Inverted light emitting diode, LED core particle and light emitting device

Abstract

The utility model provides a flip light-emitting diode, an LED core particle and a light-emitting device. The flip light-emitting diode comprises a substrate; the semiconductor lamination layer is positioned on the front surface of the substrate and is divided into a plurality of core particles, and scribing channels are formed between the adjacent core particles; the reflecting layer covers the upper part and the side wall of the semiconductor lamination layer and the upper part of the scribing channel; wherein the reflecting layer positioned above the scribing channel is provided with at least one groove, and the groove extends from the reflecting layer to the direction of the substrate. The reflecting layer covering the scribing channel area is pre-etched to form the groove, and the splinter path is located in the groove when the LED core particle is segmented, so that the structural damage of splinters to the reflecting layer at the edge of the core particle is reduced, the undesirable phenomenon of structural stripping or crack extension at the edge of the reflecting layer due to the splinters is avoided, and the service life of the LED chip particle is prolonged. The sealing performance of the reflecting layer to the LED core particles is effectively improved, water vapor invasion is blocked, and the product quality reliability and the service life are ensured.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a flip-chip light emitting diode, an LED core particle and a light emitting device. Background Art

[0002] Light Emitting Diode (LED) is a semiconductor device whose basic structure includes a PN junction between a P-type semiconductor and an N-type semiconductor. When a forward voltage is applied to the LED, electrons and holes recombine at the junction of the PN junction, releasing energy, which is emitted in the form of photons to form light radiation.

[0003] Flip-chip LEDs have the characteristics of high luminous efficiency, energy saving, environmental protection and long life, and are widely used in various fields. The mainstream cutting method of flip-chip LEDs is invisible cutting, that is, a certain wavelength of laser is used to act on a certain depth inside the flip-chip LED substrate to form a series of intermittent tiny "explosion points", and then combined with the splitting process to achieve the purpose of cutting.

[0004] Flip-chip products usually use a front DBR (Distributed Bragg Reflector) structure. First, the DBR layer covering the PN electrode needs to be dry-etched to form an electrode hole to expose the electrode for conduction. The structure of the electrode hole is crucial to whether the subsequent electrode can form a good conductivity. Secondly, since the scribe line is also covered with a DBR layer, when the core particles on the wafer are separated, the DBR layer covering the GaN outside will be damaged to a certain extent, affecting the sealing of the core particles. The GaN layer reacts with the water vapor in the environment, which in turn affects the electrical performance of the core particles and reduces the service life of the chip and product reliability. For small-sized flip-chip light-emitting diodes, the above abnormal phenomena are particularly obvious.

[0005] Based on the technical problems involved in the DBR structure of the above-mentioned flip-chip light-emitting diode, the performance of the traditional flip-chip light-emitting diode can no longer meet the actual application requirements. Therefore, it is necessary to provide an improved technical solution for the above-mentioned technical problems to ensure the luminous brightness of the LED chip and / or the electrical performance of the LED chip. Utility Model Content

[0006] In view of the defects and shortcomings of light-emitting diodes in the prior art as described above, the purpose of the present application is to provide a flip-chip light-emitting diode, an LED core and a light-emitting device, by providing grooves in the reflective layer in the scribe line area between the LED cores, thereby reducing the structural damage to the edge of the reflective layer caused by the core segmentation, thereby ensuring the core performance and improving the luminous brightness of the LED chip and the product reliability.

[0007] In some embodiments, the present application provides a flip-chip light emitting diode, comprising at least:

[0008] A substrate, wherein the substrate has a substrate front side and a substrate back side that are arranged opposite to each other;

[0009] A semiconductor stack is located on the front side of the substrate and includes a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence; the semiconductor stack is divided into a plurality of core particles, and scribe lines are formed between adjacent core particles;

[0010] A reflective layer covering the top and sidewalls of the semiconductor stack and the top of the scribe line;

[0011] The reflective layer located above the scribe line has at least one groove, and the groove extends from the reflective layer toward the substrate.

[0012] In some embodiments, the present application further provides an LED core particle, wherein the LED core particle at least comprises:

[0013] A substrate, wherein the substrate has a substrate front side and a substrate back side that are arranged opposite to each other;

[0014] A semiconductor stack, located on the front side of the substrate, and comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence;

[0015] A reflective layer covers the top and sidewalls of the semiconductor stack and the front surface of the substrate in the scribe line area; wherein,

[0016] The reflective layer located on the front side of the substrate has at least one notch, the notch surrounds the edge of the LED core and extends from the reflective layer toward the substrate, the notch has a side wall, the side wall forms an angle α with the front side of the substrate, 70°≤α<90°;

[0017] The reflective layer located above the first semiconductor layer and the second semiconductor layer has a through hole for conducting the electrode structure. The through hole has an inclined inner wall. The inner wall forms an angle β with the corresponding upper surface of the first semiconductor layer or the second semiconductor layer, β≤50°.

[0018] In some embodiments, the present application also provides a light-emitting device, including a circuit substrate and a light-emitting element arranged above the circuit substrate, the light-emitting element includes at least one LED core particle described in the above technical solution, and the light-emitting element is electrically connected to the circuit substrate through an electrode structure.

[0019] Compared with the prior art, the technical solution provided by this application has the following beneficial effects:

[0020] In the technical solution of the present application, a groove is formed by pre-etching the reflective layer covering the scribe line area between the LED core particles, so that the crack path when the LED core particles are divided is located inside the groove. This design reduces the structural damage of the reflective layer at the edge of the LED core particles by the cracks, avoids the undesirable phenomenon of structural peeling or crack extension at the edge of the reflective layer due to the cracks in the prior art, effectively improves the sealing of the reflective layer to the LED core particles, blocks the intrusion of water vapor, and ensures the quality reliability of the LED core particles and the service life of the chip. In addition, the light-emitting device provided by the present application includes the LED core particles provided by the above technical solution, so the light-emitting device also has better quality reliability and longer service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of a flip-chip light-emitting diode in the prior art;

[0022] Figure 2 A schematic diagram of the structure of the flip-chip light-emitting diode provided in this application;

[0023] Figure 3 for Figure 2 A local enlarged schematic diagram of the middle A;

[0024] Figure 4 for Figure 2 A partial enlarged schematic diagram of point B in the middle;

[0025] Figure 5 A schematic diagram of the structure of an LED core particle provided in Example 4 of the present application;

[0026] Figure 6 This is a schematic diagram of the structure of the light-emitting device provided in Example 5 of the present application.

[0027] Description of reference numerals:

[0028] 100, substrate;

[0029] 200, semiconductor stack; 210, first semiconductor layer; 220, active layer; 230, second semiconductor layer;

[0030] 310, first contact electrode; 320, second contact electrode;

[0031] 400, first reflective layer; 410, first through hole; 420, second through hole; 430, groove;

[0032] 510, a first electrode; 520, a second electrode;

[0033] 600, second reflection layer;

[0034] 10. Light-emitting device; 101. Circuit substrate; 102. Light-emitting element. DETAILED DESCRIPTION

[0035] like Figure 1 As shown, a flip-chip LED generally adopts a front DBR structure, which covers the top and sidewalls of the semiconductor stack and the top of the scribe line to form a good light reflection effect and ensure the sealing of the flip-chip LED. In the LED chip manufacturing process, first, the DBR layer covering the PN electrode needs to be dry-etched to form an electrode hole to expose the electrode for conduction. The structure of the electrode hole is crucial to whether the subsequent electrode can form a good conductivity; secondly, because the scribe line position is also covered with the DBR layer, in the chip manufacturing later cracking process, usually the hidden cutting method is used to focus the high-frequency laser beam emitted by the laser on the inside of the wafer, and the cracks are connected into a straight line through dense dot explosions, and then the wafer is split by a splitter to divide the wafer into individual chips. When the core particles on the wafer are separated, the DBR layer covering the outside of the GaN (semiconductor stack) will be damaged to a certain extent, resulting in undesirable phenomena such as DBR interlayer peeling or structural cracks. The structural damage or cracks extend to the MESA table, which affects the sealing of the core particles. The GaN layer reacts with the water vapor in the environment, which in turn affects the electrical performance of the core particles and reduces the service life of the chip and product reliability. For small-sized flip-chip light-emitting diodes, the above abnormal phenomena are particularly obvious.

[0036] In view of the above defects, the present application provides a flip-chip light emitting diode, which at least comprises:

[0037] A substrate, wherein the substrate has a substrate front side and a substrate back side that are arranged opposite to each other;

[0038] A semiconductor stack is located on the front side of the substrate and includes a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence; the semiconductor stack is divided into a plurality of core particles, and scribe lines are formed between adjacent core particles;

[0039] A reflective layer covering the top and sidewalls of the semiconductor stack and the top of the scribe line;

[0040] The reflective layer located above the scribe line has at least one groove, and the groove extends from the reflective layer toward the substrate.

[0041] By adopting the above technical scheme, the reflective layer covering the scribe line area between the LED core particles is pre-etched to form a groove, so that the crack path when the LED core particle is divided is located inside the groove. This design still has effective protection and good sealing for the semiconductor stack. The connection between the edge of the semiconductor stack and the substrate is covered with the reflective layer structure separated by the groove, which reduces the structural damage of the reflective layer at the edge of the LED core particle by the cracks, avoids the undesirable phenomenon of structural peeling or crack extension at the edge of the reflective layer due to the cracks in the prior art, effectively improves the sealing of the reflective layer to the light-emitting diode, and can effectively block the intrusion of water vapor before and after cutting, thereby extending the service life of the light-emitting diode.

[0042] In one embodiment, the thickness of the reflective layer is 1 μm to 6 μm, so as to form an effective seal for the semiconductor stack and a high reflectivity for light, thereby reducing undesirable phenomena such as uneven light output or reduced light output brightness caused by light overflowing along the front of the light emitting diode.

[0043] In one embodiment, the groove has an extension depth in the thickness direction of the reflective layer, and the extension depth is greater than or equal to 1 μm. By limiting the groove to a minimum depth, or limiting the thickness of the bottom surface of the groove to a maximum thickness, the reflective layer in the scribe line area is not prone to major structural damage or large-area peeling during chipping.

[0044] In one embodiment, the groove passes through the reflective layer and exposes the front side of the substrate. The reflective layer covered by the scribe line area is completely broken to ensure that the edge of the reflective layer will not be structurally damaged during the splitting process.

[0045] In one embodiment, the reflective layer located on both sides of the groove and covering the scribe line has a margin L, and the margin L is greater than or equal to 3.5 μm. The margin L is the distance that the reflective layer extends from the edge of the semiconductor stack to cover the substrate. This part of the reflective layer forms a barrier of sufficient distance for water vapor intrusion, ensuring the sealing of the core particle and the reflectivity and brightness of light.

[0046] In one embodiment, the margins of the reflective layers on both sides of the groove are equal or different. A better groove etching position is selected according to the different process table slopes and thicknesses of the core particles on both sides.

[0047] In one embodiment, the bottom of the groove has a width D, and the width D is 5 μm to 30 μm. By leaving a certain distance at the bottom of the groove, damage to the reflective layer during chip separation can be avoided to affect the luminous brightness and the sealing of the core particles.

[0048] In one embodiment, the width D is 10 μm to 20 μm. The groove size is further optimized.

[0049] In one embodiment, the groove has oppositely disposed side walls, the side walls and the front surface of the substrate form an angle α, wherein 70°≤α<90°. The area of ​​the region where the reflective layer is etched away in the scribe line is adjusted to obtain a better balance between light reflectivity and edge structure strength.

[0050] In one embodiment, the reflective layer further has a through hole penetrating the reflective layer for connecting the electrode structure; the through hole comprises a first through hole extending to the first semiconductor layer and a second through hole extending to the second semiconductor layer.

[0051] In one embodiment, the through hole has an inclined inner wall, and the inner wall forms an angle β with the upper surface of the corresponding first semiconductor layer or the second semiconductor layer, wherein β≤50°. The through hole has a relatively large opening, forming an inclined inner wall, so that it is not easy to accumulate excessive internal stress during the subsequent evaporation of the electrode structure, thereby ensuring good contact of the electrode structure and stable electrical performance.

[0052] In one embodiment, the inner wall inclination angles of the first through hole and the second through hole are the same or different. The inner wall inclination angles of the first through hole and the second through hole are preset with different through hole structures according to the thickness of the reflective layer covering the first semiconductor layer and the second semiconductor layer, so as to ensure that both electrodes can achieve better structure and good electrical performance.

[0053] In one embodiment, the flip-chip light emitting diode further comprises:

[0054] The contact electrode is located between the reflective layer and the semiconductor stack and corresponds to the first through hole and the second through hole respectively. The electrode structure passes through the first through hole and the second through hole respectively and is electrically connected to the contact electrode. The contact electrode serves as a connection point between the semiconductor stack and the external circuit, provides a path for current input and output, and also has functions such as controlling voltage, thereby improving the working performance of the light-emitting diode.

[0055] In one embodiment, the reflective layer further comprises a second reflective layer covering the back side of the substrate. Reflective layers are disposed above and below the semiconductor stack to form a flip-chip light emitting diode with side light emission.

[0056] In one embodiment, the reflective layer is a distributed Bragg reflector. A higher reflectivity can be achieved through the specific design of the DBR structure, and selective reflection of light of a specific wavelength can be achieved by controlling the thickness of different material layers, making the use range of semiconductor devices more flexible.

[0057] The present application also provides an LED core particle, wherein the LED core particle at least comprises:

[0058] A substrate, wherein the substrate has a substrate front side and a substrate back side that are arranged opposite to each other;

[0059] A semiconductor stack, located on the front side of the substrate, and comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence;

[0060] A reflective layer covers the top and sidewalls of the semiconductor stack and the front surface of the substrate in the scribe line area; wherein,

[0061] The reflective layer located on the front side of the substrate has at least one notch, the notch surrounds the edge of the LED core and extends from the reflective layer toward the substrate, the notch has a side wall, the side wall forms an angle α with the front side of the substrate, 70°≤α<90°;

[0062] The reflective layer located above the first semiconductor layer and the second semiconductor layer has a through hole for conducting the electrode structure. The through hole has an inclined inner wall. The inner wall forms an angle β with the corresponding upper surface of the first semiconductor layer or the second semiconductor layer, β≤50°.

[0063] By adopting the above technical scheme, the edge notch structure is obtained after the grooves in the dicing area between the core particles are split, and the grooves can effectively isolate adjacent core particles. The formed notch can protect the semiconductor stacking structure and the reflective layer structure at the edge of the single core particle from being cut and damaged, and the side wall of the notch is formed with a certain slope, so that the reflective layer can better protect the edge of the core particle. In addition, the electrode hole is also opened as a through hole with an inner wall with a certain slope, so that the electrode structure forms a good contact, so as to obtain an LED core particle with stable structural quality and optical performance.

[0064] In one embodiment, the bottom of the notch has a width d, and the width d is 2.5 μm to 15 μm.

[0065] The present application also provides a light-emitting device, comprising a circuit substrate and a light-emitting element arranged above the circuit substrate, wherein the light-emitting element comprises at least one LED core particle described in the above technical solution, and the light-emitting element is electrically connected to the circuit substrate through an electrode structure. The light-emitting device has better light-emitting effect and quality reliability as the flip-chip light-emitting diode.

[0066] The following describes the implementation methods of the present application through Examples 1 to 5, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application.

[0067] Embodiment 1:

[0068] See also Figures 2-3 The present embodiment provides a flip-chip light-emitting diode, which at least includes a substrate 100, a semiconductor stack 200 located on the front side of the substrate, and a first reflective layer 400 covering the top and sidewalls of the semiconductor stack 200 and the top of the scribe line, wherein the first reflective layer 400 located above the scribe line has at least one groove 430, and the groove 430 extends from the first reflective layer 400 toward the substrate.

[0069] Specifically, the substrate 100 has a substrate front side and a substrate back side that are arranged opposite to each other; as an example, the substrate 100 can be a sapphire flat substrate, a sapphire patterned substrate, a silicon carbide substrate, a gallium nitride substrate, a gallium arsenide substrate, or a silicon substrate. In this embodiment, the substrate 100 is a sapphire patterned substrate, and the semiconductor stack 200 is formed on the upper surface of the sapphire patterned substrate.

[0070] Specifically, the semiconductor stack 200 includes a first semiconductor layer 210, an active layer 220 and a second semiconductor layer 230 stacked in sequence, and the semiconductor stack 200 is divided into a plurality of core particles, and dicing lanes are formed between adjacent core particles; as an example, the first semiconductor layer 210 is an N-type semiconductor layer, the second semiconductor layer 230 is a P-type semiconductor layer, and the active layer 220 is a multi-layer quantum well layer.

[0071] Specifically, the first reflective layer 400 covers the top and sidewalls of the semiconductor stack 200 and the top of the scribe line. The first reflective layer 400 includes but is not limited to a distributed Bragg reflector. The material of the first reflective layer 400 is at least two of different materials such as SiO2, TiO2, ZnO2, ZrO2, Cu2O3, etc. The first reflective layer 400 specifically includes a distributed Bragg reflector that is made by using techniques such as electron beam evaporation or ion beam sputtering to alternately and repeatedly stack two materials into multiple layers.

[0072] By adopting the above technical solution, the first reflective layer 400 covering the dicing area between the LED core particles is pre-etched to form a groove 430, so that the crack path when the LED core particles are divided is located inside the groove 430. This design still has effective protection and good sealing for the semiconductor stack 200. The connection between the edge of the semiconductor stack 200 and the substrate 100 is covered with the reflective layer structure separated by the groove 430, which reduces the structural damage of the reflective layer at the edge of the LED core particle caused by the cracks, avoids the undesirable phenomenon of structural peeling or crack extension at the edge of the reflective layer due to the cracks in the prior art, effectively improves the sealing of the reflective layer to the light-emitting diode, and can effectively block the intrusion of water vapor before and after cutting, thereby extending the service life of the light-emitting diode.

[0073] In one embodiment, see Figure 2 , a second reflection layer 600 is also provided on the back of the substrate, and reflection layers are provided above and below the semiconductor stack 200. The light emitted by the active layer 220 is respectively reflected by the upper and lower reflection layer structures and finally escapes from the side, forming a flip-chip light-emitting diode with side light emission. Similar to the first reflection layer 400, the second reflection layer 600 can be a distributed Bragg reflector, which can achieve a higher reflectivity through the specific design of the DBR structure, and can achieve selective reflection of light of a specific wavelength by controlling the thickness of different material layers, making the use range of semiconductor devices more flexible.

[0074] In one embodiment, see Figure 2 The thickness of the first reflective layer 400 is 1 μm to 6 μm, so as to form an effective seal for the semiconductor stack 200 and a high reflectivity for light, and reduce undesirable phenomena such as uneven light output or reduced light output brightness caused by light overflowing along the front of the light-emitting diode. In addition, the outermost side of the first reflective layer 400 can be a SiO2 layer material layer to play an insulating role, or a dense insulating layer can be formed again on the first reflective layer 400 to improve the protection of the core particles.

[0075] In one embodiment, see Figure 3 The groove 430 located at the scribe line has an extension depth H in the thickness direction of the first reflective layer 400, and the extension depth H is greater than or equal to 1 μm, until it penetrates the first reflective layer 400 and exposes the front side of the substrate. By limiting the groove 430 to a minimum depth, or limiting the thickness of the bottom surface of the groove to a maximum thickness, the first reflective layer 400 in the scribe line area is not prone to major structural damage or large-area peeling during chipping; when the first reflective layer 400 covered by the scribe line area is completely interrupted, the LED chip only needs to split the substrate 100 in the scribe line area, and the chipping position is at a certain distance from the side wall of the groove 430, ensuring that no structural damage is caused to the edge of the reflective layer during chipping.

[0076] In one embodiment, see Figure 3 , the first reflective layer 400 located on both sides of the groove 430 and covering the scribe line has a margin L, which is greater than or equal to 3.5μm. As an example, the margin L can be 3.5μm, 4μm, 5μm, 8μm or 10μm. It can be understood that the margin L is the distance that the first reflective layer 400 extends from the edge of the semiconductor stack 200 to cover the substrate 100. The edge structure of this part of the reflective layer forms a protective barrier of sufficient distance for water vapor intrusion, ensuring the sealing of the core particles, the reflectivity of the edge light, and the light output brightness of the light-emitting diode.

[0077] In one embodiment, the margins L of the reflective layer structures on both sides of the groove 430 are equal or unequal. It is understandable that in the top view direction of the light-emitting diode, the groove 430 is a continuous groove structure formed around each core particle, and the adjacent process tables inside the groove 430 are also different, and their physical properties such as thickness, formation angle, material type and density are also different. Therefore, the remaining length of the reflective layer on both sides of the groove 430 can also be designed differently. For example, the side with poor density or more prone to accumulating structural stress has a larger margin L, while the side with higher structural strength and less prone to cracks or crack transmission can have a smaller margin L, so as to increase the width of the groove 430 or leave a larger margin L for the edge of the reflective layer on the other side of the groove 430, so as to achieve the optimal structure of the groove 430. It is understandable that the margins L on both sides of the groove 430 from the adjacent core particles can also be the same, that is, the groove 430 is always located at the exact center of the scribe line, so that the etching process of the groove 430 is simpler and more controllable.

[0078] In one embodiment, see Figure 3 , the bottom of the groove 430 has a width D. By leaving a certain distance at the bottom of the groove 430, damage to the reflective layer is avoided when the chip is separated, affecting the luminous brightness and the sealing of the core particles. The width D is the deviation distance of the center of the allowable cracking path, and the width D is usually 5μm to 30μm. As an example, the width D can be 5μm, 10μm, 15μm, 20μm, 25μm or 30μm. When the width D is less than 5μm, the reflective layer at the edge of the groove still has the risk of structural damage or peeling when the chip is cracked; when the width is greater than 30μm, the effective luminous area of ​​the core particles will be sacrificed, resulting in an increase in production costs. Further, the width D is 10μm to 20μm. As an example, the width D can be 10μm, 12μm, 14μm, 16μm, 18μm or 20μm to further optimize the size of the groove 430.

[0079] In one embodiment, see Figure 3 , the groove 430 has side walls that are relatively arranged, and the side walls form an angle α with the front side of the substrate, wherein 70°≤α<90°. As an example, the angle α can be 70°, 80°, 85° or 89°. The groove 430 is formed with a larger opening to obtain a reflective layer with a more stable edge structure, while substantially not reducing the light reflectivity. By adjusting the area of ​​the region where the first reflective layer 400 is etched away in the dicing lane, a better balance between the light reflectivity and the edge structure strength is obtained. When the angle α is less than 70°, the strength of the edge coverage structure of the reflective layer cannot be guaranteed, and the edge light cannot be well reflected, resulting in reduced light brightness.

[0080] It can be understood that the number of grooves 430 in the scribe line area is at least one, and may also be two, three or more, to ensure that there is sufficient isolation area during chipping so that the crack cannot extend to the edge of the reflective layer of the adjacent core particles, and the first reflective layer 400 forms effective sealing and good light reflection capability for the core particles.

[0081] Embodiment 2:

[0082] See also Figure 2 and Figure 4 The present embodiment provides a flip-chip light-emitting diode, which at least includes a substrate 100, a semiconductor stack 200 located on the front side of the substrate, and a first reflective layer 400 covering the top and sidewalls of the semiconductor stack 200 and the top of the scribe line, wherein the first reflective layer 400 located above the scribe line has at least one groove 430, and the groove 430 extends from the first reflective layer 400 toward the substrate.

[0083] Specifically, the substrate 100 has a substrate front side and a substrate back side that are arranged opposite to each other; as an example, the substrate 100 can be a sapphire flat substrate, a sapphire patterned substrate, a silicon carbide substrate, a gallium nitride substrate, a gallium arsenide substrate, or a silicon substrate. In this embodiment, the substrate 100 is a sapphire patterned substrate, and the semiconductor stack 200 is formed on the upper surface of the sapphire patterned substrate.

[0084] Specifically, the semiconductor stack 200 includes a first semiconductor layer 210, an active layer 220 and a second semiconductor layer 230 stacked in sequence, and the semiconductor stack 200 is divided into a plurality of core particles, and dicing lanes are formed between adjacent core particles; as an example, the first semiconductor layer 210 is an N-type semiconductor layer, the second semiconductor layer 230 is a P-type semiconductor layer, and the active layer 220 is a multi-layer quantum well layer.

[0085] Specifically, the first reflective layer 400 covers the top and sidewalls of the semiconductor stack 200 and the top of the scribe line. The first reflective layer 400 includes but is not limited to a distributed Bragg reflector. The material of the first reflective layer 400 is at least two of different materials such as SiO2, TiO2, ZnO2, ZrO2, Cu2O3, etc. The first reflective layer 400 specifically includes a distributed Bragg reflector that is made by using techniques such as electron beam evaporation or ion beam sputtering to alternately and repeatedly stack two materials into multiple layers.

[0086] The similarities between this embodiment and the first embodiment are not repeated here. The difference from the first embodiment is that the first reflective layer 400 in this embodiment further has a through hole penetrating the first reflective layer 400 for connecting the electrode structure; the through hole includes a first through hole 410 extending to the first semiconductor layer 210 and a second through hole 420 extending to the second semiconductor layer 230.

[0087] In one embodiment, see Figure 4 The first through hole 410 has an inclined inner wall, which forms an angle β1 with the corresponding upper surface of the first semiconductor layer 210, wherein β1≤50°. The first through hole 410 has a relatively large opening to form an inclined inner wall, so that excessive internal stress is not easily accumulated during the subsequent evaporation of the first electrode 510, thereby ensuring good contact of the first electrode 510 and stable electrical performance.

[0088] In one embodiment, the structure of the second through hole 420 can be similar to that of the first through hole 410, and the second through hole 420 also has an inclined inner wall, which forms an angle β2 with the upper surface of the corresponding second semiconductor layer 230, wherein when β2≤50°, the second electrode 520 evaporated in the second through hole 420 also has good contact and stable electrical properties.

[0089] In one embodiment, the inner wall inclination angles of the first through hole 410 and the second through hole 420 are the same or different. The first through hole inner wall inclination angle β1 and the second through hole inner wall inclination angle β2 can be preset to have different through hole structures according to the thickness of the first reflective layer 400 covered on the first semiconductor layer 210 and the second semiconductor layer 230 to ensure that both electrodes can achieve a better structure and good electrical performance. For example, for a second through hole 420 with a smaller depth, the second electrode 520 is not prone to forming a defective structure, and the angle β2 can be smaller than β1.

[0090] In one embodiment, see Figure 2 The flip-chip light-emitting diode further includes a contact electrode, which is located between the first reflective layer 400 and the semiconductor stack 200. Specifically, the contact electrode includes a first contact electrode 310 and a second contact electrode 320. The first contact electrode 310 is located between the first semiconductor layer 210 and the first reflective layer 400, and corresponds to the first through hole 410. The first electrode 510 penetrates the first through hole 410 and is electrically connected to the first contact electrode 310. The second contact electrode 320 is located between the second semiconductor layer 230 and the first reflective layer 400, and corresponds to the second through hole 420. The second electrode 520 penetrates the second through hole 420 and is electrically connected to the second contact electrode 320. The contact electrode serves as a connection point between the semiconductor stack 200 and the external circuit, provides an effective path for current input and output, and also has functions such as controlling voltage, thereby improving the working performance of the light-emitting diode.

[0091] Embodiment three:

[0092] See also Figure 2 , this embodiment provides a light emitting diode, comprising at least:

[0093] A substrate 100, wherein the substrate 100 has a substrate front surface and a substrate back surface which are arranged opposite to each other;

[0094] The semiconductor stack 200 is located on the front side of the substrate and includes a first semiconductor layer 210, an active layer 220 and a second semiconductor layer 230 stacked in sequence; the semiconductor stack 200 is divided into a plurality of core particles, and scribe lines are formed between adjacent core particles;

[0095] The first reflective layer 400 covers the top and sidewalls of the semiconductor stack 200 and the top of the scribe line; wherein,

[0096] The first reflective layer 400 located above the scribe line has at least one groove 430, which extends from the first reflective layer 400 toward the substrate and penetrates the first reflective layer 400, and the groove 430 also has oppositely arranged side walls, which form an angle α with the front surface of the substrate, 70°≤α<90°;

[0097] The first reflective layer 400 located above the first semiconductor layer 210 and the second semiconductor layer 230 also has a through hole for connecting the electrode structure. The through hole has an inclined inner wall, which forms an angle β with the upper surface of the corresponding first semiconductor layer 210 or second semiconductor layer 230, β≤50°.

[0098] Embodiment 4:

[0099] See also Figure 5 This embodiment provides an LED core particle, which is obtained by cutting the flip-chip light-emitting diode described in the above technical solution. Specifically, the LED core particle at least includes:

[0100] A substrate 100, wherein the substrate 100 has a substrate front surface and a substrate back surface which are arranged opposite to each other;

[0101] The semiconductor stack is located on the front side of the substrate and includes a first semiconductor layer 210, an active layer 220 and a second semiconductor layer 230 stacked in sequence;

[0102] The first reflective layer 400 covers the top and sidewalls of the semiconductor stack 200 and the front surface of the substrate in the scribe line area; wherein,

[0103] The first reflective layer 400 located on the front surface of the substrate has at least one notch, which surrounds the edge of the LED core and extends from the first reflective layer toward the substrate. The notch has a side wall, and the side wall forms an angle α with the front surface of the substrate, 70°≤α<90°;

[0104] The first reflective layer 400 located above the first semiconductor layer 210 and the second semiconductor layer 230 has a through hole for connecting the electrode structure. The through hole has an inclined inner wall, which forms an angle β with the upper surface of the corresponding first semiconductor layer 210 or second semiconductor layer 230, β≤50°.

[0105] The reflective layer structure of the LED core obtained by cutting the flip-chip light-emitting diode provided in Examples 1 to 3 has a notch in the scribe area. It can be understood that the notch is a partial structure of the groove 430 obtained after the light-emitting diode is split from the scribe area. The notch effectively isolates adjacent cores and protects the semiconductor stacking structure and reflective layer structure at the edge of a single core from being damaged by cutting. The notch has an inclined sidewall, which enables the reflective layer to better protect the edge of the core while maintaining the light reflectivity. In addition, the electrode hole is also opened as a through hole with a certain slope inner wall, so that the electrode structure formed in the electrode hole has better structural strength and forms good contact, so as to obtain an LED core with stable structural quality and optical performance.

[0106] In one embodiment, see Figure 5 The bottom of the notch has a width d, and the width d is 2.5 μm to 15 μm. It can be understood that when the LED chip is located at the center line of the groove 430 of the scribe line, the notch is exactly half of the groove 430 .

[0107] Embodiment five:

[0108] See also Figure 6 This embodiment provides a light-emitting device 10, which includes a circuit substrate 101 and a light-emitting element 102 disposed above the circuit substrate 101. The light-emitting element 102 includes at least one LED core particle provided in the fourth embodiment, and the light-emitting element 102 is electrically connected to the circuit substrate 101 through an electrode structure. The light-emitting device 10 and the LED core particles also have better light emission effect and quality reliability.

[0109] In summary, the flip-chip light emitting diode, LED core particle and light emitting device provided by the present application effectively overcome various shortcomings in the prior art and have high industrial utilization value.

[0110] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A flip-chip light emitting diode, characterized in that: At least: A substrate, wherein the substrate has a substrate front side and a substrate back side that are arranged opposite to each other; A semiconductor stack is located on the front side of the substrate and includes a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence; the semiconductor stack is divided into a plurality of core particles, and scribe lines are formed between adjacent core particles; A reflective layer covering the top and sidewalls of the semiconductor stack and the top of the scribe line; The reflective layer located above the scribe line has at least one groove, and the groove extends from the reflective layer toward the substrate.

2. The flip-chip light emitting diode according to claim 1, characterized in that: The thickness of the reflective layer is 1 μm to 6 μm.

3. The flip-chip light emitting diode according to claim 1, characterized in that: The groove has an extension depth in the thickness direction of the reflective layer, and the extension depth is greater than or equal to 1 μm.

4. The flip-chip light emitting diode according to claim 1, characterized in that: The groove penetrates the reflective layer and exposes the front surface of the substrate.

5. The flip-chip light emitting diode according to claim 4, characterized in that: The reflective layer located at both sides of the groove and covering the scribe line has a margin L, and the margin L is greater than or equal to 3.5 μm.

6. The flip-chip light emitting diode according to claim 5, characterized in that: The margins of the reflective layer on both sides of the groove are equal or unequal.

7. The flip-chip light emitting diode according to claim 1, characterized in that: The bottom of the groove has a width D, and the width D is 5 μm to 30 μm.

8. The flip-chip light emitting diode according to claim 7, characterized in that: The width D is 10 μm to 20 μm.

9. The flip-chip light emitting diode according to claim 1, characterized in that: The groove has side walls that are arranged opposite to each other, and the side walls form an angle α with the front surface of the substrate, wherein 70°≤α<90°.

10. The flip-chip light emitting diode according to claim 1, characterized in that: The reflective layer also has a through hole penetrating the reflective layer for conducting the electrode structure; the through hole includes a first through hole extending to the first semiconductor layer and a second through hole extending to the second semiconductor layer.

11. The flip-chip light emitting diode according to claim 10, characterized in that: The through hole has an inclined inner wall, and the inner wall forms an angle β with the corresponding upper surface of the first semiconductor layer or the second semiconductor layer, wherein β≤50°.

12. The flip-chip light emitting diode according to claim 11, characterized in that: The inner wall inclination angles of the first through hole and the second through hole are the same or different.

13. The flip-chip light emitting diode according to claim 10, characterized in that: Also includes: The contact electrode is located between the reflective layer and the semiconductor stack and corresponds to the first through hole and the second through hole respectively. The electrode structure passes through the first through hole and the second through hole respectively and is electrically connected to the contact electrode.

14. The flip-chip light emitting diode according to any one of claims 1 to 13, characterized in that: The reflective layer also includes a second reflective layer covering the back side of the substrate.

15. The flip-chip light emitting diode according to claim 14, characterized in that: The reflection layer is a distributed Bragg reflector.

16. An LED chip, characterized in that: At least: A substrate, wherein the substrate has a substrate front side and a substrate back side that are arranged opposite to each other; A semiconductor stack, located on the front side of the substrate, and comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence; A reflective layer covers the top and sidewalls of the semiconductor stack and the front surface of the substrate in the scribe line area; wherein, The reflective layer located on the front surface of the substrate has at least one notch, the notch surrounds the edge of the LED core and extends from the reflective layer toward the substrate, the notch has a side wall, the side wall forms an angle α with the front surface of the substrate, 70°≤α<90°; The reflective layer located above the first semiconductor layer and the second semiconductor layer has a through hole for conducting the electrode structure. The through hole has an inclined inner wall. The inner wall forms an angle β with the corresponding upper surface of the first semiconductor layer or the second semiconductor layer, β≤50°.

17. The LED chip according to claim 16, characterized in that: The bottom of the notch has a width d, and the width d is 2.5 μm to 15 μm.

18. A light emitting device, characterized in that: It comprises a circuit substrate and a light-emitting element arranged above the circuit substrate, wherein the light-emitting element comprises at least one LED core particle according to claim 16, and the light-emitting element is electrically connected to the circuit substrate through an electrode structure.

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