CN103985804A - LED chip and manufacturing method thereof - Google Patents

Abstract

The invention discloses an LED chip and a manufacturing method thereof, comprising the following steps: a substrate, a first conductive type semiconductor layer, a light emitting layer, a second conductive type semiconductor layer, and a reflective layer which are sequentially stacked; at least one first electrode hole each extending through the reflective layer, the second conductive type semiconductor layer, and the light emitting layer; a plurality of second electrode holes each extending through the reflective layer; a first electrode at least partially disposed on the front surface of the reflective layer and electrically contacting the first conductive type semiconductor layer through the first electrode hole; a second electrode at least partially disposed on the front surface of the reflective layer and electrically contacting the second conductive type semiconductor layer through the second electrode hole; and the isolation layer is positioned on the front surface of the reflection layer and used for insulating and isolating the first electrode from the second electrode. The second electrode holes at least surrounding one first electrode hole are distributed in a symmetrical pattern on the front surface of the reflecting layer, so that the light emitting uniformity is improved.

Description

LED chip and manufacturing method thereof

technical field

The invention relates to the technical field of light emitting elements, in particular to an LED chip and a manufacturing method thereof.

Background technique

With the development of LED (Light Emitting Diode, light-emitting diode) lighting technology, the application of LED in people's daily life is becoming more and more extensive.

The light emission of the LED is completed by using the current from the positive pole to the negative pole. The current will travel from the positive pole to the negative pole with the smallest resistance route. Generally, the resistance value is determined by the distance of the current route. The closer the positive pole to the negative pole, the smaller the resistance value, and the closer the positive pole to the negative pole. The farther away the greater the resistance. However, the electrodes in existing LEDs are usually in the form of metal wires, which makes a single point of current flow from the positive pole to the negative pole, and the shortest distance from the positive pole to the negative pole is the brightest, and other positions will be far away from the metal wire. Larger and relatively dark, there is a problem of uneven current density and uneven luminescence.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is how to make the light emission of the LED as uniform as possible.

In order to solve the above problems, according to an embodiment of the present invention, an LED chip is provided, which includes: a substrate; a first conductivity type semiconductor layer located on the front surface of the substrate; a light emitting layer located on the first conductivity type The front side of the semiconductor layer; the second conductive type semiconductor layer is located on the front side of the light emitting layer; the reflective layer is located on the front side of the second conductive type semiconductor layer; at least one first electrode hole extends through the reflective layer respectively , the second conductive type semiconductor layer and the light-emitting layer; a plurality of second electrode holes, each extending through the reflective layer; a first electrode, at least partially located on the front side of the reflective layer, via the first An electrode hole is in electrical contact with the first conductivity type semiconductor layer; a second electrode, at least partially located on the front surface of the reflective layer, is in electrical contact with the second conductivity type semiconductor layer through the second electrode hole; and The isolation layer is located on the front of the reflective layer and is used to insulate and isolate the first electrode from the second electrode. Wherein, at least the second electrode holes surrounding one of the first electrode holes are distributed in a symmetrical pattern.

For the above LED chip, in a possible implementation manner, the first electrode holes are evenly distributed on the front surface of the first conductivity type semiconductor layer.

For the LED chip above, in a possible implementation manner, the symmetrical figure is a symmetrical polygon, an arc or a circle.

For the above-mentioned LED chip, in a possible implementation manner, it also includes a conductive layer, the conductive layer is formed of a conductive material with high transmittance, and the conductive layer is located between the second conductive type semiconductor layer and the reflective layer. between, and the first electrode hole extends through the conductive layer. Wherein, the conductive material with high transmittance can be, for example, ITO, ZnO, conductive polymer material, PEDOT or conductive glass made of nano-carbon material.

For the above LED chip, in a possible implementation manner, a protective layer is formed on at least one of the conductive layer, the first electrode and the second electrode, and the protective layer can be made of titanium, nickel, chromium Made of one or more of gold.

For the above-mentioned LED chip, in a possible implementation manner, the first electrode includes: an electrode material that fills each of the first electrode holes, and an electrode that will fill the first electrode holes in the second electrode region The material is connected to the lead wire of the electrode material in the first electrode hole in the first electrode area, wherein the first electrode area refers to the existing area of the first electrode on the front surface of the reflective layer, and the first electrode area The two-electrode region refers to the region where the second electrode exists on the front surface of the reflective layer. On the other hand, the second electrode includes: an electrode material filling each of the second electrode holes, and making the electrode material filling each of the second electrode holes avoid each of the first electrode holes and the lead wire interconnected parts.

For the above-mentioned LED chip, in a possible implementation manner, the reflective layer is made of a single layer or multiple layers of high-reflectivity insulating material, and the high-reflectivity insulating material can be SiO ₂ , DBR or photonic crystal structure, the DBR can be made of one or more of SiO ₂ , TiO ₂ , SiN _x , Ta ₂ O ₅ , MgF ₂ , and ZnS.

For the LED chip above, in a possible implementation, the isolation layer is made of insulating material, the insulating material can be SiO ₂ , DBR or photonic crystal structure, and the DBR can be made of SiO ₂ , TiO ₂ , SiN _x , Ta ₂ O ₅ , MgF ₂ , ZnS or more.

For the above-mentioned LED chip, in a possible implementation manner, it also includes an insulating protective film. The insulating protective film is preferably made of a high-hardness insulating material such as silicon dioxide, covering all sides of the LED chip, and only exposing the first electrode and the second electrode.

In order to solve the above problems, according to another embodiment of the present invention, a method for manufacturing an LED chip is provided, which includes: for a substrate sequentially stacked with a first conductivity type semiconductor layer, a light emitting layer and a second conductivity type semiconductor layer Layered LED epitaxial wafers, using a first mask to etch the second conductivity type semiconductor layer and the light emitting layer to form at least one first electrode hole exposing the first conductivity type semiconductor layer; The front surface of the second conductivity type semiconductor layer is covered with a high-reflectivity insulating material to form a reflective layer extending through the first electrode hole; the reflective layer is etched using a second mask to form a second electrode exposed A plurality of second electrode holes in the conductive type semiconductor layer, wherein at least one of the second electrode holes surrounding one of the first electrode holes is distributed in a symmetrical pattern; forming a hole connected to the first conductive type through the first electrode hole The first electrode of the semiconductor layer and the second electrode connected to the second conductivity type semiconductor layer through the second electrode hole.

Regarding the above method for manufacturing an LED chip, in a possible implementation manner, the first electrode holes are evenly distributed on the front surface of the first conductivity type semiconductor layer.

Regarding the manufacturing method of the above LED chip, in a possible implementation manner, the symmetrical figure is a symmetrical polygon, an arc or a circle.

Regarding the manufacturing method of the above-mentioned LED chip, in a possible implementation manner, it also includes: before forming the reflective layer, covering the front surface of the second conductive type semiconductor layer with a conductive material with high transmittance, so as to form a The conductive layer through which the first electrode hole extends; and, by covering the front surface of the conductive layer with the insulating material with high reflectivity, to form the reflective layer through which the first electrode hole extends .

Regarding the manufacturing method of the above-mentioned LED chip, in a possible implementation manner, a protective layer is formed on at least one of the conductive layer, the first electrode, and the second electrode, and the protective layer can be made of titanium, One or more of nickel, chromium and gold.

Regarding the manufacturing method of the above-mentioned LED chip, in a possible implementation manner, the step of forming the first electrode and the second electrode includes: filling each of the first electrode holes and each of the second electrodes with an electrode material. Electrode holes; connecting the electrode material in the first electrode holes located in the predetermined second electrode area to the electrode material in the first electrode holes located in the predetermined first electrode area via lead wires; filling each of the first electrode holes The electrode material of the two electrode holes avoids each of the first electrode holes and the lead wires are connected to each other; at least the front surface of the reflective layer is covered with an insulating material to form an isolation layer; the isolation layer is formed using a third mask. Etching is performed to expose the electrode material filling each of the first electrode holes in the first electrode area, and at least expose the electrode material filling each of the second electrode holes and its connection part in the second electrode area ; at least covering the front surface of the first electrode region with electrode material to form the first electrode; and covering at least the front surface of the second electrode region with electrode material to form the second electrode.

By making at least part of the first electrode holes surrounded by a plurality of second electrode holes in a symmetrical shape, wherein the first electrode holes are used to electrically connect the first electrode with the first conductivity type semiconductor layer, and the second electrode holes are used to The second electrode is electrically connected to the second conductive type semiconductor layer, and the LED chip and the manufacturing method thereof according to the embodiment of the present invention can make the distance from at least part of the positive electrode to the negative electrode consistent in the LED, and the current flow from at least part of the positive electrode to the negative electrode The resistance is consistent, so that compared with the prior art, the uniformity of current density and the uniformity of light emission can be improved.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is the flow chart of the LED chip manufacturing method of the embodiment of the present invention;

Figure 2(a)-Figure 2(d) are cross-sectional views of structures formed in the LED chip manufacturing method of the embodiment of the present invention;

Fig. 3(a)-Fig. 3(e) are top views of structures formed in the LED chip manufacturing method according to the embodiment of the present invention;

FIG. 4( a )- FIG. 4( c ) are cross-sectional views of LED chips according to embodiments of the present invention.

FIG. 5( a )- FIG. 5( b ) are a top view and a cross-sectional view of an HV-LED structure formed by using an LED chip according to an embodiment of the present invention.

Explanation of reference signs

10: substrate; 20: first conductivity type semiconductor layer; 30: light emitting layer; 40: second conductivity type semiconductor layer; 50: first electrode hole; 60: conductive layer; 70: reflective layer; 80: second electrode Hole; 90: insulating protective layer; 500: first electrode; 510: first electrode contact; 800: second electrode; 810: second electrode contact; 900: conductive metal; 1000: substrate.

Detailed ways

Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the accompanying drawings. The same reference numbers in the figures indicate functionally identical or similar elements. While various aspects of the embodiments are shown in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or better than other embodiments.

In addition, in order to better illustrate the present invention, numerous specific details are given in the specific embodiments below. It will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, means, components and circuits are not described in detail so as to highlight the gist of the present invention.

Fig. 1 is a flow chart of a method for manufacturing an LED chip according to an embodiment of the present invention, which is described in detail in conjunction with Fig. 2(a)-Fig. 2(d) and Fig. 3(a)-Fig. 3(e). The method includes:

Step S1, for the LED epitaxial wafer on which the first conductivity type semiconductor layer 20, the light emitting layer 30, and the second conductivity type semiconductor layer 40 are laminated in sequence on the substrate 10, for example, dry or wet etching, using the first mask Etching the second conductive type semiconductor layer 40 and the light emitting layer 30 to expose the first conductive type semiconductor layer 20, forming at least one second conductive type semiconductor layer 40 and the light emitting layer 30 as shown in FIG. 2(a). The structure of an electrode hole 50. Among them, the first electrode holes 50 are used to make the first electrodes described below contact the first conductivity type semiconductor layer 20 , and are preferably distributed as evenly as possible as shown in FIG. 3( a ).

In a possible implementation manner, the substrate 10 may specifically be various substrates with different crystal orientations, such as sapphire, silicon or silicon carbide substrates.

In addition, the material of the first conductive type semiconductor layer 20 may be n-type gallium nitride or n-type aluminum indium gallium phosphide (AlGaInP). The material of the second conductive type semiconductor layer 40 may be p-type gallium nitride, or p-type aluminum indium gallium phosphide. In a possible implementation manner, the first conductive type semiconductor layer 20 and the second conductive type semiconductor layer 40 are respectively made of n-type gallium nitride and p-type gallium nitride.

Step S2, plate a high-transmittance conductive material such as ITO, ZnO, conductive polymer material, PEDOT or nano-carbon material on the second conductive type semiconductor layer 40 etched with the first electrode hole 50 as the conductive layer 60, wherein The conductive layer 60 must expose the bottom of the first electrode hole 50 , thereby forming a structure in which the first electrode hole 50 extends through the conductive layer 60 as shown in FIG. 2( b ).

Step S3, covering the side wall of the first electrode hole 50 and the conductive layer 60 with a single layer or multiple layers such as silicon dioxide (SiO ₂ ), DBR (which can be made of SiO ₂ , TiO ₂ , SiN _x , Ta ₂ O ₅ , MgF ₂ , made of one or more of ZnS) or photonic crystal structure and other high-reflectivity insulating materials as the reflective layer 70, wherein the reflective layer 70 must expose the first conductive type semiconductor layer at the bottom of the first electrode hole 50 20, thereby forming a structure in which the first electrode hole 50 extends through the reflective layer 70 as shown in FIG. 2(c). Wherein, the reflective layer 70 itself is not conductive, therefore, in addition to reflecting light, the reflective layer 70 also plays the role of insulation.

Step S4, on the reflective layer 70, etch using a second mask to expose the second conductivity type semiconductor layer 40 or the conductive layer 60 by, for example, dry or wet etching, forming The reflective layer 70 also includes a plurality of second electrode holes 80 . Wherein, the second electrode hole 80 is used to make the second electrode described below contact the second conductivity type semiconductor layer 40 , and the plurality of second electrode holes 80 surrounding at least one first electrode hole 50 are distributed in a symmetrical pattern. In this way, since at least part of the distance from the second electrode hole 80 to a first electrode hole 50 is consistent, the distance between the positive and negative electrodes formed through these electrode holes in the final LED chip is consistent, and the flow through this part The resistance experienced by the current of the positive and negative electrodes is consistent, so that compared with the prior art, the current density and the uniformity of light emission can be effectively improved.

In a possible implementation manner, preferably as shown in FIG. 3( b ), the second electrode holes 80 surrounding each first electrode hole 50 are distributed in a symmetrical pattern. Compared with the implementation in which part of the first electrode hole is surrounded by the second electrode hole in a symmetrical pattern, this implementation can further improve the current density and the uniformity of light emission.

In a possible implementation manner, the symmetrical figure formed by a plurality of second electrode holes 80 surrounding each first electrode hole 50 may be triangular, square (as shown in FIG. 4(b) ), rhombus (as shown in FIG. 4 (c)) or hexagon (as shown in Figure 4 (a) and other arbitrary polygons, it can also be arc or circle.

Step S5 , forming a first electrode connected to the first conductivity type semiconductor layer 20 through the first electrode hole 50 and a second electrode connected to the second conductivity type semiconductor layer 40 through the second electrode hole 80 .

In a possible implementation manner, the operation for forming the first electrode and the second electrode in the above step S5 may include a bottom electrode fabrication step, an isolation step, and a surface electrode fabrication step, wherein:

In the bottom electrode manufacturing step, each first electrode hole 50 and each second electrode hole 80 are filled with electrode material, so that the electrode material in each first electrode hole 50 in the predetermined second electrode area is connected to the electrode material located in the second electrode area via a lead wire. The electrode material in the first electrode hole 50 in the predetermined first electrode area, and the electrode material filling each second electrode hole 80 avoids each first electrode hole 50 and the leads are connected to each other, thereby forming a top view structure as shown in Figure 3 (c) Bottom electrode shown.

In a possible implementation, as shown in Figure 3(c), the lead wires can enter the first electrode area from the second electrode area along the side of the LED chip, so as to minimize the possibility of contact with the second electrode sex.

In the isolation step, at least the front surface of the reflective layer 70 is covered with an insulating material to form an isolation layer, and the isolation layer is etched using a third mask to expose and fill each first electrode hole 50 in the first electrode region. The electrode material, and at least the electrode material filling each second electrode hole 80 and its connection part are exposed in the second electrode region, thereby forming a top view structure as shown in FIG. 3( d ).

Among them, as shown in Figure 3(d), the first electrode area can be located at the left end of the front of the LED chip, and the second electrode area can be located at the right end of the front of the LED chip, and there is an isolation area composed of an isolation layer between the two to ensure The two are not in electrical contact.

In the surface electrode manufacturing step, at least the front surface of the first electrode region is covered with electrode material to complete the first electrode, and at least the front surface of the second electrode region is covered with electrode material to complete the second electrode, thus forming the electrode shown in Figure 3 (e) The top view structure shown.

In this way, since the first electrode and the second electrode are arranged on both sides of the central axis of the front surface of the LED chip through the isolation area, the front areas of the two electrodes will not differ too much, and when installing, especially when installing by flip-chip , the conductive metal will not just point to the two electrodes and the size is moderate, thereby preventing the overflow of the conductive metal and further improving the yield of the product.

It should be noted that, in the above method, the conductive layer 60 is formed between the second conductive type semiconductor layer 40 and the reflective layer 70 through step S2, so as to make the current more uniform. However, those skilled in the art should be able to understand that even if the conductive layer 60 is not formed, as long as the part of the second electrode hole 80 used to make the second electrode electrically contact with the second conductive type semiconductor layer 40 surrounds the part of the second electrode hole 80 used to make the first electrode contact with the second conductive type semiconductor layer 40 The first electrode holes 50 in electrical contact with the first conductivity type semiconductor layer 20 are distributed in a symmetrical pattern, so that at least part of the current from the positive electrode to the negative electrode experiences the same resistance, which can effectively improve the uniformity of light emission.

In addition, in a possible implementation manner, a protective layer may also be formed on at least one of the conductive layer 60 , the first electrode and the second electrode. The protective layer can be made of one or several metal materials such as titanium, nickel, chromium and gold, and its thickness is It can be soldered by solder paste or silver glue when used.

In a possible implementation, in the step of forming the surface electrodes, a highly insulating material such as silicon dioxide (SiO ₂ ) is also used as an insulating protective layer 90 to cover the entire LED chip, and only the first electrode region 500 and the first electrode region 500 are exposed. The second electrode region 800 can form a top view structure as shown in FIG. 3(e) and a partial cross-sectional structure as shown in FIG. IR due to conductivity. Since silicon dioxide is a relatively hard material, it is very likely that the silicon dioxide protective layer of the split LED chip will crack due to the internal stress generated during the splitting process using a tungsten steel knife. , so that the material used to bond the light-emitting element and the substrate penetrates into the element. In this case, when splitting with a tungsten steel knife during splitting, a layer of soft material is coated on the surface of the split LED chip, which can effectively offset the internal stress caused by the tungsten steel knife during splitting, thereby It can prevent the silicon dioxide protective layer from cracking.

According to another embodiment of the present invention, an LED chip is also provided, which will be described in detail as follows with reference to FIGS. 2( a )- 2 ( d ) and FIGS. 3( a )- 3 ( e ).

The LED chip provided according to the embodiment of the present invention may include: a sequentially stacked substrate 10, a first conductive type semiconductor layer 20, a light emitting layer 30, a second conductive type semiconductor layer 40, and a single layer or multiple layers with high reflectivity. Reflective layer 70 made of insulating material (such as SiO ₂ , DBR (can be made of one or more of SiO ₂ , TiO ₂ , SiN _x , Ta ₂ O ₅ , MgF ₂ , ZnS) or photonic crystal structure, etc.) ; At least one first electrode hole 50, each extending through the reflective layer 70, the second conductivity type semiconductor layer 40, and the light emitting layer 30; a plurality of second electrode holes 80, each extending through the reflective layer 70; the first electrode, at least partially located on the front of the reflective layer, electrically contacting the first conductive type semiconductor layer through the first electrode hole; the second electrode, at least partially located on the front of the reflective layer, via the second electrode The hole is in electrical contact with the semiconductor layer of the second conductivity type; and the isolation layer is located on the front of the reflective layer and is used to insulate and isolate the first electrode from the second electrode.

Wherein, viewed from the front of the reflective layer 70, at least a plurality of second electrode holes 80 surrounding one first electrode hole 50 are distributed in a symmetrical pattern. In this way, since at least part of the distance from the second electrode hole 80 to the first electrode hole 50 is consistent, the distance between the positive and negative electrodes formed by these electrode holes is consistent, and the resistance experienced by the current flowing through this part of the positive and negative electrodes Therefore, compared with the prior art, the current density and the uniformity of light emission can be effectively improved.

In a possible implementation manner, as shown in FIG. 3( b ), on the front surface of the reflective layer 70 , the second electrode holes 80 surrounding the first electrode holes 50 are distributed in a symmetrical pattern. Compared with the implementation in which part of the first electrode hole is surrounded by the second electrode hole in a symmetrical pattern, this implementation can obviously further improve the current density and the uniformity of light emission.

In a possible implementation manner, the substrate 10 may specifically be various substrates with different crystal orientations, such as sapphire, silicon or silicon carbide substrates.

In addition, the material of the first conductive type semiconductor layer 20 may be n-type gallium nitride or n-type aluminum indium gallium phosphide (AlGaInP). The material of the second conductive type semiconductor layer 40 may be p-type gallium nitride, or p-type aluminum indium gallium phosphide. In a possible implementation manner, the first conductive type semiconductor layer 20 and the second conductive type semiconductor layer 40 are respectively made of n-type gallium nitride and p-type gallium nitride. Correspondingly, the first electrode and the second electrode are respectively a negative electrode and a positive electrode.

In a possible implementation manner, the first electrode holes 50 are evenly distributed on the front surface of the first conductivity type semiconductor layer 20 , for example, as shown in FIG. 3( a ) and FIG. 3( b ).

In a possible implementation, the symmetrical figure formed by a plurality of second electrode holes 80 surrounding each first electrode hole 50 may be any polygon such as triangle, square, rhombus or hexagon, or may be arc or round.

In a possible implementation, a conductive layer 60 may also be formed between the reflective layer 70 and the second conductive type semiconductor layer 40, and the conductive layer 60 is preferably made of, for example, ITO, ZnO, conductive polymer materials, PEDOT or nano Carbon materials and other conductive materials with high transmittance are formed to further obtain the effect of more uniform current density and better reflection effect.

In a possible implementation, as shown in FIG. 3(c), the first electrode may include: an electrode material that fills each first electrode hole 50; and, will fill the first electrode hole located in the second electrode region The electrode material in 50 is connected to the leads of the electrode material in the first electrode hole 50 located in the first electrode region. Wherein, the first electrode area refers to the area where the first electrode exists on the front surface of the reflective layer 70, which is shown as the left end of the cross-sectional view in FIG. The presence area of the front is shown as the right end of the cross-sectional view in Fig. 3(c).

Correspondingly, as shown in FIG. 3( c ), the second electrode may include: electrode material filling each second electrode hole 80 ; and making the electrode material filling each second electrode hole 80 avoid each first electrode hole 50 The part connected to each other with the above-mentioned leads.

In addition, as described above with reference to Figure 3(d) and Figure 3(e), in order to better isolate the first electrode and the second electrode, the above isolation step can also be carried out on the structure shown in Figure 3(c) and surface electrode fabrication steps to further improve the quality of the LED chip.

In a possible implementation manner, a protective layer may further be formed on at least one of the conductive layer 60 , the first electrode and the second electrode. The protective layer can be made of one or several metal materials such as titanium, nickel, chromium and gold, and its thickness is It can be soldered by solder paste or silver glue when used.

In addition, in a possible implementation manner, the LED chip may further include an insulating protection layer 90 made of a high-hardness insulating material, and the insulating protection layer 90 covers all sides of the LED chip and only exposes the first electrode 500 and the second electrode 800, thereby forming a top view structure as shown in FIG. 3(e) and a partial cross-sectional structure as shown in FIG. 5(b).

According to yet another embodiment of the present invention, an HV-LED structure is also provided. It will be described in detail below with reference to FIG. 5( a )- FIG. 5( b ).

As shown in Fig. 5(a), each LED chip in this HV-LED structure has a top view structure as shown in Fig. 3(e). In addition, the substrate 1000 on which the LED chip is to be mounted is itself insulated, but as shown in FIG. 5( b ), a first electrode contact 510 and a second electrode contact 810 are formed on the substrate 1000 .

In a possible implementation, before the LED chips are connected in series, as shown in FIG. Gallium nitride semiconductor material, otherwise leakage may occur. Then, as shown in FIG. 5( a ), the first electrode 500 and the second electrode 800 of the connected LED chips are connected with a conductive metal 900 to form a HV-LED structure by connecting multiple LED chips in series.

Among them, as shown in Figure 5(b), only the first electrode 500 of the first LED chip is connected to the first electrode contact 510 on the substrate 1000, and only the second electrode 800 of the last LED chip is connected to the contact point 510 on the substrate 1000. The second electrode contact 810 is turned on, and the first electrode 500 of any intermediate LED chip is connected to the second electrode 800 of the previous LED chip through the conductive metal 900, and its second electrode 800 is connected to the second electrode 800 of the next LED chip through the conductive metal 900. The first electrode 500 is connected and not conducted with the substrate 1000 as a whole.

Claims (16)

1. A LED chip, characterized in that, comprising: Substrate; a first conductivity type semiconductor layer located on the front side of the substrate; a light emitting layer located on the front side of the first conductivity type semiconductor layer; a second conductivity type semiconductor layer located on the front side of the light-emitting layer; a reflective layer located on the front side of the second conductivity type semiconductor layer; at least one first electrode hole each extending through the reflective layer, the second conductivity type semiconductor layer, and the light emitting layer; a plurality of second electrode holes each extending through the reflective layer; a first electrode, at least partially located on the front surface of the reflective layer, electrically contacting the first conductivity type semiconductor layer through the first electrode hole; a second electrode, at least partially located on the front surface of the reflective layer, electrically contacting the second conductivity type semiconductor layer through the second electrode hole; and an isolation layer, located on the front of the reflective layer, used to insulate and isolate the first electrode from the second electrode, Wherein, on the front surface of the reflective layer, at least the second electrode holes surrounding one of the first electrode holes are distributed in a symmetrical pattern. 2. The LED chip according to claim 1, wherein the first electrode holes are evenly distributed on the front surface of the first conductive type semiconductor layer. 3. The LED chip according to claim 1, wherein the symmetrical figure is a symmetrical polygon, arc or circle. 4. The LED chip according to claim 1, characterized in that, The first electrode includes: an electrode material filling each of said first electrode holes, and Connecting the electrode material filling the first electrode hole in the second electrode region to the electrode material in the first electrode hole in the first electrode region, wherein the first electrode region refers to the first electrode region An area where an electrode exists on the front of the reflective layer, the second electrode area refers to an area where the second electrode exists on the front of the reflective layer; The second electrode includes: an electrode material filling each of said second electrode holes, and The electrode material filling each of the second electrode holes avoids the parts where the first electrode holes and the lead wires are connected to each other. 5. The LED chip according to any one of claims 1 to 4, further comprising a conductive layer, the conductive layer is formed of a conductive material with high transmittance, and the conductive layer is located on the second conductive layer. type semiconductor layer and the reflective layer, and the first electrode hole extends through the conductive layer. 6 . The LED chip according to claim 5 , wherein the conductive material with high transmittance is ITO, ZnO, conductive polymer material, PEDOT or nano-carbon material. 7. The LED chip according to any one of claims 1 to 4, characterized in that a protective layer is formed on at least one of the conductive layer, the first electrode and the second electrode, and the The protective layer is made of one or more of titanium, nickel, chromium and gold. 8. The LED chip according to any one of claims 1 to 4, wherein the reflective layer is made of a single-layer or multi-layer high-reflectivity insulating material, and the high-reflectivity insulating material is SiO ₂ , DBR or photonic crystal structure, the DBR is made of one or more of SiO ₂ , TiO ₂ , SiN _x , Ta ₂ O ₅ , MgF ₂ , and ZnS. 9. The LED chip according to any one of claims 1 to 4, wherein the isolation layer is made of insulating material, the insulating material is SiO ₂ , DBR or photonic crystal structure, and the DBR is made of One or more of SiO ₂ , TiO ₂ , SiN _x , Ta ₂ O ₅ , MgF ₂ , ZnS. 10. The LED chip according to any one of claims 1 to 4, further comprising an insulating protective film, the insulating protective film is made of a high-hardness insulating material, covering all sides of the LED chip, And only the first electrode and the second electrode are exposed. 11. A method for manufacturing an LED chip, comprising: For an LED epitaxial wafer in which a first conductivity type semiconductor layer, a light emitting layer and a second conductivity type semiconductor layer are sequentially stacked on a substrate, the second conductivity type semiconductor layer and the light emitting layer are etched using a first mask, to form at least one first electrode hole exposing the first conductivity type semiconductor layer; Covering the sidewall of the first electrode hole and the front surface of the second conductivity type semiconductor layer with a high-reflectivity insulating material to form a reflective layer extending through the first electrode hole; Etching the reflective layer using a second mask to form a plurality of second electrode holes exposing the second conductivity type semiconductor layer, wherein at least one of the second electrode holes surrounding one of the first electrode holes is symmetrical graphic distribution; A first electrode connected to the first conductive type semiconductor layer through the first electrode hole and a second electrode connected to the second conductive type semiconductor layer through the second electrode hole are formed. 12. The method according to claim 11, wherein the step of forming the first electrode and the second electrode comprises: filling each of the first electrode holes and each of the second electrode holes with an electrode material; connecting the electrode material in each first electrode hole located in the predetermined second electrode area to the electrode material in the first electrode hole located in the predetermined first electrode area via a lead wire; making the electrode material filling each of the second electrode holes avoid each of the first electrode holes and connect the leads to each other; covering at least the front surface of the reflective layer with an insulating material to form an isolation layer; The isolation layer is etched using a third mask, so as to expose the electrode material filling each of the first electrode holes in the first electrode area, and at least expose and fill each of the first electrode holes in the second electrode area. The electrode material of the second electrode hole and its connection part; covering at least the front surface of the first electrode region with an electrode material to form the first electrode; and At least the front surface of the second electrode region is covered with electrode material to form the second electrode. 13. The method according to claim 11, wherein the first electrode holes are evenly distributed on the front surface of the first conductivity type semiconductor layer. 14. The method according to claim 11, wherein the symmetrical figure is a symmetrical polygon, arc or circle. 15. A method according to any one of claims 11 to 14, wherein It also includes: before forming the reflective layer, covering the front surface of the second conductivity type semiconductor layer with a conductive material with high transmittance, so as to form a conductive layer extending through the first electrode hole; Furthermore, the front surface of the conductive layer is covered with the insulating material with high reflectivity to form the reflective layer extending through the first electrode hole. 16. The method according to any one of claims 11 to 14, characterized in that a protective layer is formed on at least one of the conductive layer, the first electrode and the second electrode, the protective layer The layers are made of one or more of titanium, nickel, chromium and gold.