CN115579438A - LED chip with inverted silver mirror and preparation method thereof - Google Patents

Abstract

The present invention relates to the technical field of semiconductor devices, in particular to a flip-chip silver mirror light-emitting diode chip and a preparation method thereof. The chip includes: a substrate and an epitaxial layer, and the epitaxial layer includes an N-type semiconductor layer, an N-type semiconductor layer, and a semiconductor layer from bottom to top. Active light-emitting layer, P-type semiconductor layer; the chip also includes a current blocking layer, a current spreading layer, a first silver reflective layer, a Bragg reflective layer, a second silver reflective layer, a metal protection layer, a first insulating protection layer, a series Metal layer, second insulating protection layer, pad layer, tin ball; Wherein, Bragg reflective layer is provided with Bragg reflective layer through hole, and described second silver reflective layer is placed on Bragg reflective layer, and described first silver reflective layer Placed under the through hole of the Bragg reflective layer, the orthographic projection area of the first silver reflective layer is larger than the area of the through hole of the Bragg reflective layer. The invention enhances the luminance of the blue light emitting diode chip by setting the structure of the first silver reflective layer plus the Bragg reflective layer plus the second silver reflective layer.

Description

A flip-chip silver mirror light-emitting diode chip and its preparation method

technical field

The invention belongs to the technical field of semiconductor devices, and in particular relates to a flip-chip silver mirror light-emitting diode chip and a preparation method thereof.

Background technique

In recent years, light-emitting diode technology has become more and more mature, and its applications have gradually diversified. There are more and more applications such as lighting, backlight display, and direct display. For lighting or backlight display, it is necessary to package blue light-emitting diode chips with phosphor powder into white light applications. .

The existing flip-chip light-emitting diode chips use metal Al plus a Bragg reflector to achieve total reflection, but the reflectivity of metal Al decreases gradually with the increase of wavelength in the visible light band, resulting in blue light-emitting diode chips being packaged into white light. The luminous efficiency is reduced, and a layer of SiO ₂ or SiN material will be prepared at the bottom of the Bragg reflective layer for chemical wet etching to prevent the plasma gas from damaging the current spreading layer below the Bragg reflective layer during chemical dry etching, resulting in chip failure, but Preparation of SiO ₂ or SiN material at the bottom of the Bragg reflective layer will result in low reflectivity of the Bragg reflective layer, resulting in low brightness of the blue light emitting diode chip.

Contents of the invention

In order to solve the above technical problems, the present invention provides a flip-chip silver mirror light-emitting diode chip and a preparation method thereof.

The present invention adopts the following technical solutions: a flip-chip silver mirror light-emitting diode chip, said chip comprising:

Substrate;

an epitaxial layer stacked on the substrate;

A current blocking layer, a current spreading layer, a first silver reflective layer, a Bragg reflective layer, a second silver reflective layer, a metal protective layer, a first insulating protective layer, a series metal layer, a second insulating Protective layer, pad layer, solder ball;

Wherein, the Bragg reflective layer is provided with a through hole of the Bragg reflective layer, the first silver reflective layer is placed under the through hole of the Bragg reflective layer, and the second silver reflective layer at least partially passes through the through hole of the Bragg reflective layer. The hole interferes with the first silver reflective layer to form an electrical connection, and the orthographic area of the first silver reflective layer on the current spreading layer is larger than the bottom area of the through hole of the Bragg reflective layer.

Compared with the prior art, the beneficial effect of the present invention is: by setting the structure of the first silver reflective layer plus the Bragg reflective layer plus the second silver reflective layer, the total reflection of 100% light-emitting area area can be realized, the reflective area increases, and the corresponding The luminance of blue light-emitting diodes also increases; and because the reflectivity of metallic silver increases with the increase of wavelength in the visible light band, the reflectivity of metal Ag in the visible light band is greater than that of metal Al, so metal silver light-emitting diode chips are used. After white light, the luminous efficiency can be greatly improved; and the front projection area of the first silver reflective layer is larger than the area of the through hole of the Bragg reflective layer, so that the bottom of the Bragg reflective layer does not need to be prepared for wet etching. _SiO2 layer or SiN layer, It can prevent the current spreading layer from being damaged when the Bragg reflection layer is etched by dry method, thereby improving the reflectivity of the Bragg reflection layer and increasing the luminance of the blue light emitting diode chip.

Preferably, the epitaxial layer includes an N-type semiconductor layer, an active light-emitting layer, and a P-type semiconductor layer from bottom to top, and the first insulating protection layer is provided with an N-type first insulating protection layer through hole and a P-type The through hole in the first insulating protection layer, the series metal layer includes an N-type series metal layer and a P-type series metal layer, and the N-type series metal layer passes through the N-type first insulating protection layer through hole and the N-type series metal layer. The P-type semiconductor layer interferes to form an electrical connection, and the P-type series metal layer interferes with the metal protection layer through the through hole of the P-type first insulating protection layer to form an electrical connection.

Preferably, the second insulating protective layer is provided with an N-type second insulating protective layer via hole and a P-type second insulating protective layer via hole, and the pad layer includes an N-type pad layer and a P-type pad layer , the N-type pad layer is electrically connected to the N-type series metal layer through the through hole of the N-type second insulating protection layer, and the P-type pad layer is connected through the P-type first The through hole of the two insulating protection layers is in conflict with the P-type series metal layer to form an electrical connection.

Preferably, the current blocking layer includes several current blocking sublayers distributed on the P-type semiconductor layer at intervals, and the first silver reflective layer includes several first silver sublayers distributed at intervals on the current spreading layer. Reflective sublayer, the first silver reflective sublayer is located directly above the corresponding current blocking sublayer and its orthographic projection area on the epitaxial layer is smaller than the orthographic area of the current blocking sublayer on the epitaxial layer shadow area.

Preferably, both the first silver reflective layer and the second silver reflective layer are composed of an Ag layer or an Ag layer and one or more of a Ni layer, a Ti layer, and a Pt layer stacked in sequence.

Preferably, the thickness of the Ag layer of the first silver reflective layer and the second silver reflective layer is between 1000-3000 Å, the thickness of the Ni layer is between 100-2000 Å, the thickness of the Ti layer is between 500-5000 Å, and the thickness of the Pt layer is between at 100-3000 Å.

Preferably, the thickness of the Bragg reflection layer is between 1-5um, and the diameter of the hole of the Bragg reflection layer is between 1-20um.

Preferably, the current blocking layer is composed of one or more stacks of SiO ₂ layer, SiN layer and Al ₂ O ₃ layer.

Preferably, the pad layer is composed of one or more stacks of Al layer, AlCu layer, Ti layer, Pt layer, Ni layer, Au layer, Sn layer, SnAg layer, and SnCu layer.

The present invention also provides a method for preparing a flip-chip silver mirror light-emitting diode chip. The preparation method is used to prepare the flip-chip silver mirror light-emitting diode chip described in the above technical solution. The preparation method includes:

A substrate is provided, and an epitaxial layer is formed on the substrate, and the epitaxial layer sequentially includes an N-type semiconductor layer, an active light-emitting layer, and a P-type semiconductor layer from bottom to top;

Etching the N-type semiconductor layer, active light-emitting layer, and P-type semiconductor layer to expose N-type semiconductor conductive steps;

forming a current blocking layer on the P-type semiconductor layer;

making a current spreading layer on the current blocking layer;

making a first silver reflective layer on the current spreading layer;

Fabricating a Bragg reflection layer on the first silver reflection layer, etching the Bragg reflection layer to form through holes in the Bragg reflection layer;

making a second silver reflective layer on the Bragg reflective layer;

Making a metal protection layer on the second silver reflective layer;

forming a first insulating protective layer on the metal protective layer, and etching the first insulating protective layer to form an N-type first insulating protective layer via hole and a P-type first insulating protective layer via hole;

Fabricating a series metal layer on the first insulating protection layer, the series metal layer including an N-type series metal layer and a P-type series metal layer;

forming a second insulating protective layer on the series metal layer, and etching the second insulating protective layer to form an N-type second insulating protective layer via hole and a P-type second insulating protective layer via hole;

Making a pad layer on the second insulating protection layer, the pad layer including an N-type pad layer and a P-type pad layer;

Solder balls are formed on the pad layer.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the descriptions of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only of the present invention. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without paying creative efforts.

Fig. 1 is the schematic cross-sectional structure diagram of the first embodiment of the present invention;

Fig. 2 is a schematic view of the top structure of the first embodiment of the present invention;

Fig. 3 is an enlarged schematic diagram of part A in Fig. 2;

Fig. 4 is the enlarged schematic diagram of part B in Fig. 2;

FIG. 5 is a flow chart of a method for manufacturing a flip-chip silver mirror light-emitting diode chip in the first embodiment of the present invention.

Explanation of reference signs:

11 substrate, 12 epitaxial layer, 121 N-type semiconductor layer, 122 active light-emitting layer, 123 P-type semiconductor layer, 124 N-type semiconductor conductive step, 13 current blocking layer, 14 current spreading layer, 15 first silver reflective layer, 16 Bragg reflection layer, 161 Bragg reflection layer through hole, 17 Second silver reflection layer, 18 Metal protection layer, 19 First insulation protection layer, 191 N-type first insulation protection layer through hole, 192 P-type first insulation protection layer Through hole, 20 series metal layer, 201 N type series metal layer, 202 P type series metal layer, 21 second insulating protective layer, 211 N type second insulating protective layer through hole, 212 P type second insulating protective layer through hole , 22 pad layers, 221 N-type pad layers, 222 P-type pad layers, 23 solder balls.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the embodiments of the present invention and should not be construed as limitations of the present invention.

In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical ", "horizontal", "top", "bottom", "inner", "outer" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying Describes, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and operate in a specific orientation, and therefore should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

In the embodiments of the present invention, terms such as "installation", "connection", "connection" and "fixation" should be interpreted in a broad sense unless otherwise clearly specified and limited. Disassembled connection, or integration; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the present invention according to specific situations.

Embodiment one

1 to 4, a flip-chip silver mirror light-emitting diode chip, the chip includes: a substrate 11; an epitaxial layer 12 stacked on the substrate 11; a current blocking layer 13, a current expansion layer stacked on the epitaxial layer 12 Layer 14, first silver reflective layer 15, Bragg reflective layer 16, second silver reflective layer 17, metal protective layer 18, first insulating protective layer 19, series metal layer 20, second insulating protective layer 21, pad layer 22 , tin ball 23;

Wherein, the Bragg reflective layer 16 is provided with a Bragg reflective layer through hole 161, the first silver reflective layer 15 is placed below the Bragg reflective layer through hole 161, and at least part of the second silver reflective layer 17 passes through the Bragg reflective layer through hole 161 and the first silver reflective layer through hole 161. A silver reflective layer 15 interferes to form an electrical connection, and the orthographic area of the first silver reflective layer 15 on the current spreading layer 14 is larger than the bottom area of the Bragg reflective layer through hole 161 .

In this embodiment, by setting the structure of the first silver reflective layer 15 plus the Bragg reflective layer 16 plus the second silver reflective layer 17, total reflection of 100% of the light-emitting area area can be realized, the reflective area increases, and the corresponding blue light-emitting diode emits light. The brightness also increases; and because the reflectivity of metal silver increases with the increase of wavelength in the visible light band, the reflectivity of metal Ag in the visible light band is greater than that of metal Al, so after the metal silver light-emitting diode chip is packaged into white light, it emits light. Efficiency can be greatly improved; and the front projection area of the first silver reflective layer 15 is greater than the area of the Bragg reflective layer through hole 161, so that the bottom of the Bragg reflective layer 16 does not need to be prepared for wet etching SiO ₂ layer or SiN layer, that is It can prevent the current spreading layer 14 from being damaged when the Bragg reflection layer 16 is etched by dry method, thereby improving the reflectivity of the Bragg reflection layer 16 and increasing the luminance of the blue light emitting diode chip.

In this embodiment, the epitaxial layer includes an N-type semiconductor layer, an active light-emitting layer, and a P-type semiconductor layer from bottom to top; the first insulating protective layer 19 is provided with an N-type first insulating protective layer through hole 191 and a P-type The first insulating protection layer through hole 192, the series metal layer 20 includes an N-type series metal layer 201 and a P-type series metal layer 202, the N-type series metal layer 201 passes through the N-type first insulating protection layer through hole 191 and the N-type semiconductor The layers 121 are in contact with each other to form an electrical connection, and the P-type series metal layer 202 is in contact with the metal protection layer 18 through the P-type first insulating protective layer via hole 192 to form an electrical connection; the second insulating protective layer 21 is provided with an N-type The second insulating protective layer via hole 211 and the P-type second insulating protective layer via hole 212, the pad layer 22 includes an N-type pad layer 221 and a P-type pad layer 222, and the N-type pad layer 221 penetrates the N-type pad layer. The through hole 211 of the second insulation protection layer interferes with the N-type series metal layer 201 to form an electrical connection, and the P-type pad layer 222 interferes with the P-type series metal layer 202 through the P-type second insulation protection layer through hole 212 to form an electrical connection. sexual connection.

In this embodiment, the current blocking layer 13 includes nine current blocking sublayers distributed on the P-type semiconductor layer 123 at intervals, and the first silver reflective layer 15 includes nine first silver reflectors distributed on the current spreading layer 14 at intervals. layer, the first silver reflective sublayer is located directly above the corresponding current blocking sublayer and its orthographic projection area on the epitaxial layer 12 is smaller than the orthographic projection area of the current blocking sublayer on the epitaxial layer 12 .

In this embodiment, the substrate 11 can be a sapphire substrate, the first silver reflective layer 15 and the second silver reflective layer 17 are composed of an Ag layer, a Ni layer, a Ti layer, and a Pt layer stacked in sequence, and the first silver reflective layer 15 The lowermost layer of the second silver reflective layer 17 and the second silver reflective layer 17 is an Ag layer, so that the reflectivity of the first silver reflective layer 15 and the second silver reflective layer 17 can be ensured.

In this embodiment, the thickness of the Ag layer of the first silver reflective layer 15 and the second silver reflective layer 17 is 2000 Å, the thickness of the Ni layer is 1050 Å, the thickness of the Ti layer is 3000 Å, and the thickness of the Pt layer is 2550 Å; the Bragg reflective layer 16 has a thickness of 3um; the diameter of the through hole 161 of the Bragg reflection layer is 10um.

In this embodiment, the current blocking layer 13 is composed of a SiN layer; the current spreading layer 14 is an ITO layer; the metal protection layer 18 is composed of an AlCu layer; the series metal layer 20 is composed of a Cr layer; the pad layer 22 is composed of an Al layer; The first insulating protection layer 19 and the second insulating protection layer 21 are composed of SiN layer; the solder balls 23 are Sn layer.

Referring to FIG. 5, the present invention provides a method for preparing a flip-chip silver mirror light-emitting diode chip. The preparation method is used to prepare the flip-chip silver mirror light-emitting diode chip in the above embodiment. The preparation method includes the following steps:

S1: A substrate 11 is provided, and an epitaxial layer 12 is formed on the substrate 11. The epitaxial layer 12 sequentially includes an N-type semiconductor layer 121, an active light-emitting layer 122, and a P-type semiconductor layer 123 from bottom to top;

S2: Etching the P-type semiconductor layer 123 to expose the N-type semiconductor conductive step 124;

S3: making the current blocking layer 13 on the P-type semiconductor layer 123;

S4: making the current spreading layer 14 on the current blocking layer 13;

S5: make the first silver reflection layer 15 on the current spreading layer 14;

S6: make the Bragg reflection layer 16 on the first silver reflection layer 15, etch the Bragg reflection layer 16 to form the Bragg reflection layer through hole 161;

S7: making the second silver reflective layer 17 on the Bragg reflective layer 16;

S8: make metal protective layer 18 on the second silver reflection layer 17;

S9: making the first insulating protective layer 19 on the metal protective layer 18, and etching the first insulating protective layer 19 to form an N-type first insulating protective layer via hole 191 and a P-type first insulating protective layer via hole 192;

S10: Fabricate a series metal layer 20 on the first insulating protection layer 19, the series metal layer 20 includes an N-type series metal layer 201 and a P-type series metal layer 202;

S11: making a second insulating protective layer 21 on the series metal layer 20, and etching the second insulating protective layer 21 to form an N-type second insulating protective layer via hole 211 and a P-type second insulating protective layer via hole 212;

S12: making pad layer 22 on the second insulation protection layer 21, pad layer 22 includes N-type pad layer 221 and P-type pad layer 222;

S13: making solder balls 23 on the pad layer 22.

Specifically, the steps of the method for preparing a flip-chip silver mirror light-emitting diode chip shown in this embodiment specifically include:

Provide a substrate 11, and prepare an N-type semiconductor layer 121, an active light-emitting layer 122, and a P-type semiconductor layer 123 on the substrate 11;

Using photolithography and inductively coupled plasma etching processes to prepare N-type semiconductor conductive steps 124;

Depositing a SiN layer on the basis of the above steps using an isostereochemical vapor deposition process, and then removing part of the SiN layer by photolithography and chemical wet etching to form a current blocking layer 13;

Using a magnetron sputtering or electron beam evaporation process to coat an ITO film on the basis of the above steps, and then using a photolithography and chemical wet etching process to remove part of the ITO film to form a current spreading layer 14;

Use the photolithography process to form patterns on the basis of the above steps, then use the electron beam evaporation process to evaporate the Ag layer, Ni layer, Ti layer, Pt layer metal layer, and then use the Lift-Off process to remove the excess metal layer to form The first silver reflective layer 15;

Using an electron beam evaporation process to vapor-deposit 4-60 layers of alternating layers of SiO2 and Ti3O5 to form a Bragg reflection layer 16, and then use a photolithography and inductively coupled plasma etching process to prepare a Bragg reflection layer through hole 161;

Use the photolithography process to form patterns on the basis of the above steps, then use the electron beam evaporation process to evaporate the Ag layer, Ni layer, Ti layer, Pt layer metal layer, and then use the Lift-Off process to remove the excess metal layer to form The second silver reflective layer 17;

Using a photolithography process to form a pattern on the basis of the above steps, then using an electron beam evaporation process to evaporate an AlCu layer, and then using a Lift-Off process to remove the excess metal layer to form a metal protection layer 18;

Deposit a SiN layer on the basis of the above steps by using an isostereochemical vapor deposition process to form a first insulating protective layer 19, and then use photolithography and chemical dry etching to remove part of the SiN layer to form an N-type first insulating protective layer Through holes 191 and through holes 192 in the P-type first insulating protective layer;

Utilize the photolithography process to form patterns on the basis of the above steps, then use the electron beam evaporation process to evaporate the Cr layer, and then use the Lift-Off process to remove the redundant metal layer to form the series metal layer 20, including the N-type series metal layer 201, P-type series metal layer 202;

Deposit a SiN layer on the basis of the above steps by using an isostereochemical vapor deposition process to form a second insulating protective layer 21, and then use photolithography and chemical dry etching to remove part of the SiN layer to form an N-type second insulating protective layer A through hole 211 and a P-type second insulating protective layer through hole 212;

Use a photolithography process to form a pattern on the basis of the above steps, then use an electron beam evaporation worker to evaporate an Al layer, and then use a Lift-Off process to remove the excess metal layer to form a pad layer 22, including an N-type pad layer 221 and a P-type pad layer 222;

Sn metal is printed by screen printing process, and then reflowed at high temperature to prepare solder balls 23 .

The flip-chip silver mirror light-emitting diode chip prepared by the preparation method of this example has the same size specification as the chip prepared by the comparative example, and the light efficiency tested by the testing instrument is 236lm/W, which is 1.29% higher than that of the comparative example. The specific results are shown in Table 1. .

Embodiment two

The difference between this embodiment and Embodiment 1 lies in that the thickness of the Bragg reflection layer in this embodiment is 1 μm, and the diameter of the hole in the Bragg reflection layer is 20 μm.

The flip-chip silver mirror light-emitting diode chip prepared by the preparation method of this example has the same size and specification as the chip prepared by the comparative example, and the light efficiency tested by the testing instrument is 234lm/W, which is 0.43% higher than that of the comparative example. The specific results are shown in Table 1. .

Embodiment three

The difference between this embodiment and Embodiment 1 lies in that the thickness of the Bragg reflection layer in this embodiment is 4 μm, and the diameter of the through hole of the Bragg reflection layer is 15 μm.

The flip-chip silver mirror light-emitting diode chip prepared by the preparation method of this example has the same size specification as the chip prepared by the comparative example, and the light efficiency tested by the testing instrument is 236.5lm/W, which is 1.5% higher than that of the comparative example. The specific results are shown in Table 1. Show.

Embodiment four

The difference between this embodiment and Embodiment 1 lies in that the thickness of the Bragg reflection layer in this embodiment is 5 μm, and the diameter of the hole in the Bragg reflection layer is 5 μm.

The flip-chip silver mirror light-emitting diode chip prepared by the preparation method of this example has the same size and specification as the chip prepared by the comparative example, and the light efficiency tested by the testing instrument is 238lm/W, which is 2.15% higher than that of the comparative example. The specific results are shown in Table 1. .

Comparative example

This comparative example adopts the flip-chip light-emitting diode chip prepared by the prior art, which includes a substrate and an epitaxial layer arranged on the substrate, and a current blocking layer, a current spreading layer, a protective layer, and a Bragg reflective layer deposited on the epitaxial layer in sequence. , metal reflective layer, metal protective layer, series metal layer, insulating protective layer, pad layer, solder ball. Wherein, the protective layer is a _SiO2 layer or a SiN layer, and the metal reflective layer is an Al layer. The luminous efficiency of this chip is 233lm/W tested by the testing instrument.

Table 1: Comparison of some parameters of each embodiment and comparative example and a comparison table of the corresponding light effect results

As can be seen from Table 1, the present invention replaces the SiN protective layer of the comparative example plus the Bragg reflective layer plus the metal Al reflective layer by setting the first silver reflective layer 15 plus the structure of the Bragg reflective layer 16 plus the second silver reflective layer 17, and then by each Embodiments Adjust the thickness of the Bragg reflection layer 16 and the diameter of the through hole 161 of the Bragg reflection layer, so that the light efficiency of each embodiment of the present invention is better than that of the comparative example.

To sum up, the flip-chip silver mirror light-emitting diode chip produced by the above implementation can achieve total reflection of 100% of the light-emitting area by setting the structure of the first silver reflective layer 15 plus the Bragg reflective layer 16 plus the second silver reflective layer 17, As the reflection area increases, the luminous brightness of the corresponding blue light-emitting diodes also increases; and because the reflectivity of metallic silver increases with the increase of wavelength in the visible light band, the reflectivity of metallic Ag in the visible light band is greater than that of metallic Al, so metallic silver is used After the light-emitting diode chip is packaged into white light, the luminous efficiency can be greatly improved; and the front projection area of the first silver reflective layer 15 is larger than the area of the through hole 161 of the Bragg reflective layer, so that the bottom of the Bragg reflective layer 16 does not need to be prepared for wet process. The corroded SiO ₂ layer and SiN layer can prevent the current spreading layer 14 from being damaged during dry etching of the Bragg reflective layer 16, thereby improving the reflectivity of the Bragg reflective layer 16 and increasing the luminance of the blue light-emitting diode chip.

On the premise of no conflict, those skilled in the art can freely combine and superimpose the above additional technical features.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. A flip-chip silver mirror light-emitting diode chip is characterized in that the chip comprises: Substrate; an epitaxial layer stacked on the substrate; A current blocking layer, a current spreading layer, a first silver reflective layer, a Bragg reflective layer, a second silver reflective layer, a metal protective layer, a first insulating protective layer, a series metal layer, a second insulating Protective layer, pad layer, solder ball; Wherein, the Bragg reflective layer is provided with a through hole of the Bragg reflective layer, the first silver reflective layer is placed under the through hole of the Bragg reflective layer, and the second silver reflective layer at least partially passes through the through hole of the Bragg reflective layer. The hole interferes with the first silver reflective layer to form an electrical connection, and the orthographic area of the first silver reflective layer on the current spreading layer is larger than the bottom area of the through hole of the Bragg reflective layer. 2. A flip-chip silver mirror light-emitting diode chip according to claim 1, wherein the epitaxial layer comprises an N-type semiconductor layer, an active light-emitting layer, and a P-type semiconductor layer from bottom to top, and the The first insulating protective layer is provided with an N-type first insulating protective layer through hole and a P-type first insulating protective layer through hole, and the series metal layer includes an N-type series metal layer and a P-type series metal layer, and the N-type The series metal layer contacts the N-type semiconductor layer through the through hole of the N-type first insulating protection layer to form an electrical connection, and the P-type series metal layer passes through the through hole of the P-type first insulating protection layer. Interfere with the metal protection layer to form an electrical connection. 3. A flip-chip silver mirror light-emitting diode chip according to claim 2, characterized in that, the second insulating protective layer is provided with an N-type second insulating protective layer through hole and a P-type second insulating protective layer through hole. hole, the pad layer includes an N-type pad layer and a P-type pad layer, and the N-type pad layer penetrates through the N-type second insulating protective layer through hole and interferes with the N-type series metal layer to An electrical connection is formed, and the P-type pad layer interferes with the P-type series metal layer through the through hole of the P-type second insulating protection layer to form an electrical connection. 4. A flip-chip silver mirror light-emitting diode chip according to claim 2, wherein the current blocking layer comprises a plurality of current blocking sublayers distributed on the P-type semiconductor layer at intervals, and the first A silver reflective layer includes a plurality of first silver reflective sublayers distributed on the current spreading layer at intervals, and the first silver reflective sublayer is located directly above the corresponding current blocking sublayer and is located on the epitaxial layer The area of the orthographic projection on the current blocking sublayer is smaller than the area of the orthographic projection of the current blocking sublayer on the epitaxial layer. 5. A kind of flip-chip silver mirror LED chip according to any one of claims 1-4, characterized in that, the first silver reflective layer and the second silver reflective layer are all made of Ag layer or Ag layer It is sequentially stacked with one or more of Ni layer, Ti layer and Pt layer. 6. A kind of flip-chip silver mirror LED chip according to claim 5, characterized in that, the Ag layer thickness of the first silver reflective layer and the second silver reflective layer is between 1000-3000 Å, and the Ni layer thickness is between 1000-3000 Å. At 100-2000 Å, the thickness of the Ti layer is between 500-5000 Å, and the thickness of the Pt layer is between 100-3000 Å. 7. A flip-chip silver mirror light-emitting diode chip according to any one of claims 1-4, characterized in that, the thickness of the Bragg reflective layer is between 1-5um, and the diameter of the through hole of the Bragg reflective layer is between 1-20um. 8. A kind of flip-chip silver mirror LED chip according to any one of claims 1-4, characterized in that, the current blocking layer is one of SiO ₂ layer, SiN layer, Al ₂ O ₃ layer or multiple stacks. 9. A kind of flip-chip silver mirror light-emitting diode chip according to claim 1, is characterized in that, described pad layer is Al layer, AlCu layer, Ti layer, Pt layer, Ni layer, Au layer, Sn layer, One or more stacked compositions of SnAg layer and SnCu layer. 10. A method for preparing a flip-chip silver mirror light-emitting diode chip, characterized in that, the preparation method is used to prepare the flip-chip silver mirror light-emitting diode chip described in any one of claims 1-9, and the preparation method comprises : A substrate is provided, and an epitaxial layer is formed on the substrate, and the epitaxial layer sequentially includes an N-type semiconductor layer, an active light-emitting layer, and a P-type semiconductor layer from bottom to top; Etching the N-type semiconductor layer, active light-emitting layer, and P-type semiconductor layer to expose N-type semiconductor conductive steps; forming a current blocking layer on the P-type semiconductor layer; making a current spreading layer on the current blocking layer; making a first silver reflective layer on the current spreading layer; Fabricating a Bragg reflection layer on the first silver reflection layer, etching the Bragg reflection layer to form through holes in the Bragg reflection layer; making a second silver reflective layer on the Bragg reflective layer; Making a metal protection layer on the second silver reflective layer; Forming a first insulating protective layer on the metal protective layer, and etching the first insulating protective layer to form an N-type first insulating protective layer via hole and a P-type first insulating protective layer via hole; Fabricating a series metal layer on the first insulating protection layer, the series metal layer including an N-type series metal layer and a P-type series metal layer; Forming a second insulating protective layer on the series metal layer, and etching the second insulating protective layer to form an N-type second insulating protective layer via hole and a P-type second insulating protective layer via hole; Making a pad layer on the second insulating protection layer, the pad layer including an N-type pad layer and a P-type pad layer; Solder balls are formed on the pad layer.

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