colloidal layer 500 stacked sequentially from bottom to top. The thickness of the first colloidal layer 500 includes: 1μm to 50μm, and the thickness of the second colloidal layer 600 includes: 1μm to 50μm. In some embodiments, the epitaxial layer 800 includes a second semiconductor layer 400, a light-emitting layer 300 and a first semiconductor layer 200 stacked sequentially from bottom to top. In some embodiments, the light-emitting layer 300 is a multi-quantum well (MQW) layer. The edge of the epitaxial layer 800 has a step structure to expose a portion of the second semiconductor layer 400 . The first electrode 13 is electrically connected to the second semiconductor layer 400 , and the second electrode 14 is electrically connected to the first semiconductor layer 200 .

[0031] It should be noted that the first semiconductor layer 200 and the second semiconductor layer 400 may be conductive material layers that provide at least electrons or holes respectively through a first type (eg, N-type) doping process or a second type (eg, P-type) doping process.

[0032] In some embodiments, the first semiconductor layer 200 may be a first-type semiconductor layer, in which a first-type dopant such as Si, Ge or Sn may be doped; the second semiconductor layer 400 may be a second-type semiconductor layer, in which a second-type dopant such as C, Mg, Zn, Ca, Sr or Ba may be doped. In some embodiments, the first semiconductor layer 200 includes a first-type confinement layer 230, a first-type window layer 220 and a first-type ohmic contact layer 210 stacked sequentially from bottom to top, and the second electrode 14 is electrically connected to the first-type ohmic contact layer 210. In some embodiments, the second semiconductor layer 400 includes a second-type ohmic contact layer 430, a second-type window layer 420 and a second-type confinement layer 410 stacked sequentially from bottom to top, the step structure of the epitaxial layer 800 exposes the second-type ohmic contact layer 430, and the first electrode 13 is electrically connected to the second-type ohmic contact layer 430.

[0033] The first type confinement layer 230 provides electrons, and the second type confinement layer 410 provides holes.

[0034] In some embodiments, the first colloid layer 500 and the second colloid layer 600 include an organic colloid layer, the organic colloid layer has a thermal conductivity of 0.25 to 0.7 W / mK at 24°C, a glass transition temperature (Tg) of 350 to 800°C, and a residual stress of Si in the organic colloid layer of 20 to 40 MPa at 25°C, and a thermal expansion coefficient of 20 to 60 ppm / °C. In some embodiments, the organic colloid layer includes a combination of one or more layers of a b-class bisbenzocyclobutene layer, a polyimide layer, and a perfluorocyclobutane layer, but is not limited thereto. In some embodiments, the first colloid layer 500 and the second colloid layer 600 include different fluorescent powders. It should be noted that the fluorescent powder emits fluorescence based on the fluorescence effect. The fluorescence effect refers to the process in which the electrons absorbing energy of the fluorescent powder transition to a higher energy level after being excited, and then return from the high energy level to the low energy level in a short time to release energy. In this process, part of the energy is radiated in the form of light to form fluorescence. It is easy to understand that the phosphor can absorb light of a specific wavelength and excite fluorescence of a certain peak wavelength. The peak wavelength of the fluorescence excited by the phosphor depends on the characteristics of the phosphor. Different phosphors have different absorption and emission characteristics for light of different wavelengths. Common phosphors can emit various colors in the visible light range, such as blue, green, yellow and red. Therefore, by arranging different phosphors in the first colloid layer 500 and the second colloid layer 600, the first colloid layer 500 and the second colloid layer 600 can be designed to emit fluorescence of different peak wavelengths. In some embodiments, the peak wavelength range of the fluorescence radiated by the phosphor in the first colloid layer 500 is within the wavelength range of the light radiated by the light-emitting layer 300. The peak wavelength range of the fluorescence radiated by the phosphor in the second colloid layer 600 is within the peak wavelength range of the fluorescence radiated by the first colloid layer 500. The first colloid layer 500 and the second colloid layer 600 can both include one or more phosphors. In some embodiments, the wavelength range of the light radiated by the light emitting layer 300 includes: 190nm to 960nm. In one example, the light emitting layer 300 emits blue light, for example, with a wavelength range of 450nm to 495nm, and the phosphor in the first colloid layer 500 includes phosphors such as aluminate, and the phosphor in the first colloid layer 500 absorbs the blue light emitted by the light emitting layer 300, and excites fluorescence with a peak wavelength of 500nm to 575nm; the phosphor in the second colloid layer 600 may include fluoroboron dipyrrole phosphors, and the phosphor in the second colloid layer 600 absorbs the light with a wavelength of 500nm to 575nm excited by the phosphor in the first colloid layer 500, and excites fluorescence with a peak wavelength of 580nm or 615nm.The phosphor in the second colloid layer 600 may also include phosphors of nitride or other components. In this case, the phosphor in the second colloid layer 600 absorbs the light with a wavelength of 500nm to 575nm excited by the phosphor in the first colloid layer 500, and excites fluorescence with a peak wavelength between 600nm and 660nm. In this way, by using the first colloid layer 500 and the second colloid layer 600 with different phosphors, the light emitted by the light-emitting layer 300 is subjected to multiple wavelength conversions in different wavelength bands, thereby avoiding the light emitted by the light-emitting layer 300 being absorbed multiple times in the same wavelength band, reducing the energy loss of the light emitted by the light-emitting layer 300, and improving the light efficiency of the flip-chip light-emitting diode 1000.

[0035] In some embodiments, the flip-chip light-emitting diode 1000 further includes a first metal layer 11, a second metal layer 12, and an insulating layer 21. The first metal layer 11 is located on the second-type ohmic contact layer 430 exposed by the step structure, and the second metal layer 12 is located on the first-type ohmic contact layer 210. The insulating layer 21 covers the epitaxial layer 800, the first metal layer 11, and the second metal layer 12, and the insulating layer 21 includes a first opening and a second opening, the first opening exposes a portion of the surface of the first metal layer 11, and the second opening exposes a portion of the surface of the second metal layer 12. The insulating layer 21 may include a single-layer structure or a multi-layer structure, and the multi-layer structure includes, for example, a DBR (distributed Bragg reflector) structure. The material of the insulating layer 21 may include: one or more of SiO2, Si3N4, MgF2, Al2O3, TiO2, and ZrO2, and the thickness of the insulating layer 21 includes, for example: 10nm to 1000nm. The first electrode 13 and the second electrode 14 are located on the insulating layer 21 and separated from each other. The first electrode 13 and the second electrode 14 are connected to the first metal layer 11 and the second metal layer 12 through the first opening and the second opening, respectively. The first metal layer 11 and the second metal layer 12 may include an extension strip, and the material of the first metal layer 11 and the second metal layer 12 includes: one or more of metals such as Cr, Ti, Pt, Au, Al, Ge, Be, etc., but is not limited thereto.

[0036] Figures 2 to 5 The cross-sectional schematic diagrams of different stages of the method for manufacturing a flip-chip light-emitting diode according to an embodiment of the present disclosure are shown. Figures 2 to 5 The manufacturing method of the flip-chip light emitting diode 1000 includes the following steps.

[0037] like Figure 2As shown, a growth substrate (not shown in the figure) is provided. A first semiconductor layer 200, a light-emitting layer 300, and a second semiconductor layer 400 are sequentially formed from bottom to top on the growth substrate by one of a metal organic chemical vapor deposition (MOCVD) process, a molecular beam epitaxy (MBE) process, or an ultra-high vacuum chemical vapor deposition (UHVCVD) process. Preferably, the first semiconductor layer 200, the light-emitting layer 300, and the second semiconductor layer 400 are formed by an MOCVD process. The first semiconductor layer 200, the light-emitting layer 300, and the second semiconductor layer 400 form an epitaxial layer 800 of the flip-chip light-emitting diode 1000. The first semiconductor layer 200, for example, includes a first-type ohmic contact layer 210, a first-type window layer 220, and a first-type confinement layer 230 stacked sequentially from bottom to top. The second semiconductor layer 400, for example, includes a second-type confinement layer 410, a second-type window layer 420, and a second-type ohmic contact layer 430 stacked sequentially from bottom to top.

[0038] A first colloidal layer 500 is formed by coating the first surface of the second-type ohmic contact layer 430 away from the growth substrate. The thickness of the first colloidal layer 500 includes: 1 μm to 50 μm. A second colloidal layer 600 is formed by coating the first surface of the substrate 100. The thickness of the second colloidal layer 600 includes: 1 μm to 50 μm. In some embodiments, the material of the substrate 100 includes one of aluminum oxide, gallium arsenide, gallium nitride, gallium oxide, silicon and silicon carbide, but is not limited thereto. The thickness of the substrate 100 includes: 100 μm to 500 μm. The first colloidal layer 500 is bonded to the second colloidal layer 600 to form a bonding layer 700. The growth substrate is turned over and removed to expose the surface of the first-type ohmic contact layer 210. As Figure 2 As shown, after the substrate transfer is realized, a second colloidal layer 600, a first colloidal layer 500, a second-type ohmic contact layer 430, a second-type window layer 420, a second-type confinement layer 410, a light-emitting layer 300, a first-type confinement layer 230, a first-type window layer 220 and a first-type ohmic contact layer 210 are sequentially stacked on the substrate 100 from bottom to top.

[0039] In some embodiments, the first colloid layer 500 and the second colloid layer 600 include an organic colloid layer, and the organic colloid layer has a thermal conductivity of 0.25 to 0.7 W / mK at 24°C, a glass transition temperature (Tg) of 350 to 800°C, and a residual stress of Si in the organic colloid layer of 20 to 40 MPa and a thermal expansion coefficient of 20 to 60 ppm / °C at 25°C. In some embodiments, the organic colloid layer of the first colloid layer 500 and the second colloid layer 600 includes a combination of one or more layers of a b-class bisbenzocyclobutene layer, a polyimide layer, and a perfluorocyclobutane layer, but is not limited thereto. In some embodiments, the first colloid layer 500 and the second colloid layer 600 include different phosphors. It should be noted that the phosphor emits fluorescence based on the fluorescence effect. The fluorescence effect refers to the process in which the electrons that absorb energy jump to a higher energy level after the phosphor is excited, and then return from the high energy level to the low energy level in a short time to release energy. In this process, part of the energy is radiated in the form of light to form fluorescence. It is easy to understand that the phosphor can absorb light of a specific wavelength and excite fluorescence of a certain peak wavelength. The peak wavelength of the fluorescence excited by the phosphor depends on the characteristics of the phosphor. Different phosphors have different absorption and emission characteristics for light of different wavelengths. Common phosphors can emit various colors in the visible light range, such as blue, green, yellow and red. Therefore, by arranging different phosphors in the first colloidal layer 500 and the second colloidal layer 600, the first colloidal layer 500 and the second colloidal layer 600 can be designed to emit fluorescence with different peak wavelengths. In some embodiments, the peak wavelength range of the fluorescence radiated by the phosphor in the first colloidal layer 500 is within the wavelength range of the light radiated by the light-emitting layer 300. The peak wavelength range of the fluorescence radiated by the fluorescent powder in the second colloid layer 600 is within the peak wavelength range of the fluorescence radiated by the first colloid layer 500. The first colloid layer 500 and the second colloid layer 600 may each include one or more fluorescent powders. In some embodiments, the wavelength range of the light radiated by the light emitting layer 300 includes: 190nm to 960nm. In one example, the light-emitting layer 300 emits blue light, whose wavelength range includes 450nm to 495nm. The phosphor in the first colloidal layer 500 includes phosphors such as aluminate. The phosphor of the first colloidal layer 500 absorbs the blue light emitted by the light-emitting layer 300, and excites fluorescence with a peak wavelength of 500nm to 575nm. The phosphor in the second colloidal layer 600 may include fluoroboron dipyrrole phosphor. The phosphor of the second colloidal layer 600 absorbs the light with a wavelength of 500nm to 575nm excited by the phosphor of the first colloidal layer 500, and excites fluorescence with a peak wavelength of 580nm or 615nm.The phosphor in the second colloid layer 600 may also include phosphors of nitride or other components. In this case, the phosphor in the second colloid layer 600 absorbs the light with a wavelength of 500nm to 575nm excited by the phosphor in the first colloid layer 500, and excites fluorescence with a peak wavelength between 600nm and 660nm. In this way, by using the first colloid layer 500 and the second colloid layer 600 with different phosphors, the light emitted by the light-emitting layer 300 is subjected to multiple wavelength conversions in different wavelength bands, thereby avoiding the light emitted by the light-emitting layer 300 being absorbed multiple times in the same wavelength band, reducing the energy loss of the light emitted by the light-emitting layer 300, and improving the light efficiency of the flip-chip light-emitting diode 1000.

[0040] Different fluorescent powders are arranged in the first colloid layer 500 and the second colloid layer 600, and the first colloid layer 500 and the second colloid layer 600 can be designed to emit fluorescence with different peak wavelengths, without the need to prepare fluorescent glue, thereby reducing the packaging cost of the flip-chip light-emitting diode 1000. Compared with the traditional dispensing packaging form, the first colloid layer 500 and the second colloid layer 600 bonding packaging can reduce the packaging thickness of the flip-chip light-emitting diode 1000, thereby achieving an ultra-thin light-emitting diode.

[0041] like Figure 3 As shown, the first semiconductor layer 200, the light emitting layer 300 and the second semiconductor layer 400 at the edge of the epitaxial layer 800 are etched by photolithography, etching and other processes to form a step structure, which penetrates the first semiconductor layer 200, the light emitting layer 300 and a part of the second semiconductor layer 400 from the surface of the first semiconductor layer 200 and exposes the surface of the second-type ohmic contact layer 430. The second metal layer 12 is formed on the first semiconductor layer 200 and the first metal layer 11 is formed on the second semiconductor layer 400 by conventional semiconductor process technology such as sputtering or evaporation and a lift-off process. Specifically, the first metal layer 11 is located on the second-type ohmic contact layer 430 exposed by the step structure, and the second metal layer 12 is located on the first-type ohmic contact layer 210. The first metal layer 11 and the second metal layer 12 may include an extended strip, and the materials of the first metal layer 11 and the second metal layer 12 include: one or more of metals such as Cr, Ti, Pt, Au, Al, Ge, Be, etc., but are not limited thereto.

[0042] like Figure 4As shown, the second type ohmic contact layer 430, the first colloidal layer 500 and the second colloidal layer 600 are etched by photolithography, etching and other processes to expose the substrate 100 and form an isolation groove. An insulating layer material is deposited on the epitaxial layer 800 by chemical vapor deposition (CVD), such as low temperature chemical vapor deposition (LTCVD), low pressure chemical vapor deposition (LPCVD), rapid thermal chemical vapor deposition (RTCVD), atomic layer deposition (ALD), plasma enhanced chemical vapor deposition (PECVD), and the insulating layer material covers the first metal layer 11, the second metal layer 12, the surface and sidewall of the epitaxial layer 800 and the sidewall of the bonding layer 700. The insulating layer material is etched by photolithography, etching and other processes to form a first opening and a second opening in the insulating layer material, the first metal layer 11 is exposed through the first opening, and the second metal layer 12 is exposed through the second opening to form an insulating layer 21. The material of the insulating layer 21 includes: one or more of SiO2, Si3N4, MgF2, Al2O3, TiO2, and ZrO2, and the thickness of the insulating layer 21 includes: 10nm to 1000nm.

[0043] like Figure 5 As shown, the first electrode 13 and the second electrode 14 are formed on the insulating layer 21 by conventional semiconductor process technology such as sputtering or evaporation and a lift-off process. The first electrode 13 and the second electrode 14 are electrically connected to the first metal layer 11 and the second metal layer 12 through the first opening and the second opening, respectively.

[0044] According to the flip-chip light-emitting diode provided by the embodiment of the present disclosure, the bonding layer located on the substrate includes a second colloidal layer and a first colloidal layer stacked in sequence from bottom to top, the light emitted by the light-emitting layer is absorbed by the first colloidal layer and converted into fluorescence in a first peak wavelength range, and the fluorescence in the first peak wavelength range is absorbed by the second colloidal layer and converted into fluorescence in a second peak wavelength range. In this way, by using the first colloidal layer and the second colloidal layer with different phosphors, the light emitted by the light-emitting layer is subjected to multiple wavelength conversions in different bands, thereby avoiding multiple absorption of the light emitted by the light-emitting layer in the same band, reducing the energy loss of the light emitted by the light-emitting layer, and improving the light efficiency of the flip-chip light-emitting diode.

[0045] Furthermore, by arranging different fluorescent powders in the first colloid layer and the second colloid layer, the first colloid layer and the second colloid layer can be designed to emit fluorescence with different peak wavelengths without the need to prepare fluorescent glue, thereby reducing the packaging cost of the flip-chip light emitting diode.

[0046] Furthermore, compared with the traditional dispensing packaging form, the bonding packaging of the first colloid layer and the second colloid layer can reduce the packaging thickness of the flip-chip light-emitting diode, thereby achieving an ultra-thin light-emitting diode.

[0047] The embodiments of the present disclosure are described above, and these embodiments do not describe all the details in detail, nor do they limit the present disclosure to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present disclosure, so that those skilled in the art can make good use of the present disclosure and the modifications based on the present disclosure. The present disclosure is limited only by the claims and their full scope and equivalents.

Claims

1. A flip-chip light emitting diode, characterized in that: include: substrate; A bonding layer, located on the substrate, comprising a second colloid layer and a first colloid layer stacked in sequence from bottom to top, wherein the first colloid layer and the second colloid layer comprise different fluorescent powders; An epitaxial layer, located on the bonding layer, the epitaxial layer comprising a second semiconductor layer, a light emitting layer and a first semiconductor layer stacked in sequence from bottom to top, and an edge of the epitaxial layer having a step structure to expose a portion of the second semiconductor layer; a first electrode electrically connected to the second semiconductor layer; The second electrode is electrically connected to the first semiconductor layer.

2. The flip-chip light emitting diode according to claim 1, characterized in that: The first colloid layer and the second colloid layer include organic colloid layers.

3. The flip-chip light emitting diode according to claim 1, characterized in that: The peak wavelength range of the fluorescence radiated by the first colloidal layer when excited is within the wavelength range of the light radiated by the luminescent layer.

4. The flip-chip light emitting diode according to claim 3, characterized in that: The peak wavelength range of the fluorescence radiated by the second colloidal layer when excited is within the peak wavelength range of the fluorescence radiated by the first colloidal layer when excited.

5. The flip-chip light emitting diode according to claim 1, characterized in that: The first colloid layer includes one or more fluorescent powders, and the second colloid layer includes one or more fluorescent powders.

6. The flip-chip light emitting diode according to claim 1, characterized in that: The thickness of the first colloid layer is in a range of 1 μm to 50 μm, and the thickness of the second colloid layer is in a range of 1 μm to 50 μm.

7. The flip-chip light emitting diode according to claim 2, characterized in that: The organic colloid layer comprises: a combination of one or more layers of a b-stage bisbenzocyclobutene layer, a polyimide layer and a perfluorocyclobutane layer.

8. The flip-chip light emitting diode according to claim 1, characterized in that: The first semiconductor layer includes a first-type confinement layer, a first-type window layer and a first-type ohmic contact layer stacked in sequence from bottom to top, and the second electrode is electrically connected to the first-type ohmic contact layer; The second semiconductor layer includes a second-type ohmic contact layer, a second-type window layer, and a second-type confinement layer stacked in sequence from bottom to top, the step structure of the epitaxial layer exposes the second-type ohmic contact layer, and the first electrode is electrically connected to the second-type ohmic contact layer.

9. The flip-chip light emitting diode according to claim 1, characterized in that: The flip-chip light emitting diode further comprises: an insulating layer, The insulating layer covers the epitaxial layer, the insulating layer includes a first opening and a second opening, the first electrode and the second electrode are located on the insulating layer, the first electrode is electrically connected to the second semiconductor layer through the first opening, and the second electrode is electrically connected to the first semiconductor layer through the second opening.

10. The flip-chip light emitting diode according to claim 9, characterized in that: The flip-chip light emitting diode further comprises: a first metal layer and a second metal layer, The first metal layer is located on the second semiconductor layer exposed by the step structure, the second metal layer is located on the first semiconductor layer, the first electrode is electrically connected to the first metal layer through the first opening, and the second electrode is electrically connected to the second metal layer through the second opening.

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