CN116825921A

CN116825921A - Light emitting diode, manufacturing method thereof and light emitting device

Info

Publication number: CN116825921A
Application number: CN202310724365.8A
Authority: CN
Inventors: 陈文志; 蔡家豪; 王润红; 石杜娟; 余明志; 王德云; 林兓兓
Original assignee: Anhui Sanan Optoelectronics Co Ltd
Current assignee: Anhui Sanan Optoelectronics Co Ltd
Priority date: 2023-06-19
Filing date: 2023-06-19
Publication date: 2023-09-29

Abstract

The application belongs to the technical field of semiconductors, and particularly relates to a light-emitting diode, a manufacturing method thereof and a light-emitting device, wherein the light-emitting diode comprises the following components: a substrate, wherein the side surface of the substrate is provided with a tangent plane; the LED chip is positioned on the substrate and is provided with a long side and a short side, wherein the substrate tangent plane corresponding to the lower part of the long side of the LED chip is a first tangent plane, and the substrate tangent plane corresponding to the lower part of the short side of the LED chip is a second tangent plane; in the vertical direction, the height h1 of the first tangential plane is different from the height h2 of the second tangential plane. The application can improve the side reflection capability, so that light rays can be more emitted from the front surface, thereby improving the light-emitting efficiency.

Description

Light emitting diode, manufacturing method thereof and light emitting device

Technical Field

The present application relates to the field of semiconductor technologies, and in particular, to a light emitting diode, a manufacturing method thereof, and a light emitting device.

Background

Currently, light-emitting diodes (LEDs) have been widely used in both lighting and display fields, due to their advantages of high efficiency, long lifetime, full solid state, self-luminescence, and green environmental protection. In particular, gallium nitride light emitting diodes are the subject of intensive research in various domestic and foreign industries because of the coverage of various color lights by band gaps, and have made significant progress in the field of epitaxy and chip technology. However, the current LED still has a problem of low light emitting efficiency, which is limited by the light emitting area and the light emitting efficiency of the LED.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present application is to provide a light emitting diode, a manufacturing method thereof, and a light emitting device for improving the light emitting efficiency of the light emitting diode.

In order to achieve the above object, according to a first aspect of the present application, there is provided a light emitting diode comprising: a substrate, wherein the side surface of the substrate is provided with a tangent plane; the LED chip is positioned on the substrate and is provided with a long side and a short side, wherein the substrate tangent plane corresponding to the lower part of the long side of the LED chip is a first tangent plane, and the substrate tangent plane corresponding to the lower part of the short side of the LED chip is a second tangent plane; in the vertical direction, the height h1 of the first tangential plane is different from the height h2 of the second tangential plane.

Preferably, the cut surface is located at the side top of the substrate.

Preferably, the surface of the first section and/or the second section is a rough surface.

Preferably, the surface of the first section and/or the second section has a plurality of transverse stripes.

Preferably, the height h1 of the first tangential plane is greater than the height h2 of the second tangential plane.

Preferably, the height h1 of the first section is greater than 7 μm, and the height h2 of the second section is 5-7 μm.

Preferably, the included angle between the first tangent plane and the horizontal direction is theta 1, and the included angle between the second tangent plane and the horizontal direction is theta 2, wherein the included angle is 60 degrees less than theta 1 less than 90 degrees, and the included angle is 60 degrees less than theta 2 less than 90 degrees.

Preferably, the angles of the included angle θ1 and the included angle θ2 are the same or different.

According to a second aspect of the present application, there is provided a light emitting device employing a light emitting diode as any one of the above.

According to a third aspect of the present application, there is provided a method for manufacturing a light emitting diode, comprising the steps of:

s1, providing an original substrate, and growing an epitaxial layer on the original substrate;

s2, etching the epitaxial layer to form a plurality of LED chips, and defining long sides and short sides of the LED chips;

s3, scribing from the long side of the LED chip by adopting first laser scribing, and scribing into the original substrate to generate a first V-shaped groove;

s4, scribing from the short side of the LED chip by adopting second laser scribing, and scribing into the original substrate to generate a second V-shaped groove, wherein the depth of the second V-shaped groove is different from that of the first V-shaped groove;

s5, thinning an original substrate and separating an LED chip along a V-shaped groove to form an independent light-emitting diode with the substrate, wherein a tangent plane is formed on the side surface of the substrate, the tangent plane of the substrate corresponding to the lower part of the long side of the LED chip is a first tangent plane, and the tangent plane of the substrate corresponding to the lower part of the short side of the LED chip is a second tangent plane; in the vertical direction, the height h1 of the first tangential plane is different from the height h2 of the second tangential plane.

Preferably, before each laser scribing, a protective layer is deposited on the surface of the LED chip.

Preferably, after each laser scribing, slag generated during laser scribing is removed by an etching process, and then a protective layer on the surface of the LED chip is removed.

Preferably, the depth of the first V-shaped groove is greater than the depth of the second V-shaped groove.

Preferably, the depth of the first V-shaped groove is larger than 7 μm, and the depth of the second V-shaped groove is 5-7 μm.

Preferably, the long side etching time for the LED chip is shorter than the short side etching time for the LED chip.

Preferably, a plurality of transverse stripes are formed on the inner wall of the first V-shaped groove and/or the second V-shaped groove by a laser scribing process.

Preferably, the etching process employs wet etching.

Compared with the prior art, the light-emitting diode, the light-emitting device and the preparation method of the light-emitting diode have the following beneficial effects:

the application is applicable to light emitting diodes having long and short sides. In terms of structure, the side surface area of the light-emitting diode is increased by forming a tangent plane on the side surface of the substrate, so that the side reflection capacity is improved, and more light can be emitted from the front surface. The substrate tangent plane corresponding to the lower side of the long side of the LED chip is a first tangent plane, and the substrate tangent plane corresponding to the lower side of the short side of the LED chip is a second tangent plane. The setting is in vertical orientation, and the height h1 of first tangent plane is different with the height h2 of second tangent plane, can effectively improve the coverage that light openly was emergent to promote light efficiency. In the process of separating the LED chips into independent LEDs, the LED chips are subjected to step-by-step treatment aiming at the long and short sides of the LED chips, rather than synchronous treatment of the long and short sides of the LED chips in the prior art, so that slag can be removed better, the defect of subsequent overetching can be avoided effectively, and the luminous brightness of the LED chips is ensured.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. The objectives and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

Fig. 1 is a schematic cross-sectional structure of an original substrate.

Fig. 2 is a schematic cross-sectional structure of an epitaxial layer grown on a starting substrate.

Fig. 3 to 4 are schematic cross-sectional structures of LED chips (long side and short side) after the epitaxial layers are etched.

Fig. 5 is a schematic cross-sectional structure of the first laser dicing.

Fig. 6 is a schematic cross-sectional view of the second laser dicing.

Fig. 7 is a schematic cross-sectional view of the first protective layer after deposition.

Fig. 8 is a schematic cross-sectional view of the second passivation layer after deposition.

Fig. 9 to 10 are schematic cross-sectional views of the electrode structures after fabrication.

Fig. 11 is a schematic top view of a light emitting diode.

Fig. 12 to 13 are schematic cross-sectional views of light emitting diodes.

Fig. 14 is a schematic view showing a cut-out structure of a light emitting diode.

Reference numerals:

1. an original substrate; 2. an epitaxial layer; 21. a first semiconductor layer; 22. an active layer; 23. a second semiconductor layer; 24. an isolation trench; 25. a step structure; 251. a lower step surface; 252. an upper step surface; 3. a V-shaped groove; 31. a first V-shaped groove; 32. a second V-shaped groove; 4. a protective layer; 41. a first protective layer; 42. a second protective layer; 5. an electrode structure; 51. a first electrode; 52. a second electrode; 6. a laser dicing machine;

10. a substrate; 101. cutting into sections; 1011. a first cut surface; 1012. a second cut surface; 20. an LED chip; 201. a long side; 202. short sides; 30. transverse stripes.

Description of the embodiments

The following will describe embodiments of the present application in detail with reference to the drawings and examples, thereby solving the technical problems by applying technical means to the present application, and realizing the technical effects can be fully understood and implemented accordingly. It should be noted that, as long as no conflict is formed, each embodiment of the present application and each feature of each embodiment may be combined with each other, and the formed technical solutions are all within the protection scope of the present application.

Example 1

The embodiment provides a manufacturing method of a light emitting diode, which comprises the following steps:

step S1, providing an original substrate 1, and growing an epitaxial layer 2 on the original substrate 1, as shown in figures 1-2;

specifically, the original substrate 1 may be an insulating substrate or a conductive substrate. The substrate is made of one selected from Al2O3, siC, gaAs, gaN, alN, gaP, si, znO, mnO and any combination thereof. In this embodiment, the original substrate 1 is preferably a sapphire (Al 2O 3) substrate.

The present embodiment grows an epitaxial layer 2 on the base substrate 1, and the epitaxial layer 2 may be formed on the base substrate 1 by Physical Vapor Deposition (PVD), chemical Vapor Deposition (CVD), epitaxial growth, or the like. The epitaxial layer 2 includes at least a first semiconductor layer 21, an active layer 22 and a second semiconductor layer 23 sequentially formed on the upper surface of the original substrate 1, wherein the second semiconductor layer 23 has a conductivity type opposite to that of the first semiconductor layer 21, for example, the first semiconductor layer 21 may be an n-type semiconductor, and the second semiconductor layer 22 may be a p-type semiconductor. The active layer 22 is a quantum well region for emitting light, and the active layer 22 may be of a light emitting type such as red light, green light, blue light, and the like.

Next, step S2 is performed to etch the epitaxial layer 2 to form a plurality of LED chips 20, defining long sides 201 and short sides 202 of the LED chips 20, as shown in fig. 3 to 4;

the isolation trenches 24 and the step structures 25 are formed by etching the epitaxial layer 2 according to actual production requirements, the isolation trenches 24 isolating the epitaxial layer 2 to form a plurality of mutually independent LED chips 20. The LED chip 20 (light emitting diode) finally obtained in this embodiment has long and short sides, and the long side 201 and the short side 202 of the LED chip 20 are defined by comparing the side sizes of the LED chip 20.

Specifically, each LED chip 20 includes at least an epitaxial layer 2 having a step structure 25, and the step structure 25 is also called a MESA, which is a more common structure in a light emitting diode and is used for subsequent fabrication of the connected electrode structure 5. The step structure 25 includes a lower step surface 251 and an upper step surface 252, the lower step surface 252 is an upper surface of the first semiconductor layer 21 exposed by etching, and the upper step surface 252 is an upper surface of the second semiconductor layer 23.

Next, step S3 is performed, in which the long side 201 of the LED chip 20 is diced by first laser dicing, and the dicing is performed into the original substrate 1, so as to generate a first V-shaped groove 31, as shown in fig. 5;

specifically, in the isolation trench 24 between the adjacent LED chips 20, the laser dicing machine 6 is used to perform the first laser dicing along the long side 201 direction of the LED chips 20, the first laser dicing being performed from the upper surface of the original substrate 1 to the inside of the substrate to form the first V-shaped groove 31. At this time, the scribe depth of the first laser scribe is the depth of the first V-groove 31. The inner wall of the first V-shaped groove 31 becomes a cut surface 101 of the substrate after the subsequent separation of the light emitting diode.

In the laser dicing, a laser beam pulse of a predetermined power, wavelength, and focal length is emitted to the original substrate 1 at a predetermined frequency by a laser dicing machine 6, and a V-shaped groove 3 is formed on the original substrate 1 by focusing the laser beam. The frequency and power of the laser are not limited in the laser scribing process, and the laser scribing process is determined according to practical situations. The present embodiment keeps the laser processing speed constant, and can be realized by increasing the processing power of the laser when making the deeper V-shaped groove 3.

Because the LED chip 20 is easily damaged during the laser dicing process, and chips and slag are generated in the dicing area of the original substrate 1, the slag absorbs the light emitted by the LED chip 20, thereby affecting the light-emitting efficiency of the light-emitting diode. In order to avoid damage to the LED chip 20, the present embodiment further includes: before the first laser dicing, a first protective layer 41 is deposited on the surface of the LED chip 20, as shown in fig. 7. The first protection layer 41 can effectively protect the LED chip 20 to avoid damage to the LED chip 20 caused by subsequent operations, and the specific material can be silicon dioxide or silicon nitride. Due to the arrangement of the first protective layer 41, the first laser dicing will be performed by the first protective layer 41 into the original substrate 1. At this time, the scribe depth of the first laser scribe is greater than the depth of the first V-groove 31. It should be noted that the depth of all V-grooves 3 mentioned in the present application refers to the distance from the bottom of V-grooves 3 to the upper surface of original substrate 1.

In order to improve the defect of slag absorption, the embodiment further comprises: after the first laser dicing, slag generated during the first laser dicing is removed by adopting a first etching process. The first etching process may include dry etching, wet etching, or a combination of both. Wet etching is preferably employed, and specifically, wet etching uses a mixed solution of phosphoric acid and sulfuric acid. Slag can be effectively removed by the first etching process to expose the inner wall of the first V-shaped groove 31, so that light emitted to the region can be effectively emitted, thereby increasing the light emitting range and further improving the light emitting efficiency. After the first etching process is finished, the remaining first protection layer 41 on the surface of the LED chip 20 needs to be removed, and along with the removal of the first protection layer 41, the residual debris and slag carried on the surface of the first protection layer can be removed together, so that the absorption of impurities to light is further avoided, and the light extraction efficiency is improved. Specifically, the first protective layer 41 is preferably removed with a solution containing hydrogen fluoride.

Next, step S4 is performed, and a second laser dicing is performed to scribe the LED chip 20 from the short side 202 into the original substrate 1, so as to generate a second V-shaped groove 32, wherein the depth of the second V-shaped groove 32 is different from the depth of the first V-shaped groove 31, as shown in fig. 6;

specifically, in the isolation trench 24 between the adjacent LED chips 20, the laser dicing machine 6 is used to perform the second laser dicing in the direction of the short side 202 of the LED chip 20, and the second laser dicing is also diced from the upper surface of the original substrate 1 into the substrate interior to form the second V-shaped groove 32. At this time, the scribe depth of the second laser scribe is the depth of the second V-groove 32. It should be noted that, the inner wall of the second V-shaped groove 32 becomes another cut surface 101 of the substrate 10 after the subsequent separation of the light emitting diode.

The depth of the second V-shaped groove 32 is required to be different from the scribing depth (depth) of the first V-shaped groove 31, so that the coverage of light emission is effectively improved, and the luminous efficiency is improved. Experiments prove that the light emitting diode with the structure has higher light emitting efficiency when the depth of the first V-shaped groove 31 is larger than that of the second V-shaped groove 32. The depth of the second V-shaped groove 32 may be a conventional depth, and is smaller, typically not larger than 7 μm, preferably the depth of the second V-shaped groove 32 is 5 to 7 μm, and the first V-shaped groove 31 has a deeper depth, which needs to be larger than 7 μm. By limiting the depth of the first V-shaped groove 31 and the second V-shaped groove 32, a better light emitting effect can be obtained, and the light emitting luminance can be improved.

By deepening the depth of the first V-shaped groove 31, the area of the inner wall thereof can be effectively increased to enhance the light reflection effect of the light emitting diode. In addition, the rough surface is formed on the inner wall of the first V-shaped groove 31, thereby further improving the light emitting efficiency of the light emitting diode. Because the scribing depth of the laser scribing in the prior art is shallow, oxygen is sufficient during scribing, so that the scribing efficiency is kept in a higher state, the melting speed is high, so that the inner wall of the finally formed V-shaped groove 3 is flat and smooth, the scribing depth of the first laser scribing is deepened, and no oxygen is additionally provided, so that the efficiency of the laser scribing is lower, the melting speed is low, and therefore irregular transverse stripes 30 are easier to form on the inner wall of the first V-shaped groove 31, and the inner wall of the first V-shaped groove 31 has high roughness, so that the light extraction efficiency is improved. The inner wall of the second V-shaped groove 32 may be roughened to form irregular lateral stripes 30, for example, by controlling the processing power and speed of the laser dicing machine 6 to be reduced and the laser dicing operation time to be prolonged, but the implementation is not limited thereto. The method of the embodiment can be realized by adjusting the process parameters of the related process without adding additional process flows, so that the cost is not increased, and the mass production is facilitated.

Similarly, to avoid damage to the LED chip 20 and slag residue, the present embodiment further includes: before the second laser scribing is performed, a second protective layer 42 is deposited on the surface of the LED chip 20, as shown in fig. 8. The material of the second protective layer 42 may be the same as or different from the material of the first protective layer 41. Due to the arrangement of the second protective layer 42, the second laser scribe will be scribed inside the original substrate 1 by the second protective layer 42. At this time, the scribe depth of the second laser scribe is greater than the depth of the second V-groove 32. It should be noted that the depth of all V-grooves 3 mentioned in the present application refers to the distance from the bottom of V-grooves 3 to the upper surface of original substrate 1.

The embodiment further includes: after the second laser scribing, a second etching process is used to remove slag generated during the second laser scribing. The second etching process may be the same as or different from the first etching process, preferably the same wet etching as the first etching process is used. Taking the case that the depth of the first V-shaped groove 31 is greater than the depth of the second V-shaped groove 32, the etching time for performing the first etching process (long side 201 etching) on the LED chip 20 is shorter than the etching time for performing the second etching process (short side 202 etching) on the LED chip 20, thereby avoiding the occurrence of an over-etching abnormality in the long side portion of the LED chip 20. In addition, after the second etching process is completed, the remaining second protective layer 42 on the surface of the LED chip 20 needs to be removed. The removal manner of the second protection layer 42 may refer to the removal manner of the first protection layer 41.

The present embodiment adopts a step-by-step processing manner for the long and short sides of the LED chip 20, rather than the synchronous processing manner for the long and short sides of the LED chip 20 in the prior art. Since the depth of the second V-shaped groove 32 is different from that of the first V-shaped groove 31, it is necessary to match an etching process after each laser dicing to improve the overetching phenomenon at one side. Since the depths of the first V-shaped groove 31 and the second V-shaped groove 32 are different, the amounts of slag adhering to the inner walls of the two are different, i.e., different etching times are required to remove slag. If two consecutive etching processes (corresponding to an extended etching time) are used, slag can be removed better, but overetching defects of the long side 201 or the short side 202 are very liable to occur, thereby affecting the brightness of the light emitting diode.

Next, step S5 is performed to thin the original substrate 1 and separate the LED chips 20 along the V-shaped grooves 3, forming individual light emitting diodes having the substrate 10, as shown in fig. 6;

since the original substrate 1 has a relatively thick thickness, it is not easy to separate it into individual light emitting diodes, and therefore, it is generally necessary to thin the original substrate 1 by a thinning process such as grinding, and then separate it by a splitting process using the V-grooves 3. The splitting process in this embodiment may be implemented by splitting, for example, by back splitting, and the specific process of back splitting is well known to those skilled in the art, which is not described herein. In other embodiments, the substrate 10 may be cleaved along the V-shaped groove 3 by film expansion, so as to form a plurality of light emitting diodes.

More specifically, a plurality of light emitting diodes having the substrate 10 are formed by separating along the first V-shaped groove 31 and the second V-shaped groove 32. Due to the separation of the V-shaped groove 3, the inner wall of the V-shaped groove 3 is formed as a cut surface 101 of the side surface of the substrate 10. The cut surface 101 of the substrate 10 corresponding to the lower side 201 of the LED chip 20 is a first cut surface 1011, and the cut surface 101 of the substrate 10 corresponding to the lower side 202 of the LED chip 20 is a second cut surface 1012. Since the depth of the first V-shaped groove 31 is different from the depth of the second V-shaped groove 32, the height h1 of the first tangential surface 1011 and the height h2 of the second tangential surface 1012 are also different in the vertical direction.

Each LED chip 20 further includes a fabrication electrode structure 5, which electrode structure 5 may be fabricated by vapor deposition, prior to separation into individual LEDs. In this embodiment, the electrode structure 5 includes a first electrode 51 and a second electrode 52, wherein the first electrode 51 is formed on the lower step surface 251 and electrically connected to the first semiconductor layer 21, and the second electrode 52 is formed on the upper step surface 252 and electrically connected to the second semiconductor layer 23, as shown in fig. 9 to 10.

Example 2

The present embodiment provides a light emitting diode, as shown in fig. 11 to 13, which can be manufactured by the method in the above embodiment 1, but is not limited to the method in embodiment 1, and the light emitting diode specifically includes: a substrate 10 and an LED chip 20 on the substrate 10, wherein the side of the substrate 10 has a cut surface 101 and the LED chip 20 has a long side 201 and a short side 202.

Specifically, the four sides of the substrate 10 have a cut surface 101, and the LED chip 20 has two long sides 201 and two short sides 202, wherein the cut surface of the substrate 10 corresponding to the lower side of the long side 201 of the LED chip 20 is a first cut surface 1011, and the cut surface of the substrate 10 corresponding to the lower side of the short side 202 of the LED chip 20 is a second cut surface 1012. In other embodiments, the surface area, height and slope of the two first sections 1011 may be different, as may the surface area, height and slope of the two second sections 1012.

The cut surface 101 is located at the side top of the substrate 10, which is a slope with the top inclined outward, and is formed by the inner wall of the V-shaped groove 3 after separation. Since the first V-shaped groove 31 and the second V-shaped groove 32 are different in depth, the height h1 of the first tangential surface 1011 is different from the height h2 of the second tangential surface 1012 in the vertical direction.

Preferably, in the vertical direction, the height h1 of the first tangent plane 1011 is greater than the height h2 of the second tangent plane 1012. Further preferably, the height h1 of the first tangential plane 1011 is greater than 7 μm, and the height h2 of the second tangential plane 1012 is 5 to 7 μm. The side surface area of the light-emitting diode is increased to improve the side reflection and reduce the refracted light, so that the light can be emitted from the front surface of the light-emitting diode more, and the light-emitting efficiency of the light-emitting diode is improved.

More preferably, the surface of the first cut surface 1011 and/or the second cut surface 1012 is roughened, which further improves the light reflecting ability of the side surface. Preferably, the surface of the first section 1011 and/or the second section 1012 has a plurality of lateral stripes 30, the lateral stripes 30 being distributed over all areas of the section 101, as shown in FIG. 14. The transverse stripe 30 can be manufactured without adopting other processes independently, and can be realized by controlling the laser scribing process, so that the working procedure is shortened, the cost is saved, the other processes are not excluded, and the application is not limited in particular.

More specifically, the first tangent plane 1011 forms an angle θ1 with the horizontal direction, and the second tangent plane 1012 forms an angle θ2 with the horizontal direction, wherein 0 ° < θ1 < 90 °,0 ° < θ2 < 90 °, for example, the angles θ1, θ2 may be 10 °, 20 °, 30 °, 40 °, 50 °,60 °, 70 °, 80 °, but are not limited to the above-mentioned angles. Further preferably, 60 DEG < theta 1 < 90 DEG, 60 DEG < theta 2 < 90 deg. In an embodiment of the present application, the angles of the included angle θ1 and the included angle θ2 are the same or different. Under the same angle, the larger the height of the tangent plane 101 in the vertical direction is, the larger the area of the tangent plane of the substrate of the light emitting diode is, the more the light reflecting effect of the tangent plane 101 can be improved, and the higher the light emitting efficiency of the light emitting diode is. And under the same height, the smaller the angle between the tangent plane 101 and the horizontal plane is, the more inclined the side wall of the substrate 10 is, the larger the area of the tangent plane of the substrate of the light emitting diode is, the more the light reflecting effect of the tangent plane 101 can be improved, and the higher the light emitting efficiency of the light emitting diode is. In other embodiments, the angles formed by the two first tangential surfaces 1011 and the horizontal direction may be different, or the angles formed by the two second tangential surfaces 1012 and the horizontal direction may be different.

The LED chip 20 is obtained by separating the initial epitaxial layer 2 and the original substrate 1. The LED chip 20 comprises at least an epitaxial layer 2 and an electrode structure 5 on the epitaxial layer 2. Wherein the epitaxial layer 2 includes at least a first semiconductor layer 21, an active layer 22 and a second semiconductor layer 23 sequentially formed on the upper surface of the substrate 10. In other embodiments, the epitaxial layer 2 may further include other layer materials, such as a buffer layer, a current blocking layer, a transparent conductive layer, or an ohmic contact layer, which may be disposed according to practical situations, and the above layer structures are well known to those skilled in the art, and the disclosure is not repeated here.

The electrode structure 5 includes a first electrode 51 and a second electrode 52, wherein the first electrode 51 is located on the lower step surface 251 and electrically connected to the first semiconductor layer 21, and the second electrode 52 is located on the upper step surface 252 and electrically connected to the second semiconductor layer 23.

Specifically, the first electrode 51 and the second electrode 52 are metal electrodes, and the materials of the second electrode 52 and the first electrode 51 are selected from one or a combination of several of nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), gold (Au), titanium (Ti), silver (Ag), aluminum (Al), germanium (Ge), tungsten (W), tungsten Silicide (SiW), tantalum (Ta), gold zinc alloy (AuZn), gold beryllium alloy (AuBe), gold germanium alloy (AuGe), and gold germanium nickel alloy (augeneni). Typically, the first electrode 51 and the second electrode 52 are deposited from a plurality of layers of metallic materials.

Through comparison experiments of the light-emitting diode in the prior art, the light-emitting efficiency of the light-emitting diode is greatly improved, and the light-emitting efficiency is particularly as follows:

table 1 spot test data for leds

Table 2 led package lamp data

Referring to tables 1 and 2, under the same test conditions, the luminance of the present application is improved by 1.87% compared with the luminance of the prior art under spot measurement, and the luminance of the present application is reduced by 0.85% under the lamp, and the luminous efficiency of the present application is improved by 1.02% compared with the luminous efficiency of the light emitting diode of the prior art.

Example 3

The embodiment also provides a light-emitting device, which comprises the light-emitting diode provided by the embodiment. The light emitting device may be, for example, a white light lighting device, a backlight display device, a car light, a flash, a projection light, a stage light, or the like. The light-emitting device has the characteristics of higher light-emitting efficiency and light-emitting brightness.

the application is applicable to light emitting diodes having long and short sides. Structurally, by forming the cut surface 101 on the side surface of the substrate 10, the side surface area of the light emitting diode is increased, so that the side reflection capability is improved, and more light can be emitted from the front surface. The substrate cut surface corresponding to the lower side 201 of the LED chip 20 is a first cut surface 1011, and the substrate cut surface corresponding to the lower side 202 of the LED chip 20 is a second cut surface 1012. The height h1 of the first tangent plane 1011 is different from the height h2 of the second tangent plane 1012 in the vertical direction, so that the coverage range of front emergent light can be effectively improved, and the light-emitting efficiency is improved. In terms of technology, in the process of separating the LED chips into independent LEDs, the LED chips 20 are subjected to step treatment aiming at the long and short sides of the LED chips, rather than synchronous treatment of the long and short sides of the LED chips in the prior art, so that slag can be removed better, the defect of subsequent overetching can be avoided effectively, and the luminous brightness of the LED chips is ensured.

The foregoing embodiments are merely illustrative of the principles of the present application and its effectiveness, and are not intended to limit the application. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and principles of the present application. The scope of the application is therefore intended to be set forth in the following claims.

Claims

1. A light emitting diode, comprising:

a substrate, wherein the side surface of the substrate is provided with a tangent plane;

an LED chip on the substrate, the LED chip having a long side and a short side, wherein,

the substrate tangent plane corresponding to the lower part of the long side of the LED chip is a first tangent plane, and the substrate tangent plane corresponding to the lower part of the short side of the LED chip is a second tangent plane; in the vertical direction, the height h1 of the first tangential plane is different from the height h2 of the second tangential plane.

2. The led of claim 1, wherein the cut surface is located at a side top of the substrate.

3. A light emitting diode according to claim 1 or 2, wherein the surface of the first and/or second cut surface is roughened.

4. A light emitting diode according to claim 3 wherein the surface of the first and/or second facets has a plurality of transverse stripes.

5. The led of claim 1, wherein the height h1 of the first facet is greater than the height h2 of the second facet.

6. The led of claim 1 or 5, wherein the height h1 of the first facet is greater than 7 μm and the height h2 of the second facet is 5-7 μm.

7. The led of claim 1, wherein the first facet is angled at θ1 from horizontal and the second facet is angled at θ2 from horizontal, wherein 60 ° < θ1 < 90 °,60 ° < θ2 < 90 °.

8. The led of claim 7, wherein the angles of included angle θ1 and included angle θ2 are the same or different.

9. A light emitting device, characterized in that: a light emitting diode according to any one of claims 1 to 8.

10. The manufacturing method of the light-emitting diode is characterized by comprising the following steps:

11. The method of claim 10, wherein a protective layer is deposited on the surface of the LED chip prior to each laser scribe.

12. The method of claim 10, wherein after each laser dicing, an etching process is used to remove slag generated during the laser dicing, and then the protective layer on the surface of the LED chip is removed.

13. The method of claim 10, wherein the first V-shaped groove has a depth greater than a depth of the second V-shaped groove.

14. The method for manufacturing a light emitting diode according to claim 10 or 13, wherein the depth of the first V-shaped groove is greater than 7 μm, and the depth of the second V-shaped groove is 5-7 μm.

15. The method of claim 12, wherein the long side of the LED chip is etched for a shorter time than the short side of the LED chip.

16. The method of claim 10, wherein the plurality of lateral stripes are formed on the inner wall of the first V-shaped groove and/or the second V-shaped groove by a laser scribing process.

17. The method of claim 12, wherein the etching process is wet etching.