VERTICAL LIGHT-EMPLOYING DIODE WITH AN ELECTRODE CONFIGURATION AND LIGHT-EMPLOYING DIODE PACKAGE COMPLETING THE SAME

Abstract

Light-emitting diode (100) comprising: a semiconductor layer sequence (30) comprising a lower semiconductor layer (27), an active layer (25) and an upper semiconductor layer (23), wherein the upper semiconductor layer (23) comprises a roughened surface (R); an upper electrode (80a, 80b, 80c) connected to the upper semiconductor layer (23); and a lower electrode (40) connected to the lower semiconductor layer (27), wherein the upper electrode (80a, 80b, 80c) comprises an electrode pad (80a) with extensions (80b, 80c), wherein the extensions (80b, 80c) are extendable from the electrode pad (80a), the electrode pad (80a) comprises a first electrode pad (80a) which is arranged in an elongated shape along an edge of the upper semiconductor layer (23) and covers the upper semiconductor layer (23) near one edge, wherein the extensions (80b, 80c) comprise an edge extension (80b) which is extendable along an edge of the upper semiconductor layer (23) in the electrode pad (80a), and mean extensions (80c) which are extendable from the edge extension (80b) or the electrode pad (80a), and subdivide luminescent regions, characterized by an insulating layer (70) covering the roughened area (R) of the upper semiconductor layer (23), and a wavelength converter (90) which covers the insulating layer (70) of the upper semiconductor layer (23) and the extensions (80b, 80c).

Description

TECHNICAL FIELD

[0001] Exemplary embodiments of the present disclosure relate to a light-emitting diode and in particular a vertical light-emitting diode with an electrode configuration. BACKGROUND

[0002] A vertical light-emitting diode (VLED) with a growth substrate removed from it is used in various fields. In particular, a VLED is capable of emitting light with high output and is therefore used in projectors and vehicle headlights.

[0003] A vertical light-emitting diode (LED) is generally packaged using a packaging process. An LED package includes a wavelength converter, which is formed by mixing phosphors in a resin, such as silicone or epoxy resin, to convert blue or UV light emitted by the LED into visible light with a long wavelength.

[0004] Since a projector or headlight for vehicles emits high-output light in an enclosed space, the ambient temperature increases significantly. Therefore, a light-emitting diode package in these applications requires not only good heat dissipation properties but also high temperature resistance. However, conventional wavelength converters, which are formed by mixing phosphors in a resin, silicone, or epoxy resin, are temperature-sensitive and unsuitable for vehicle headlights and similar applications. Therefore, a new light-emitting diode package with high temperature resistance is needed.

[0005] Examples of conventional light-emitting diodes are disclosed, for example, in US 2012 / 0 061 704 A1, US 2012 / 0 175 662 A1, WO 2013 / 085 255 A1, US 2007 / 0 114 636 A1, US 2013 / 0 001 605 A1, US 2014 / 0 117 389 A1 and US 2016 / 0 072 031 A9. SUMMARY

[0006] Exemplary embodiments of the present disclosure relate to a vertical light-emitting diode which makes it possible to easily couple a wavelength converter with high temperature resistance to it and a light-emitting diode package comprising the same.

[0007] Exemplary embodiments of the present disclosure reveal a light-emitting diode package with high temperature resistance.

[0008] Exemplary embodiments of the present disclosure relate to a vertical light-emitting diode suitable for a projector or a headlight for vehicles, and a light-emitting diode package comprising the same.

[0009] The present invention provides a light-emitting diode with the features of claim 1 and a light-emitting diode package with the features of claim 10.

[0010] Exemplary embodiments of the present disclosure relate to a light-emitting diode in which the shape of an electrode pad is modified to easily accommodate a high-temperature-resistant phosphor-in-glass (LIG) on it. Furthermore, the present disclosure provides exemplary embodiments of a high-temperature-resistant light-emitting diode package using the light-emitting diode with the arranged LIG. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are introduced for a further understanding of the disclosed technology, are part of this description to which reference is made and illustrate exemplary embodiments of the disclosed technology, and together with the description they serve to describe the principles of the disclosed technology. Fig. 1A, Fig. 1B and Fig. Figure 1C shows a schematic perspective view, a cross-sectional view and a perspective cross-sectional view of a light-emitting diode package according to an exemplary embodiment of the present disclosure. Fig. 2A and Fig. Figure 2B shows a schematic top view and a cross-sectional view of a light-emitting diode according to an exemplary embodiment of the present disclosure. Fig. 3A and Fig. Figure 3B shows a schematic top view and a cross-sectional view of the light-emitting diode according to one exemplary embodiment of the present disclosure, wherein a wavelength converter is arranged on it. Fig. 4A and Fig. Figures 4B are a schematic top view and a cross-sectional view of a light-emitting diode according to a further exemplary embodiment of the present invention. Fig. Figure 5 is a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present invention. Fig. Figure 6 is a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present invention. Fig. Figure 7 is a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present disclosure. Fig. Figure 8 is a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0012] Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. These embodiments are provided as examples to convey the full core idea of ​​the present disclosure to the relevant persons skilled in the art, to whom the present disclosure is addressed. Accordingly, the embodiments are not limited to the present disclosure and can also be implemented in different forms. In the drawings, widths, lengths, thicknesses, and the like relating to elements may be enlarged for clarity and descriptive purposes. It should also be understood that when an element, for example, a layer, film, region, or substrate, refers "to" another element, it may be located directly on the other element or between the elements.In contrast, when one element is positioned "directly on" another, there are no intervening elements. In the figures, identical reference symbols denote identical, functionally equivalent, or functionally similar elements.

[0013] According to an exemplary embodiment of the present disclosure, a light-emitting diode is provided. The light-emitting diode comprises a sequence of semiconductor layers with a lower semiconductor layer, an active layer, and an upper semiconductor layer; an upper electrode connected to the upper semiconductor layer; and a lower electrode connected to the lower semiconductor layer, wherein the upper electrode comprises an electrode pad with extensions, the extensions being extendable from the electrode pad.The electrode pad comprises a first electrode pad, which is arranged in an elongated shape along an edge of the upper semiconductor layer and covers the upper semiconductor layer near that edge, and the extensions comprise an edge extension, which is extendable along an edge of the upper semiconductor layer in the electrode pad, and middle extensions, which are extendable from the edge extension or the electrode pad, and subdivide luminescent regions.

[0014] With this structure, in which the first electrode pad is arranged with an elongated shape along an edge of the upper semiconductor layer, it is possible to form a luminescent region in a rectangular shape, particularly a square one. Accordingly, it is possible to achieve effective control of the luminescent region, while simplifying the area on which a wavelength converter is located.

[0015] In some exemplary embodiments, the central extensions can be arranged parallel to a longitudinal direction of the electrode pad. The central extensions can be arranged to divide the luminescent regions into equal widths. Alternatively, the widths of the luminescent regions divided by the central extensions can vary with increasing distance from the electrode pad. For example, the widths of the luminescent regions divided by the central extensions can decrease with increasing distance from the electrode pad.

[0016] In further exemplary embodiments, the central extensions can be arranged perpendicular to a longitudinal direction of the electrode pad.

[0017] The light-emitting diode can further comprise an insulating layer that covers an area of ​​the upper semiconductor layer. The insulating layer can improve the adhesion properties of a wavelength converter placed on it.

[0018] The upper semiconductor layer can include a roughened surface. The roughened surface improves the extraction efficiency of light emitted through the upper semiconductor layer.

[0019] The light-emitting diode can further include a wavelength converter covering the upper semiconductor layer and the extensions. The wavelength converter can have a rectangular shape, particularly a square one. A rectangular, or especially a square, wavelength converter structure can significantly simplify the manufacturing process. Furthermore, it is possible to minimize material waste during the manufacturing of the wavelength converter.

[0020] In particular, the wavelength converter can be a LIG (fluorescent-in-glass) wavelength converter. The LIG wavelength converter exhibits good resistance to high temperatures and is therefore suitable for a projector or a vehicle headlight.

[0021] The wavelength converter can cover the entire luminous region with a rectangular shape to convert wavelengths of outwardly emitted light. The wavelength converter can cover the entire luminous region between the far edge opposite the first edge and the first electrode pad.

[0022] The electrode pad can further include a second electrode pad arranged in an elongated shape along the far edge of the upper semiconductor layer, opposite one edge of the same, and cover the upper semiconductor layer near the far edge. With this structure, wire bonding can be performed on both sides of the upper semiconductor layer, thus enabling a more efficient power supply.

[0023] The wavelength converter can cover the entire luminous regions between the first electrode pad and the second electrode pad.

[0024] According to a further exemplary embodiment of the present invention, a light-emitting diode package is provided. The light-emitting diode package comprises: a base substrate with a first electrode and a second electrode; a light-emitting diode arranged on the base substrate and electrically connected to the first electrode and the second electrode; a wavelength converter arranged on the light-emitting diode; a housing arranged on the base substrate and surrounding the light-emitting diode; and an encapsulation which covers the light-emitting diode within the housing while exposing an upper surface of the wavelength converter, wherein the light-emitting diode comprises a sequence of semiconductor layers comprising a lower semiconductor layer, an active layer, and an upper semiconductor layer; and an upper electrode connected to the upper semiconductor layer.and a lower electrode connected to the lower semiconductor layer, wherein the upper electrode comprises an electrode pad with extensions, the extensions being extendable from the electrode pad. The electrode pad comprises a first electrode pad arranged in an elongated shape along an edge of the upper semiconductor layer and covering the upper semiconductor layer near that edge, and the extensions comprising an edge extension extending along an edge of the upper semiconductor layer in the electrode pad, and intermediate extensions extending from the edge extension or the electrode pad, and subdividing luminescent regions.

[0025] A luminescent region of the light-emitting diode can be shaped into a desired form by controlling the shape of the electrode pad, which can simplify the shape of the wavelength converter, thus making a method for manufacturing the wavelength converter easily available.

[0026] In particular, the wavelength converter can comprise a LIG (phosphor-in-glass) wavelength converter with a rectangular shape, for example, a square shape. Since the LIG wavelength converter has a rigid structure, it is difficult to form an LIG wavelength converter with a complex structure. Since a typical light-emitting diode has a complicated luminescent region, it is difficult to form the LIG wavelength converter with a rectangular shape. However, according to the exemplary embodiments, the luminescent regions of the light-emitting diode are controllable using the electrode pad, thus enabling the adoption of the LIG wavelength converter with a rectangular shape, particularly a square shape.

[0027] The encapsulation can be formed from a white reflector. This white reflector can be created by mixing white pigments with a resin, such as an epoxy or silicone resin. In particular, a white reflector made of polycarbonate or polycyclohexylenedimethyl terephthalate (PCT) can be suitable as a heat-resistant reflector. Conventional encapsulation is generally made of a transparent resin to allow transmission of the light passing through it, whereas the encapsulation according to the exemplary embodiments is made of a material through which no light can pass. Furthermore, although not specifically limited to this, encapsulation with a reflective surface can prevent light loss through the encapsulation, thereby improving light extraction efficiency.

[0028] The white reflector covers four sides of the light-emitting diode (LED) to prevent light emission through these sides. Furthermore, the white reflector can cover the first electrode pad. Therefore, without wavelength conversion, the LED package can block light emitted through the area around the electrode pad. With the white reflector, the LED package allows light to be emitted through a top surface of the wavelength converter, thus improving the integration of the emitted light in the vertical direction. Consequently, the LED package can have a narrow beam angle and is suitable for application in a vehicle headlight.

[0029] In some exemplary embodiments, the electrode pad can further comprise a second electrode pad arranged in an elongated shape along the far edge of the upper semiconductor layer, opposite one edge thereof, and covering the upper semiconductor layer near the far edge. The white reflector can cover the second electrode pad. Accordingly, the light-emitting diode package can block light emitted through a region around the second electrode pad without wavelength conversion.

[0030] In some exemplary embodiments, the central extensions can be arranged parallel to a longitudinal direction of the electrode pad. The central extensions can be arranged to subdivide the luminous regions with the same width. Alternatively, the widths of the luminous regions divided by the central extensions can vary with increasing distance from the electrode pad. For example, the widths of the luminous regions divided by the central extensions can decrease with increasing distance from the electrode pad.

[0031] In further exemplary embodiments, the central extensions can be arranged perpendicular to a longitudinal direction of the electrode pad.

[0032] The base substrate and the package can be made of different materials. For example, the base substrate can be a ceramic substrate with relatively high thermal conductivity, such as an AIN ceramic substrate, and the package can be made of a silicone molding compound. Accordingly, the light-emitting diode package can exhibit improved heat dissipation through the base substrate. The package can be open on the top and bottom. Furthermore, the package can form a closed recess, but is not limited to this. Alternatively, the package can be partially open on one side.

[0033] The light-emitting diode can be arranged on the first electrode and the first electrode pad of the light-emitting diode and electrically connected to the second electrode by a plurality of bond wires. Furthermore, areas of the first electrode pad that are connected to the bond wires can have the same width as other areas of the same arranged between them.

[0034] Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0035] Fig. Figure 1A is a perspective view of a light-emitting diode package according to an exemplary embodiment of the present invention. Fig. 1B is a cross-sectional view along a line AA of the Fig. 1A, and Fig. 1C is a partially perspective sectional view along line BB of the Fig. 1A.

[0036] Referring to Fig. 1A, Fig. 1B and Fig. 1C, the light-emitting diode package according to this exemplary embodiment comprises a light-emitting diode 100, a wavelength converter 90, a base substrate 200 and a housing 100, and may include bond wires 310.

[0037] The base substrate 200 comprises an insulating substrate 101, a first electrode 203, and a second electrode 205, and may include a heat dissipation path 207. The insulating substrate 201 can be a ceramic substrate, for example, an AIN substrate. The AIN substrate exhibits good resistance to high temperatures and good heat dissipation properties.

[0038] The first electrode 203 and the second electrode 205 comprise upper terminals 203a, 205a, lower terminals 203c, 205c, and vias 203b, 205b, respectively. The upper terminals 203a, 205a are located on an upper surface of the insulating substrate 201. The lower terminals 203c, 205c are located on a lower surface of the insulating substrate 201, and the vias 203b, 205b are formed through the insulating substrate 201 to connect the upper terminals 203a, 205a to the lower terminals 203c, 205c.

[0039] In an exemplary embodiment, the first and second electrodes 203, 205 can have a multilayer structure, for example, a multilayer structure of Ni / Cu / Au layers. The Ni layer serves to improve the adhesion of electrode patterns to an AIN substrate, and the Au layer serves to prevent oxidation of the copper layer while improving adhesion to the light-emitting diode, as described below. Additionally, the copper layer serves to promote current and heat transfer and can have a greater thickness than the Ni and Au layers. However, it should be understood that the first and second electrodes 203, 205 are not limited to these metal layers.

[0040] The heat dissipation path 207 is located between the first and second lower terminals 203c, 205c and is electrically insulated from them. The heat dissipation path 207 facilitates heat dissipation by contacting a printed circuit board, particularly a metal one, such as a metallic PCB. The heat dissipation path 207 can be made of the same material as the first and second electrodes 203, 205.

[0041] The light-emitting diode 100 is arranged on the upper terminal 203a and is electrically connected to the upper terminal 205a by the bond wires 310. A plurality of bond wires 310 can be bonded to an electrode pad of the light-emitting diode 100. Although three bond wires are connected to it in this exemplary embodiment, it should be understood that other implementations are also possible and a larger number of bond wires can be connected. Furthermore, the light-emitting diode 100 can have a vertical structure. Details of the light-emitting diode 100 are described below.

[0042] The wavelength converter 90 is arranged on the light-emitting diode 100. The wavelength converter 90 can be bonded to the light-emitting diode 100 by a bonding material, for example, silicone. The wavelength converter 90 can cover part of an upper surface of the light-emitting diode. The wavelength converter 90 can be a rigid plate, for example, a LIG (phosphor-in-glass) wavelength converter. The wavelength converter 90 has a rectangular shape and covers part of the light-emitting diode. The wavelength converter 90 can be used after a large plate has been divided into separate parts. If the wavelength converter 90, for example, an LIG, has a complex shape, separating such a plate requires a difficult singulation process.In contrast, in this exemplary embodiment the wavelength converter 90 has a rectangular shape, for example a square shape, and thus allows a very simple singulation method.

[0043] The housing 300 surrounds the light-emitting diode 100. The housing 300 can be made of a different material than the insulating substrate 201, for example, a silicone molding compound. The housing 300 provides a recess for receiving the encapsulation 350. The housing 300 is open at the top and bottom and provides the base substrate 200 at its base. Furthermore, the housing 300 can be designed to surround, for example, the light-emitting diode 100 and can be open at some of its side surfaces.

[0044] The housing 300 can have different thicknesses depending on its location. Since, in particular, the upper terminal 205a for connecting to the bond wires 310 is located in a limited area, a region of the housing near the upper terminal 205a can have a relatively thin thickness. Furthermore, at least part of an inner wall of the housing 300 can be inclined such that the thickness of the housing gradually increases downwards.

[0045] The encapsulation 350 fills the recess in the package 300 to cover the light-emitting diode 100. The encapsulation 350 exposes one upper surface of the wavelength converter 90, while four side surfaces of the light-emitting diode 100 and a portion of the upper surface of the light-emitting diode, where the wavelength converter 90 is not formed, remain covered. The encapsulation 350 covers the bond wires 310, so that only the wavelength converter 90 above the upper surface of the package is visible.

[0046] The encapsulation 350 can be formed from a white reflector. For example, the encapsulation 350 can be formed from a mixture of a white pigment and a resin, such as a silicone resin or an epoxy resin. Furthermore, polycarbonate or a reflector, such as PCT, can be used as a material for the encapsulation 350.

[0047] In this exemplary embodiment, the encapsulation 350 is opaque and allows light emitted by the light-emitting diode 100 to escape outside the package through the wavelength converter 90. Accordingly, the light-emitting diode package according to this exemplary embodiment can simplify control with regard to wavelength conversion and light emission direction.

[0048] Although not shown in this exemplary embodiment, the light-emitting diode package may further include a protective device, for example a Zener diode.

[0049] The light-emitting diode 100 is described in detail below. Fig. Figure 2A is a top view of a light-emitting diode according to an exemplary embodiment of the present disclosure and Fig. 2B is a cross-sectional view along a line CC of the Fig. 2A.

[0050] Referring to Fig. 2A and Fig. 2B The light-emitting diode 100 according to this embodiment comprises a light-emitting structure 30, a lower electrode 40, and an upper electrode. The upper electrode can, for example, comprise an electrode pad 80a and extensions 80b, 80c. The light-emitting diode 100 can further comprise a support substrate 60, an adhesive metal layer 50, a current barrier layer 31, and a passivation layer 70.

[0051] The support substrate 60 is arranged on a lower side of the light-emitting structure 30 to support the light-emitting structure 30 and to carry out conductivity, so that it can be used as an electrode pad. The support substrate 60 can, for example, comprise a metallic material with electrical conductivity. The support substrate 60 can, for example, comprise Mo, Cu, Ag, Au, Ni, Ti, Al, and the like, and can be composed of one or more layers. However, it should be understood that other implementations are possible. In alternative embodiments, the support substrate 60 can comprise an insulating substrate.

[0052] The light-emitting structure 30 is arranged on an upper side of the support substrate 60. The light-emitting structure 30 can comprise an upper semiconductor layer 23 and a lower semiconductor layer 27, which have different conductivities, and can include an active layer 25 arranged between the upper semiconductor layer 23 and the lower semiconductor layer 27. The active layer 25 and the upper and lower semiconductor layers 23, 27 can be based on III-V compound semiconductors, for example, a nitride semiconductor, such as (Al, Ga, In)N. The upper semiconductor layer 23 can include n-type dopants (for example, Si) to exhibit n-type conductivity, and the lower semiconductor layer 27 can include p-type dopants (for example, Mg) to exhibit p-type conductivity. The n-type upper semiconductor layer 23 can be arranged on top of the active layer 25, which can be arranged on top of the p-type lower semiconductor layer 27.

[0053] After growth on a growth substrate, the light-emitting structure 30 can be separated from the growth substrate. In this case, the upper semiconductor layer 23, the active layer 25, and the lower semiconductor layer 27 can be formed sequentially on the growth substrate. Alternatively, the upper semiconductor layer 23 can comprise a portion of the growth substrate.

[0054] The growth substrate can be selected from any substrate on which a nitridic semiconductor layer can be grown and which exhibits electrical conductivity. If the substrate is an insulating substrate, it can be separated from the light-emitting structure 30 by a laser lift-off process or the like. Alternatively, the growth substrate can be a silicon carbide substrate, a gallium nitride substrate, or an aluminum nitride substrate, with at least a portion of these substrates remaining on the light-emitting structure 30.

[0055] Das Aufwachssubstrat kann eine polare, nicht-polare oder semi-polare Aufwachsebene aufweisen. Dementsprechend kann eine Polarität von jeder der oberen Halbleiterschicht 23, der aktiven Schicht 25 und der unteren Halbleiterschicht 27 aufgewachsen auf dem Aufwachssubstrat bestimmt werden in Abhängigkeit der Polarität des Aufwachssubstrats.

[0056] On the other hand, an upper surface of the light-emitting structure 30 can have a roughened surface R or a highly roughened surface R. The roughened surface means that the surface has been further roughened by a specific physical or chemical treatment. The roughened surface R can be formed by at least one wet etching, dry etching, and electrochemical etching process, for example, PEC etching, or it can be formed by an etching process using an etching solution containing KOH and NaOH. Alternatively, the roughened surface R can be formed by a dry etching process. For example, the roughened surface R can be formed by dry etching using a SiO2 layer as an etching mask. In one embodiment, an SiO2 layer on an upper surface of the light-emitting structure 30 is formed by PECVD and is subjected to structuring by photolithography to form an etching mask.Subsequently, the roughened surface R can be formed by partially dry etching the light-emitting structure 30 through the etching mask. In another embodiment, a structured photomask can be formed on the light-emitting structure 30, and a SiO2 layer can be formed to cover the photomask and the upper surface of the light-emitting structure 30. The SiO2 layer is exposed for structuring by lifting off the photomask, followed by partial dry etching of the light-emitting structure 120 through the structured SiO2 layer, which serves as an etching mask for forming protrusions 211. Alternatively, the roughened surface R can be formed using metal particles as the etching mask. In these embodiments, the etching masks are produced by different methods and have different shapes depending on the mask-forming method.The shapes of the protrusions formed on the roughened surface R can differ depending on the shape of the etching mask.

[0057] The SiO2 layer, which is used as an etching mask, can improve light extraction efficiency compared to the photoresist on its own.

[0058] The barrier layer 31 prevents the flow of electric current vertically from the upper electrode towards below the upper electrode, thus allowing the electric current to spread over a wide area of ​​the light-emitting structure 30. The barrier layer 31 is therefore formed on a lower surface of the lower semiconductor layer 27 to overlap the lower electrodes 80a, 80b, and 80c. Additionally, the barrier layer 31 can be formed to have a greater width than that of each of the corresponding upper electrodes. In particular, a region of the barrier layer 31 can be arranged near an edge of the light-emitting structure 30 and protrude from it. For example, a side surface of the barrier layer 31 can be parallel to a side surface of the support substrate 60.

[0059] The current barrier layer 31 can be formed from an insulating material, for example SiO2 or Si3N4. Furthermore, the current barrier layer 31 can be formed by repeatedly stacking insulating layers with different refractive indices and can form a distributed Bragg reflector (DBR).

[0060] The lower electrode 40 can be electrically connected to the lower semiconductor layer 27. The lower electrode 40 is arranged on the lower surface of the light-emitting structure 30 and can, in particular, contact the lower surface of the light-emitting structure 30. The lower electrode 40 can comprise a reflective layer 33 and a cover layer 35.

[0061] The reflective layer can form an ohmic contact with the lower semiconductor layer 27. The reflective layer 33 not only serves to reflect light but also acts as an electrode, which is electrically contacted with the light-emitting structure 30. The reflective layer can comprise a metal layer made of at least one of the following materials: Ni, Pt, Pd, Rh, W, Ti, Al, Mg, Ag, and Au. Furthermore, the reflective layer 33 can include a distributed Bragg reflector (DBR). The reflective layer 33 can be subdivided into a multitude of regions by the current-blocking layer 31.

[0062] The cover layer 35 can be formed to cover the reflective layer 33 and can prevent interdiffusion of materials different from the reflective layer 33. The cover layer 35 can also cover the depletion layer 31. The cover layer 35 can, for example, comprise Au, Ni, Ti, Cr, Pt, W, and the like, and can be composed of a single layer or multiple layers. The cover layer 35 can contact the lower semiconductor layer 27 in some regions between depletion layers 31a, 31b, and the reflective layer 33. In particular, the cover layer 35 can comprise high-reflectivity aluminum and can form a Schottky contact in some regions between depletion layer 31 and the reflective layer 33.

[0063] The adhesive metal layer 50 connects the support substrate 60 to the lower electrode 40. For example, the lower electrode 40 and the support substrate 60 can be connected to each other by eutectic bonding using AuSn, and consequently the adhesive metal layer 50 comprises AuSn.

[0064] On the other hand, the upper electrode is electrically connected to the upper semiconductor layer 23. The upper electrode comprises an electrode pad 80a, a central extension 80c, and an edge extension 80b. The electrode pad 80a has a relatively wide area for wire bonding. In particular, in exemplary embodiments, the electrode pad 80a is formed in an elongated shape along an edge of the upper semiconductor layer 23 and covers the upper semiconductor layer 23 near one edge thereof, as shown in Fig. 2 shown. A large number of bond wires 110 can be bonded to the electrode pad 80a (see Fig. 1) The electrode pad 80a can have a constant width. This means that areas of the electrode pad 80a which are connected to the bond wires 310 can have essentially the same width as other areas arranged in between.

[0065] The electrode pad 80a can be formed over a length of three-quarters or more of the length of one edge of the upper semiconductor layer 23. The electrode pad 80a can be exactly congruent with one edge of the upper semiconductor layer 23 without being restricted to it. A certain area between one edge of the upper semiconductor layer 23 and the electrode pad 80a can be exposed.

[0066] The elongated structure of electrode pad 80a allows for the connection of numerous bond wires, thus preventing wire breakage in high-current applications and improving the reliability of the light-emitting diode. Furthermore, the elongated structure of electrode pad 80a allows for the formation of rectangular main luminescent regions.

[0067] On the other hand, edge extension 80b extends from electrode pad 80a along edges of the upper semiconductor layer 23, and middle extension 80c extends from edge extension 80b to subdivide the luminescent region into a plurality of regions. Although in this exemplary embodiment the luminescent region is illustrated as being divided into three luminescent regions, it should be understood that other implementations are also possible. Edge extension 80b and middle edge extension 80c distribute carriers to assist in current distribution.

[0068] The upper electrode 80a, 80b, 80c can be formed in a flat region by etching after forming the roughened surface R. As in Fig. As shown in Figure 2B, projections on the roughened surface, formed by etching, can have a greater height than the electrode pad 80a or the extensions 80b, 80c. In further exemplary embodiments, the upper electrode can have a greater height than the projections and can be formed on the roughened surface. In a light-emitting diode configured to operate at high current densities, the droop phenomenon and luminous efficacy can be further improved with increasing distance between the upper electrode 80a, 80b, 80c and the active layer 25. Conversely, current distribution can be further improved with decreasing distance between the upper electrode 80a, 80b, 80c and the active layer 25. Accordingly, the position of the upper electrode 80a, 80b, 80c can be adapted taking into account the drive current of the light-emitting diode.

[0069] The top electrode can be formed from a single layer or multiple layers and can comprise Ni, W, Pt, Cu, Ti, Pd, Ta, Au, Ag, Al, Sn, and the like. For example, the top electrode can comprise 80 metal layers, which are formed from multiple layers, such as Ti / Al, Ni / Al, Cr / Al, or Pt / Al layers, and can further include a layer comprising Ni, W, Pt, Cu, Ti, Pd, Ta, or Au, which is formed on top of the multiple layers to prevent agglomeration of aluminum.

[0070] The passivation layer 70 can at least partially cover the upper and side surfaces of the light-emitting structure 30. The passivation layer 70 protects the light-emitting structure 30 from external environmental influences. The passivation layer 70 can be made of an insulating material and can be formed as a single layer or multiple layers. For example, the passivation layer 70 can be SiO2, SiN xand the like.

[0071] The passivation layer 70 can cover the current-blocking layer 31, which projects from the light-emitting structure 30. Accordingly, the current-blocking layer 31 overlaps the passivation layer 70 outside the light-emitting structure 30. Consequently, the total thickness of the insulating layers (the current-blocking layer 31 and the passivation layer 70) arranged on the cover layer 35 outside the light-emitting structure 30 can be greater than the thickness of the insulating layer (current-blocking layer 31) arranged on the cover layer 35 below the light-emitting structure 30.

[0072] Fig. Figure 3A is a schematic top view of the light-emitting diode according to one exemplary embodiment of the present disclosure, on which a wavelength converter is arranged, and Fig. 3B is a cross-sectional view along a line CC of the Fig. 3A.

[0073] Referring to the Fig. 3A and Fig. 3B is the wavelength converter 90 on the light-emitting diode, as shown in Fig. The wavelength converter 90 is arranged as shown in Figure 2. It can comprise phosphors contained in a thermally resistant medium, for example, LIG ​​(phosphor-in-glass). LIG can be used for extended periods without deterioration, discoloration, or cracking in high-temperature environments. The wavelength converter 90 can have a rectangular shape, for example, a square shape. Thus, the wavelength converter can be designed in a simple form using a rigid material, such as LIG, and a simple process. Since the electrode pad 80a is arranged in an elongated shape along an edge of the upper semiconductor layer, the wavelength converter 90 covers a rectangular area between the electrode pad 80a and the other edge of the upper semiconductor layer 23.In particular, the wavelength converter 90 can have a greater width than the upper semiconductor layer 23 in one direction from one edge of the upper semiconductor layer 23 to the region between the electrode pad 80a and the other edge of the upper semiconductor layer 23. Accordingly, the electrode pad 80a can cover all other edges of the upper semiconductor layer 23 except for one edge. Furthermore, a region of the wavelength converter 90 can overlap a region of the electrode pad 80a. Therefore, according to the exemplary embodiments, the light-emitting diode can minimize the emission of light generated in the active layer 25 without wavelength conversion. However, it should be understood that other implementations are also possible.

[0074] The wavelength converter 90 can be connected to the light-emitting diode 100 by means of a transparent connecting element 85. For example, the transparent connecting element 85 can be made of silicone or epoxy resin.

[0075] Fig. Figure 4A is a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present disclosure and Fig. 4B is a cross-sectional view along a line BB of the Fig. 4A.

[0076] Referring to Fig. 4A and Fig. 4B is a light-emitting diode 101 according to this exemplary embodiment similar to the light-emitting diode 100 in terms of Fig. 2 described, with the exception of an arrangement of an electrode pad 180a, an edge extension 180b, and a central extension 180c. That is, the central extension 180c connects the electrode pad 180a to the edge extension 180b and divides it into luminescent regions. Thus, the luminescent regions are arranged perpendicular to the electrode pad 180a. In this arrangement, the position of the central extension 180c is modified to overlap with the current-disconnect layer 31b or the central extension 180c, and the reflective layer 33 is arranged in a region surrounded by the current-disconnect layer 31b and is perpendicular to the electrode pad 180a.

[0077] In this exemplary embodiment, the electrode pad 180a is also arranged in an elongated shape along an edge of the upper semiconductor layer 23. Thus, as with respect to Fig. As described in section 3, a rectangular wavelength converter 90 can cover the luminous regions.

[0078] Fig. Figure 5 is a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present disclosure.

[0079] Referring to Fig. 5. Although the luminous regions are divided by the central extension of 80c or 180c with equal widths, as illustrated in the exemplary embodiments above, the luminous regions may have different widths. For example, as shown in Fig. As shown in Figure 5, the widths of the luminescent regions can gradually increase with decreasing distance from electrode pad 80a (i.e., W1>W2>W3). Alternatively, the widths of the luminescent regions can gradually decrease with decreasing distance from electrode pad 80a.

[0080] Fig. Figure 6 shows a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present disclosure.

[0081] Referring to Fig. 6. Although three luminous regions are illustrated in the exemplary embodiments above, the number of luminous regions is not limited. That is to say, the number of luminous regions can increase with the increasing number of central extensions 80c. In addition, the luminous regions can have the same width or different widths.

[0082] Fig. Figure 7 is a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present disclosure.

[0083] Referring to Fig. 7. Although the electrode pad 80a or 180a is illustrated as arranged along one edge of the upper semiconductor layer 23 in the exemplary embodiments above, the electrode pad 80a can be arranged on either of the opposite edges of the upper semiconductor layer 23. In this exemplary embodiment, the wavelength converter 90 can be arranged to cover the luminescent regions located between the electrode pads 80a.

[0084] Fig. Figure 8 is a schematic top view of a light-emitting diode according to a further exemplary embodiment of the present disclosure.

[0085] Referring to Fig. 8, although in the exemplary embodiment, as in Fig.Figure 7 shows that the mean extensions 80c are illustrated as extending away from the edge extension 80b and arranged parallel to the electrode pad 80a. The mean extensions 80c can extend away from the electrode pads 80a to be perpendicular to the electrode pads 80a.

Claims

[1] Light-emitting diode (100) comprising: a semiconductor layer sequence (30) comprising a lower semiconductor layer (27), an active layer (25) and an upper semiconductor layer (23), wherein the upper semiconductor layer (23) comprises a roughened surface (R); an upper electrode (80a, 80b, 80c) connected to the upper semiconductor layer (23); and a lower electrode (40) connected to the lower semiconductor layer (27), wherein the upper electrode (80a, 80b, 80c) comprises an electrode pad (80a) with extensions (80b, 80c), wherein the extensions (80b, 80c) are extendable from the electrode pad (80a), the electrode pad (80a) comprises a first electrode pad (80a) which is arranged in an elongated shape along an edge of the upper semiconductor layer (23) and covers the upper semiconductor layer (23) near one edge, wherein the extensions (80b, 80c) comprise an edge extension (80b) which is extendable along an edge of the upper semiconductor layer (23) in the electrode pad (80a), and mean extensions (80c) which are extendable from the edge extension (80b) or the electrode pad (80a), and subdivide luminescent regions, characterized by an insulating layer (70) covering the roughened area (R) of the upper semiconductor layer (23), and a wavelength converter (90) which covers the insulating layer (70) of the upper semiconductor layer (23) and the extensions (80b, 80c). [2] Light-emitting diode (100) according to claim 1, wherein the central extensions (80c) are arranged parallel to a longitudinal direction of the electrode pad (80a). [3] Light-emitting diode (100) according to claim 2, wherein the widths of the light-emitting areas divided by the middle areas (80c) vary with increasing distance from the electrode pad (80a). [4] Light-emitting diode (100) according to claim 1, wherein the central extensions (80c) are arranged perpendicular to a longitudinal direction of the electrode pad (80a). [5] Light-emitting diode (100) according to claim 1, wherein the wavelength converter (90) has a rectangular shape. [6] Light-emitting diode (100) according to claim 1, wherein the wavelength converter (90) is a phosphor-in-glass wavelength converter. [7] Light-emitting diode (100) according to claim 6, wherein the wavelength converter (90) covers the entire luminous regions between the further edge opposite the one edge and the first electrode pad (80a). [8] Light-emitting diode (100) according to claim 6, wherein the electrode pad (80a) further comprises a second electrode pad (80a) arranged in an elongated shape along the far edge of the upper semiconductor layer (23) opposite one edge of the same and covers the upper semiconductor layer (23) near the far edge. [9] Light-emitting diode (100) according to claim 8, wherein the wavelength converter (90) covers the entire luminous regions between the first electrode pad (80a) and the second electrode pad (80a). [10] Light-emitting diode package comprising: a base substrate (200) with a first electrode (203) and a second electrode (205); a light-emitting diode (100) according to claim 1, arranged on the base substrate (200) and electrically connected to the first electrode (203) and the second electrode (205), a housing (300) arranged on the base substrate (200) and surrounding the light-emitting diode (100); and an encapsulation (350) which covers the light-emitting diode (100) inside the housing (300) while exposing an upper surface of the wavelength converter (90). [11] Light-emitting diode package according to claim 10, wherein the encapsulation (350) is formed from a white reflector. [12] Light-emitting diode package according to claim 11, wherein the white reflector covers four side surfaces of the light-emitting diode (100) and the first electrode pad (80a). [13] Light-emitting diode package according to claim 10, wherein the electrode pad (80a) further comprises a second electrode pad (80b) arranged in an elongated shape along the far edge of the upper semiconductor layer (23) opposite one edge of the same and covers the upper semiconductor layer (23) near the far edge, and the white reflector covers the second electrode pad (80a). [14] Light-emitting diode package according to claim 10, wherein the central extensions (80c) are arranged parallel to a longitudinal direction of the electrode pad (80a). [15] Light-emitting diode package according to claim 14, wherein the widths of the light-emitting areas divided by the middle areas (80c) vary with increasing distance from the electrode pad (80a). [16] Light-emitting diode package according to claim 10, wherein the central extensions (80c) are arranged perpendicular to a longitudinal direction of the electrode pad (80a). [17] Light-emitting diode package according to claim 10, wherein the base substrate (200) comprises an AIN ceramic and the housing (300) is formed from a silicone molding compound. [18] Light-emitting diode package according to claim 10, wherein the light-emitting diode (100) is arranged on the first electrode (203) and the first electrode pad (80a) of the light-emitting diode (100) and is electrically connected to the second electrode (205) by a plurality of bond wires (310). [19] Light-emitting diode package according to claim 18, wherein areas of the first electrode pad (80a) which are connected to the bond wires (310) have the same width as other areas of the same arranged between them.

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