Light-emitting element and light-emitting module including the same

Abstract

The present invention provides a light-emitting element and a light-emitting module including the same. The light-emitting module includes a mounting substrate, a plurality of light-emitting chips, and a plurality of conductive bonding parts, each of the light-emitting chips includes a first substrate, a first light-emitting part, a second substrate arranged to be separated from the first substrate, and a second light-emitting part, and a side surface of the first substrate includes a first modified surface, a side surface of the second substrate opposite to the side surface of the first substrate includes a second modified surface, the first modified surface includes a modified area extending along the thickness direction of the first substrate and a fracture area arranged between the modified areas, the second modified surface includes a modified area extending along the thickness direction of the second substrate and a fracture area arranged between the modified areas, and the width of each of the fracture areas of the first modified surface is the same as the width of each of the fracture areas of the second modified surface.

Description

Technical Field

[0001] The present invention relates to a light-emitting element and a light-emitting module including the same, and more particularly to a nitride-based light-emitting element and a light-emitting module including the same. Background Art

[0002] Light-emitting diodes are inorganic light sources that are used in various forms in various fields such as display devices, automotive lighting, general lighting, etc. Light-emitting diodes have the advantages of long life, low power consumption, and fast response speed, and are therefore rapidly replacing existing light sources.

[0003] After the light emitting diode is formed on a wafer such as sapphire, it is separated into light emitting chips through a dicing process. The following is a description of the process of separating the light emitting chips from the wafer.

[0004] Figure 1 is a cross-sectional view for explaining a method of cutting an ingot to manufacture a wafer. Figure 2 It is used to illustrate Figure 1 A cross-sectional view of a wafer.

[0005] Reference Figure 1 , the ingot is grown along the c-axis, and the ingot is cut for processing to form a wafer WF with a flat zone (FZ). Since the ingot is cut off the c-axis at a specific angle θ, when the wafer WF is diced for chip division, the m-plane exposed from the chip becomes inclined relative to the upper surface of the chip.

[0006] Reference Figure 2 In the wafer WF, the direction parallel to the extension direction of the flat zone FZ is the m-axis. The m-axis direction is referred to as the first direction DR1, and the direction perpendicular to the m-axis is referred to as the second direction DR2. For example, the second direction DR2 is the a-axis. The a-plane is the surface exposed after the wafer WF is cut along the first direction DR1, and the m-plane is the surface exposed after the wafer WF is cut along the second direction DR2.

[0007] As a general process, a plurality of light emitting diodes are formed on a wafer, but since this is a well-known technique, a detailed description thereof will be omitted.

[0008] Furthermore, the light emitting diodes formed on the wafer are separated using laser.

[0009] Figure 3a This is a schematic diagram for explaining a method of using laser to cut a wafer according to the prior art.

[0010] Reference Figure 3aThe laser light is focused to a depth of the wafer for irradiation to form a dotted type modified area. The wafer is broken based on the modified area to separate into light-emitting chips including light-emitting diodes. The broken area is extended in a direction perpendicular to the thickness direction of the wafer in the dotted type modified area in a manner of connecting the dotted type modified areas.

[0011] Due to its crystal structure characteristics, it is easier to cut along the second direction than to cut along the first direction. Therefore, even if the laser light is irradiated in the second direction with less laser light than that irradiated in the first direction, the wafer can be cut quickly and easily in the second direction. The surface cut along the second direction has an inclined m-plane.

[0012] The size of the light-emitting chip is small, and the light-emitting chip cut by the conventional process has an inclined side surface relative to the upper surface of the light-emitting chip, so the light-emitting chip rotates during the picking up and transferring to the destination position, and there is a case where the light-emitting chip falls on the transferred circuit substrate due to the inclined side surface. In addition, since each of the light-emitting chips rotates arbitrarily during the picking up and moving and is mounted on the circuit substrate, the inclined side surfaces are irregularly arranged, and the directional angles of light generated from the plurality of light-emitting chips mounted on the circuit substrate each show uneven brightness.

[0013] Figure 3b is used in Figure 3a A photograph of a substrate formed by the method described in the invention. Figure 3b In the figure, the left side is a photograph of the upper surface of the substrate, the middle is a photograph obtained by cutting the first side of the wafer along a first direction, and the right side is a photograph of the second side of the wafer along a second direction. A portion of the second side can be observed in the left part of the middle photo.

[0014] like Figure 3b As shown, it can be seen that the cut substrate is tilted in one direction. The angles between the upper surface of the substrate and the first side surface and the second side surface include 84.3 degrees and 95.4 degrees, which are slightly away from 90 degrees, so it can be seen that the cut substrate is tilted in one direction. In addition, it can be observed that the modified area and the fractured area are parallel to the thickness direction of the substrate. Summary of the invention

[0015] [Problems to be solved by the invention]

[0016] The problem to be solved by the present invention is to provide a light-emitting chip with uniform brightness and a light-emitting module including the same.

[0017] The problems to be solved by the present invention are not limited to the problems mentioned above, and those skilled in the art can clearly understand other problems not mentioned from the following description.

[0018] [Technical means to solve the problem]

[0019] In order to achieve the problem to be solved, the light-emitting module of an embodiment of the present invention includes: a mounting substrate; a plurality of light-emitting chips mounted on the mounting substrate; and a plurality of conductive adhesive portions arranged between the light-emitting chip and the mounting substrate, and each of the light-emitting chips includes: a first substrate; a first light-emitting portion arranged on one side of the first substrate; a second substrate arranged separated from the first substrate; and a second light-emitting portion arranged on one side of the second substrate, and one side surface of the first substrate includes a first modified surface, and one side surface of the second substrate opposite to the one side surface of the first substrate includes a second modified surface, the first modified surface includes a modified region extended along the thickness direction of the first substrate and a fracture region arranged between the modified regions, the second modified surface includes a modified region extended along the thickness direction of the second substrate and a fracture region arranged between the modified regions, and the width of each of the fracture regions of the first modified surface is the same as the width of each of the fracture regions of the second modified surface.

[0020] According to an embodiment, each of the modified regions may be modified by laser irradiation.

[0021] According to an embodiment, the width of each of the fractured regions may be greater than the width of each of the modified regions.

[0022] According to an embodiment, a width of each of the fracture regions of the first modified surface may be the same as a width of each of the fracture regions of the second modified surface.

[0023] According to an embodiment, another side surface adjacent to the one side surface of the first substrate includes a third modified surface, and the third modified surface may include modified regions extending along a thickness direction of the first substrate and fracture regions arranged between the modified regions.

[0024] According to an embodiment, a width of each of the fracture regions of the first modified surface may be smaller than a width of each of the fracture regions of the third modified surface.

[0025] According to an embodiment, when the first substrate includes sapphire, the one side surface of the first substrate includes an m-plane and a surface inclined relative to the m-plane, and the other side surface of the first substrate may include an a-plane and a surface inclined relative to the a-plane.

[0026] According to an embodiment, the fracture zone of the third modified surface has a first width, and the third modified surface may also include a cut-off zone having a second width smaller than the first width between a corner where the one side surface meets the other side surface and a modified zone closest to the corner.

[0027] According to an embodiment, the one side surface of the first substrate and an interface between the first substrate and the first light emitting portion may have an inclination of 88.5 degrees to 91.5 degrees.

[0028] According to an embodiment, the one side surface of the second substrate and an interface between the second substrate and the second light emitting portion may have an inclination of 88.5 degrees to 91.5 degrees.

[0029] According to an embodiment, the fracture zone of the first modified surface has a first width, and the first modified surface may also include a cut-off zone having a second width smaller than the first width between a corner where the one side surface meets another side surface adjacent to the one side surface and a modified zone closest to the corner.

[0030] According to an embodiment, the first light emitting portion may include: a first conductive semiconductor layer, which is arranged on one side of the first substrate; an active layer, which is arranged on the first conductive semiconductor layer and exposes a portion of the first conductive semiconductor layer; a second conductive semiconductor layer, which is arranged on the active layer and exposes a portion of the first conductive semiconductor layer; a first reflective film, which covers the first substrate, the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer, and has a first hole and a second hole that expose the first conductive semiconductor layer and the second conductive semiconductor layer; a first pad, which is arranged on the first reflective film and electrically connected to the first conductive semiconductor layer through the first hole; and a second pad, which is arranged on the first reflective film and electrically connected to the second conductive semiconductor layer through the second hole.

[0031] According to an embodiment, the first reflective film may expose an edge of the one side of the first substrate.

[0032] According to an embodiment, the light emitting module may further include: a second reflective film disposed on the other surface facing the one surface of the first substrate on which the first light emitting unit is disposed.

[0033] According to an embodiment, the first reflective film may reflect light having two wavelengths different from each other, and the second reflective film may reflect light of one wavelength.

[0034] According to an embodiment, a thickness of the first reflective film may be greater than a thickness of the second reflective film.

[0035] According to an embodiment, the second reflective film may expose an edge of the other surface of the first substrate.

[0036] According to an embodiment of the present invention, the light-emitting element includes: a substrate; and a light-emitting portion, which is arranged on one side of the substrate, and the one side of the substrate includes a modified region extending along the thickness direction of the substrate and having a first width, and a fracture region arranged between the modified regions and having a second width, and the one side includes a cut-off region, and the cut-off region is arranged between a corner where the one side meets another side adjacent to the one side and the modified region closest to the corner and has a third width narrower than the second width.

[0037] According to an embodiment, each of the modified regions may be modified by laser irradiation.

[0038] According to an embodiment, the one side surface of the substrate and an interface between the substrate and the light emitting portion may have an inclination of 88.5 degrees to 91.5 degrees.

[0039] According to an embodiment, the other side surface adjacent to the one side surface includes a modified region continuously extending along the thickness direction of the substrate and a fracture region arranged between the modified regions, and the width of each of the fracture regions of the other side surface may be smaller than the first width.

[0040] According to an embodiment, the one side surface includes an a-plane and a surface inclined relative to the a-plane, and the other side surface may include an m-plane and a surface inclined relative to the m-plane.

[0041] According to an embodiment, the light emitting portion may include: a first conductive semiconductor layer, which is arranged on the substrate; an active layer, which is arranged on the first conductive semiconductor layer and exposes a portion of the first conductive semiconductor layer; a second conductive semiconductor layer, which is arranged on the active layer and exposes a portion of the first conductive semiconductor layer; a first reflective film, which covers the substrate, the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer, and has a first hole and a second hole that expose the first conductive semiconductor layer and the second conductive semiconductor layer; a first pad, which is arranged on the first reflective film and electrically connected to the first conductive semiconductor layer through the first hole; and a second pad, which is arranged on the first reflective film and electrically connected to the second conductive semiconductor layer through the second hole.

[0042] According to an embodiment, the first reflective film may expose an edge of the one side of the substrate.

[0043] According to an embodiment, the light emitting element may further include: a second reflective film disposed on the other surface of the substrate facing the one surface.

[0044] According to an embodiment, the first reflective film may reflect light having two wavelengths different from each other, and the second reflective film may reflect light of one wavelength.

[0045] According to an embodiment, a thickness of the first reflective film may be greater than a thickness of the second reflective film.

[0046] According to an embodiment, the second reflective film may expose an edge of the other surface of the substrate.

[0047] According to an embodiment, the first width may be narrower than the third width.

[0048] Specific matters of other embodiments are included in the detailed description and drawings.

[0049] [Effects of the Invention]

[0050] In the light emitting chip according to the embodiment of the present invention, it can have substantially vertical side surfaces and prevent rotation during picking up and transferring, or falling at the place of transfer. In addition, the light emitting chip having vertical side surfaces and a reflective film disposed on the upper and lower parts of the light emitting chip can emit light uniformly through the side surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a cross-sectional view for explaining a method of cutting an ingot to produce wafers.

[0052] Figure 2 It is used to illustrate Figure 1 A cross-sectional view of a wafer.

[0053] Figure 3a This is a schematic diagram for explaining a method of using laser to cut a wafer according to the prior art.

[0054] Figure 3b This is a photograph of a substrate cut using conventional technology.

[0055] Figure 4a , Figure 4b , Figure 5 , Figure 6a , Figure 6b , Figure 7 , Figure 8a , Figure 8b , Figure 9a , Figure 9b , Fig.10a , Fig.10b , Fig.11 , Fig.12 , Fig.13 , Fig.14a , Fig.14b , Fig.15a , Fig.15b , Fig.16a , Fig.16b , Fig.17a ,as well as Fig.17bis a cross-sectional view for explaining a method of manufacturing a light emitting module according to an embodiment of the present invention.

[0056] Fig.18a This is a schematic diagram for explaining a general method of using laser to cut a wafer.

[0057] Fig.18b Is to use Fig.18a Photograph of a substrate formed by the method illustrating the method.

[0058] [Explanation of Symbols]

[0059] 102: One side

[0060] 110: first conductive semiconductor layer

[0061] 120: Active layer

[0062] 130: Second conductivity type semiconductor layer

[0063] 140: Ohm layer

[0064] CAD1: First conductive bonding part

[0065] CAD2: Second conductive bonding part

[0066] CN: Yujiao

[0067] CP1: First conductive pattern

[0068] CP2: Second conductive pattern

[0069] CR: Chip area / unit area

[0070] CT1: First fracture zone

[0071] CT2: Second fracture zone

[0072] DR1: First Direction

[0073] DR2: Second Direction

[0074] ECT1: First cut-off area

[0075] ECT2: Second cut-off area

[0076] EXT: Expansion tape

[0077] FZ: Flat Zone

[0078] H1: First hole

[0079] H2: Second hole

[0080] LB: Laser Light

[0081] LEC: Light Emitting Chip

[0082] LEC1: The first light-emitting chip

[0083] LEC2: Second Light Emitting Chip

[0084] LEC3: The third light-emitting chip

[0085] LEC4: The fourth light-emitting chip

[0086] LN1: First Lane

[0087] LN2: Second channel

[0088] MDF: Modified Area

[0089] MDF1: First modification zone

[0090] MDF1-1: Modified zone 1-1

[0091] MDF1-2: Modification zone 1-2

[0092] MDF2: Second modification zone

[0093] MDF2-1: Modified Zone 2-1

[0094] MDF2-2: Modification Zone 2-2

[0095] MPD: Mounting Pads

[0096] MS: table structure

[0097] MSUB: Mounting Baseboard

[0098] PD1: First pad

[0099] PD2: Second pad

[0100] PRT: Protective film

[0101] PT1: Part 1

[0102] PT2: Part 2

[0103] RFT1: First Reflective Film

[0104] RFT2: Second reflective film

[0105] SD1: First side

[0106] SD2: Second side

[0107] SL: Lane

[0108] SUB: Substrate

[0109] TH1: First thickness

[0110] TH2: Second thickness

[0111] WF: Wafer

[0112] WT1: First Width

[0113] WT2: Second Width

[0114] WT3: Third Width

[0115] WT4: The fourth width

[0116] WT5: Fifth Width

[0117] A-A': section line

[0118] α, β, θ: angle DETAILED DESCRIPTION

[0119] In order to fully understand the configuration and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be implemented in various forms and various modifications can be added.

[0120] In addition, the terms used in the embodiments of the present invention may be interpreted as meanings generally known to those skilled in the art in the corresponding technical field unless otherwise specifically defined.

[0121] Hereinafter, a light emitting chip according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0122] Figure 4a , Figure 4b , Figure 5 , Figure 6a , Figure 6b , Figure 7 , Figure 8a , Figure 8b , Figure 9a , Figure 9b , Fig.10a , Fig.10b , Fig.11 , Fig.12 , Fig.13 , Fig.14a , Fig.14b , Fig.15a , Fig.15b , Fig.16a , Fig.16b , Fig.17a ,as well as Fig.17b is a cross-sectional view for explaining a method of manufacturing a light emitting module according to an embodiment of the present invention.

[0123] Reference Figure 4a and Figure 4b, a first conductive type semiconductor layer 110 , an active layer 120 , a second conductive type semiconductor layer 130 , and an ohmic layer 140 may be formed on the wafer WF.

[0124] According to one embodiment, the wafer WF may be Figure 1 The wafer WF is obtained from the ingot, and the wafer WF may contain sapphire. Figure 4a In the wafer WF, the direction parallel to the extension direction of the flat zone FZ may be the m-axis. The m-axis direction is referred to as the first direction DR1, and the direction perpendicular to the m-axis is referred to as the second direction DR2. For example, the second direction DR2 may be the a-axis. The a-plane is the surface exposed after the wafer WF is cut along the first direction DR1, and the m-plane may be the surface exposed after the wafer WF is cut along the second direction DR2.

[0125] According to one embodiment, the wafer WF may include chip regions (CR) and scribe lanes (SL) defining the chip regions CR and separating them from each other. Each of the light emitting structures may be formed in each of the chip regions CR. As an example, each of the chip regions CR has a regular quadrangular structure in a plane view, and the scribe lanes SL may include first lanes LN1 extending along a first direction DR1 and parallel to each other and second lanes LN2 extending along a second direction DR2 and parallel to each other. The scribe lanes SL may make the first lanes LN1 and the second lanes LN2 intersect each other to have a mesh structure.

[0126] On the other hand, as an example, sapphire may have a crystal structure having hexa-rhombo R3c symmetry. In the case of sapphire, the lattice constants in the c-axis direction and the a-axis direction are and It has C(0001) plane, A(1120) plane, R(1102) plane, etc. The C-plane of sapphire is more conducive to the growth of nitride thin films and is stable at high temperatures, so it can be used as a substrate for the growth of nitride semiconductors.

[0127] The first conductive semiconductor layer 110, the active layer 120, and the second conductive semiconductor layer 130 can be formed on the wafer WF using growth methods such as Metal-Organic Chemical Vapor Deposition (MOCVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), and Metal-Organic Chloride.

[0128] The first conductive semiconductor layer 110 may be an n-type impurity, such as a silicon (Si) doped gallium nitride semiconductor layer. The second conductive semiconductor layer 130 may be a p-type impurity, such as a magnesium (Mg) doped gallium nitride semiconductor layer. Different from this, the first conductive semiconductor layer 110 is a p-type semiconductor layer, and the second conductive semiconductor layer 130 may be an n-type semiconductor layer. On the other hand, the first conductive semiconductor layer 110 and the second conductive semiconductor layer 130 may be a single layer, but are not limited thereto, and may also be a multilayer, or may include a superlattice layer. The active layer 120 may include a multi quantum well (MQW) structure, and its composition ratio may be determined in a manner to emit light of a desired peak wavelength. For example, the active layer 120 may emit light having a peak wavelength in an ultraviolet (UV) wavelength band or light having a peak wavelength in a blue wavelength band.

[0129] The ohmic layer 140 may be formed on the second conductive semiconductor layer 130 by a deposition process such as a chemical vapor deposition (CVD) process. For example, the ohmic layer 140 may use a transparent oxide layer (transparent conductive oxide (TCO)) such as indium tin oxide (ITO) or zinc oxide (ZnO).

[0130] Reference Figure 5 The ohmic layer 140, the second conductive type semiconductor layer 130, and the active layer 120 are etched to form a plurality of mesa structures MS exposing the first conductive type semiconductor layer 110. Each of the mesa structures MS may be disposed in the chip region CR.

[0131] The first conductive semiconductor layer 110 is etched to form the first conductive semiconductor layer 110 for element separation. The first conductive semiconductor layer 110 may be disposed in the chip region CR. The mesa structure MS may have a smaller size than the first conductive semiconductor layer 110 and expose a portion of the first conductive semiconductor layer 110.

[0132] As one example, after the mesa structure MS is formed, the first conductive type semiconductor layer 110 may be etched to separate the elements. As another example, after the first conductive type semiconductor layer 110 is etched to separate the elements, the mesa structure MS may be formed.

[0133] Reference Figure 6a and Figure 6b , first conductive patterns CP1 may be formed on each of the first conductive type semiconductor layers 110 exposed by each of the mesa structures MS, and second conductive patterns CP2 may be formed on the ohmic layer 140 .

[0134] For example, the first conductive pattern CP1 and the second conductive pattern CP2 may respectively include at least one selected from the group consisting of nickel (Ni), titanium (Ti), chromium (Cr), aluminum (Al), gold (Au), and tantalum (Ta).

[0135] According to one embodiment, Figure 6b 1 is a plan view of the first conductive pattern CP1 and the second conductive pattern CP2 formed in one unit region CR as viewed from the direction of the first conductive pattern CP1 and the second conductive pattern CP2. Figure 6b As shown, the second conductive pattern CP2 may include: a first portion PT1 extending along the direction of the first conductive pattern CP1; and a second portion PT2 extending from the first portion PT1 and extending along a direction perpendicular to the direction of the first conductive pattern CP1. As an example, the second portion PT2 may have a structure with an edge bent along the direction of the first conductive pattern CP1. By using the second conductive pattern CP2 including the first portion PT1 of the second conductive pattern CP2 and the second portion PT2, the current spreading characteristics of the light-emitting chip can be improved.

[0136] As an example, a conductive film may be formed on the wafer WF having the mesa structure MS and the first conductive type semiconductor layer 110 formed thereon. The conductive film may include a multilayer film. Further, a lift-off process is performed on the conductive film to form a first conductive pattern CP1 electrically connected to the first conductive type semiconductor layer 110 and a second conductive pattern CP2 electrically connected to the ohmic layer 140.

[0137] Reference Figure 7 , a first reflective film RFT1 covering the first conductive pattern CP1, the second conductive pattern CP2, the mesa structure MS, and the first conductive type semiconductor layer 110 may be formed on the wafer WF.

[0138] The first reflective film RFT1 may include silicon oxide (SiO 2 ) and titanium oxide (TiO 2 ) is a distributed Bragg reflector (DBR) having an alternately stacked structure. According to one embodiment, the first reflective film RFT1 can reflect a plurality of lights having different wavelengths from each other and is formed to have a first thickness TH1. For example, the first reflective film RFT1 includes a first DBR and a second DBR, the first DBR can reflect light of a first wavelength and the second DBR can reflect light of a second wavelength shorter than the first wavelength. As an example, the first DBR can reflect light of 550nm or 630nm, and the second DBR can reflect light of 460nm.

[0139] Reference Figure 8a and Figure 8b The first reflective film RFT1 is etched to form a first hole H1 exposing the first conductive pattern CP1 and a second hole H2 exposing the second conductive pattern CP2.

[0140] according to Figure 8b In the embodiment shown, during the formation of the first hole H1 and the second hole H2, the first reflective film RFT1 formed on the scribe line SL is removed to expose the edge of each chip region CR. This is to prevent the first reflective film RFT1 from being damaged in the subsequent laser process for cutting the wafer WF. The first reflective film RFT1 formed on the scribe line SL and the chip region CR adjacent to the scribe line SL (i.e., the edge of the chip region CR) can be etched.

[0141] On the other hand, the process of removing the first reflective film RFT1 of the scribe line SL may be omitted depending on the irradiation depth of the laser light LB. Figure 3a ) When the irradiation depth is the same as the thickness of the ground wafer WF, the laser light LB may not affect the first reflective film RFT1. Figure 7 As shown, the process of removing the first reflective film RFT1 of the scribe line SL may be omitted.

[0142] Reference Figure 9a and Figure 9b The first hole H1 and the second hole H2 are filled in the first reflective film RFT1, respectively, so that the first pad PD1 and the second pad PD2 configured on the first reflective film RFT1 can be formed respectively.

[0143] For example, the first pad PD1 and the second pad PD2 may include at least one selected from the group consisting of aluminum (Al), nickel (Ni), titanium (Ti), and gold (Au). The pad film may have a multi-layer structure.

[0144] As an example, a first hole H1 and a second hole H2 are filled in the first reflective film RFT1, and a pad film can be formed on the first reflective film RFT1. A stripping process is performed on the pad film to form a first pad PD1 electrically contacting the first conductive pattern CP1 and a second pad PD2 electrically contacting the second conductive pattern CP2.

[0145] Thus, a plurality of light emitting structures may be formed on the wafer WF. Each of the light emitting structures may be formed in each of the chip regions CR. Figure 9b This is a diagram showing a light emitting structure viewed from the direction of the first pad PD1 and the second pad PD2 .

[0146] Reference Fig.10a and Fig.10b, a first conductive bonding portion CAD1 and a second conductive bonding portion CAD2 may be formed on each of the first pads PD1 and the second pads PD2 , respectively.

[0147] According to one embodiment, a stencil may be used to form a first conductive bonding portion CAD1 and a second conductive bonding portion CAD2. Specifically, a stencil including openings exposing the first pad PD1 and the second pad PD2 may be aligned on a wafer WF. By filling each opening with a conductive bonding film, a first conductive bonding portion CAD1 electrically connected to the first pad PD1 and a second conductive bonding portion CAD2 electrically connected to the second pad PD2 may be formed respectively. The first conductive bonding portion CAD1 and the second conductive bonding portion CAD2 may respectively include at least one selected from the group consisting of indium (In), tin (Sn), nickel (Ni), and copper (Cu). Furthermore, the stencil is removed, and a reflow process may be performed on the first conductive bonding portion CAD1 and the second conductive bonding portion CAD2. The first conductive bonding portion CAD1 may have a surface 102 connected to the first pad PD1 and another surface opposite to the surface 102.

[0148] According to Fig.10a In the embodiment shown, the other side of the first conductive bonding portion CAD1 may have a curved surface. The second conductive bonding portion CAD2 may have a first side 102 connected to the second pad PD2 and another side opposite to the first side 102. The other side of the second conductive bonding portion CAD2 may have a curved surface.

[0149] According to Fig.10b In another embodiment shown in FIG. 1 , the upper portions of the first conductive bonding portion CAD1 and the second conductive bonding portion CAD2 are etched, and the other side of the first conductive bonding portion CAD1 and the other side of the second conductive bonding portion CAD2 can each have a flat straight line surface. Fig.10b The first conductive bonding portion CAD1 and the second conductive bonding portion CAD2 are illustrated and described.

[0150] Optionally, the process of forming the first conductive bonding portion CAD1 and the second conductive bonding portion CAD2 may be omitted.

[0151] Reference Fig.11 A protection film PRT for protecting the light emitting structure may be covered on one side 102 of the wafer WF. The protection film PRT may be temporarily bonded to the light emitting structure by an attachable / detachable adhesive.

[0152] Furthermore, the wafer WF is turned over and the thickness of the wafer WF can be reduced by grinding and polishing the other surface of the wafer WF opposite to the one surface 102 of the wafer WF.

[0153] During the flattening and grinding of the wafer WF, the light emitting structure is protected by the protective film PRT, so that particles can be prevented from intruding into the light emitting structure during the wafer WF grinding process.

[0154] In this embodiment, it is described that the first conductive bonding portion CAD1 and the second conductive bonding portion CAD2 are first formed and then the other side of the chip WF is ground and polished. However, the first conductive bonding portion CAD1 and the second conductive bonding portion CAD2 can also be formed after the other side of the chip WF is ground and polished.

[0155] Reference Fig.12 , a second reflective film RFT2 may be formed on the other surface of the ground wafer WF.

[0156] The second reflective film RFT2 may include silicon oxide (SiO 2 ) and titanium oxide (TiO 2 ) DBR of a structure in which the second reflective film RFT2 is alternately stacked. According to an embodiment, the second reflective film RFT2 may have a second thickness TH2 that is smaller than the first thickness TH1 of the first reflective film RFT1. In addition, the second reflective film RFT2 may reflect light of a second wavelength.

[0157] Reference Fig.13 , the second reflective film RFT2 formed on the scribe line SL is etched to expose the edge of each chip region CR.

[0158] This is to prevent the second reflective film RFT2 from being damaged in the subsequent laser irradiation process for cutting the wafer WF. The second reflective film RFT2 formed on the scribe line SL and the chip region CR adjacent to the scribe line SL (that is, the edge of the chip region CR) can be partially etched.

[0159] Reference Fig.14a , Fig.14b , Fig.16a and Fig.16b The laser beam LB is irradiated along the scribe line SL of the wafer WF to form a modified region MDF. The modified region MDF may include a first modified region MDF1 formed along the first direction DR1 and a second modified region MDF2 formed along the second direction DR2.

[0160] According to one embodiment, the laser light LB may be -15The wafer WF is irradiated with a femtosecond laser of a very short pulse width of 10000 Hz (femtosecond). By utilizing the short pulse width and high peak power characteristics of the femtosecond laser, the time of the irradiated laser pulse is short compared to the thermal diffusion time of the wafer WF, so non-thermal processing without thermal modification of the material in the wafer WF can be performed. In addition, since the femtosecond laser can generate a large peak power with relatively less energy than the existing continuous wave laser or nanosecond laser, the impact applied to the wafer WF is small. In addition, the nonlinear optical effect called multiphoton absorption can be used for a width smaller than the diffraction limit of the laser beam.

[0161] Multiphoton absorption is briefly explained. If the energy (hv) of a photon is smaller than the absorption band gap (EG) of a material, it is optically transparent. Therefore, the condition for absorption to occur in a material is hv>EG. However, if the intensity of the laser light LB is very high even if it is optically transparent, absorption will occur in the material under the condition of nhv>EG (n=2, 3, 4, ...). This phenomenon is called multiphoton absorption. In the case of a pulse wave, the intensity of the laser light LB determines the peak power density (W / cm 2 ), for example, at a peak power density of 1×10 8 (W / cm 2 ) and above.

[0162] According to one embodiment, the laser light LB may be irradiated along each of the first lines LN1 of the scribe lines SL to form the first modified region MDF1. The laser light LB is irradiated continuously along the thickness direction of the wafer WF and may be irradiated at a first spacing distance along the first direction DR1. Each of the first modified regions MDF1 may have a line shape continuously extended along the thickness direction of the wafer WF and may be spaced apart from each other by a first spacing distance.

[0163] The laser light LB may be irradiated along each of the second lanes LN2 of the scribe lanes SL to form the second modified region MDF2. The laser light LB may be irradiated continuously along the thickness direction of the wafer WF and may be irradiated at a second spacing distance along the second direction DR2. Each of the second modified regions MDF2 may have a line shape continuously extended along the thickness direction of the wafer WF and may be spaced apart from each other by a second spacing distance smaller than the first spacing distance.

[0164] The laser light LB irradiation process may be performed more densely and frequently along the second direction DR2 than in the first direction DR1. Therefore, the second modified regions MDF2 may be formed more and denser than the first modified regions MDF1. According to one example, the second modified regions MDF2 may also overlap each other.

[0165] The exposed surface cut along the second direction DR2 includes the m-plane. In terms of crystal structure, since the m-plane is a crystal plane, it is easier to cut along the second direction DR2 than to cut the wafer WF along the first direction DR1.

[0166] However, as described above, when the wafer WF is cut in the ingot, an inclined m-plane is formed, and if the cutting is performed more rapidly in the second direction DR2 than in the first direction DR1 as described above, the exposed m-plane has an inclined surface with respect to one surface 102 of the substrate. Therefore, by irradiating the laser light LB more densely and frequently in the second direction DR2 and continuously irradiating the irradiated laser light LB in the thickness direction of the wafer WF, each of the second modified regions MDF2 can be formed vertically with respect to one surface 102 of the wafer WF.

[0167] According to one embodiment, the width between the first modified regions MDF1 and the width between the second modified regions MDF2 can be adjusted by the irradiation speed of the femtosecond laser. The wafer WF is fixed, and the femtosecond laser can adjust the irradiation speed along the first direction DR1 faster than the irradiation speed along the second direction DR2 to determine the first spacing distance and the second spacing distance. As another example, the femtosecond laser can be fixed to adjust the first spacing distance and the second spacing distance by making the wafer WF move at different speeds along the first direction DR1 and the second direction DR2.

[0168] On the other hand, the first reflective film RFT1 and the second reflective film RFT2 include DBR, which can be damaged by the laser light LB. Therefore, the second reflective film RFT2 disposed on the other side of the wafer WF, i.e., the side irradiated with the laser light LB, is removed along the scribe line SL, and the second reflective film RFT2 is not damaged by the laser light LB during the irradiation of the laser light LB.

[0169] Furthermore, as an example, in the case of the first reflective film RFT1, when the irradiation depth of the laser light LB is exactly consistent with the thickness of the wafer WF, the process of removing the first reflective film RFT1 along the scribe line SL can be omitted. As another example, when the irradiation depth of the laser light LB is greater than the thickness of the wafer WF, the process of removing the first reflective film RFT1 along the scribe line SL can be performed.

[0170] Reference Fig.15a , Fig.15b , Fig.16a , Fig.16b, an expansion tape (EXT) may be attached to the other side of the wafer WF where the laser light LB irradiation process is performed. The expansion tape EXT may be temporarily attached to the other side of the wafer WF by an adhesive that can be attached and peeled off.

[0171] After the expansion tape EXT is subsequently applied, the protective film PRT may be removed to expose the light emitting structure on the one side 102 of the wafer WF.

[0172] The expansion tape EXT is expanded to the end, and the wafer WF irradiated with the laser light LB along the scribe line SL is broken, thereby forming a plurality of light emitting chips LEC. The plurality of light emitting chips LEC may be spaced apart from each other in the first direction DR1 and the second direction DR2.

[0173] Each of the light emitting chips LEC may include a substrate SUB and a light emitting structure disposed on a surface 102 of the substrate SUB. The substrate SUB has the same size as the chip region CR and may include a first side surface SD1 cut along a first direction DR1 and opposite to each other and a second side surface SD2 cut along a second direction DR2 and opposite to each other. Fig.16a , each of the first side surfaces SD1 may have an angle α of 88.5 to 91.5 degrees with the surface 102 of the substrate SUB. Fig.16b Each of the second side surfaces SD2 may have an angle β of 88.5 to 91.5 degrees with the one surface 102 of the substrate SUB. That is, each of the first side surface SD1 and the second side surface SD2 may be substantially perpendicular to the one surface 102 of the substrate SUB.

[0174] According to one embodiment, referring to Fig.15b and Fig.16a , the surface cut along the first direction DR1 may include an a-plane group. Each of the first side surfaces SD1 cut along the first direction DR1 may include a first modified region MDF1 and a first fracture region CT1 arranged between the first modified regions MDF1. The first modified region MDF1 is a portion modified by the laser light LB, and the first fracture region CT1 may be a portion physically cut by the expansion of the expansion band EXT. As described above, each of the first modified regions MDF1 is continuously formed along the thickness direction of the wafer WF, so that each of the physically cut first fracture regions CT1 may also have a linear shape continuously extended along the thickness direction of the wafer WF, that is, the substrate SUB. The first modified region MDF1 has a first width WT1, and the first fracture region CT1 may have a second width WT2 greater than the first width WT1. As described above, adjacent first modified regions MDF1 are separated by a first spacing distance, and the second width WT2 may be the same as the first spacing distance.

[0175] For ease of explanation, in the substrate SUB, the surface where the end of the first side surface SD1 and the end of the second side surface SD2 of the substrate SUB meet is called a corner (corner, CN). In addition, in the substrate, the point where one surface 102 of the substrate, the first side surface SD1 and the second side surface SD2 meet is called a corner point.

[0176] According to one embodiment, the first fracture region CT1 may include a first cut region ECT1 located at the corner CN. To explain in more detail, the first modified region MDF1 may include a 1-1 modified region MDF1-1 closest to the corner CN, and a 1-2 modified region MDF1-2 located after the 1-1 modified region MDF1-1. The first cut region ECT1 may be an interval between the corner CN and the 1-1 modified region MDF1-1. The width between the corner CN and the 1-1 modified region MDF1-1 may be smaller than the width between the 1-1 modified region MDF1-1 and the 1-2 modified region MDF1-2. Therefore, the first cut region ECT1 may have a third width WT3 smaller than the second width WT2. The first cut region ECT1 may be an interval formed by cutting the first fracture region CT1 at a portion adjacent to the corner CN during physical fracture of the wafer WF irradiated with the laser light LB along the first direction DR1.

[0177] Reference Fig.15b and Fig.16b , the surface cut along the second direction DR2 may include an m-surface group. Each of the second side surfaces SD2 cut along the second direction DR2 may include a second modified region MDF2 and a second fracture region CT2 arranged between the second modified regions MDF2. The second modified region MDF2 is a portion modified by the laser light LB, and the second fracture region CT2 may be a portion physically cut by the expansion of the expansion band EXT. As described above, each of the second modified regions MDF2 is continuously formed along the thickness direction of the wafer WF, so that each of the physically cut second fracture regions CT2 may also have a linear shape continuously extended along the thickness direction of the wafer WF, that is, the substrate SUB. The second modified region MDF2 has a first width WT1, and the second fracture region CT2 may have a fourth width WT4 greater than the first width WT1. As described above, adjacent second modified regions MDF2 are separated by a second spacing distance, and the fourth width WT4 may be the same as the second spacing distance.

[0178] According to one embodiment, in addition, the second fracture zone CT2 may include a second cut-off zone ECT2 located at the corner CN. To explain in more detail, the second modified region MDF2 may include a 2-1 modified region MDF2-1 closest to the corner CN, and a 2-2 modified region MDF2-2 located after the 2-1 modified region MDF2-1. The second cut-off zone ECT2 may be an interval between the corner CN and the 2-1 modified region MDF2-1. The width between the corner CN and the 2-1 modified region MDF2-1 may be smaller than the width between the 2-1 modified region MDF2-1 and the 2-2 modified region MDF2-2. Therefore, the second cut-off zone ECT2 may have a fifth width WT5 smaller than the fourth width WT4. The second cut-off zone may be an interval formed by cutting the second fracture zone CT2 at a portion adjacent to the corner CN during physical fracture of the wafer WF irradiated with the laser light LB along the second direction DR2.

[0179] According to an embodiment of the present invention, the modified region MDF is a line type penetrating the substrate SUB, and may include a first modified region MDF1 separated by a first width WT1 along a first direction DR1 and a second modified region MDF2 separated by a second width WT2 along a second direction DR2. In particular, the second modified region MDF2 is formed more densely than the first modified region MDF1, so that the m-plane exposed along the second direction DR2 can be formed perpendicular to a surface 102 of the substrate SUB.

[0180] According to one embodiment, a light emitting chip LEC may include a substrate SUB, a light emitting structure formed on one side 102 of the substrate SUB, and a second reflective film RFT2 formed on the other side of the substrate SUB. The light emitting structure may include a first conductive semiconductor layer 110 having a smaller width than the substrate SUB, a mesa structure MS having a smaller width than the first conductive semiconductor layer 110 on the first conductive semiconductor layer 110, a first conductive pattern CP1, a second conductive pattern CP2, a first reflective film RFT1, a first pad PD1, and a second pad PD2 on the one side 102 of the substrate SUB. The mesa structure MS may include an active layer 120, a second conductive semiconductor layer 130, and an ohmic layer 140. In this case, the other side of the substrate SUB of the light emitting chip LEC may be a light extraction surface. Most of the light generated from the active layer 120 of the light emitting chip LEC is reflected toward the substrate SUB through the first reflective film RFT1, and a part of the light may be reflected toward the light emitting structure through the second reflective film RFT2. Therefore, the light emitting chip LEC may emit 20% to 30% of the light generated from the active layer 120 through the light extraction surface, and the remaining 70% to 80% of the light may be emitted through the first side surface SD1 and the second side surface SD2 of the substrate SUB.

[0181] Reference Fig.17a and Fig.17b, each of the light emitting chips LEC can be picked up and mounted on the mounting substrate MSUB to form a light emitting module. Fig.17b Cut along the section line A-A' Fig.17a Cross-sectional view of the light-emitting chip.

[0182] Each of the light emitting chips LEC can make the first side surface SD1 and the second side surface SD2 of the substrate SUB substantially perpendicular to the one surface 102 of the substrate SUB, so it will not rotate during the picking movement and will not fall after being mounted on the mounting substrate MSUB.

[0183] On the mounting substrate MSUB, each of the light emitting chips LEC can electrically connect the first conductive bonding portion CAD1 and the second conductive bonding portion CAD2 to the mounting pad MPD of the mounting substrate MSUB. Fig.10a and Fig.10b As shown, the first conductive bonding part CAD1 and the second conductive bonding part CAD2 can be formed on the light emitting chip LEC. As another example, the first conductive bonding part CAD1 and the second conductive bonding part CAD2 can be formed on the mounting pad MPD of the mounting substrate MSUB. As another example, the first conductive bonding part CAD1 and the second conductive bonding part CAD2 are formed on the light emitting chip LEC, and the third conductive bonding part and the fourth conductive bonding part are further formed on the mounting pad MPD, the first conductive bonding part CAD1 is in electrical contact with the third conductive bonding part, and the second conductive bonding part CAD2 can also be in electrical contact with the fourth conductive bonding part.

[0184] According to one embodiment, even if the first side surface SD1 and the second side surface SD2 of the substrate SUB are substantially perpendicular to the surface 102 of the substrate SUB in each of the light emitting chips LEC, the thickness of each of the light emitting chips LEC is larger than the area and thus the chip will fall off. 2 In the case of the following chips, the thickness of the light emitting chip LEC should be less than 1 / 2 of one side of the light emitting chip LEC. As an example, when the length and width of the light emitting chip LEC are 200 μm respectively, the light emitting chip LEC may have a thickness of 100 μm or less.

[0185] In addition, in the first modified region MDF1 of the first side SD1 and the second modified region MDF2 of the second side SD2 of the substrate SUB of each of the light emitting chips LEC, light generated from the active layer 120 is scattered, so that light extraction of the light emitting chip LEC can be improved.

[0186] In this embodiment, the light emitting chip LEC may include a first light emitting chip LEC1, a second light emitting chip LEC2, a third light emitting chip LEC3, and a fourth light emitting chip LEC4. The first light emitting chip LEC1, the second light emitting chip LEC2, the third light emitting chip LEC3, and the fourth light emitting chip LEC4 may have the same structure.

[0187] The light emitting chip LEC as described above may not rotate when picked up and moved, and the opposite side surfaces of the light emitting chip LEC disposed on the mounting substrate MSUB may have the same structure. For example, one of the first side surfaces SD1 of the substrate SUB of the first light emitting chip LEC1 is opposite to one of the first side surfaces SD1 of the substrate SUB of the second light emitting chip LEC2, and one of the second side surfaces SD2 of the substrate SUB of the first light emitting chip LEC1 may be opposite to one of the second side surfaces SD2 of the substrate SUB of the third light emitting chip LEC3.

[0188] In addition, the first light-emitting chip LEC1, the second light-emitting chip LEC2, the third light-emitting chip LEC3, and the fourth light-emitting chip LEC4 have their respective corners facing each other, and as described above, the first cut-off region ECT1 and the second cut-off region ECT2 are formed at the corners. The first cut-off region ECT1 has a smaller width than the first fracture region CT1, and the second cut-off region ECT2 has a smaller width than the second fracture region CT2, which means that the modified region MDF is arranged adjacent to the corner. Therefore, the modified region MDF of each of the opposite corners can be used to prevent total reflection of light, so that light extraction is improved.

[0189] Generally, when there is no second reflective film RFT2, the light generated from the active layer 120 of the light emitting chip is absorbed, reflected and extinguished during the period of passing through the light emitting structure and the substrate SUB, and the light emitted through the other side of the substrate SUB is 100%. However, the light emitting chip according to the embodiment of the present invention uses the first reflective film RFT1 and the second reflective film RFT2, so that the light emitted through the other side of the substrate SUB is 20% to 30%. The remaining 70% to 80% of the light can be emitted through the first side surface SD1 and the second side surface SD2 of the substrate SUB.

[0190] Therefore, the light emitting chip LEC according to the embodiment emits more light in the horizontal direction than in the vertical direction, and thus may have uniform brightness. The light emitting chip LEC may be used in a backlight unit (BLU) requiring uniform brightness.

[0191] Hereinafter, a wafer cut by the process according to the embodiment of the present invention will be described.

[0192] Fig.18aThis is a schematic diagram for explaining a method of using a laser to cut a wafer according to one embodiment of the present invention.

[0193] A wafer is prepared with the first direction parallel to the extension direction of the flat region as the m-axis direction and the second direction perpendicular to the first direction as the a-axis direction. The size of the substrate desired by cutting the wafer is 200 μm in length, 200 μm in width, and 85 μm in thickness.

[0194] Reference Fig.18a , laser light LB is continuously irradiated along the thickness direction of the wafer to form a linear modified region MDF. The laser light LB forms the modified region MDF by a first spacing distance along a first direction, and forms the modified region MDF by a second spacing distance smaller than the first spacing distance along a second direction. If the wafer with the linear modified region formed is broken, a broken region extending continuously along the thickness direction is formed between the modified regions, and the wafer is cut into a plurality of substrates.

[0195] Fig.18b Is to use Fig.18a A photograph of a substrate formed by the method of illustrating the invention. Fig.18b In the figure, the left side is a photograph of the upper surface of the substrate, the middle is a photograph obtained by cutting the first side of the wafer along the first direction at an angle, and the right side is a photograph of the second side of the wafer along the second direction. A portion of the second side can be observed in the left part of the middle photograph.

[0196] like Fig.18b As shown, it can be seen that the cut substrate is close to vertical. The angle between the upper surface of the substrate and the first side surface and the second side surface is in the range of 88.9 degrees to 90.6 degrees, which can be said to be substantially vertical. In addition, it can be observed that the modified area and the fractured area are parallel to the thickness direction of the substrate.

[0197] Although the embodiments of the present invention are described above with reference to the accompanying drawings, a person skilled in the art with common knowledge in the technical field to which the present invention belongs can understand that the present invention can be implemented in other specific ways without changing the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood to be illustrative in all aspects and not restrictive.

Claims

1. A light emitting module, comprising: Install the base plate; A plurality of light-emitting chips are mounted on the mounting substrate; as well as A plurality of pads are arranged between the light emitting chip and the mounting substrate, and Each of the light emitting chips comprises: a first substrate; A first light emitting portion, disposed on one side of the first substrate; a second substrate, spaced apart from the first substrate; and The second light emitting portion is disposed on one side of the second substrate, and A side surface of the first substrate includes a first modified surface, and a side surface of the second substrate opposite to the side surface of the first substrate includes a second modified surface. The first modified surface includes a modified region extending along the thickness direction of the first substrate and a fracture region arranged between the modified regions. The second modified surface includes a modified area extending along the thickness direction of the second substrate and a fracture area arranged between the modified areas. The width of each of the fracture regions of the first modified surface is the same as the width of each of the fracture regions of the second modified surface, The fracture zone of the first modified surface has a first width, The first modified surface also includes a cut-off region, which is located between a corner where the one side surface meets another side surface adjacent to the one side surface and a modified region closest to the corner and has a second width smaller than the first width.

2. The light emitting module according to claim 1, wherein Each of the modified regions is modified by laser irradiation.

3. The light emitting module according to claim 1, wherein The width of each of the fractured regions is greater than the width of each of the modified regions.

4. The light emitting module according to claim 1, wherein Another side surface adjacent to the one side surface of the first substrate includes a third modified surface, The third modified surface includes modified regions extending along the thickness direction of the first substrate and fractured regions arranged between the modified regions.

5. The light emitting module according to claim 4, wherein A width of each of the fracture regions of the first modified surface is smaller than a width of each of the fracture regions of the third modified surface.

6. The light emitting module according to claim 4, wherein The fracture zone of the third modified surface has a first width, The third modified surface further includes a cut-off region, which is located between a corner where the one side surface meets the other side surface and a modified region closest to the corner and has a second width smaller than the first width.

7. The light emitting module according to claim 1, wherein The one side surface of the first substrate and an interface between the first substrate and the first light emitting portion have an inclination of 88.5 degrees to 91.5 degrees.

8. The light emitting module according to claim 1, wherein The one side surface of the second substrate and an interface between the second substrate and the second light emitting portion have an inclination of 88.5 degrees to 91.5 degrees.

9. The light emitting module according to claim 1, wherein The first light emitting unit comprises: A first conductive semiconductor layer is disposed on the one surface of the first substrate; an active layer, disposed on the first conductive type semiconductor layer and exposing a portion of the first conductive type semiconductor layer; A second conductive semiconductor layer is disposed on the active layer and exposes a portion of the first conductive semiconductor layer; a first reflective film covering the first substrate, the first conductive type semiconductor layer, the active layer, and the second conductive type semiconductor layer, and having a first hole and a second hole for exposing the first conductive type semiconductor layer and the second conductive type semiconductor layer; A first pad, disposed on the first reflective film and electrically connected to the first conductive semiconductor layer through the first hole; as well as The second pad is disposed on the first reflective film and is electrically connected to the second conductive semiconductor layer through the second hole.

10. The light emitting module according to claim 9, wherein The first reflective film exposes an edge of the one surface of the first substrate.

11. The light emitting module according to claim 9, further comprising: The second reflective film is arranged on the other surface facing the one surface of the first substrate on which the first light emitting portion is arranged.

12. The light emitting module according to claim 11, wherein The first reflective film reflects light having two wavelengths different from each other, The second reflective film reflects light of one wavelength.

13. The light emitting module according to claim 11, wherein The thickness of the first reflective film is greater than the thickness of the second reflective film.

14. The light emitting module according to claim 11, wherein The second reflective film exposes an edge of the other surface of the first substrate.

15. A light emitting element, comprising: substrate; as well as The light emitting portion is arranged on one side of the substrate. One side surface of the substrate includes a modified region extending along a thickness direction of the substrate and having a first width, and a fracture region disposed between the modified regions and having a second width, The one side surface includes a cut-off area, which is arranged between a corner where the one side surface meets another side surface adjacent to the one side surface and a modified area closest to the corner and has a third width smaller than the second width.

16. The light emitting element according to claim 15, wherein Each of the modified regions is modified by laser irradiation.

17. The light emitting element according to claim 15, wherein The one side surface of the substrate and an interface between the substrate and the light emitting portion have an inclination of 88.5 degrees to 91.5 degrees.

18. The light emitting element according to claim 15, wherein The other side surface adjacent to the one side surface includes a modified region extending continuously along the thickness direction of the substrate and a fractured region arranged between the modified regions. A width of each of the fracture areas of the other side is smaller than the first width.

19. The light emitting element according to claim 15, wherein The light emitting unit comprises: A first conductive semiconductor layer is disposed on the substrate; an active layer, disposed on the first conductive type semiconductor layer and exposing a portion of the first conductive type semiconductor layer; A second conductive semiconductor layer is disposed on the active layer and exposes a portion of the first conductive semiconductor layer; a first reflective film covering the substrate, the first conductive type semiconductor layer, the active layer, and the second conductive type semiconductor layer, and having a first hole and a second hole for exposing the first conductive type semiconductor layer and the second conductive type semiconductor layer; A first pad, disposed on the first reflective film and electrically connected to the first conductive semiconductor layer through the first hole; as well as The second pad is disposed on the first reflective film and is electrically connected to the second conductive semiconductor layer through the second hole.

20. The light emitting element according to claim 19, wherein The first reflective film exposes an edge of the one surface of the substrate.

21. The light emitting element according to claim 19, further comprising: The second reflective film is disposed on the other surface of the substrate facing the one surface.

22. The light-emitting element according to claim 21, wherein The first reflective film reflects light having two wavelengths different from each other, The second reflective film reflects light of one wavelength.

23. The light-emitting element according to claim 21, wherein The thickness of the first reflective film is greater than the thickness of the second reflective film.

24. The light-emitting element according to claim 21, wherein The second reflective film exposes an edge of the other surface of the substrate.

25. The light emitting element according to claim 15, wherein The first width is smaller than the third width.

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