CN108538985A - Light emitting diode and filament light-emitting diode lights including the light emitting diode - Google Patents

Abstract

The present invention provides a kind of light emitting diode and the filament light-emitting diode lights including the light emitting diode.According to the light emitting diode of an embodiment it is characterised in that it includes：Semiconductor layer stack comprising the first conductive type semiconductor layer, the second conductive type semiconductor layer and the active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer；ZnO transparent electrode layers are located on the second conductive type semiconductor layer；First electrode is connected with the first conductive type semiconductor layer；And second electrode, it is connected with the ZnO transparent electrode layers, wherein the surface of the ZnO transparent electrode layers, which has, is confined to the part for not forming the second electrode and the bumps formed.

Description

Light-emitting diode and filament light-emitting diode lamp including the light-emitting diode

technical field

The invention relates to a light-emitting diode and a filament light-emitting diode lamp including the light-emitting diode, in particular, provides a light-emitting diode with low calorific value and a filament light-emitting diode lamp including the light-emitting diode.

Background technique

Generally, incandescent lamps or fluorescent lamps are often used as indoor or outdoor lighting lamps, but such incandescent lamps or fluorescent lamps have disadvantages of short service life and high power consumption.

In order to solve such problems, a filament light-emitting diode lamp using a light-emitting diode having characteristics of simple driving control, fast response speed, long service life, low power consumption, and high brightness has been developed.

However, the LEDs contained in filament LED lamps are generally smaller in size, so they are driven with a higher current density and thus generate higher temperature heat. In addition, since the filament light-emitting diode lamp includes a plurality of light-emitting diodes, and the arrangement of the plurality of light-emitting diodes is closely spaced, there is a high possibility of heat damage.

Contents of the invention

The problem to be solved by the present invention is to provide a light-emitting diode with less heat generation.

Another problem to be solved by the present invention is to provide a light emitting diode with low forward voltage and improved light extraction efficiency.

Still another problem to be solved by the present invention is to provide a light emitting diode capable of preventing peeling of electrodes.

Another problem to be solved by the present invention is to provide a filament light-emitting module with high reliability.

Another problem to be solved by the present invention is to provide a filament light-emitting diode lamp including a filament light-emitting module with high reliability.

A light emitting diode according to an embodiment of the present invention is characterized by comprising: a semiconductor laminate including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and a semiconductor layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer The active layer between the two conductivity type semiconductor layers; the ZnO transparent electrode layer, which is located on the second conductivity type semiconductor layer; the first electrode, which is connected to the first conductivity type semiconductor layer; and the second electrode, It is connected with the ZnO transparent electrode layer, wherein the surface of the ZnO transparent electrode layer includes unevenness formed limited to the part where the second electrode is not formed.

An angle formed by the end of the ZnO transparent electrode layer and the upper surface of the second conductive type semiconductor layer may be a right angle or an acute angle.

An angle formed by an end of the ZnO transparent electrode layer and an upper surface of the second conductive type semiconductor layer may be an obtuse angle.

The semiconductor stacked body may include a mesa-etched region exposing a part of the first conductive type semiconductor layer, and the first electrode is connected to the first conductive type semiconductor layer in the mesa-etched region.

The first electrode may include a first electrode pad and a first electrode extension extending from the first electrode pad, and the second electrode may include a second electrode pad and a first electrode extension extending from the second electrode pad. An extended second electrode extension.

A filament light-emitting diode lamp according to an embodiment of the present invention is characterized by comprising: a lamp holder; a transparent cover fixed to the lamp holder; and a transparent cover located in the transparent cover and connected to the lamp holder At least one filament light-emitting module, wherein the at least one filament light-emitting module includes a plurality of light-emitting diodes, and each light-emitting diode includes: a semiconductor stack, which includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an intervening The active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer; the ZnO transparent electrode layer, which is located on the second conductive type semiconductor layer; the first electrode, which is connected to the first conductive type semiconductor layer The semiconductor layer is connected; and a second electrode is connected to the ZnO transparent electrode layer, wherein the surface of the ZnO transparent electrode layer includes unevenness limited to a portion where the second electrode is not formed.

An angle formed by the end of the ZnO transparent electrode layer and the upper surface of the second conductive type semiconductor layer may be a right angle or an acute angle.

An angle formed by an end of the ZnO transparent electrode layer and an upper surface of the second conductive type semiconductor layer may be an obtuse angle.

The semiconductor stacked body may include a mesa-etched region exposing a part of the first conductive type semiconductor layer, and the first electrode is connected to the first conductive type semiconductor layer in the mesa-etched region.

The first electrode may include a first electrode pad and a first electrode extension extending from the first electrode pad, and the second electrode may include a second electrode pad and a first electrode extension extending from the second electrode pad. An extended second electrode extension.

A driver for controlling the driving of the at least one filament light emitting module may also be included.

A supporting body for fixing the at least one filament light-emitting module to the lamp socket part may also be included.

The filament light-emitting module may further include: a support substrate; and electrodes located at both ends of the support substrate, and the plurality of light-emitting diodes are mounted on the support substrate.

The filament light-emitting module may further include a wavelength conversion layer covering the support substrate on which the plurality of light-emitting diodes are mounted.

The support substrate may have a linear rod shape.

The support substrate includes at least a portion of a curved area.

The inside of the transparent cover may be in a vacuum state.

The light emitting diode according to the embodiment of the present invention includes a thicker ZnO transparent electrode layer, so that it can be driven with a lower forward voltage, and thus less heat can be generated by itself. In addition, the filament light-emitting diode lamp including light-emitting diodes that generate less heat can work efficiently even without including other heat dissipation plates and heat dissipation gas for heat dissipation.

Description of drawings

Fig. 1 is a plan view of a light emitting diode according to an embodiment of the present invention; Fig. 2 is a cross-sectional view obtained along the cutting line AA' of Fig. 1; Fig. 3 is obtained along the cutting line BB' of Fig. 1 Sectional view.

4 to 10 are schematic cross-sectional views for explaining a method of manufacturing a light emitting diode according to an embodiment of the present invention.

11a to 11c show a method for manufacturing a filament light-emitting module and a filament light-emitting module according to an embodiment of the present invention.

12 to 15 show various embodiments of filament LED lamps according to the invention.

Detailed ways

In order to enable those of ordinary skill in the technical field of the present invention to fully understand the idea of the present invention, the following embodiments are exemplified. Therefore, the present invention is not limited to the embodiments described below, but can also be implemented in other ways. In addition, in the drawings, in order to illustrate the width, length, thickness, etc. of the components, exaggerated descriptions are sometimes used. In addition, when it is described that one component is located "on" or "above" another component, not only the case where each part is located "directly above" or "directly above" another part, but also the case where each component is located on the other side is also included. A case where other components are placed between other components. Throughout the specification, the same reference symbols refer to the same components.

A light emitting diode according to an embodiment of the present invention is characterized by comprising: a semiconductor laminate including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and a semiconductor layer between the first conductivity type semiconductor layer and the second conductivity type active layer between the semiconductor layers; ZnO transparent electrode layer, which is located on the second conductive semiconductor layer; a first electrode, which is connected with the first conductive semiconductor layer; and a second electrode, which is connected with the semiconductor layer of the second conductive type. The ZnO transparent electrode layers are connected, wherein the surface of the ZnO transparent electrode layer has concavities and convexities limited to a portion where the second electrode is not formed.

It is characterized in that the unevenness has a size of 50 nm or more.

In addition, it is characterized in that the angle formed by the end of the ZnO transparent electrode layer and the upper surface of the second conductivity type semiconductor layer is a right angle or an acute angle or an obtuse angle.

The semiconductor laminate includes a mesa-etched region exposing a part of the semiconductor layer of the first conductivity type, and the first electrode pad and the first electrode extension are in the mesa-etched region in contact with the first conductivity-type semiconductor layer. The semiconductor layer is connected.

The first electrode includes a first electrode pad and a first electrode extension extending from the first electrode pad, and the second electrode includes a second electrode pad and a first electrode extension extending from the second electrode pad. The second electrode extension.

The filament light-emitting diode lamp according to the embodiment of the present invention is characterized in that it comprises: a lamp holder; a transparent cover fixed on the lamp holder; at least one filament light-emitting module located in the transparent cover and connected to the lamp The seats are connected, wherein the at least one filament light-emitting module includes a plurality of light-emitting diodes, and each light-emitting diode includes: a semiconductor stack, which includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and a semiconductor layer interposed between the The active layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; the ZnO transparent electrode layer, which is located on the second conductivity type semiconductor layer; the first electrode, which is connected with the first conductivity type semiconductor layer and a second electrode, which is connected to the ZnO transparent electrode layer, wherein the surface of the ZnO transparent electrode layer has unevenness limited to a portion where the second electrode is not formed.

The filament light-emitting diode lamp may further include a driver for controlling the driving of the at least one filament light-emitting module, and may further include a support for fixing the at least one filament light-emitting module to the lamp socket.

Here, the filament light-emitting module is characterized in that it further includes a support substrate; and electrodes located at both ends of the support substrate, and the plurality of light-emitting diodes are mounted on the support substrate.

The filament light-emitting module may further include a wavelength conversion layer covering the support substrate on which the plurality of light-emitting diodes are mounted.

Here, the support substrate may have a linear rod shape as a whole or include at least a part of a curved area. The inside of the transparent cover can maintain a vacuum state.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a plan view of a light emitting diode according to an embodiment of the present invention; Fig. 2 is a cross-sectional view obtained along the cutting line AA' of Fig. 1; Fig. 3 is obtained along the cutting line BB' of Fig. 1 Sectional view.

Referring to FIGS. 1 to 3 , the light emitting diode according to the present embodiment includes: a substrate 10; a semiconductor stack 20, which is located on the substrate 10, and includes a first conductivity type semiconductor layer 21, an active layer 23 and a second conductivity type semiconductor layer 21; a semiconductor layer 25 ; and a transparent electrode layer 30 located on the semiconductor stack 20 . In addition, the light emitting diode further includes a first electrode 40 connected to the first conductive type semiconductor layer 21 and a second electrode 50 connected to the transparent electrode layer 30 .

The light emitting diode may have a rectangular planar shape, thereby including a first side 1 , a second side 2 , a third side 3 opposite to the first side 1 , and a fourth side 4 opposite to the second side 2 . However, the planar shape of the light emitting diode according to the present invention is not limited thereto, and various shapes may be included.

The substrate 10 is not particularly limited as long as it is a substrate 10 suitable for growing the gallium nitride-based semiconductor laminate 20 . The substrate 10 may include, for example, a sapphire substrate 10 , a silicon carbide substrate 10 , a gallium nitride substrate 10 , an aluminum nitride substrate 10 , a silicon substrate 10 and the like.

The first conductive type semiconductor layer 21 may be located on the substrate 10 . The first conductivity type semiconductor layer 21 is a semiconductor layer doped with a first conductivity type dopant. The first conductivity type semiconductor layer 21 can be formed by at least one of a GaN layer, an InGaN layer, an AlGaN layer, and an InAlGaN layer. When the first conductivity type semiconductor layer 21 is an n-type semiconductor layer, the first conductivity type The dopant may include one or more of Si, Ge, Sn, Se, and Te as n-type dopants.

The active layer 23 may be on the first conductive type semiconductor layer 21 . The active layer 23 may be formed in a single quantum well or multiple quantum well (MQW) structure. The active layer 23 may be formed as at least one of a GaN layer, an InGaN layer, an AlGaN layer, and an InAlGaN layer using a Group 3-5 compound semiconductor material. For example, the active layer 23 may have a structure in which well layers including InGaN layers and barrier layers (barrier layers) including GaN layers are alternately and repeatedly stacked. The active layer 23 can generate light by a mechanism of recombination of carriers supplied from the first conductive type semiconductor layer 21 and carriers supplied from the second conductive type semiconductor layer 25 described later. When the first conductivity type semiconductor layer 21 is an n-type semiconductor layer, the carriers supplied from the first conductivity type semiconductor layer 21 may be electrons; when the second conductivity type semiconductor layer 25 is a p-type semiconductor layer, Carriers supplied from the second conductive type semiconductor layer 25 may be holes.

Although not shown in the drawings, the light emitting diode may further include a superlattice layer between the first conductive type semiconductor layer 21 and the active layer 23 . The superlattice layer can block the transfer of the dislocation (dislocation) formed in the first conductivity type semiconductor layer 21 to the active layer 23 according to the lattice constant difference between the substrate 10 and the first conductivity type semiconductor layer 21, thereby improving the activity of the active layer. 23 node quality.

The second conductive type semiconductor layer 25 may be on the active layer 23 . The second conductivity type semiconductor layer 25 includes a semiconductor layer doped with a second conductivity type dopant, and may be formed as a single layer or multiple layers. The second conductivity type semiconductor layer 25 may be formed of at least one of a GaN layer, an InGaN layer, an AlGaN layer, and an InAlGaN layer. When the second conductivity type semiconductor layer 25 is a p-type semiconductor layer, the second conductivity type dopant may include more than one of Mg, Zn, Ca, Sr, and Ba as a p-type dopant.

In addition to the first conductivity type semiconductor layer 21, the active layer 23 and the second conductivity type semiconductor layer 25, in order to improve the crystal quality, the semiconductor laminate 20 may include an undoped layer or other buffer layers, when the second conductivity type semiconductor layer When 25 is a p-type semiconductor layer, various functional layers may be included such as a current blocking layer (not shown) formed between the active layer 23 and the second conductivity type semiconductor layer 25 .

The semiconductor laminate 20 can be grown on the substrate 10 in a cavity by using MOCVD (Metal Organic Chemical Vapor Depositin, Metal Organic Chemical Vapor Deposition) technology. However, the embodiments of the present invention are not limited thereto, and the semiconductor laminate 20 can be grown on the semiconductor laminate 20 by techniques such as MBE (Molecular Beam Epitaxy, Molecular Beam Epitaxy), HVPE (Hydride Vapor Phase Epitaxy, Hydride Vapor Phase Epitaxy) and the like. on the substrate 10.

The semiconductor stacked body 20 may include a mesa-etched region 20 a exposing a part of the first conductivity type semiconductor layer 21 . The mesa etching region 20 a may be formed by etching a part of the second conductive type semiconductor layer 25 and the active layer 23 . In addition, a part of the first conductive type semiconductor layer 21 may also be etched during the formation of the mesa-etched region 20a. Referring to FIG. 1 , the mesa-etched region 20a may have a relatively wide shape at a portion extending from the corner where the second side 2 and the third side 3 of the light emitting diode meet along the second side 2 toward the first side 1 . The mesa-etched region 20 a can provide a region for forming a first electrode 40 described later.

The transparent electrode layer 30 may be located on the second conductive type semiconductor layer 25 . The transparent electrode layer 30 is an ohmic contact layer formed of a metal oxide. Especially, when the second conductive type semiconductor layer 25 is a p-type semiconductor layer, the current spreading effect can be improved by forming an ohmic contact with the second conductive type semiconductor layer 25. .

A light emitting diode according to the present invention may include a ZnO transparent electrode layer 30 . The ZnO transparent electrode layer 30 has a lower light absorption rate than the ITO transparent electrode layer 30 . For example, when assuming the same thickness, the light absorptivity of the ZnO transparent electrode layer 30 can be equivalent to the 1/20 level of the light absorptivity of the ITO transparent electrode layer 30, thus, the amount of light absorbed by the ZnO transparent electrode layer 30 and lost It may be smaller than the ITO transparent electrode layer 30 .

Since the ZnO transparent electrode layer 30 has a characteristic of low light absorption rate, it can be formed thick. As the thickness of the transparent electrode layer 30 is formed thicker, the following effects can be expected.

First, according to the property that the resistance value is inversely proportional to the thickness, when the thickness of the transparent electrode layer 30 is formed thicker, the resistance value of the transparent electrode layer 30 can be reduced. When the resistance value of the transparent electrode layer 30 becomes smaller, the current spreads more easily, and as a result, the forward voltage (Vf) of the LED becomes smaller. When the same magnitude of current is applied, the smaller the forward voltage (Vf) of the light-emitting diode is, the smaller the power consumption will be. As a result, the heat generation of the light-emitting diode can also be reduced.

In addition, when the thickness of the transparent electrode layer 30 is thicker, the step of forming the unevenness 31 on the surface of the transparent electrode layer 30 is facilitated, and there may be less restrictions on the size of the formed unevenness 31 . The irregularities 31 of a certain size formed on the surface of the transparent electrode layer 30 can reduce the total reflectance of light so as to improve the light extraction efficiency of the LED. The unevenness formed on the surface of the ZnO transparent electrode layer 30 of the light emitting diode according to the invention of the present application may have a size of 50 nm or more. However, in the case where the transparent electrode layer 30 is as thin as the ITO transparent electrode layer, unevenness can also be formed on the surface, but in this case, the unevenness forming process may be difficult, and the size of the formed unevenness may be will be greatly restricted. When the size of the bumps is limited, the total reflection of light cannot be effectively reduced.

Referring to FIGS. 2 and 3 , although the unevenness 31 is formed on the surface of the transparent electrode layer 30 , it has a characteristic that it is not formed in the region α connected to the second electrode 50 . That is, the unevenness 31 may be formed in other areas of the surface of the transparent electrode layer 30 except the area α where the second electrode pad 51 and the second electrode extension 53 are connected. This is because the second electrode 50 is easily peeled off from the transparent electrode layer 30 when the surface of the transparent electrode layer 30 is uneven in the region α connected to the second electrode 50 . Therefore, in order to improve the reliability of the light emitting diode, the region α where the surface of the transparent electrode layer 30 is connected to the second electrode 50 may not include the unevenness 31 .

The first electrode 40 may be located on the first conductive type semiconductor layer 21 exposed by the mesa-etched region 20a. The first electrode 40 may include a first electrode pad 41 and a first electrode extension 43 extending from the first electrode pad 41 . Referring to FIG. 1 , the first electrode pad 41 may be located on the first conductivity type semiconductor layer 21 in the mesa etching region 20a near the corner where the second side 2 and the third side 3 of the LED meet. In addition, the first electrode extension 43 may extend from the first electrode pad 41 and extend toward the first side 1 along the second side 2 of the LED.

The second electrode 50 may be located on the transparent electrode layer 30 . That is, the second electrode 50 may be located on the transparent electrode layer 30 and electrically connected to the second conductive type semiconductor layer 25 . The second electrode 50 may include a second electrode pad 51 and a second electrode extension 53 extending from the second electrode pad 51 . Referring to FIG. 1 , the second electrode pad 51 may be located on the transparent electrode layer 30 near the corner where the first side 1 and the fourth side 4 of the LED meet. In addition, the second electrode extension part 53 may extend from the second electrode pad 51 and extend along the direction from the fourth side 4 to the third side 3 of the LED.

The first electrode pad 41 and the second electrode pad 51 are used to electrically connect the light emitting diodes, for example, wire bonding can be formed on the first electrode pad 41 and the second electrode pad 51 respectively. Through the wires respectively bonded to the first electrode pad 41 and the second electrode pad 51 , the light emitting diode can be electrically connected to an external device and can be supplied with power. According to the structure in which the two corners of the first electrode pad 41 and the second electrode pad 51 are arranged facing each other on the light emitting diode, current spreading can be effectively realized. In addition, the first electrode extension 43 and the second electrode extension 53 can efficiently spread current in the light emitting diode, and as a result, the output of the light emitting diode can be improved.

Although the first electrode 40 and the second electrode 50 are not limited thereto, they may be made of at least one selected from gold (Au), silver (Ag), aluminum (Al), copper (Cu), or alloys including these. Conductive material is formed. Also, the first electrode 40 and the second electrode 50 may be formed through the same process.

4 to 10 are schematic cross-sectional views for explaining a method of manufacturing a light emitting diode according to an embodiment of the present invention.

Referring to FIG. 4 , first, a substrate 10 is prepared, and then a semiconductor laminate 20 and a transparent electrode layer 30 are formed on the substrate 10 . The semiconductor laminate 20 may include a nitride-based semiconductor layer, and the transparent electrode layer 30 may include a ZnO transparent electrode layer 30 . The semiconductor laminate 20 can be grown on the substrate 10 by, for example, disposing the substrate 10 in a cavity and utilizing MOCVD (Metal Organic Chemical Vapor Depositin) technology. The ZnO transparent electrode layer 30 can be grown on the semiconductor stack 20 by arranging the substrate 10 on which the semiconductor stack 20 has been grown in a cavity, and utilizing a hydrothermal synthesis technique. The ZnO transparent electrode layer 30 has the same wurtzite crystal structure as the semiconductor laminate 20 located thereunder.

Referring to FIG. 5 , a first mask 60 is formed on the transparent electrode layer 30 . The first mask 60 may include a first opening part 60 a exposing a part of the transparent electrode layer 30 .

Referring to FIGS. 6 a to 6 c , the transparent electrode layer 30 may be etched using the first opening portion 60 a of the first mask 60 . The light emitting diode according to the present invention comprises a transparent electrode layer 30 of ZnO, which has a property of being very fragile to acids. Therefore, the transparent electrode layer 30 exposed through the first opening 60 a of the first mask 60 may be wet-etched using an acidic solution.

In this case, during wet etching, the gradient formed between the end of the transparent electrode layer 30 and the upper surface of the second conductive type semiconductor layer 25 can be controlled by controlling the pH value of the acidic solution. For example, when using a strong acidic solution with a lower pH value to wet etch the ZnO transparent electrode layer 30, as shown in FIG. The inverted mesa structure 30a with an obtuse angle. When the end of the ZnO transparent electrode layer 30 has the inverted mesa structure 30a, light extraction efficiency may be excellent. That is, when the end of the ZnO transparent electrode layer 30 has the inverted mesa structure 30a, the light that is totally reflected on the surface of the ZnO transparent electrode layer 30 and goes toward the end of the ZnO transparent electrode layer 30 is no longer totally reflected and emitted to the outside.

On the contrary, when the ZnO transparent electrode layer 30 is wet-etched with a weakly acidic solution with a higher pH value, as shown in FIG. Mesa structures (30c) with acute corners. And, when utilizing the pH value in the middle acidic solution wet etching ZnO transparent electrode layer 30, as shown in Fig. A structure with right angles (30b). When the end of the ZnO transparent electrode layer 30 has the mesa structure 30c, it may be more effective in electrical characteristics than the inverted mesa structure 30a. That is, when the end of the ZnO transparent electrode layer 30 has a mesa structure 30c, the area where the ZnO transparent electrode layer 30 is in contact with the second conductivity type semiconductor layer 25 may be wider than the inverted mesa structure 30a, so that the current flow can be realized more effectively. diffusion.

Referring to FIG. 7 , a portion of the semiconductor laminate 20 exposed by etching of the transparent electrode layer 30 in FIGS. 6 a to 6 c is etched to form a mesa-etched region 20 a. The mesa-etched region 20a may be formed by dry etching. Specifically, the second conductive type semiconductor layer 25 and the active layer 23 are etched by using the first opening 60a of the first mask 60 and using methods such as sputter etching, reactive ion etching, and vapor phase etching, so that the second conductive type semiconductor layer 25 can be etched. A conductive semiconductor layer 21 is exposed. In this case, a part of the first conductive type semiconductor layer 21 may also be etched. Referring to FIG. 7, the sides of the mesa-etched region 20a may be formed obliquely.

Referring to FIG. 8, a second mask 70 may be formed on the transparent electrode layer 30 and the mesa etching region 20a. The second mask 70 may include a second opening portion 70a. The second opening portion 70a may be formed in plural. For example, one of the second openings 70a may be located on the transparent electrode layer 30 to expose a part of the transparent electrode layer 30, and the other of the second openings 70a may be located on the mesa-etched region 20a to expose the first conductive layer 30. A part of the semiconductor layer 21 is exposed.

Referring to FIG. 9 , the first electrode 40 and the second electrode 50 may be formed using the second opening 70 a of the second mask 70 . Although only the first electrode extension 43 formed by the second opening 70a is disclosed in FIG. 9 , it can be fully deduced that the same method can be used to form the first electrode pad 41 , the second electrode pad 51 and the second electrode. extension 53 . In addition, although the drawing only shows the first electrode extension 43, the first electrode 40 and the second electrode 50 can be formed by a common lift-off technique.

Referring to FIG. 10 , unevenness 31 may be formed on the surface of the transparent electrode layer 30 . Specifically, the unevenness 31 can be formed by etching the surface of the transparent electrode layer 30 using an acidic solution. The light emitting diode according to the invention of the present application may include the ZnO transparent electrode 30, and as described above, the thickness of the ZnO transparent electrode layer 30 can be formed thicker due to lower light absorption characteristics. That is, the ZnO transparent electrode layer 30 may have a thickness sufficient to include unevenness 31 on its surface. ZnO has a property of being very fragile to acids. Therefore, the unevenness 31 can be formed on the surface of the ZnO transparent electrode layer 30 by treating the ZnO transparent electrode layer 30 with a relatively diluted acidic solution for a short time, and the size of the unevenness 31 can be controlled according to the treatment time and the concentration of the acidic solution. For example, the ZnO transparent electrode layer 30 may be treated for about 40 seconds with an acidic solution diluted at a ratio of approximately 1000:1 to form unevenness 31 on its surface. The unevenness 31 formed by this method can have a size of about 50 nm or more.

Since the formation of the unevenness 31 is performed after the formation of the second electrode 50 , the unevenness 31 pattern cannot be formed on the surface of the transparent electrode layer 30 where the second electrode pad 51 and the second electrode extension 53 are connected. This feature has already been disclosed by the aforementioned FIG. 3 . That is, the unevenness 31 may be formed in the remaining area of the transparent electrode layer 30 except for the portion where the second electrode 50 is formed. If the concave-convex 31 pattern is formed on the surface of the transparent electrode layer 30 connected with the second electrode 50, then since the second electrode 50 is easily peeled off from the transparent electrode layer 30, the surface of the transparent electrode layer 30 connected with the second electrode 50 will not A concavo-convex 31 pattern is formed.

11a to 11c show a method for manufacturing a filament light-emitting module and a filament light-emitting module according to an embodiment of the present invention.

Referring to FIG. 11a, firstly, a support substrate 310 is prepared. The supporting substrate 310 may be formed of glass, hard glass, quartz glass, transparent ceramics, plastic, or the like. Alternatively, the supporting substrate 310 may be formed of a flexible material according to an embodiment. Both ends of the supporting substrate 310 may have electrodes 320 respectively. The electrodes 320 are used to supply external power to the filament light emitting module 300 . The electrodes 320 may be fixed on the support substrate 310 by adhesive or the like.

Although a case where the support substrate 310 has a linear bar shape is disclosed in FIG. 11a, it is not limited thereto. That is, at least a portion of an area of the support substrate 310 may include a curved shape. The supporting substrate 310 may be formed to have a curved shape, or the linear rod-shaped supporting substrate 310 may be formed of a flexible material so that at least a part thereof can be deformed into a curved shape due to external force. Due to the curved support substrate 310 , various shapes of filament light emitting modules 300 such as those shown in FIGS. 13 to 15 can be fabricated.

Referring to FIG. 11 b , at least one light emitting diode 330 can be mounted on the support substrate 310 . The light-emitting diodes 330 attached to the filament light-emitting module 300 are relatively small, so they can be driven under high current density conditions, thereby generating high-temperature heat in each light-emitting diode. In addition, the light emitting diodes 330 attached to the filament light emitting module 300 can be arranged at a very high density. That is, the distance between the light emitting diodes 330 may be relatively very small, so the heat generated per unit area may be very large. In this case, the filament light emitting module 300 may be damaged due to the high heat generated by itself.

Therefore, the filament light emitting module 300 according to the invention of the present application may include the light emitting diode shown in FIGS. 1 to 10 including the ZnO transparent electrode layer 30 . As described above, the light emitting diode including the ZnO transparent electrode layer 30 can be driven with a relatively low forward voltage (Vf), and thus has a feature of generating less heat. Therefore, the light emitting diode including the ZnO transparent electrode layer 30 can be driven under a high current density condition, and is suitable for a high density filament light emitting module.

Referring again to FIG. 11 b , a plurality of light emitting diodes 330 may be electrically connected by wires 331 . Although a situation in which a plurality of light emitting diodes 330 are connected in series by wires 331 is shown in FIG. 11 b , this should not be construed as a limitation to the embodiment. That is, according to other embodiments, the plurality of light emitting diodes 330 may also be connected in parallel or in series/parallel. The outermost light emitting diode 330 among the plurality of light emitting diodes 330 may be electrically connected through the electrode 320 and the lead wire 331 .

In addition, the support substrate 310 may include electrical wiring (not shown), and at this time, the respective light emitting diodes do not require bonding by wires 331 . That is, in this case, the light emitting diodes can be electrically connected in series/parallel through electrical wiring (not shown) included in the support substrate 310 .

Referring to FIG. 11c, a wavelength converting layer 340 may be formed covering the supporting substrate 310 on which the at least one light emitting diode 330 is mounted. The wavelength conversion layer 340 may cover a part of the electrode 320 in order to improve the stability of the structure. The wavelength conversion layer 340 includes phosphors that can change the wavelength of light from the light emitting diodes. The wavelength conversion layer 340 may include phosphors in various combinations, so that the wavelength of light emitted from the filament light emitting module 300 may be controlled.

12 to 15 show various embodiments of filament LED lamps according to the invention.

Referring to FIG. 12 to FIG. 15 , the filament light-emitting diode lamp may include a lamp base part 100 , a transparent cover 200 and a filament light-emitting module 300 at the same time. In addition, the filament LED lamp may further include a wiring part 400 and a supporting body 500 .

The socket part 100 can be made of a conductor, and can be connected to an external device to play a role of supplying electric power to the filament light emitting module 300 .

The transparent cover 200 can be made of a transparent material that can transmit light, and its lower end can be connected and fixed with the lamp socket part 100 . The transparent cover 200 may be a light diffusion cover that diffuses light to be emitted to the outside, and thus, the filament LED lamp may have a wider directivity angle. In addition, the transparent cover 200 can protect the filament light-emitting module 300 inside it. The shape of the transparent cover 200 shown in FIGS. 12 to 15 may be a substantially spherical shape with its lower end open, but is not limited thereto.

The filament light emitting module 300 may include a plurality of light emitting diodes. In addition, the filament light emitting module 300 may further include a supporting substrate, electrodes and a wavelength conversion layer. A plurality of light emitting diodes are mounted on the supporting substrate and can be electrically connected in series, parallel or series/parallel respectively.

The filament light emitting module 300 includes the filament light emitting module 300 shown in FIGS. 11 a to 11 c , and the plurality of light emitting diodes included in the filament light emitting module 300 may include the light emitting diodes shown in FIGS. 1 to 10 . That is, the filament light-emitting module 300 may include the above-mentioned ZnO transparent electrode layer, and may include a light-emitting diode that can be driven with a lower forward voltage and generates less heat. Accordingly, the filament light-emitting module 300 itself may generate less heat, so the risk of damage due to high temperature can be less.

In contrast, the filament light emitting module according to the prior art includes a light emitting diode having a relatively high forward voltage by means of an ITO transparent electrode layer formed with a thin thickness, thus generating light emission due to a high heat generation. A problem that reduces reliability due to damaged modules. Therefore, the heat generated in the filament light emitting module is discharged to the outside by using a gas such as helium gas with a small viscosity coefficient and high thermal conductivity. That is, a method of filling the inside of the transparent cover with a gas with a low viscosity coefficient and high thermal conductivity, and utilizing convection of the gas to discharge heat generated from the filament light emitting module to the outside.

However, the filament light-emitting module 300 according to the present application has the advantage of not containing other gases for heat dissipation in the transparent cover 200 due to the low forward voltage of the light-emitting diodes, so that it generates less heat. Accordingly, the filament LED lamp according to the present application does not contain gas, so it has advantages in manufacturing cost and manufacturing process, and there are less restrictions when selecting the material and shape of the transparent cover. For example, the transparent cover 200 may be sealed, and the inside thereof may maintain a vacuum state that does not contain gas. As another example, the transparent cover 200 may include an opening connected to the outside, and the inside of the transparent cover 200 may be filled with air.

The wiring part 400 plays a role of supporting the filament light emitting module 300 and may play a role of electrically connecting the filament light emitting module 300 to the lamp socket part 100 . One end of the wiring part 400 is connected to the electrode part of the filament light emitting module 300 , and the other end may be connected to the socket part 100 .

The supporting body 500 can play a role of supporting the wiring part 400 and the filament light emitting module 300 . The supporting body 500 may be fixed to the lamp socket part 100 , and a part of the wiring part 400 may be fixed to the supporting body 500 through a structure passing through the supporting body 500 .

And, although not disclosed in the drawings, the filament light emitting diode lamp may further include a driving part for controlling driving of the filament light emitting module. The driving part can control the driving of a single filament light emitting module or a plurality of filament light emitting modules connected in series/parallel. The driving part may be located in a space inside the lamp socket part 100 .

According to a separate study, the filament LED lamp shown in FIG. 12 includes two linear filament light emitting modules 300a, 300b having a structure connected in series. However, this should not be construed as a limitation to the embodiment, so the filament light emitting diode lamp may include one, three, four filament light emitting modules 300 and other various numbers. In addition, the plurality of filament light emitting modules 300 may not only have a structure connected in series, but may also have a structure connected in parallel or in series/parallel. In addition, the plurality of filament light emitting modules 300 may have various configuration structures that can minimize mutual shadows.

The filament light-emitting diode lamp shown in FIG. 13 includes a curved filament light-emitting module 300 and has a structure in which two ends of the filament light-emitting module 300 are connected to wiring parts 400 . In addition, a lead wire 510 for fixing the filament light emitting module 300 on the support body 500 may also be included.

The filament light-emitting diode lamp shown in FIG. 14 may include two filament light-emitting modules 300a, 300b, and each filament light-emitting module 300a, 300b may include a straight line area and a curved line area.

The filament light-emitting diode lamp shown in FIG. 15 includes a spiral filament light-emitting module 300 , and has a structure in which the filament light-emitting module 300 spirally rotates around the support body 500 to surround the support body 500 .

Claims (17)

1. A light-emitting diode, characterized in that, comprising: A semiconductor stack, including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a ZnO transparent electrode layer located on the second conductivity type semiconductor layer; a first electrode connected to the first conductivity type semiconductor layer; and a second electrode connected to the ZnO transparent electrode layer, The surface of the ZnO transparent electrode layer includes unevenness limited to a portion where the second electrode is not formed. 2. The light emitting diode according to claim 1, characterized in that, The angle formed by the end of the ZnO transparent electrode layer and the upper surface of the second conductivity type semiconductor layer is a right angle or an acute angle. 3. The light emitting diode according to claim 1, characterized in that, The angle formed by the end of the ZnO transparent electrode layer and the upper surface of the second conductivity type semiconductor layer is an obtuse angle. 4. The light emitting diode according to claim 1, characterized in that, The semiconductor laminate includes a mesa-etched region exposing a part of the first conductivity type semiconductor layer, The first electrode is connected to the first conductivity type semiconductor layer in the mesa etching region. 5. The light emitting diode according to claim 1, characterized in that, The first electrode includes a first electrode pad and a first electrode extension extending from the first electrode pad, The second electrode includes a second electrode pad and a second electrode extension extending from the second electrode pad. 6. A filament light-emitting diode lamp, characterized in that it comprises: lamp holder; a transparent cover fixed to the lamp socket; and at least one filament light-emitting module is located in the transparent cover and connected to the lamp socket, The at least one filament light emitting module includes a plurality of light emitting diodes, Individual LEDs include: A semiconductor stack, including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a ZnO transparent electrode layer located on the second conductivity type semiconductor layer; a first electrode connected to the first conductivity type semiconductor layer; and a second electrode connected to the ZnO transparent electrode layer, The surface of the ZnO transparent electrode layer includes unevenness limited to a portion where the second electrode is not formed. 7. The filament light-emitting diode lamp according to claim 6, characterized in that, The angle formed by the end of the ZnO transparent electrode layer and the upper surface of the second conductivity type semiconductor layer is a right angle or an acute angle. 8. The filament light-emitting diode lamp according to claim 6, characterized in that, The angle formed by the end of the ZnO transparent electrode layer and the upper surface of the second conductivity type semiconductor layer is an obtuse angle. 9. The filament LED lamp according to claim 6, characterized in that, The semiconductor laminate includes a mesa-etched region exposing a part of the first conductivity type semiconductor layer, The first electrode is connected to the first conductivity type semiconductor layer in the mesa etching region. 10. The filament LED lamp according to claim 6, characterized in that, The first electrode includes a first electrode pad and a first electrode extension extending from the first electrode pad, The second electrode includes a second electrode pad and a second electrode extension extending from the second electrode pad. 11. The filament LED lamp according to claim 6, characterized in that, A driver for controlling the driving of the at least one filament light emitting module is also included. 12. The filament LED lamp according to claim 11, characterized in that, It also includes a supporting body for fixing the at least one filament light emitting module to the lamp socket part. 13. The filament LED lamp according to claim 6, characterized in that, The filament light emitting module also includes: support substrate; and electrodes located at both ends of the supporting substrate, The plurality of light emitting diodes are mounted on the supporting substrate. 14. The filament LED lamp according to claim 13, characterized in that, The filament light-emitting module further includes a wavelength conversion layer covering the support substrate on which the plurality of light-emitting diodes are mounted. 15. The filament LED lamp according to claim 13, characterized in that, The support substrate has a linear rod shape. 16. The filament LED lamp according to claim 13, characterized in that, The support substrate includes at least a portion of a curved region. 17. The filament LED lamp of claim 6, wherein: The inside of the transparent cover is in a vacuum state.